Research Article
Sepideh Etezazian; Mohammad Fazel; Hajar Abbasi
Abstract
Introduction: Sponge cake is one of the most demanded and consuming grain products, but due to its gluten content, it is not usable for patients with celiac disease. In recent years, gluten-free products have gained a great attraction. However, producing gluten-free products has several difficulties ...
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Introduction: Sponge cake is one of the most demanded and consuming grain products, but due to its gluten content, it is not usable for patients with celiac disease. In recent years, gluten-free products have gained a great attraction. However, producing gluten-free products has several difficulties such as lack of gluten viscoelastic network protein constituents, lower technological quality and advent of some quality problems in production including low volume and weak texture. Some compounds such as certain enzymes and gums with the aim of improving the texture, mouth feeling and general acceptance, as well as imitating viscoelastic properties of gluten could be employed in the formulation of gluten-free products to make them acceptable for the celiac patients. For this purpose, guar gum is used widely as a thickener and stabilizer for producing gluten-free products. Also, addition of enzymes to grains produce could help in increasing the holding water capacity, improving softness and dough flexibility, enhancing texture and final product’s volume. Furthermore, notwithstanding widely researches on the cake, comparing to other production, this production has low nutrition values yet. So, enriched cakes with dietary fiber and natural antioxidants, is one of the goals of the industry. The researches has shown that dried, powdered and extracted pomegranate peel has rich fiber, bioactive materials and high antioxidative characteristics. Therefore, the main purpose of the present research is to study the effect of replacing the pomegranate peel (0-12 %), Guar gum (0-1.5 %) and Hemicellulase enzyme (0-90 ppm), respectively on the physiochemical properties.
Material &Methods: Moisture content measurement of moisture by oven, density by using rapeseed seeds displacement method, hardness (STM 200 device), color index of crumb and crust by using CIE Lab colorimetric system that measure L* (brightness), a* (redness) and b* (yellowish), antioxidant activity with spectrophotometery method in 517 nm wavelength, and sensory properties of gluten-free sponge cake based on wheat starch. In association with sensory test,30 panelists was used for checking desirability of mouth texture, appearance texture, smell and taste, color, after-taste and general acceptance with six point hedonic test that they rated samples from most agreeability to most un agreeability. For this aim, the statistical plan of response surface method (RSM) of central composite design (CCD) with three variables and four central points were used and the texture test was applied four times and the other tests were applied three times. For this purpose the Design-Expert 7.0.0 software was utilized for determining of optimum point (a point in which the minimum density and hardness that this parameters considered as a blank in the cake limits), Duncan examination was used for comparing the average of data and analyze of data was implemented with SPSS 16 software.
Results & Discussion: The results have shown that increasing the percentage of pomegranate peel in the formulation, density and bright and yellowish cakes were decreased and moisture, a* index, DPPH and hardness were increased. From the other hand, increasing the amount of replacing the gum caused to increase density, moisture and hardness. Adding the enzyme had effect in decreasing the light of crust and increasing density and color index in the crust of the cake. Totally was determined pomegranate peel had more effect on the antioxidant activity, density, hardness and colorful properties. Guar gum had fewer effect on this parameters and played most important roll on moisture of cakes. About enzyme can say it didn’t have significant effect on properties of cakes. Then, the optimum points has been defined via the software that the amounts of pomegranate peel and the guar gum were estimated at 9.1 and 0.56 %respectively, and the amount for hemicellulase enzyme calculated as 0 ppm. After that, the properties of the optimum cake were compared with blank cake and in addition to previous tests, sensory test was also performed. Moreover moisture and hardness of optimum cake was investigated in during of 14 days storage (days of 1, 7 and 14).The results have shown the physical, chemical and texture properties of optimum cake were largely similar to the blank samples and the main difference was in taste sensory properties of pomegranate peel that will corrected with the use of flavor agents. Over time, also, moisture was decreased and hardness was increased primarily and decreased later in both of blank and optimum sample. Therefore, gluten-free cake based on wheat starch with 9.1 percent pomegranate peel and 0.56 percent guar gum can be used, that only doesn’t have adverse effect on its properties, but also is acceptable for celiac patient.
