Food Technology
Vahid Hakimzadeh; Fatemeh Ghorbanpour; Hassan Rashidi
Abstract
Introduction: One of the relatively new dairy products is cheese sauce, which can increase the consumption of cheese per capita and replace unhealthy sauces. Functionality process by adding useful compounds to food while maintaining its appearance improves properties of foods. Nowadays, due to the importance ...
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Introduction: One of the relatively new dairy products is cheese sauce, which can increase the consumption of cheese per capita and replace unhealthy sauces. Functionality process by adding useful compounds to food while maintaining its appearance improves properties of foods. Nowadays, due to the importance of compounds such as essential fatty acids, antioxidants and fiber, the demand for consuming products containing these compounds in the diet is very high. Date seed extract contains fiber, antioxidants, lignans and essential fatty acids. On the other hand, whey also has many nutritional properties. The purpose of this research is to prepare cheese sauce using such compounds so that while preparing a useful product, it is possible to prevent the wastage of valuable by-products. Material and Methods: In this research, the effect of Date kernel extract in amounts of zero (control), 5 and 15% to cheese sauce formula in the presence (15%) and absence of whey on the physicochemical characteristics of cheese sauce powder samples was investigated. The organoleptic properties of samples, also were studied in 5-hedonic form. All experiments were done based on completely randomized block design and in three replications. Duncan's test was used to compare the average dataResults and Discussion: The results showed that the addition of whey and date kernel extract to the cheese sauce significantly increased the characteristics such as dry matter percentage, powder solubility, phenolic compounds, antioxidant property and viscosity compared to the control sample. But on the other hand, the increase of Date kernel extract and whey in amounts of 15% decreased the amount of protein in cheese sauce. The results of the sensory properties of the samples also showed that the highest acceptability was related to the sample with 5% of seed date extract in the presence of whey.
Food Chemistry
Hassan Rezadoost; Maryam Manzari Tavakoli; Samad Nejad Ebrahimi; Mohammad Reza Vazifeshenas; Mohammad Hossein Mirjalili
Abstract
Over the past decades, the use of natural additives has increased as an alternative to artificial ingredients in the food industry. The purpose of this study was to investigate the potential of pomegranate peel (PP) as a natural food additive. Many factors, including genotype, could affect the quality ...
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Over the past decades, the use of natural additives has increased as an alternative to artificial ingredients in the food industry. The purpose of this study was to investigate the potential of pomegranate peel (PP) as a natural food additive. Many factors, including genotype, could affect the quality of PP as a by-product of juice production with many nutritional, functional and anti-infective properties. In this study, the most significant phytochemical characters of thirty Iranian pomegranate peels (IPP) from different genotypes, including total phenolic (TPC) and flavonoid content (TFC), and nine phenolic compounds were determined. The HPLC-DAD-MS results of PPEs revealed nine phenolic compounds in the IPP extracts. Punicalagin β, punicalagin α, and ellagic acid were the main components constituting 20.8–48.7, 13.9–30.1, and 1.6–13.4 μg/mg DW, respectively. The peel of IPP23 (Kabdar-Shirin-e- Behshahr) contained the highest quantity of polyphenolic compounds. Also, TPC and TFC of the peel extracts ranged between 66.38 and 181.41 mg GAE/ g DW and 38.5 to 144.13 mg RE/ g DW, respectively. Eventually, antioxidant potential estimated by the DPPH assay ranged between 4.1 and 14.4 μg/ml. The results showed that the antioxidant property of pomegranate peel extracts is significantly higher than the standard of gallic acid. Also, the peel of the genotypes that had high phenolic compounds were introduced as superior genotypes. The results of HCA showed that, among the studied genotypes, the peel of IPP23 can be introduced as a potential source of natural preservatives in the food industry.
Food Technology
S. Mostafa Sadeghi; Mandana Tayefe; Leili Fadayi Eshkiki; Kambiz Ghiasvand
Abstract
IntroductionBakery products such as cakes are consumed in a relatively large amount all over the world due to their ready to eat format. Among different foods, bakery products provide a great opportunity to use edible portions of seeds, vegetables or other unconventional food sources. On the other hand, ...
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IntroductionBakery products such as cakes are consumed in a relatively large amount all over the world due to their ready to eat format. Among different foods, bakery products provide a great opportunity to use edible portions of seeds, vegetables or other unconventional food sources. On the other hand, cakes are susceptible to oxidation due to high amounts of fat and consequently reduce shelf life. Therefore, due to the high nutritional value of cake, improving its characteristics seems necessary. Wheat germ is the richest known source of vitamin E of plant origin. Consumption of wheat germ can prevent artery- clogging and also helps fight against free radical damage and procrastination are effective in the aging process of cells and preventing coronary disease. Despite the beneficial properties of wheat germ, it is difficult to keep it raw in the formulation of crops due to the presence of high unsaturated fatty acids and lipase enzymes. However, by performing thermal processes such as steam, fluidized substrate or thermal dryer, enzymes such as lipase and lipoxygenase can be deactivated. In this study, the effect of adding wheat germ as a rich source of fiber, tocopherols and essential fatty acids as well as ascorbyl palmitate as antioxidant compound on the qualitative and structural properties of cake was investigated. Materials and MethodsIn this study, five treatments of oil cake including control, ascorbyl palmitate (100 ppm), wheat germ (5, 10 and 15%), were prepared and physic-chemical properties including the moisture, firmness and volume of cake at the beginning of storage period, peroxide number and acidity during 14-day storage period were investigated. In order to evaluate the texture of the cake, texture analyzer was performed with dimensions of 25 mm and penetration of 50% in the sample at a speed of 2 mm/s and a 30-second stop between the first and second compressions. The specific volume of the produced samples and moisture of the middle part of the samples were measured 3 hours after baking. Results and DiscussionThe results showed that addition of L-ascorbyl palmitate had no significant effect on moisture content, hardness and cake volume. However, wheat germ increased hardness (in amounts more than 5%), decreased moisture content and specific volume of cake. Also, with increasing the amount of wheat germ, a significant decrease in peroxide and acidity of the samples were observed during the storage period. However, the values of the mentioned indices in the sample containing palmitate ascorbyl were lower than those containing wheat germ. According to the results, it seems that the sample containing 5% processed wheat germ can be recommended as a suitable formulation for cake enrichment. ConclusionConsidering that oxidation of cakes and reduction shelf life in different type of cakes are probable due to the presence of considerable amounts of fatty acids, in this study the effect of adding L-ascorbyl palmitate as a common antioxidant and processed wheat germ due to its antioxidant behavior on the moisture content, hardness, specific volume, texture and shelf-life characteristics of the oil cake was investigated. The overall results show that by adding L-ascorbyl palmitate, there was no significant effect on moisture content, hardness and specific volume. However, processed wheat germ increased hardness (in amounts more than 5%), decreased moisture content and specific volume of cake. Also, with increasing the amount of wheat germ, a significant decrease in peroxide value and acidity of the cake was observed during the storage period. However, the values of moisture content, hardness and specific volume in the sample containing palmitate ascorbyl were lower than samples containing wheat germ. According to the results, it seems that sample containing 5% processed wheat germ can be recommended as a suitable formulation for cake enrichment and artificial antioxidant replacement.
Food Chemistry
Mahbobe Mohammadi; Soheila Aghaei Dargiri; Somayeh Rastegar
Abstract
The use of edible coatings has been considered as an effective solution to improve the shelf life and quality of fruits. In this research, increase in the shelf life of citrus fruits (Citrus aurantifolia cv. Mexican lime) coated with Persian gum and pomegranate seed oil was investigated. Different treatments ...
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The use of edible coatings has been considered as an effective solution to improve the shelf life and quality of fruits. In this research, increase in the shelf life of citrus fruits (Citrus aurantifolia cv. Mexican lime) coated with Persian gum and pomegranate seed oil was investigated. Different treatments of lemon fruit coated with Persian gum and pomegranate seed oil with concentrations (zero (control), 0.5% and 1% gum, combination of 0.5% and 1% gum and pomegranate seed oil, 0.05% and pomegranate seed oil 0.05 percent) were prepared and after 24 days of storage at ambient temperature (20 ± 2 °C and relative humidity of 50-60 percent) were statistically evaluated in the form of a completely random design with three replications. The results of this research showed that the treatments used had an effective role in controlling the weight loss of fruit during storage. Thus, the lowest percentage of weight loss was observed in the pomegranate seed oil treatment. Except pomegranate seed oil treatment, other treatments showed less TSS than the control. In most of the treatments, the content of phenol, flavonoid and antioxidant was at a higher level than the control. The average comparison results showed that the fruits coated with 1% gum (85.36 units/ml) showed significantly more peroxidase activity than the control (60.35 U/ml). Persian gum edible coating 1% and 0.5% as well as Persian gum 1% in combination with pomegranate seed oil significantly controlled the activity of polyphenol oxidase enzyme. The treated samples showed less yellowness (b*) than the control. In general, the best marketability was observed in fruits coated with 1% gum. Therefore, it is recommended to use this coating to preserve the freshness and quality of the Mexican lime fruit during storage in the environment.
Food Technology
Reza Farahmandfar; Sahar Aboutalebzadeh; Hannaneh Moniri; Massoud Kaykhaii
Abstract
Black tea, which is obtained from the leaves of small tree Camellia sinensis, is a popular drink that has been consumed for centuries all around the world. In this study, a sample of Iranian black tea was brewed by two methods of microwave and traditional brewing and their extracts were then assessed ...
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Black tea, which is obtained from the leaves of small tree Camellia sinensis, is a popular drink that has been consumed for centuries all around the world. In this study, a sample of Iranian black tea was brewed by two methods of microwave and traditional brewing and their extracts were then assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing/antioxidant power (FRAP) assays to determine their phenolic and flavonoid contents as well as heavy metal (HM) (copper, nickel, chromium, cadmium and lead) content. It was observed that there is a direct relationship between the antioxidant activity with their phenolic and flavonoid contents. The highest and lowest antioxidant activities were observed for samples brewed by microwave at 360 W for 2.5 min and 900 W for 7.5 min, respectively. As the brewing power and time increased, the antioxidant activity decreased. Brewing tea by microwave and traditional methods caused a significant reduction in the amount of heavy metals, which was lower than the allowable limit according to the Iranian national standards. These results demonstrate the importance of exposure time and radiation power when tea is prepared by microwave.