Research Article
Seyed Mahdi Ojagh; Bahareh Shabanpour; Aniseh Jamshidi; Azam Siyamiyan
Abstract
Introduction: Value added products are defined as a set of products that are made up of the primary food with the help of different types of human or mechanical processing, and vary in appearance, texture, flavor and odor with their primary substance. One examples of value added products is battered ...
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Introduction: Value added products are defined as a set of products that are made up of the primary food with the help of different types of human or mechanical processing, and vary in appearance, texture, flavor and odor with their primary substance. One examples of value added products is battered and breaded products. Nuggets are products which are made of mixing mince or surimi with flavored and additive ingredients. The mixture is prepared after battering and being coated with toasted flour. It is then primary fried in oil and after freezing, packaged and stored. Therefore, the consumer only uses the final baking step, which usually involves frying in oil, consuming the product after thawing. Deep fat frying is a common cooking method in which fat is used as a heat transfer medium, during which foods with unique characteristics are produced in terms of taste, texture and appearance. During the frying process, along with shifting and moving the temperature, transferring and moving the material happens. Usually, with increasing frying time, the amount of oil absorption increases, but there is no linear relationship between. The amount of oil absorption depends on several factors such as oil quality, frying time, oil and food temperature, food form, porosity and chemical composition, especially the initial moisture content of the product.In general, fried foods at temperatures between 175 and 190°C have good brittle properties. Temperatures above 175°C may be associated with acrylamide formation, which is a carcinogenic substance. Therefore, the purpose of this study was to investigate the effect of frying medium (different vegetable oils) and temperature on the variations in the approximate composition and physical parameters of the fried silver carp nugget.
Materials and methods: In order to produce fish nuggets, 87% of minis were mixed with additive and flavoring ingredients, 5% breadcrumbs, 5% onions, 1% garlic, 1.5% salt and 0.5% spices. The mixture was shaped into round shapes and immersed in the glaze with a specific formulation and after dripping the extra glaze was covered with toasted flour. Then, nuggets were prepared using sunflower, olive, canola and sesame oil for 30 seconds at temperatures of 150, 170 and 190 degrees of celsius preheated by frying deep frying and after cooling to room temperature was packed in zipper bags and was frozen at -20°C. After a day, the nuggets were removed from the freezer and after de-damping at ambient temperature, chemical (including approximate analysis, pH measurements, water holding capacity) and physical tests (including viscosity, yield of product, shrinkage, Colorimetric and sensory analysis) were performed on fish nuggets. For physical tests and sensory analysis, nuggets were deep fried in sunflower oil for 3 minutes at 180°C.
Results & Discussion: The findings showed that fried nugget in sunflower oil and sesame oil contained moisture content, yield and high red color index, and oil absorption and yellowness index were less than fried nugget in olive oil and canola. From the temperatures of 150, 170 and 190°C in the primary frying, the temperature of 170°C had the highest moisture content and yield, and the average value of the brightness and redness index was 150 and 190°C. The temperature of 150°C showed lower oil absorption than 170°C and 190°C. According to the sensory evaluation, the sensory indexes of color, taste, smell, fat sensation in the mouth, texture, juiciness and general acceptance of the treatments in different oils and different temperatures of the initial frying were the same and did not show any significant difference. The priority was to select the panel of fried nugget panels in olive oil and prefer the initial frying temperature of 170 and 190°C. According to the results of this study, in terms of physical factors and the rate of absorption, fried nuggets in sunflower and sesame oil were more effective. Between the different temperatures of the initial frying, temperatures of 170°C for all of the measured indexes yielded better results than temperatures of 150 and 190°C.
Research Article
Atefe Maqsoudlou; Alireza Sadeghi Mahoonak; Mohammad Ghorbani; Fidel Toldta
Abstract
Introduction: Bee pollen, commonly referred as the ‘‘life-giving dust’’, results from the agglutination of flower pollens with nectar using salivary substances of the honeybees (Almeida-Muradian et al., 2005). Pollen contains 10 to 40% protein, 1 to 13% lipid, 13 to 55% carbohydrates and 2 to ...