Food Biotechnology
Behrooz Alizadeh Behbahani; Mohammad Noshad; Mostafa Rahmati-Joneidabad
Abstract
[1]Introduction: Oxidation and food pathogens are considered two important and influential factors affecting food quality and health. Recently, due to the increasing demand for natural products, the application of synthetic preservatives to control microbial growth and lipid oxidation have been decreased ...
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[1]Introduction: Oxidation and food pathogens are considered two important and influential factors affecting food quality and health. Recently, due to the increasing demand for natural products, the application of synthetic preservatives to control microbial growth and lipid oxidation have been decreased significantly. Therefore, natural antioxidant and antimicrobial compounds are receiving more attention in food preservation technologies. In the last 2 decades, the use of herbal medicines rich in bioactive molecules (including polyphenols, carotenoids and flavonoids) with medicinal and health effects such as delaying the onset of some diseases such as cardiovascular disorders, diabetes, and cancer have increased. Furthermore, secondary metabolites in plant extracts and essential oils are able to control and inhibit free radical-mediated reactions. The olive tree (Olea europaea) is an evergreen plant that grows in tropical and subtropical regions. Iran is one of the most important olive growers in the world due to its suitable conditions for olive cultivation. The leaves of the olive plant have a high potential for the production of various products such as tea and extracts. Olive leaf extract can be used as a raw material in the production of various products, due to exhibiting various biological activities such as antimicrobial and antiviral activity, lipid stabilizer, blood pressure regulator, antioxidant activity, and free radical scavenger. The leaves of the olive tree also contain various phenolic compounds, mainly Oleuropein and hydroxytyrosol, with antioxidant and antimicrobial activities. Therefore, in this study, the amount of phenolic and flavonoid compounds of olive leaf ethanolic extract and its antioxidant effect and antimicrobial properties on Escherichia coli, Enterobacter aerogenesis, Bacillus cereus and Listeria innocua were investigated. Materials and Methods: The olive leaf ethanolic extract was prepared through maceration method and its total phenolic content (Folin-Ciocalteu method), total flavonoids content (aluminum chloride colorimetric assay), antioxidant activity (ABTS and DPPH free radical scavenging methods), and antimicrobial effect on E. coli, E. aerogenesis, B. cereus and L. innocua (based on disk diffusion agar, well diffusion agar, minimum inhibitory concentration, and minimum bactericidal concentration) were determined according to standard methods. Data were analyzed by SPSS software through one-way ANOVA and Duncan test at p<0.05. Results and Discussion: The ethanolic extract of olive leaves contained 176.58 ± 0.72 mg GAE/g total phenol and 69.85 ± 0.26 mg QE/g total flavonoids. In addition, ethanolic extract of olive leaf was able to inhibit free radicals DPPH (70.62 ± 0.59%) and ABTS (76.15 ± 0.43%). The antimicrobial results showed that the antimicrobial effect of the extract depended on its concentration and type of bacteria. Antimicrobial effect was increased as a function of ethanolic extract, and Gram-positive bacteria (B. cereus and L. innocua) were more sensitive to ethanolic extract of olive leaf than Gram-negative bacteria (E. aerogenesis and E. coli). Generally, B. cereus and E. aerogenesis were the most sensitive and resistant microbial strains to ethanolic extract of olive leaf, respectively.The results of this study showed that the high antioxidant and antimicrobial activity of olive leaf ethanolic extract is mainly due to its phenolic and flavonoid compounds. Olive leaf ethanolic extract was able to neutralize DPPH and ABTS free radicals. Also, Gram-positive bacteria were more sensitive to ethanolic extract of olive leaf than Gram-negative bacteria. In general, the ethanolic extract of olive leaf can be used as a nutraceutical to control or prevent the growth of spoilage/infection-causing microorganisms and free radical reactions in food and the human body. However, more in-depth studies are needed to determine the mechanism of antimicrobial and antioxidant effects of olive ethanolic extract in vitro and in vivo.
Zahra Sheikholeslami; Mahdi Karimi; Bahareh Sahraiyan
Abstract
Introduction: Doughnuts are fried foods that absorb significant amounts of oil, and commercial doughnuts made from wheat flour typically contain 24 to 26 percent oil. Fresh doughnut is soft and has a pleasant taste and aroma. One of the main ways to enrich bakery products is to mix wheat flour with other ...
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Introduction: Doughnuts are fried foods that absorb significant amounts of oil, and commercial doughnuts made from wheat flour typically contain 24 to 26 percent oil. Fresh doughnut is soft and has a pleasant taste and aroma. One of the main ways to enrich bakery products is to mix wheat flour with other flours. Triticale has a higher
percentage of protein compared to wheat, rice, corn, rye and oats and is in good condition in terms of essential amino acids. Lysine in triticale is higher than wheat and less than rye. Also triticale has the same amount of vitamins as wheat. The positive properties of gums extracted from native seeds such as basil can be used to reduce oil absorption and improve shelf- life of fried bakery products. Basil seeds are soaked in water due to the presence of polysaccharides, the outer pericarp swells and turns into a gelatinous substance. Green cardamom with scientific name of Elettaria cardamomum belongs to Zingiberaceae family. Cardamom is one of the most widely used aromatic condiments in some foods, breads, sweets, especially jams. 23 compounds have been identified in green cardamom essential oil, the highest composition (31.53%) belonging to Eucalyptol. Therefore, in this study, enrichment the wheat flour of fried fermented doughnuts by replacing part of wheat flour with triticale flour, reducing oil absorption by using basil seed gum and improving antioxidant and sensory properties and reducing fungal activity in the presence of green cardamom essential oil were investigated.
Material and Methods: In the first part of this research, Triticale flour at 0, 15 and 30% and Basil seed gum at 0, 0.50 and 1% were used to improve the quality and decrease oil absorption of fermented doughnut. Control doughnut formulation had 500 g wheat flour, 20 g milk powder, 4 g salt, 80 g oil, 12 g baker’s yeast, 80 g sugar, 500 ml water, 100 g egg and 1 g vanilla, 1.5 % guar gum and 0.5 % xanthan gum. Moisture, specific volume, porosity, firmness, crust color and oil absorption were evaluated. To study the effect of processing parameters on crust color components of doughnut, the RGB color space images were converted to L*a*b space. For determination of doughnut porosity using image analysis, the color images were first gray scaled and then thresholded using isodata algorithm. The porosity was measured from the ratio of white to the total numbers of pixels. Results were reported as the average of three replications. In the second part of this research, Cardamomum essential oil at 0, 50, 100, 150 and 200 ppm were used to improve antioxidant and sensory properties and decrease microbial contamination of doughnut. . In order to assess significant differences among samples, a complete randomized design of triplicate analyses of samples was performed using the Mini-Tab17. Tukey’s new multiple range tests were used to study the statistical differences of the means with 95% confidence.
Result and Discussion: The results of the first part showed that the sample contained 15% triticale flour and 0.50% gum with the highest specific volume (3.4 cm3g-1) and porosity (0.81) and the lowest firmness after one week of storage (11.91 N) and was introduced as the best example of the first part. Also, the results of oil absorption showed a decrease of 29.83% in the selected sample (0.17 g/g dry matter) compared to the control sample (0.24 g/g dry matter). The moisture content of the mentioned sample was 21.09% one week after production and L*, a* and b* of crust color was 55.27, 8.86 and 11.91, respectively. Brightness and redness of this sample was more than the control. The results of second part showed that cardamom essential oil had antioxidant activity in all concentrations. Also, the results indicated the concentrations of more than 50 ppm of cardamom essential oil can be considered as an antifungal agent and inhibit positive growth in doughnut. The microbial load of samples containing 100, 150 and 200 ppm had 3.97, 3.81 and 2.94 log cfu g-1 after 15 days of production, respectively. The microbial load of these samples was 51.05, 53.03 and 63.75% less than the sample without essential oil (10.11 log cfu g-1). Finally, the results of sensory evaluation showed that the sample containing 15% triticale flour, 0.50% basil seed gum and 100 ppm cardamom essential oil had the highest overall acceptance score and this sample is introduced as the best sample of this study.
Sanaz Fallh-Taftizadeh; Gholamreza Abdi; Fatemeh Zendeboodi; Mahdi Mohammadi
Abstract
Introduction: Virgin olive oil has high oxidative stability due to its special compounds, including large amounts of monounsaturated fatty acids (MUFAs) and a wide range of natural antioxidants. However, virgin olive oil is easily oxidized due to the presence of polyunsaturated fatty acids (PUFAs), ...