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Introduction: Bee pollen, commonly referred as the ‘‘life-giving dust’’, results from the agglutination of flower pollens with nectar using salivary substances of the honeybees (Almeida-Muradian et al., 2005). Pollen contains 10 to 40% protein, 1 to 13% lipid, 13 to 55% carbohydrates and 2 to 6% minerals. Royal Jelly is produced by enzymatic digesting of bee pollen by proteases and other natural enzymes. Based on dry weight, it contains 27-41% protein, 30% carbohydrates, 8-19% lipids, minerals, trace elements and some vitamins (Sabatini et al., 2009; Wytrychowski et al., 2013). The antioxidant properties of royal jelly and bee pollen, are related to main proteins and phenolic compounds and flavonoids (Nagai and Inue, 2004). The antioxidant activity of peptides can be evaluated using DPPH, radicals scavenging activity, Ferric reducing, Ferrous chelating activity (Khantaphant et al., 2011). Antioxidant and ACE inhibitory activity of pollen, royal jelly and peptides were investigated by different researchers (Bogdanov, 2014; Morais et al., 2011; Salampessy et al., 2015; Marinova and Tchorbanov, 2010; Wiriyaphan et al., 2012). The objective of present research was optimization of enzymatic hydrolysis of bee pollen protein by Alcalase according to its antioxidant and ACE inhibitory activity compared to royal jelly.
Materials and methods: The preparation of the bee pollen extract was performed by mixing the bee pollen with water (1:10) (w/v). The macerates were filtered and centrifuged at 12000 g. The obtained supernatant was lyophilized. The royal jelly extract were prepared using method described by Liu et al., 2008. The total phenolic content of the extracts was recorded using the Folin–Ciocalteu method (Moreira et al., 2008). DPPH radical-scavenging activity was determined as described by Bersuder, Hole, and Smith (1998). The ability of the hydrolysate to reduce iron (III) was determined according to the method of Bougatef et al. (2008). Bee pollen was added and homogenized with 5 volumes of distilled water. pH and temperature of the solution were adjusted to pH=8 and 50◦C. Alcalase in the concentration range of 1 to 2% w/w were added to the pollen protein solution. Enzymatic hydrolysis performed during different times 2 to 5 hours. Hydrolysis was stopped by heating at 80˚C for 10 min. The hydrolysats were centrifuged at 4000x g for 30 min to remove the residue. The supernatants were pooled and then lyophilized (Matsuoka et al., 2012). DPPH radical scavenging ability and reducing power of pollen hydrolysates of pollen hydrolysates were measured. Also ACE-inhibitory activity of pollen hydrolysates was measured was assayed by method reported by Nakamura et al. (1995). Statistical analysis of results before hydrolysis was done by SPSS. Optimization of enzymatic hydrolysis was done by Response Surface Methodology (RSM) in Design Expert software.
Results and discussion: Total phenol value measured for pollen ranged between 48.15 to 174 mg Gallic acid/g for royal jelly ranged from 9.24 to 87.261 mg Gallic acid/g. Considering that royal jelly is obtained by direct digestion of pollen, the amounts of their phenolic compounds were comparable (Bogdanov, 2014). Phenolic compounds increased by increasing concentration royal jelly and pollen extract in dose dependent manner. Increasing concentrations of royal jelly in range of 300 to 1000 mg/l was more effective than pollen (p
Research Article
Roya Nejatbakhsh; Sara Movahhed; Hossein Ahmadi Chenarbon
Abstract
Introduction: The quality of breads depends on the baking capability of flour, fermentation time, protein content, and type of additives. An economically important concern of the baking industry is delayingthe bread staling. In addition, the staling process changes outer and inner properties, scent, ...
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Introduction: The quality of breads depends on the baking capability of flour, fermentation time, protein content, and type of additives. An economically important concern of the baking industry is delayingthe bread staling. In addition, the staling process changes outer and inner properties, scent, flavor, and chewiness of breads, which in turn leads to staled or, in other words, non-fresh breads. The application of lactic sourdough and/or other techniques such as improved dough making, improved baking quality, packaging, and use of additives and improvers can be highly effective in delaying this process. One of the additives that improve the properties of baked products is the α-amylase enzyme. α- amylase can improve the elastic properties of the texture while delaying staling. This enzyme can also form useful sugars for yeasts and increase gas formation in dough, which in turn improves and increases the bread volume. Against this background, the current study analyzed the effects of sourdough and α-amylase on qualitative characteristics, physicochemical properties, staleness, size and sensory profile of the toast breads.