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Introduction: Virgin olive oil has high oxidative stability due to its special compounds, including large amounts of monounsaturated fatty acids (MUFAs) and a wide range of natural antioxidants. However, virgin olive oil is easily oxidized due to the presence of polyunsaturated fatty acids (PUFAs), mainly linoleic and linolenic acids. Lipid oxidation is the main cause of poor food quality; for this reason, the use of antioxidants is essential to prevent the onset and progression of oxidative damage and increase the shelf life of oils and fats. Because lipid oxidation occurs following a complex set of processes and no antioxidant alone can stop all the oxidation steps and keep oxygen away, a mixture of antioxidants can be used to create a synergistic effect. Spirulina is a dry biomass of Artrhrospira platensis cyanobacteria. Flavonoids, β-carotene, vitamin A and α- -tocopherol in spirulina are largely involved in the high antioxidant activity of this microalgae. The Moringa oleifera plant belongs to the Moringaceae family, the genus Moringa and the species Oleifera. This plant is considered as a high-potency natural antioxidant because it is rich in tocopherols, carotenoids, vitamin C, flavonoids and phenolic compounds. Therefore, the aim of this study was to investigate the synergistic and symbiotic effect of spirulina and M. oleifera extracts as natural antioxidants to increase the oxidation stability and shelf life of virgin olive oil. Materials and Methods: To prepare the extracts of s. platensis and M. oleifera plant, both plants were dried in the shade at 30°C for 24 hours in the presence of air, then ground into a powder. Then, 5 g of s. platensis and M. oleifera powders were extracted with two solvent of ethanol (96%) and methanol. Antioxidant activity was evaluated by measuring the effect of free radical scavenging of ethanolic extracts of Algae Spirulina and Acacia on the synthetic radical DPPH. Determination of total phenol and flavonoid content of all extracts was performed using Folin-Ciocalteu reagent and aluminum chloride colorimetric method, respectively. Polyphenolic compounds of the extracts were identified by HPLC. Extracts were added separately (1000 ppm each) and in combination (500 ppm each) to 100g of virgin olive oil and a sample containing the synthetic antioxidant TBHQ and a sample of virgin olive oil were considered as control. Peroxide index, refractive index and color evaluation (L*, a*, b*) of virgin olive oil samples were measured. Statistical analysis was performed using SPSS software version 19 and the results were expressed as mean ± standard deviation. Results and Discussion: Based on the results obtained from ethanolic and methanolic s. platensis extracts, the highest amount of total phenol in ethanolic extract was equal to 67.19±4.5 mg GA/g and the highest amount of flavonoids in methanolic extract was equal to 12/1±40/267 mg QU/g. In the study of the content of total phenol and flavonoids in ethanolic and methanolic extracts of M. oleifera plant, there was the highest levels of total phenols and flavonoids in ethanolic extracts of this plant, respectively, 43.43±0.71 mg GA/g and 23.78±1.57 mg QU/g. The results showed that the active compounds in the extracts of S. platensis and M. oleifera are polyphenolic compounds of rosmarinic acid, catechin, quercetin, vanillin, hesperidin, hesperetin. Changes in peroxide value from the time of production and addition of the extract for 8 hours at 2 hour intervals were investigated. According to the results, the lowest amount of peroxide value (0.38±0.005 meq O2/kg) was related to the sample containing M. oleifera extract at the third storage time. The highest amount of peroxide value was observed in the control and the sample containing TBHQ in the range of 15 meq O2/kg. Generally, Changes in peroxide value were reduced significantly in the 3 samples containing the extract compared to the control sample and the sample containing TBHQ (p<0.05). The presence of extracts in virgin olive oil reduced the parameters of L*a*b*, but the sample containing S. platensis extract was no significant difference from the control sample (p >0.05). According to the results of peroxide index of samples containing extracts, it can be stated that by recognizing the antioxidant effects of S. platensis and M. oleifera extract, they can be used for industrial use and replacement with synthetic antioxidants.
Sedigheh Yazdanpanah; Sara Mohammadi; Amir Hossein Elhami Rad
Abstract
Introduction: White tea is a new ingredient in a wide range of phenolic, antioxidant and antimicrobial compounds. The most important catechins in white tea are epicatechin, epigallocatechin, epicatechin- 3- galate, and epigallocatechin- 3- galate, which are flavonol gallates. The concentration of these ...
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Introduction: White tea is a new ingredient in a wide range of phenolic, antioxidant and antimicrobial compounds. The most important catechins in white tea are epicatechin, epigallocatechin, epicatechin- 3- galate, and epigallocatechin- 3- galate, which are flavonol gallates. The concentration of these phenolic compounds in white tea is higher than green tea. Sesame seed oil, which is produced by cold pressing method, has a great ability to preserve antioxidant compounds. Significant oxidative stability of sesame oil is due to the presence of lignan non-soapy substances. Strong antioxidant compounds in sesame seed oil include sesamol, sesamulin (antioxidant precursor), sesaminol and its isomers. The aim of this study was to investigate the effect of natural antioxidants of sesame oil and white tea on inhibiting the effect of metals on oxidation of sesame oil. Materials and Methods: In this study, aqueous extract of white tea was extracted and sesame oil was produced using cold press. In the next step, six samples including control sample (sesame oil), sesame oil containing white tea extract, sesame oil containing white tea extract and 0.1 ppm iron, Sesame oil containing white tea extract and 0.1 ppm copper, sesame oil with tea and 0.1 ppm zinc extract and sesame oil containing 100 ppm BHT were prepared. In all samples, aqueous extract of white tea in the amount of 6 mg/ 10 g was added to sesame oil. Total phenol, antioxidant capacity, power reducing on white tea extract and antioxidant power, peroxide number, oxidation stability and fatty acids profile were measured. All experiments were performed in a completely randomized design with three replications and the means were compared with Duncan’s test at the level of (P<0.05). SAS V 9.1 software was used for statistical analysis of quantitative data. Results and Discussion: The results showed that the aqueous extract of white tea contained 4.06 (mg gallic acid per gram of sample) total phenol, 6.00 (μg/ ml) antioxidant capacity 0.020 (mg/ g). Ml) is a reducing power. The reducing power of BHT antioxidant was 40 times and the antioxidant power of BHT was 14.85 times more than the aqueous extract of white tea. In the inhibition of free radicals in sesame oil, the aqueous extract of white tea had a significantly greater effect than the control sample. The iron- containing sample had more oxidation than other samples. In the inhibition of free radicals in sesame oil, the aqueous extract of white tea had a significantly greater effect than the control sample. The iron- containing sample had more oxidation than other samples. Rancimat value for samples of control sesame oil, sesame oil with tea and iron extract, sesame oil with tea and copper extract, sesame oil with tea and zinc extract, sesame oil with tea extract and sesame oil with synthetic antuioxidant BHT respectively 8.79 4.80, 9.08, 9.35, 9.42 and 9.61 hours were measured. The highest stability was related to the sample of sesame oil and synthetic antioxidant BHT and the Results and Discussion: The results showed that the aqueous extract of white tea contained 4.06 (mg gallic acid per gram of sample) total phenol, 6.00 (μg/ ml) antioxidant capacity 0.020 (mg/ g). Ml) is a reducing power. The reducing power of BHT antioxidant was 40 times and the antioxidant power of BHT was 14.85 times more than the aqueous extract of white tea. In the inhibition of free radicals in sesame oil, the aqueous extract of white tea had a significantly greater effect than the control sample. The iron- containing sample had more oxidation than other samples. In the inhibition of free radicals in sesame oil, the aqueous extract of white tea had a significantly greater effect than the control sample. The iron- containing sample had more oxidation than other samples. Rancimat value for samples of control sesame oil, sesame oil with tea and iron extract, sesame oil with tea and copper extract, sesame oil with tea and zinc extract, sesame oil with tea extract and sesame oil with synthetic antuioxidant BHT respectively 8.79 4.80, 9.08, 9.35, 9.42 and 9.61 hours were measured. The highest stability was related to the sample of sesame oil and synthetic antioxidant BHT and the lowest stability was related to the sample of sesame oil with tea and iron extracts. In comparison with the effect of metals on the oxidation of sesame oil, the addition of iron to sesame oil has increased the oxidation rate compared to the two other examined metals (copper and zinc). Rare metals increase the oxidation rate of edible oils by increasing the production of free radicals from fatty acids or hydroperoxides. The composition of of fatty acids profile showed that palmitic acid, stearic acid, oleic acid, linoleic acid and linolenic acid were the predominant fatty acids in sesame oil. In the iron- containing sample, with increasing oxidation rate, the amount of linolenic acid decreased compared to other samples. The results of the Se index were confirmatory on the results of oxidative stability index. White tea extract and sesame oil due to their antioxidant and phenolic compounds have been able to inhibit free radicals and metal peroxidants, especially copper and zinc. Sesame oil extracted by cold pressing is not suitable for frying due to its low heat resistance, but it can be used in the formulation of salad dressings.
Food Chemistry
Farideh Mojrian; Marzieh Moeenfard; Reza Farhoosh; Hadi Mahdavian Mehr
Abstract
Introduction: Date seeds (also known as pits and kernel) are among the most important wastes which are generated during direct consumption or from the date processing industries. Despite the presence of several nutrients and bioactive compounds and their subsequent beneficial health effects, these by-products ...
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Introduction: Date seeds (also known as pits and kernel) are among the most important wastes which are generated during direct consumption or from the date processing industries. Despite the presence of several nutrients and bioactive compounds and their subsequent beneficial health effects, these by-products are frequently discarded to use as soil fertilizer or as feed for livestock. Roasting opens a cost-effective way to include date seed in the human diet. The aqueous extract of roasted date seed represented a coffee-like beverage. Date seed coffee has a relatively low acceptance among consumers and is usually supplemented with a variety of additives to improve the taste. Therefore, due to rising the global coffee price, in the present studywe aimed to substitute Arabica beans with roasted date seeds in order to make a coffee beverage similar to Coffea Arabica boiled coffee brew. Results and Discussion: Substitution with roasted date seed resulted in lower lipids, protein and caffeine of coffee brews as the values were decreased from 330.67, 956.75, 76.51 mg/100 mL in Coffea Arabica (100%) to 192.61, 149.00, 45.59 mg/100 in date seed coffee (100%), respectively. Higher amounts of date seed also resulted in lower pH and acrylamide content. Accordingly, pH was decreased from 5.7 in D100 to 4.4 in A100. Acrylamide content was attenuated from 5.06 µg/100 mL in A100 to 1.71 µg/100 mL in D100. Reduction in viscosity was also observed from 0.93 (A100) to 0.86 mPa.s (D100). The mean value of the color parameter including L*, a* and b* in the 100% Coffea Arabica brew was more than the 100% date seed coffee, which indicated that the coffees brewed from date seeds in different proportions were brighter and had higher red and yellow color parameters. Substitution with date seed had less effect on the total phenol content as TPC of coffees ranged from 28 to 42 mg/100 mL for 100% date seeds brew and Coffea Arabica brew, respectively. On the other hand, the flavonoid content (TFC) of coffees was significantly affected by the amount of date seeds (5 to75 mg/100 mL for 100% date seeds and Coffea Arabica brew, respectively). All brews have high antioxidant activity. For DPPH the highest results (88/9 %) were obtained in the coffee brewed from 100% date seeds, while the FRAP value it was vice versa. The results of sensory evaluation indicated a high similarity among A100 and D10 coffees as parameters such as aroma, color and texture (concentration) of coffee were evaluated appropriate. The results also showed that substituting Coffea Arabica up to 35% with roasted date seeds can improve the overall acceptance of the coffee brews by reducing bitterness.Conclusion: In general, the ability to replace Coffea Arabica with date seeds up to 10 and 35% was reported acceptable in terms of sensory characteristics, as the color and aroma were similar to 100% Coffea Arabica. Besides that due to reduced bitterness, the overall acceptance were almost high.
Food Chemistry
Elham Ranjbar Nedamani; Alireza Sadeghi Mahoonak; Mohammad Ghorbani; Charlotte Jacobsen; Vahid Khouri
Abstract
The aim of the present study was to use the Maillard reaction as a means to glycosylate protein hydrolysates obtained from Cajanus cajan and to evaluate the effects of this chemical modification on antioxidant and emulsifying properties. Chemical properties, amino acid composition, and molecular weight ...
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The aim of the present study was to use the Maillard reaction as a means to glycosylate protein hydrolysates obtained from Cajanus cajan and to evaluate the effects of this chemical modification on antioxidant and emulsifying properties. Chemical properties, amino acid composition, and molecular weight distribution of the hydrolysates were evaluated. Glucose, galactose, and maltodextrin in the ratios of 1:2, 1:1, and 2:1 (hydrolysate: sugar, dry weight basis) were used for glycosylation. Antioxidant activity was evaluated by 1, 1- diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and nitric oxide scavenging. The sonication technique was used to prepare the (oil/water) emulsions. The droplet size distribution and zeta potential of the emulsions were measured during 4 days of storage. Results showed that glycosylation by glucose in the ratio of 2:1 increased DPPH scavenging activity from 37.96% to 85.53% and nitric oxide inhibition activity from 14.50% to 54.83%. Although glycosylation improved emulsifying stability of glycosylated hydrolysates compared to non-glycosylated hydrolysates, no significant difference was observed between the three examined sugars.
Food Chemistry
Atefeh Irankhah; Leila Nateghi; Simin Asadollahi
Abstract
Introduction: Currently, synthetic antioxidants are used to reduce the oxidation of oils and fatty foods and to prevent the reduction of the nutritional value and sensory properties of edible oils. Due to the adverse effects of synthetic antioxidants, the use of natural antioxidants seems essential. ...
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Introduction: Currently, synthetic antioxidants are used to reduce the oxidation of oils and fatty foods and to prevent the reduction of the nutritional value and sensory properties of edible oils. Due to the adverse effects of synthetic antioxidants, the use of natural antioxidants seems essential. Ferulago angulata extract is a natural source of antioxidants that, in addition to enhancing flavor, help extend the shelf life of the product. The aim of this study was to investigate the antioxidant effect of Ferulago angulata extract on the physicochemical and sensory characteristics of potato- chips and the resulting oil during shelf life. Ferulago angulata plant was purchased from the local market of Sarpol-e-Zahab city in Kermanshah province and was extracted using 96% ethanol soaking and solvent by distillation machine. The thin sheets of potatoes were fried in oils containing 1000, 2000, 3000 and 4000 ppm of chamomile extract and the oil containing 100 ppm of synthetic antioxidant TBHQ at 190°C for 9 minutes. The ability to inhibit DPPH free radicals, total phenolic compounds, and sensory evaluation on potato chips and peroxide, acidity, and thiobarbituric acid tests on oil from frying potato chips over time 1, 15 and 30 days of storage were evaluated. The results showed that the use of Ferulago angulata extract increased antioxidant power in inhibiting DPPH free radicals and total phenolic compounds and reduced the amount of peroxide, acidity and thiobarbituric acid, so that the lowest amount of peroxide, acidity. And thiobarbituric acid and the highest amount of total phenolic compounds related to treatment containing 4000 ppm of Ferulago angulata extract. A treatment containing 4000 ppm of chamomile extract has the highest resistance to oxidative spoilage and can be compared to synthetic antioxidant TBHQ. The results of this study showed that using Ferulago angulata extract with a concentration of 2000 ppm, a potato chips with desirable organoleptic properties can be obtained and used as a suitable alternative to synthetic antioxidants such as TBHQ in food and oil oxidation. Materials and Methods: Ferulago angulata plant was purchased from the local market of Sarpol-e Zahab city in Kermanshah province. Then, by Herbarium of Medicinal Plants, Faculty of Pharmacy, University of Tehran, its scientific name was confirmed as Boiss (Schlechat) Ferulago angulata, belonging to the Apiaceae family. 96% ethanol soaking and solvent were used for extraction. For this purpose, 100 grams of powdered leaves of Ferulago angulata plant were carefully weighed by a digital scale balance. Then, to prepare ethanolic extract, 500 ml of 96% ethanol was added to the Erlenmeyer flask. For 72 hours, the flask was placed at room temperature on a 1500 rpm magnetic shaker to fully extract the Ferulago angulata t. The solvent mixture and the plant were then separated by filter paper. Then squeeze the pulp until it is completely emptied and finally the initial extract is obtained. The initial extract was centrifuged for 10 min at 3000 rpm. The resulting extract was then poured into a vacuum distiller (rotary) and heated to 80 °C for one hour to evaporate the solvent from the extract. The concentrated extract contained 4.0623 mg of gallic acid per gram, total phenol and IC50. Ferulago angulata extract in concentrations of 1000, 2000, 3000 and 4000 ppm and TBHQ synthetic antioxidant with a concentration of 100 ppm in frying oil (a mixture of super olein, soybean and sunflower oils) without antioxidants in dark color glass was added and a sample of oil without antioxidants was prepared. Variegated potatoes are washed, peeled and then cut into thin slices using a slicer and immersed in water until fried. Immediately after the dewatering, the potato slices were transferred to a frying pan containing a variety of oils and fried for 9 minutes at 190 °C. The fried sheets were then cooled to room temperature. The frying oil was kept in a 20 °C oven. Then, at 1, 15 and 30 days after storage of frying oil in a 20 °C oven, t the acid number, peroxide and thiobarbituric acid on the oil from frying the potato chips were determined. Sensory and phenolic compounds and DPPH were performed on potato chips. Data analysis was performed using Minitab-16 software and ANOVA. Results and Discussion: The aim of this research was to investigate the antioxidant effect of Ferulago angulata extract on the physicochemical and sensory properties of potato chips and the resulting oil during its shelf life. According to the results, the highest and lowest levels of acidity, peroxide and thiobarbituric acid were assigned to the control treatment (synthetic anti-oxidant oil) and the treatment containing 4000 ppm of Ferulago angulata extract, respectively. Examination of phenolic compounds showed that by using Ferulago angulata extract and increasing its concentration, antioxidant properties increased and the highest antioxidant property was belonged to the treatment containing 4000 ppm of Ferulago angulata extract, which contained higher phenolic compounds. The results of sensory evaluation showed that the highest score of sensory properties was given to the control treatment and treatments containing 1000 and 2000 ppm of Ferulago angulata extract. As can be seen, antioxidant properties and polyphenolic compounds had the opposite effect on sensory scores. The fried chips in oil containing 2000 ppm of Ferulago angulata extract were selected as the optimal treatment in terms of the highest score of sensory evaluation. The results showed that the extract of Ferulago angulata plant could be a good alternative to synthetic antioxidants in frying oils to delay the oxidation of frying oil, and in addition to its antioxidant properties, it can create desirable sensory properties in fried foods and reduce the risk of consuming these foods.
Fakhri Shahidi; Farideh Tabatabaei Yazdi; Majid Nooshkam; Zahra Zareie; Fereshte Fallah
Abstract
Introduction: Lipid oxidation leads to the generation of off-flavors and potential toxic compounds. Synthetic antioxidants are frequently applied for inhibiting this reaction, however; there is a concern regarding to the potent toxic effects of synthetic antioxidants on human health. The non-enzymatic ...