Materials and methods: The ingredients of the toast bread dough, i.e. 78% wheat flour (1 kg), sugare (1-2 w/w%), salt (1.8-2.2%), oil (3-6%), yeast (1.5-2%), α-amylase (0.01-0.03%), lactic sourdough (4 and 6% of wheat weight), were prepared and weighed to make the dough required for the baking process. The dough samples were spread and then rolled after an initial resting of 10-15 minutes. The rolls (approx. 580 g) were transferred to a cast. The dough samples were finally moved to the fermentation chamber at 35°C and 80% relative humidity for final fermentation and baking. Their analyzed using different physical, chemical, and sensory tests. A completely randomized design with three replications was used to analyze experimental data (except for staleness data of bread samples from sensory and instrumental tests which were analyzed using factorial experiment with a completely randomized design). Means were compared by Duncan's multiple-range test (α = 1%) in SPSS 16.
Results and discussion: According to the results, α-amylase and lactic sourdough caused an increase in bread’s MC compared to the control samples. In other words, starch hydrolysis by α-amylase created free water in the dough. Moreover, sourdough increased water absorption of wheat through mechanisms including production of exopolysaccharides and increased production of pentosans. The application of α-amylase and lactic sourdough also increased the ash content of the breads compared to the control samples because they increased the production of dextrins and synthesis of exopolysaccharides. It should be mentioned that these additives decreased the pH of breads compared to the control samples. This is because the sourdough bacteria produced lactic, acetic and other acids that acidified the medium and reduced the pH. This enzyme also produced metabolites like dextrins and increased the amount of fermented active ingredients, which further reduced the pH. The proteolytic activity of lactic bacteria of the acid in sourdough led to decomposition of proteins, particularly gluten, into amino acids. This also reduced the protein content and diluted the gluten in breads. The results showed that the lactic acid bacteria of the sourdough hydrolyzed the fat control of bread samples by their lipase and thus lowered the fat content in bread samples compared to the control. The fiber content of samples was higher than that in the control as a result of enzyme and sourdough application. This is due to the fact that fermentation increases the pentosan content and reduces their molecular size. It also increased solubility of insoluble fibers like beta-glucans. On the other hand, their application led to larger bread size than the control because α-amylase hydrolyzes the starch and breaks the amylose and amylopectin chains to convert them into disaccharide substrates. Accordingly, yeasts could grow better and produce more CO2 in the dough, increasing the bread size. The application of this enzyme and lactic sourdough gave a brighter appearance to toast bread samples whereas a* and b* were reduced. This is because the bread undergoes changes in its crust color during the baking process, which are mainly caused by maillard and caramelization reactions. It is worth noting that these additives reduced the staleness of the samples. With respect to staling, the gluten content and its ratio to starch are highly effective. During the bread shelf life, as its kinetic energy decreases, the cross-linking increases and intensities. In other words, the bread becomes harder and staler. However, using α-amylase and sourdough, the bread hardness and staleness are decreased as the starch swelling is limited and cross-linking between protein and gluten is inhibited. These two additives improved most sensory properties including resistance to breakage and rupture, porosity, kernel color, crumb color, proportionality of shape, back-side uniformity, flavor, taste, texture, chewiness, and larger size of the bread samples. This reason for these improvements can be due to starch hydrolysis by α-amylase and production of dextrins and CO2. According to the results, the bread sample containing 0.03% α-amylase and 6% lactic sourdough was selected as the best sample.
Research Article
Samaneh Hizomi Shirejini; Hadi Koohsari; Seyedeh Zahra Seyed Alangi
Abstract
Introduction: Study in order to introduce new antimicrobial agents with natural origin to prevent the antibiotic resistance and eliminating its effects, employing chemical agents is an indispensable necessity. Honey, as an important food with natural origin has high antimicrobial potential. Several factors ...
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Introduction: Study in order to introduce new antimicrobial agents with natural origin to prevent the antibiotic resistance and eliminating its effects, employing chemical agents is an indispensable necessity. Honey, as an important food with natural origin has high antimicrobial potential. Several factors have contributed to the antibacterial activity of honey. For example, acidity, osmolarity, hydrogen peroxide, phenolic and flavonoid compounds, including these factors. Also, small amounts of glucose oxidase, protease, amylase, catalase and phosphatase enzymes and chemical compounds such as methylglyoxal are also effective. Floral origin of honey is effective on its biological properties including antimicrobial, anti-tumor, anti-inflammatory, antioxidant and antiviral activity. So this study was done to evaluate the antibacterial activity and physico-chemical analysis of four types of honey with different floral origin including: Thyme, Eryngium, Pennyroyal and Dill collected from the bee hives in Golestan province.