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Introduction: Lipid oxidation leads to the generation of off-flavors and potential toxic compounds. Synthetic antioxidants are frequently applied for inhibiting this reaction, however; there is a concern regarding to the potent toxic effects of synthetic antioxidants on human health. The non-enzymatic glycosylation reaction (Maillard reaction) has been broadly used to ameliorate the biological and functional features of proteins and polysaccharides. The Maillard reaction produces products with versatile functions such as antioxidant, antimicrobial, antihypertensive, anti-browning, and prebiotic properties. In this regard, the Maillard reaction products (MRPs) can be used in the food industry to inhibit the oxidation reaction due to their superb antioxidant effect. In this study, chitosan was glycosylated with inulin, fructose, and glucose. Chitosan is a chitin derivative with cationic nature having antimicrobial, antioxidant, metal chelation, and film-forming features. Inulin is recognized as a prebiotic sugar with vast applications in food and pharmaceutical sciences. The purpose of this study was to chemically modify chitosan through the Maillard reaction in order to boost its antioxidant and antimicrobial properties. Materials and methods: Chitosan (0.5% w/v) was dissolved in 1.0% v/v acetic acid solution followed by stirring for 1.0 h at room temperature. Afterwards, sugars inulin, glucose, and fructose were separately added to the chitosan solution at final concentration of 1.0% w/v. The obtained solutions were then stirred until complete sugar dissolution. The pH of solution was adjusted to 6.07 by adding 2.0 M sodium hydroxide and then the chitosan-sugar Maillard conjugates were fabricated through autoclaving the solutions at 121 °C. Changes in pH after the reaction were measured using a pH meter. The extent of the Maillard reaction was estimated via measuring the absorbance of the conjugated solutions at 294 nm (the intermediate products) and 420 nm (final products). Fourier transform infrared (FTIR) spectroscopy at transmission mode and 400-4000 cm-1 was employed to evaluate the structural changes of chitosan upon conjugation. Antioxidant activity of the conjugates was evaluated based on the reducing power assay. One mL of the samples was charged with 1.0 mL of distilled water and 1.0 mL of potassium ferricyanide (1.0% w/v). The solution was mixed and incubated at 50 °C for 20 min. After adding 2.5 mL of tri-chloroacetic solution (10% w/v), the obtained solution was centrifuged at 5000 g for 5.0 min. Afterwards, 2.0 mL of the supernatant was mixed with 2.0 mL of distilled water and 1.0 mL of ferric chloride (0.1% w/v). The solution was stand for 10 min at ambient temperature and then its absorbance was recorded at 700 nm. Antimicrobial effect of the conjugates against pathogenic microorganisms (E. coli, S. aureus, B. subtilis, P. aeruginosa, A. niger, and C. albicans) was measured according to the minimum inhibitory (MIC) and microbiocidal (MBC) concentrations. SPSS software (version 21) and one-way ANOVA were applied for data analysis. Duncan’s multiple range test was employed to determine the differences between means. Results & discussion: The Maillard reaction led to a significant decrement in pH value of chitosan-saccharide systems, mainly due to the covalent coupling of amino groups of chitosan to carbonyl groups of reducing sugars in conjugation with the production of acetic and formic acids. The highest intermediate compounds (A 294nm) and lowest browning intensity (A 420nm) observed in chitosan-fructose conjugate, which was likely attributed to the lower reactivity of fructose. Chitosan-inulin conjugate presented the highest A 420nm and lowest intermediate-to-final ratio (A 294nm/A 420nm), probably due to the lower inulin molecules and subsequently carbonyl groups compared to fructose and glucose. These groups may react with amino groups of chitosan at initial reaction times, leading more conversion rate of the intermediate compounds to the final ones. FTIR spectra of the chitosan and conjugates revealed that absorbance peak at 1661 cm-1 in chitosan spectrum decreased and shifted to 1578 cm-1 (in chitosan-fructose conjugate), 1579 cm-1 (in chitosan-glucose conjugate), and 1580 cm-1 (in chitosan-inulin conjugate), indicating the stretching C-N group and -C=N group and the formation of Schiff base (-C=N) between reducing end of the saccharides and amino groups of chitosan. Reducing power of the chitosan-saccharide systems improved after the thermal process. Although, chitosan-glucose and chitosan-fructose conjugates had significantly higher reducing power than unconjugated counterparts, but chitosan-inulin conjugate showed non-significantly improved antioxidant activity compared to its non-heated mixture. Antioxidant activity of the Maillard conjugates was ascribed from the electron donating ability of their hydroxyl and pyrrole groups. The conjugates had lower MIC and MBC in comparison to their unconjugated pairs, except for chitosan-glucose conjugate, which showed no differences in MIC and MBC compared with its non-heated mixture. Antimicrobial property of the Maillard products, especially melanoidins has been attributed to their metal chelating features; melanoidins exert a bacteriostatic effect at low concentration and bactericidal effect at high levels through sequestering ionic iron from medium and magnesium from outer membrane, leading to the cell membranes destabilization. Additionally, antioxidant capacity, high surface activity, and inhibiting effect towards catabolic enzymes have been reported as another antimicrobial mechanisms of the Maillard products. In general, it can be concluded that chitosan-saccharide Maillard-based conjugates, particularly inulin-chitosan one could be used in the food sector as a novel prebiotic-based active bio-compound with antioxidant and antimicrobial features.
Elham Ranjbar Nedamani; Alireza Sadeghi Mahoonak; Mohammad Ghorbani; Sharlot Jakobson; Vahid Khori
Abstract
Introduction: Proteins are being hydrolyzed to generate various properties such as antioxidant activity and nutritional values. Enzymatic hydrolysis is carried out in milder condition and is more controllable. The produced protein hydrolysates’ properties are dependent to the hydrolysis condition. ...
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Introduction: Proteins are being hydrolyzed to generate various properties such as antioxidant activity and nutritional values. Enzymatic hydrolysis is carried out in milder condition and is more controllable. The produced protein hydrolysates’ properties are dependent to the hydrolysis condition. So by optimizing the hydrolysis conditions, proteins with higher antioxidant abilities are achieved. Response surface method is a statistical way to optimize and model the process more efficiently. The aim of present study was to optimize and model the hydrolysis condition to produce and antioxidant protein hydrolysate with high nutritional value from Cajanus cajan by pepsin. Materials and methods: First, Cajanus cajan’s proteins solubility was measured. After reaching the pHs with the most and least solubility, protein extraction was carries out by using NaOH and HCl. Enzyme concentration (1, 2, 3%), temperature (30, 35, 40 °C) and time (2, 3.5, 5 h) as independent variables were given to the Design Expert software and protein hydrolysis was done in a shaker incubator according to the 20 treatments suggested by the software. 1, 1- diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, hydroxyl radical scavenging activity, Reducing power and total antioxidant activity were measured as dependent variables. Antioxidant assays were modeled by the software and the optimum condition was evaluated. The obtained optimum condition was validated by repeating the antioxidant assays for the protein hydrolysate produced in the optimum condition. The amino acid profile of the protein hydrolysate was measured using HPLC-MS and chemical score was measures. Then, the molecular weight distribution of the protein concentrate and protein hydrolysate was evaluated by FPLC. Chemical composition of the samples was also measured. Results & discussion: The optimum condition for achieving antioxidant protein hydrolysate was enzyme concentration 2.15%, temperature 39.99 °C and time 4.52 h. Model validation results for this point were including DPPH scavenging activity 58.49%, reducing power 0.31 nm, hydroxyl radical scavenging activity 38.2% and total antioxidant capacity 0.63 nm. The protein concentrate consisted of 215.84 mg/g hydrophobic and 57.04 mg/g of them were aromatic amino acids. These amino acids are responsible for antioxidant activity of the protein hydrolysates. Chemical scores for essential amino acids were good. Most of the peptides in the protein hydrolysate had molecular weights below 10 kD that is considered to have antioxidant activities. Hydrolysis also increased the protein and ash content while fat and water content decreased compared to the Cajanus cajan’s flour and protein concentrate. Results showed that Cajanus cajan’s protein hydrolysate can be a good source of antioxidants and play a positive role in human nutrition.
Fahimeh Tooryan; Maryam Azizkhani
Abstract
Introduction: Nowadays, consumers are applicant to usage of natural replacements causing to side effects of synthetic preservatives such as carcinogenicity and teratogenicity. The tendency to use natural preservatives and replacing them with chemical preservatives has led to various studies of natural ...
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Introduction: Nowadays, consumers are applicant to usage of natural replacements causing to side effects of synthetic preservatives such as carcinogenicity and teratogenicity. The tendency to use natural preservatives and replacing them with chemical preservatives has led to various studies of natural compounds with antioxidant properties such as essential oils. Considering the environmental problems raised from current plastic packaging, edible and biodegradable coating could be developed and also be effective in controlling the chemical and microbial properties of food; especially if their effect be strengthened by adding natural antioxidant and antimicrobial agents like herbal essential oils. Various herbal compounds such as black pepper essential oils with antioxidant properties can be effective in combining with natural biodegradable coatings such as chitosan in oxidation control and enhance the effects or prevent or delay the chemical spoil. Safety and shelf-life of foods can be improved by using this technologies such as using natural preservatives. Adding essential oil, as a suitable source of antioxidant, for improvement the quality of the fish is the main purpose. Many fruits, especially orange, are rich in polyphenols. These materials are the most commonly existing phytochemicals in most fruits. Orange juice concentrate can be a good source of antioxidant and can be employed as a preservative in food products. Omega-3 fatty acid is used in daily healthy diet and plays an important role in prevention of disease. Being a considerably main source of Omega-3 fatty acid groups, fish preservation against oil oxidation and any other similar causatives seems quite necessary. In the present study, the effects of orange juice concentrate and chitosan coating enriched with black pepper essential oil on the chemical degradation of rainbow trout fillet stored in a refrigerator investigated.
Materials and methods: The chemical composition of black pepper essential oils were determined using a gas chromatography equipped with mass spectroscopy (GC/MS). GC-MS analysis of the essential oil was performed using Agilent-Technologies 6890N Network gas chromatographic (GC) system, equipped with Agilent Technologies 5975 inert XL Mass selective detector and Agilent-Technologies 7683 B series auto injector (Agilent-Technologies, Little Falls, CA, USA). Samples were stored at 4 ± 1 C° up to 12 days and evaluated periodically ( on days 0, 4, 8 and 12) for chemical and sensory characteristics. The samples were divided into 8 groups and assessed for PH-values, total volatile nitrogen (TVN), thiobarbituric acid (TBA), peroxide value (PV), free fatty acids (FFA) and sensory evaluation .The samples were also evaluated for antioxidant activity by measuring their scavenging abilities to DPPH radical (2,2 diphenyl-1-picril hydrazyl) and RP (Reducing power). Statistical analysis was performed using SPSS 20 software.
Results & Discussion: Results showed that More than 21 compounds were identified in oil, representing 97.75% of the total oil. The major constituents of essential oils obtained from the black pepper were β-caryophyllene (25.56%), Limonene (15.19%), Sabinene(12.2) , α-copaene(8.5) and beta –bisabolene (7.81) respectively. Results revealed that in comparison to the other treatments the control showed a significant increase in the trend of oxidative and sensory indexes and In the coated samples, the sample of fish coated with orange juice concentrate ,chitosan, and black pepper essential oil was the least amount of indexes than the rest (p<0/05) and showed lower indexes during the storage time .The radical scavenging DPPH, orange juice concentrate with a Brix 1/39 (66/9 %)and pepper essential oil 2% (64/1%) have more ability and had a greater antioxidant activity. In investigating corruption oxidation and sensory evaluation in all samples,chitosan coating with pepper essential oil and orange juice concentrate was higher(score:7/2) than other treatments and there were significant differences between treatment and control (p<0/05). Final peroxide value (meq O2/Kg oil) and tiobarbituric acid (m gr/kg oil MD) number using chitosan coating with pepper essential oil and orange juice concentrate in sample was 0.14 and 0.015, respectively. This significant deference was also observed when comparing to control sample (p<0.05)Minimum oxidative changes were observed in samples treated with orange juice concentrate,chitosan, and black pepper essential oil and had the best conditions in reduction of oxidative rancidity. The results obtained in this study showed that the chitosan coating enriched with black pepper essential oil with orange juice concentrate has a good potential to being employed as an active packaging to preserve food products. Overall, this study demonstrated that using concentrated juice incorporated with chitosan coating with pepper essential oil has a good effect on the quality of rainbow trout fillets and can keep on the sensorial attributes acceptably during 12 days storage time and present a good potential for their application in the food industry.