Materials and methods: Four honey samples with different floral origin including, Thyme, Eryngium, Pennyroyal and Dill were collected from the bee hive in the Golestan province in north of Iran. The bacterial strains used in this study, including two species of gram-negative of Escherichia coli and Shigella dysenteriae and the two species of gram-positive of Staphylococcus aureus and Bacillus cereus were provided in lyophilized. Bacterial strains in BHI broth were activated and from each of them were prepared bacterial suspensions equivalent to the McFarland 0.5 turbidity standard (1.5×108 CFU/ml). Evaluation of antibacterial activity using agar well diffusion method was performed. For this purpose serial dilutions of honey samples were prepared aseptically in sterilized distilled water. Surface of Mueller Hinton agar were uniformly inoculated with bacterial suspension containing of 1.5×108 CFU/ml. Then wells of 8 mm in diameter were prepared and these wells were filled with different dilutions of honey samples. After incubation at 37°C for 24 h, antibacterial activity was analyzed by measuring the zones of inhibition. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of honey samples were determined by using broth macro-dilution method. For this purpose, each of the tubes from different dilutions of honey samples were added by 5×105 CFU/ml from each of the tested bacteria and incubated for 24 h at 37°C. The results for microbial turbidity of visible were recorded. The last dilution (lowest concentration) in which microbial turbidity was not observed, as the MIC was considered. For the determination of MBC, from the tube that contained honey concentrations higher than the MIC were cultured onto the agar medium. The MBC was defined as the lowest concentration that allowed no visible growth on the agar. Also the studied physico-chemical properties were moisture content, pH, acidity, ash content and reducing sugars that was performed according to the Iranian National Standard No. 92.
Results and Discussion: The results indicated that the antibacterial effects of the tested honeys, and the difference between floral origins honeys is effective in antibacterial properties. MIC and MBC values obtained for the tested honeys were in the range of %6.25-50% (vol/vol). Highest antibacterial activity was recorded for Eryngium honey by agar well diffusion method with zone of inhibition of 15.5, 14,11 and 11 mm against S. dysenteriae, S. aureus, B. cereus and E. coli at concentration of 50% v/v respectively and its MIC for this bacteria were, 6.25%, 10%, 10% and 25% respectively. also low antibacterial activity of Pennyroyal honey was confirmed so that MIC of the this honey for E. coli, S. aureus, B. cereus and S.dysenteriae was, 50%, 25%, 12.5% and 10%, respectively. The quality of honey depends on a number of physico-chemical properties such as moisture, ash content, pH, acidity, the amount of sugars. For this reason, standards for honey have been set by different countries. The physico-chemical analysis of honeys showed moisture contents in the range of 22.56-25.36%, acidity in the range of 12.58-13.59 meq/kg, pH in the range of 4.15-4.26, reducing sugars in the range of 63.7-63.8%. Also the ash content of Eryngium honey with 0.183% was higher than the other honey samples. This higher level might be due to the higher pollen count in this region. High ash contents may also depend upon the floral origin of honey and the material collected by bees during foraging. The low acidity of honey samples studied in the present study was due to the fact that there was no unwanted fermentation in these samples. Overall, the results implied that honey samples with different floral origin collected from the bee hive in the Golestan province in north of Iran have variable potential antibacterial activity. The variety of antibacterial effects of different types of honey can be due to differences in plants that honey is obtained from. In other words, different species of plants in different regions have different compounds and their obtained honey will not be the similar and thus its biological effects also will be different.
Research Article
Fatemeh Pourhaji; Farideh Tabatabaei Yazdi; Seyed Ali Mortazavi; Mohebbat Mohebbi; Mostafa Mazaheri Tehrani
Abstract
Introduction: Banana is one of the most consumed fruit in the world and is cultivated almost in all tropical countries. This fruit has a high nutritional value and is a suitable source of energy due to the presence of high amount of starch, sugar, vitamin A and C, potassium, sodium, and magnesium. Banana ...