Maryam Farahmand; Mohammad Taghi Golmakani; Asgar Farahnaki; Gholam Reza Mesbahi
Abstract
Introduction: The pomegranate (Punica granatum L.) belongs to the family Punicaceae, which is planted around the world in different microclimatic areas. The pomegranate production has grown uninterruptedly, which is presumably due to the increasing consumer awareness of the benefits attributed to pomegranate ...
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Introduction: The pomegranate (Punica granatum L.) belongs to the family Punicaceae, which is planted around the world in different microclimatic areas. The pomegranate production has grown uninterruptedly, which is presumably due to the increasing consumer awareness of the benefits attributed to pomegranate and its polyphenols. Pomegranate fruit has valuable compounds with functional and medicinal effects like antioxidant, anticancer, and anti-atherosclerotic effects. Storage of juice concentrate can have a dramatic impact on physicochemical quality. The bioactive compounds and antioxidant activity in fruit juice products are influenced by many external factors like different storage temperatures. Knowledge of the rheological behaviour of juice products is essential for product development, design and evaluation of process equipment like pumps and piping. Pomegranate concentrate is so susceptible to the condition of storage, which results in a reduction in consumer acceptability and quality losses. Accordingly, the industrial concentrate stores frozen (-20 °C) which has a lot of costs to the producer. The objectives of this study were to evaluate the degradation visual color, the rheological characteristics of pomegranate juice concentrates, the stability of phytochemicals, the antioxidant activity, and the haze formation of reconstituted pomegranate juice concentrate during storage at different temperatures to determine the best storage conditions to reduce the quality losses and solving the problem about high cost of storage.
Materials and methods: The concentrated pomegranate (Punica granatum (L.) cv. Rabab) juice used in this study supplied from Narni (Green farm, Neyriz, Iran) factory. The pomegranate juice concentrate was poured into falcons for measuring physicochemical attributes, and micro tubes for determination of antioxidant activities. Then the samples were divided into four parts and stored equally in four different temperatures (-20, 4, 20, and 35 °C). The control samples were stored at -80 °C as fresh sample for the storage period (140 days). Folin-Ciocalteu reagent and 2,2-diphenyl-1-picrylhydrazyl radical (DPPHº) were supplied from Sigma-Aldrich Company (St. Louis, MO, USA). All other chemicals were of analytical grade and purchased from Merck Company (Darmstadt, Germany). The total soluble solid (TSS) was determined with a digital refractometer (Carl Zeiss, Germany). Total insoluble solid was measured by centrifugation at (5,000 × g) according to the IFFJP method 60, using a high speed centrifuge (Ibarz et al., 2011). The haze formation of reconstituted juice was determined by “settling” in a glass tube for 3 hour at room temperature. Color measurements of the juice samples were carried out using a HunterLab (CHROMA METER CR-400/410, KONICA MINOLTA, Japan) after dilution. The rheological characteristics of the pomegranate juice concentrate stored in different temperatures were studied by using a computer controlled rotational viscometer. Sample compartment was monitored at a constant temperature (25°C) using a water bath/circulator, while TSS was 65 °Brix. The viscosity measurements, was carried out According to the methods described by Cárdenas et al., (1997), using a Brookfield cone and plate viscometer (DVII pro Brook field, USA) between the shear rate of 0.5–200 (1/s). Total phenolic content of samples was measured according to the Folin-Ciocalteu colorimetric method (Sun et al., 2007). Total flavonoid content in juices was determined via a spectrophotometer according to the method of Chang et al. (2002). Radical scavenging activities of the samples were measured by using DPPHº as described by Mazidi et al., (2012). The ferrous ion reducing antioxidant power (FRAP) of the samples was measured calorimetrically according to the method by Fawole and Opara (2013). All analyses were performed by the Statistical Analysis System (SAS) software V 9.1 (SAS Institute, Inc., Cary, NC, USA). By using the analysis of variance (ANOVA), the differences among means were determined for significance at P< 0.05.
Results and discussion: The industrial pomegranate juice concentrate stored at (-20, 4, 20, and 35 °C) for 20 weeks, and some physicochemical properties like the second turbidity, CIE Lab color parameters, the rheological properties, the bioactive component (total phenolic and flavonoid contents), and antioxidant properties (FRAP and DPPH) investigated in order to determine the best condition of storage. The second turbidity was obvious among the samples stored at 35 °C in the last fourth weeks. Although there were no significant differences among L* value of the samples stored at -20, 4, and 20 °C, a* and b* value of the samples stored at -20 and 4 °C had the same reduction trend for 14 weeks. Even though the control samples had shear thinning behavior, the samples showed a dilatant behaviour after storage. Antioxidant activities measured via DPPH and FRAP sowed reduction with increasing time and temperature. Flavonoid content increased by increasing time and temperature. In conclusion, storage at 4 °C for 14 weeks was the best storage condition to keep the quality and reduce the costs.
Soudabeh Einafshar; Hashem Pourazerang; Reza Farhoosh; Javad Asili
Abstract
Natural materials are complicated compositions; therefore, a rapid screening of the active antioxidants is being challenged in the literature. Different polarity solvents were applied to isolate four fractions (F1, F2, F3 and F4) of methanolic extract of Cuminum cyminum. Their anti-oxidative properties ...
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Natural materials are complicated compositions; therefore, a rapid screening of the active antioxidants is being challenged in the literature. Different polarity solvents were applied to isolate four fractions (F1, F2, F3 and F4) of methanolic extract of Cuminum cyminum. Their anti-oxidative properties were tested using radical scavenging and FRAP assays. F3 (with IC50=0.006mg/mL and FRAP= 521.95 mmolFe2+/L) was significantly the most active fraction. Guided isolation through bio-autography on TLC using 1, 1- diphenyl- 2 – picryl- hydrazyl radical (DPPH) as a detection reagent led to the isolation of two antioxidant compounds from F3. F3 was injected to a preparative HPLC with the proper mobile phase (acetonitril: methanol/ water) and isolated two main compounds. These compounds were identified as Luteolin 7 glugoside and Apigenin 7 glucoside by means of 1HNMR and 13CNMR and compare them with references.
Orang Khademi; Younes Nemati
Abstract
Introduction: There are two types of Japanese persimmon (Diospyros kaki Thunb.), astringent and non-astringent, based on the degree of astringent taste at maturity state. Fruits of either type are strongly astringent when small and immature, but non-astringent type loses its astringency during development ...
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Introduction: There are two types of Japanese persimmon (Diospyros kaki Thunb.), astringent and non-astringent, based on the degree of astringent taste at maturity state. Fruits of either type are strongly astringent when small and immature, but non-astringent type loses its astringency during development on the tree, still with firm flesh. However, the astringent type keeps its astringency and is inedible even when fully colored. It loses its astringency when becomes over-ripe with extremely soft flesh. At this stage, the fruits are usually over ripe with poor quality. Astringency in persimmon is caused by soluble tannins present in the fruit flesh. One mechanism useful in artificial removal of astringency from persimmon fruit is condensation or polymerization of soluble tannins into insoluble non-astringent forms, by acetaldehyde, which is being produced in the fruit flesh during different treatments. Acetaldehyde accumulates in the fruit flesh during its exposure to ethanol vapor or high level of carbon dioxide (CO2) gas, Hence, constant temperature and short duration (CTSD) is the preferred method of CO2 treatment used to remove astringency of persimmon fruit. It involves holding the fruits in ≥95% carbon dioxide atmosphere for a short duration at constant temperature of 20-30°C then transferring to normal atmosphere. However using CO2 treatment as gas form is expensive and needs special equipment. However, solid CO2 (dry ice) is easily available in Iran with low price. It release CO2 gas and can be used for removing astringency in persimmon fruit. The response of persimmon to de-astringent treatment depends on the cultivar. In this study two persimmon cultivars namely: ”Karaj” and ”Japanese” were harvested at maturity (full coloring) stage and treated with dry ice and ethanol vapor to remove astringency and the quality of treated fruits were evaluated.Materials and methods: Astringent persimmon fruits cvs ‘Karaj’ and ‘Japanese’ were harvested at maturity stage and transported immediately to the Department of Horticulture Science, University of Shahed and treated with either ethanol or dry ice. Both ethanol and dry ice treatmenttreatments were applied in low-density polyethylene bags with 0.05 mm thickness and polyethylene container with 3 mm thickness. In the polyethylene container, dry ice was applied at amounts of 3, 5 and 7% per kilograms of fruit and in the polyethylene bags dry ice was applied at amount of 0.16, 0.25 and 0.33 per kilogerams of fruits. For ethanol treatment, in both polyethylene bag and polyethylene container, 10 ml of 36% ethanol per kilogram of fruit was sprayed. Thereafter, bags and containers were sealed completely and kept for 48 hours at 25°C and 80% RH. After removing from the closed bags and containers, fruits were held in air at 25°C, 80% RH for completing astringency removing. After astringency removal treatmenttreatments, soluble tannin contents, astringent taste degree, fruit firmness, total soluble solid and ascorbic acid content were measured. The content of soluble tannin was determined by Folin-Denis method and the degree of astringency was determined by panel test. The experiments were conducted in a completely randomized design (CRD) and analysis of variance (ANOVA) was performed and the means were compared using LSD Test.Results and discussion: After performing the astringency removal treatment, fruits containing less than 1000 ppm of soluble tannin on a fresh weight basis showed no astringency. Results presented here showed that, dry ice treatment, especially at higher concentrations such as 7% in both cultivars, causes removal of astringency and decreases soluble tannin contents below the threshold of 1000 ppm, but ethanol treatment was effective only in Karaj persimmon for the removal of astringency. Similarly, it was indicated that CO2 treatment removed the astringency more easily in some Chinese cultivars than the ethanol treatment. The response of persimmon cv. Karaj was similar to a leading cultivar Hiratanenashi in Japan, for astringency removal by both CO2 and ethanol treatments, while, according to this results, Japanese cultivar had not shown suitable response to ethanol, while it successfully responded to dry ice treatment.Treatments to remove astringency of persimmon fruit often cause fruit softening. Astringency removal treatment induced ethylene production in persimmon which causes to the fruits softening. In this study, the firmness of both cultivars decreased significantly after treatments, however, the average of flesh firmness was significantly higher after dry ice than after ethanol treatments.Total soluble solid contents under the astringency removal treatments in both cultivars reduced significantly. This reduction is due to the removing of soluble tannins responsible for fruit astringency, since they are included in SSC measurements when not polymerized. Moreover, the results showed that ascorbic acid content is not affected by astringency removal treatments.Conclusions: The results presented here showed that removing astringency from persimmon cvs. Karaj and Japanese were achieved by postharvest application of dry ice in the poly ethylene container. Results also showed that dry ice was more effective than ethanol in astringency removal and retained higher quality of fruit. Dry ice is available treatment in Iran and it can be commercially used for removing astringency of Iranian persimmon.
Najmeh Molaahmadibahraseman; Reza Farhoosh; Ali Sharif
Abstract
Introduction: Medical benefits of Omega 3 fatty acids have appealeda lot of research to be done on of fish oil. Among marine fish, kilka has the most industrial application. Kilka oil contains significant amount of omega-3 fatty acids. In this study, physiochemical properties, fatty acid composition ...
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Introduction: Medical benefits of Omega 3 fatty acids have appealeda lot of research to be done on of fish oil. Among marine fish, kilka has the most industrial application. Kilka oil contains significant amount of omega-3 fatty acids. In this study, physiochemical properties, fatty acid composition and stabilization of kilka oil were investigated. p- hydroxy benzoic asid, its methyl ester and alpha-tocopherol as control were compared to each other.Materials and Methods: Crude Kilka fish oil was supplied by Khazarcompany (Babolsar, Iran). All chemicals and solvents used in this study were of analytical reagent grade and purchased from Merck (Darmstadt, Germany) and Sigma–Aldrich (St. Louis, MO). 200 ppm of the mentioned antioxidants was added to the purified oil and kinetic regime of oxidation at temperatures of 35, 45 and 55°C was prepared. After monitoring theoxidation over time using peroxide test, graph of peroxide changes over time was plotted and induction period and kinetic parameters (F, ORR and A) were calculated. In order to compare the performance of antioxidants in oil and water, 10% emulsion of Kilka oil-in-water was prepared and 200 ppm of antioxidant was added to it and its oxidation process was monitored at 55°C.Results and Discussion: Results showed that the fatty acid composition of this oil contains a variety of unsaturated fatty acids, saturated and polyunsaturated (mainly linoleic, eicosapentaenoic and docosahexaenoic acids). Temperature had significant effect on oxidation. p-hydroxymethylbenzoate, a little more than p-hydroxybenzoic asid, could increase oxidative stability of oil. Alpha-tocopherol had better performance as compared with other antioxidants. Performance of methylp-hydroxybenzoatewas better in emulsion than oil. In general, the emulsifier and emulsion preparation as compared with antioxidant had a more prominent role in the oxidative stability of Kilka oil.
Najmeh Molaahmadibahraseman; Reza Farhoosh; Saeid Johny; Ali Sharif
Abstract
Introduction: Medical benefits of omega-3 fatty acids have led to a lot of research on fish oil. Among marine fish, Kilka has the highest industrial applications. Kilka oil contains significant amounts of omega-3 fatty acids. In the present study, oxidative stability of Kilka fish oil based on the Schaal ...
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Introduction: Medical benefits of omega-3 fatty acids have led to a lot of research on fish oil. Among marine fish, Kilka has the highest industrial applications. Kilka oil contains significant amounts of omega-3 fatty acids. In the present study, oxidative stability of Kilka fish oil based on the Schaal oven test and the use of two phenolic acid derivatives (syringic and vanillic acids) was investigated.Materials and methods: Crude Kilka fish oil was supplied by Khazar company (Babolsar, Iran). All chemicals and solvents used in this study were of analytical reagent grade and purchased from Merck (Darmstadt, Germany) and Sigma–Aldrich (St. Louis, MO). Free radical scavenging activities of phenolic compounds was measured by reading the absorbance of methanolic solutions of the antioxidants containing 1,1-diphenyl-2-picrylhdrazyl (DPPH)at 517 nm. The partition coefficient (log P) of the antioxidants was measured in terms of the maximal UV absorbance of aqueous (0.3 mM) and 50:50 aqueous/acetate buffer (0.1M, pH =5.5) solutions. In order to study the antioxidant activity in lipid systems, peroxide value of the chromatographically purified Kilka fish oil as well as its 10% oil-in-water emulsion containing 200 mg/kg of antioxidants was monitored at 55 °C. Results and discussion: Syringic acid with two methoxy groups showed higher scavenging activity (IC50) than vanillic acid with one methoxy group (54.2 vs. 418.2). Radical scavenging activity in phenolic acids had direct relationship with the type and number of electron donor groups on phenolic ring. Peroxide values changed exponentially. Despite the relatively high polarity (Log P = – 0.65) and high scavenging activity, the performance of syringic acid in Kilkafish oil was degraded as affected by inter-molecular interactions and was not in accordance with the "polar paradox" hypothesis. Antioxidant activity of syringic acid in emulsion increased significantly as compared with oil and it was similar to α-tocopherol. It was concluded that the type of emulsifier and also the way of emulsion preparation as compared with antioxidant had a more prominent role in the oxidative stability of Kilka fish oil.Introduction: Medical benefits of omega-3 fatty acids have led to a lot of research on fish oil. Among marine fish, Kilka has the highest industrial applications. Kilka oil contains significant amounts of omega-3 fatty acids. In the present study, oxidative stability of Kilka fish oil based on the Schaal oven test and the use of two phenolic acid derivatives (syringic and vanillic acids) was investigated.Materials and methods: Crude Kilka fish oil was supplied by Khazar company (Babolsar, Iran). All chemicals and solvents used in this study were of analytical reagent grade and purchased from Merck (Darmstadt, Germany) and Sigma–Aldrich (St. Louis, MO). Free radical scavenging activities of phenolic compounds was measured by reading the absorbance of methanolic solutions of the antioxidants containing 1,1-diphenyl-2-picrylhdrazyl (DPPH)at 517 nm. The partition coefficient (log P) of the antioxidants was measured in terms of the maximal UV absorbance of aqueous (0.3 mM) and 50:50 aqueous/acetate buffer (0.1M, pH =5.5) solutions. In order to study the antioxidant activity in lipid systems, peroxide value of the chromatographically purified Kilka fish oil as well as its 10% oil-in-water emulsion containing 200 mg/kg of antioxidants was monitored at 55 °C. Results and discussion: Syringic acid with two methoxy groups showed higher scavenging activity (IC50) than vanillic acid with one methoxy group (54.2 vs. 418.2). Radical scavenging activity in phenolic acids had direct relationship with the type and number of electron donor groups on phenolic ring. Peroxide values changed exponentially. Despite the relatively high polarity (Log P = – 0.65) and high scavenging activity, the performance of syringic acid in Kilkafish oil was degraded as affected by inter-molecular interactions and was not in accordance with the "polar paradox" hypothesis. Antioxidant activity of syringic acid in emulsion increased significantly as compared with oil and it was similar to α-tocopherol. It was concluded that the type of emulsifier and also the way of emulsion preparation as compared with antioxidant had a more prominent role in the oxidative stability of Kilka fish oil.
Latifeh Pourakbar
Abstract
Introduction: Lipid oxidation is a major cause of food quality deterioration during storage of oils, fats and other fat-containing foods. Oxidation of lipids results in changes that may affect the nutritional quality, wholesomeness, colour, flavour and texture of food. Moreover, the products of lipid ...