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Introduction: Banana is one of the most consumed fruit in the world and is cultivated almost in all tropical countries. This fruit has a high nutritional value and is a suitable source of energy due to the presence of high amount of starch, sugar, vitamin A and C, potassium, sodium, and magnesium. Banana is highly vulnerable after harvesting and is subject to the microbial spoilage due to the high moisture content which makes difficult its sales and exports. Therefore, several methods have been used to overcome these problems. Drying and dehydration are methods to extend the shelf life of banana which usually carries out by hot air. This method can prevent some degree of microbial spoilage, but it has some disadvantages such as changing color, taste, flavor and reducing the nutritional value.
Foam-mat drying as a substitute for hot air drying introduces some advantages such as using the microwave energy. In this method, food products are whipped to form stable form and then dehydrated by thermal means. Due to the larger surface area and accelerated moisture transfer from foam, food products can be dried at lower temperature and time by this method of drying. Moreover, the porous structure of dried foam results in a faster rehydration and solubility of dried food samples. Additionally, microwave-assisted drying results in a product with better quality because of faster rate and saving energy.
Materials and methods: The fresh banana was cut into small pieces with a diameter of 1.0 mm after peeling. To prevent the enzymatic browning of samples, blanching was carried out by boiling water (100 °C) for 3 min. After that, the banana cuts were placed in a container containing 10°C water in order to cool. To produce pulps, the homemade Bosch mixer (model w600, CNSM, 30EW, Slovenia) at a speed of 1500 rpm and 1.0 min was used. Then, the pulps were mixed with skim milk at different concentrations (3-6 % w/w) and homogenized by ultra-turrax (IKA® Labortechnik) at 10000 rpm for 5.0 min. Moreover; the prepared xanthan gum was added to the mixture at concentrations of 0.15 and 0.25%. Xanthan gum was prepared by adding 1.0 g gum into 100 mL water and mixing by magnet stirrer. Afterwards, the gum solution was kept overnight at 4 °C for complete hydration. Finally, the sample transferred into the foam-maker device which was connected to a nitrogen gas tank with different flow rate (0.2-2 L min-1). The speed and time were adjusted to 16000 rpm and 5.0 min, respectively. After the producing of banana milk foam and selecting optimum sample based on the lowest density and the highest stability, the drying kinetic of this sample was studied. Then the banana milk foam was dried using microwave (360, 660 and 900 V) in a glass plate with diameter of 3.0 and 5.0 mm. Foam density and stability were determined by the methods of Xian-Zheetal (2010), Stauffer (1999) and Bag et al. (2010). The color of samples was studied by hunterlab. Moisture content also was measured based on the AACC standard method (AACC, 2000). Glass transition temperature also was determined by differential scanning calorimetry (DSC, model OIT-500 Sanaf Electronics Co, Iran).
Results and Discussion: In the present study, foam-mat method and microwave drying were used to reduce the drying damages. Nitrogen gas and xanthan gum also were used respectively to control foam generation and improve the stability of foams. Optimization of the banana milk production was carried out using response surface methodology based on three variables including the rate of nitrogen gas (0.2-2 L min-1), concentration of xanthan gum (0.15-0.25 %) and milk to banana ratio (1:6 and 1:3). Optimization was done based on the highest stability and lowest foam density. The optimum condition was proposed as the nitrogen gas rate of 0.2 L min-1, xanthan gum of 0.22 % and 3% banana which showed the density of 0.39 and the highest stability (0 mL after 1.0 h). After that, the optimum sample was dried by microwave. The effects of three levels of microwave voltage (360, 660 and 900 V) and two diameters (3 and 5 mm) were evaluated for drying of optimum sample. The results showed that the sample dried with diameter of 3 mm and voltage of 900 V had the highest L*, highest glass transition temperature and the lowest moisture content.
Research Article
Mahshid Shamloofar; Zahra Ghiasvand; Elham Payandan
Abstract
Introduction: Free radicals may cause lots of diseases in humans and 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 lipid-containing foods. Use of antioxidants during ...