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Introduction: Lipid oxidation is a major cause of food quality deterioration during storage of oils, fats and other fat-containing foods. Oxidation of lipids results in changes that may affect the nutritional quality, wholesomeness, colour, flavour and texture of food. Moreover, the products of lipid oxidation may be potentially toxic and may lead to adverse effects such as the production of carcinogens, mutagenesis and aging. Autoxidation occurs when molecular oxygen reacts with unsaturated lipids. The process involves a free radical chain reaction that is most frequently initiated by exposure of unsaturated lipids to light, heat, ionizing radiation, metal ions or metalloprotein catalysts. Free radicals are defined as any chemical species having one or more unpaired electrons. Antioxidants are a group of chemicals capable of extending the shelf life of food that contain lipids. They are used to retard the development of unpleasant flavour caused by the oxidation of unsaturated fatty acids. They retard oxidation of lipids by reacting with free radicals, chelating free catalytic metals and also by acting as oxygen scavengers. Currently the food industry uses synthetic antioxidants such as BHA, BHT and TBHQ to retard lipid oxidation. However, there is concern about the safety and toxicity of synthetic antioxidants in relation to their metabolism and accumulation in body organs and tissues. Synthetic antioxidants are known among other things to cause impairment of blood clotting, lung damage and to act as tumor promoters. As a result of this, consumers have a preference for natural ingredients and there is a growing interest in the potential use of antioxidants from natural sources. Phenolic extracts from herbs and spices, cereals and legumes have been reported to effectively retard lipid oxidation in oils and fatty foods. As a result of concern for the safety of synthetic antioxidants, there is a growing interest in the potential use of phenolic extracts from plant sources as antioxidants in lipids. The potential use of phenolic extracts from different plant sources such as sorghum, herbs and spices have been studied extensively. Extracts of spices such as rosemary and sage are now available commercially for use as natural antioxidants. Phenolic compounds are defined as substances possessing a benzene ring bearing one or more hydroxyl substituents, including their functional derivatives. There are different sources of phenols such as grapes, olive oil, sorghum, beans, spices and herbs. Phenols have many favourable effects on human health. They decrease the risk of heart diseases by inhibiting the oxidation of low-density lipoproteins (LDL). A large range of low and high molecular weight phenols exhibiting antioxidant properties have been studied and proposed to be used as antioxidants against lipid oxidation. This is particularly true for those phenolics with multiple hydroxyl groups that are generally the most efficient for preventing lipid oxidation. Phenolic compounds are also known to possess antibacterial, antiviral, antimutagenic and anticarcinogenic properties. Generally the efficacy of phenolic compounds as antioxidants depends on a number of factors such as the number of hydroxyl groups bonded to the aromatic ring, the site of bonding, mutual position of hydroxyls in the aromatic ring and their ability to act as hydrogen or electron donating agents and free radical scavengers. All polyphenols are capable of scavenging singlet oxygen and alkyl radical through electron donating properties, thus generating a relatively stable phenoxyl radical. The goals of this study were to investigate the effect of incorporation of different apple cultivars’ phenolicextracts onformation of primary oxidation products in buttercomparing tosome of thesynthetic antioxidants such as BHA and BHT Material and methods: Different apple cultivars from different places of West Azerbaijan province had been collected and their total phenol content, flavonids and antioxidant properties were measured according to Folin-Ciocalteu, Colorimetry and Diphenylpicrylhydrazyl (DPPH) methods respectively. The measurement of peroxide value and thiobarbituric acid of local butter oil samples consisting of different concentrations of extract and synthetic antioxidants was performed as well. Discussion & Results: In conclusion, this investigation demonstrates that apple is a rich source of phenolic compounds and antioxidant capacity.Fuji and Sheikh Ahmad cultivars showed the maximum and minimum content of total phenol content, flavonoids and antioxidant activity which are 2940.24 and 1350.22 microgram equivalent gallic acid/ gram of dry extract; 2530.32 and 1200.74 microgram equivalent quercetin/ gram of dry extract and 91.87 and 32%. The maximum and minimum amount of peroxide value and thiobarbituric acid was reported for control and 400 ppm apple extract samples respectively. The results of this study showed that "Fuji" cultivar contained the highest antioxidant activity.The Fuji apple extract are able to reducethe formation of hydroperoxides in butter oil during storage at 6ooC. The phenolic extracts from Fuji apple to be more effective than BHA in stabilising butter oil at 60ºC. Apple phenolic extracts inhibited oxidation of butter oil. Theextracts were able to retard oxidation because of the ability of phenolic compounds toscavenge and stabilise lipid radicals by donating hydrogen atoms.Also the concentration of the extract was an effective factor in the inhibition of oxidation; that is, as we increased the concentration, the inhibition of oxidation also increased. Conclusion:: Due to their ability to act as reducing agents, phenolic compounds in apple phenolic extracts from Fujivarieties can be used as antioxidants in butter oil toretard formation of primary oxidation products, specifically hydroperoxides.
Zahra Hashemi; Mohammad Hojjati; Mohammad Tahanejad
Abstract
Introduction: Oxidative degradation of lipids is a major factor limiting the shelf life of foods. The free radical reaction of lipid peroxidation is generally responsible for the deterioration of fatty foods. In general, use of synthetic antioxidants during the manufacturing process are applied to prevent ...
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Introduction: Oxidative degradation of lipids is a major factor limiting the shelf life of foods. The free radical reaction of lipid peroxidation is generally responsible for the deterioration of fatty foods. In general, use of synthetic antioxidants during the manufacturing process are applied to prevent fat oxidative and rancidity while their carcinogenic effects have been approved. Since the use of synthetic preservatives in food have been declined, researches on alternative natural products such as aromatic plants extract and essential oil have been extended.Aromatic plants are used traditionally in various regions of Iran for their preservation and medicinal properties, in addition to enhancing the aroma and flavor of foods. Aromatic plants components that have antiradical activities were used as natural antioxidant in food and biological products. The aim of this research was extraction and identification of the chemical compounds of Ferula gummosa Bioss essential oil and investigation of its antioxidant capacity in frying oil. Materials and methods: Aerial parts of F. gummosa were collected during fall 2013 from Khouzestan province of Iran. The collected aerial parts were then dried in the shade. The essential oil of aerial parts was extracted by hydro-distillation technique using Clevenger apparatus. Analyses of isolation, identification, and quantification of the component of the essential oil of F. gummosawere performed with a GC coupled with a mass spectrometer detector GC/MS. Analyses were carried out using helium as the carrier gas on DB-5 column (30 m×0.25 mm i.d., 0.25 μmfilmthickness). Injector and detector were hold at 240 and 300°C, respectively, and 0.5 μL of the diluted essential oil was injected. Identification of most of the compounds was made according to GC-MS retention times (authentic chemicals), Kovats indices (KI) in reference to n-alkanes (C8–C24), and mass spectra (authentic chemicals and NIST05 spectral library collection). Identification was considered tentative when it was based on mass spectral data only. Volatile compounds were quantified using percentage peak area calculations by means of a GC-FID with the same column and nitrogen as the carrier gas. The total phenol content in the F. gummosaessential oil was determined by a spectrometric method, according to the Folin–Ciocalteu phenol method by mixing of 0.2 ml of the essential oil with Folin-Ciocalteau reagent diluted and Na2CO3. The absorbance was measured at 765 nm after incubation in the dark at ambient temperature. The results of the total phenolic contents were expressed as gallic acid equivalents.The DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS [(2,2´-azino-bis 3-ethylbenzthiazoline-6-sulphonic acid)]tests were used for estimating antioxidant effects because the DPPH and ABTS radicals are the two most widely used and stable chromogen compounds to measure the antioxidant activity of biological material. In addition, the model of the DPPH radical-scavenging and ABTS radical cationdecolorization assay can be used to evaluate the antioxidant activities in a relatively short time compared with other methods. For this purpose 0.05 ml of the essential oil at different concentrations (0.05, 0.1, 0.2, 0.5, 1, 2, 5, 10 mg/ml) were mixed with 5 ml of 0.2 mMmethanolic DPPH solution and kept in the dark for 30 min at room temperature, then absorption-decrease was measured at 517 nm. The radical scavenging activity assessed by the ABTS method was expressed as the TEAC (trolox equivalent antioxidant capacity) value based on absorbance at 734 nm. In this test, ascorbic acid was used as positive control. The antioxidant activity of essential oil was evaluated against Tertiary butylhydroquinone (TBHQ) as an synthetic antioxidant in frying oil by peroxide value and thiobarbituric acid (TBA) index under rush condition in 90° C during one week. Results & Discussion: GC-MS analysis of the volatile constituents of the F. gummosa essential oil allowed the identification of twenty-nine compounds representing 96.80% of the total volatile oil. The main components were β- pinene (37.9%), α- pinene (9.05%), terpinene-4-ol (7.78%) and ρ- cymene (6.58%). The mean amount of total phenolic of obtained essential oil was 59.7 mg gallic acid/g dry plant material.In the present study, the essential oil showed good free radical scavenging capacity at all concentrations studied, however the scavenging activity increased with increasing concentration of the essential oil. Antioxidant activity of essential oil from F. gummosa at 1 mg/ml was similar to TBHQ at 0.1 mg/ml (P ≤ 0.05%). The scavenging capacity test showed that the EC50 value of the essential oil was found to be 0.094 mg/ml. ABTS test showed that the F. gummosaessential oil was able to reduce the stable radical and 1mg/ml of essential oil had the highest antiradical activity (0.113 mg/ml ascorbic acid equivalent). Oven test revealed that 500 and 1000 ppm of essential oil had the higher activity than TBHQ in 200 ppm in frying oil. Conclusion: The results indicated that F. gummosa had high total phenolic content. Also, according to these results, there was a relationship between totalphenolic content and antioxidant activity.The findings of this study showed that F. Gummosa essential oil can exhibit strong antioxidant activity, probably due to its particular chemical composition, mainly the high amounts of monoterpenes. Therefore, this essential oil could be used for the preservation of edible oil against oxidation and for increasing its shelf life as a natural preservative ingredient.
Mina Seifzadeh; Aliasghar Khanipour
Abstract
This project was carried out in order to Study of possibity of uses from 4 hexyresorcinol for prevention of melanosis in cultured shrimp.Treatments including of samples processed with 0.15% concentration of 4 hexylresorcinol and control samples. The samples were kept at -18oC. Bacterial, chemical and ...
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This project was carried out in order to Study of possibity of uses from 4 hexyresorcinol for prevention of melanosis in cultured shrimp.Treatments including of samples processed with 0.15% concentration of 4 hexylresorcinol and control samples. The samples were kept at -18oC. Bacterial, chemical and sensory examinations were carried out for a period of six months. Statistically significant difference was observed in peroxide value, free faty acids, thiobarbotouric acid and trimethylamin in test samples compared with the control samples during storage period (P
Salah Fahiminia; Lotfali Naseri
Abstract
In order to maintain the quality and increase the shelf life of fruits, many studies have been carried out in terms of the packaging specially applications of the nano-composite packages in the packaging. Because of the low storage ability of the plum fruit, in this study, the effects of the four nano-composite ...
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In order to maintain the quality and increase the shelf life of fruits, many studies have been carried out in terms of the packaging specially applications of the nano-composite packages in the packaging. Because of the low storage ability of the plum fruit, in this study, the effects of the four nano-composite packages and common polyethylene (as a control) were analyzed on maintaining quality and increasing of the plum fruit, in a factorial experiment based on a completely randomized design at two levels of the storage. So, the containers including plum fruits were kept at temperature of 1±1 ºC and relative humidity of 90±5 % during 45 days. After 22 and 45 days, the fruit different quality properties such as total antioxidant activity, ascorbic acid (vitamin C) content, total soluble solids, acidity, titratable acidity, firmness, fruit weight loss percentage and decay were measured. The results showed that the application of the nano packages as compared with common polyethylene could maintain the fruit quality at level of (P≤0.01) after 45 days of storage, and increase the post harvest shelf life of the plum fruit as the highest total antioxidant activity, vitamin C, acidity, titratable acidity, firmness and the lowest fruit weight loss percentage and content of the decay were observed in nano-composite packages. According to these results, using the nano-silver packages was effective on increasing the plum fruit quality maintenance during the storage.