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Introduction: Free radicals may cause lots of diseases in humans and 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 lipid-containing foods. Use of antioxidants during the manufacturing process can minimize the extent of lipid peroxidation. Phenolic antioxidant compounds can prevent the destructive effect of free radicals and their resulting mutation. Sunflower oil is widely used in nutrition as a source of essential linoleic (9-cis, 12-cis-octadecadienoic) acid. The present study explored the chemical constitution and antioxidant activity of Fleawort (Plantago ovate) extract and the effect of these natural antioxidants on sunflower oil. It is well known that edible oils used as cooking medium at high temperatures in the presence of oxygen are subject to therm-oxidation, polymerization, and hydrolysis, and the resulting decomposition products not only produce undesirable off-flavors, but can also decrease the nutritional quality of the fried product.
Material and methods: The present study was carried out in refined sunflower oil, free of additives, supplemented by pure concentration levels of normal and encapsulated extract of Fleawort (i.e., 200, 500, 700 and 1000 ppm) and one level of BHT (200) ppm .The doses of Fleawort extract were chosen in agreement with previous studies that have proved that the inhibitory effect on lipid oxidation increased with the antioxidant concentration In this research the phenolic content of the ethanol extract of Fleawort was determined by Folin–Ciocalteu method. The antioxidant activity of this extract was evaluated using DPPH• and ABTS methods. Furthermore, the oven tests including peroxide and thiobarbituric acid values were done at 65º C in sunflower oil.
Results and discussion: The results showed that different concentrations of this extract were effective in retarding the oil oxidation at 65ºC. Among the treatments, the 1000 ppm Concentration of encapsulated extract has higher antioxidant activity than other treatments during storage time. Based on the evaluation results of phenolic compounds in Plantago ovata extract, the amount of phenolic compounds of this extract will be increased according to the concentration of the extract. Although this index was the highest in treatment of EN 1000, there was no significant difference between the ordinary and encapsulated treatments (p>0/05). According to DPPH Evaluation Test for determining the antioxidant capacity of the samples, the highest amount of DPPH was seen in treatment of EN 1000 (p0/05). Also, based on the Restoration Power Test, treatment of EN 1000 had the most meaningful restoration power and in all concentrations of the extract and treatment showed the most meaningful restoration power (p< 0/05) . Treatments with concentration of 1000 ml/l had the maximum total antioxidant capacity and this treatment showed higher total antioxidant capacity compared to BHT treatment and numerically the total antioxidant capacity of all treatments of BHT was allocated to the treatments with concentration of 200 to 500 ml/l of fleawort extract. Peroxide value was used as indicators for the primary oxidation of sunflower oil. Hydroperoxides are the primary products of lipid oxidation. They are odorless and colorless, but are labile species that can undergo both enzymatic and non-enzymatic degradation to produce a complex array of secondary products. Determination of peroxides can be used as oxidation index for the early stages of lipid oxidation During the test time, both normal and encapsulated 1000 treatments had lower peroxide value through incubation time compared to all other treatments and 1000 EN treatment showed the lowest meaningful level of peroxide value (p
Research Article
Meysam Abediyan; Seyed Hamidreza Ziaolhagh; Ali Najafi
Abstract
Introduction. Apricot is a soft fruit that normally does not have any resistance to transportation and storage conditions. In addition, apricots are climacteric fruits, produces high levels of ethylene during ripening process and have a high respiration rate. For this reason, they are very susceptible ...
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Introduction. Apricot is a soft fruit that normally does not have any resistance to transportation and storage conditions. In addition, apricots are climacteric fruits, produces high levels of ethylene during ripening process and have a high respiration rate. For this reason, they are very susceptible to physiological and microbial spoilage and have a very short shelf life. Thus, it is difficult to export this product with good quality and low waste or it is very limited. Application of edible coatings could increase the storability of apricots and delay their spoilage. Edible coatings cover the surface of the fruit and function as a barrier against water vapor, respiration gasses, and microorganisms. The effect of different natural polymers as edible coatings on the quality and shelf life of different fruits has been investigated by many researchers. Chitosan has been used in the formulation of edible coatings to extend the shelf life of citrus, papaya, strawberries and grapes (Arnon et al. 2014; Ali et al. 2011; mehrzad et al. 2011; Mostofi et al. 2011). Apples coated with whey protein concentrate showed more lightness compared with non-coated ones (Perez-Gago et al. 2006). In most studies, the effects of single edible coatings on the quality of fruits have been studied. In this research the quantitative and qualitative changes during ripening and cold storage of apricots coated with different formulations of whey protein concentrate, sodium alginate and chitosan were studied.
Materials and methods "Rajabali" variety apricots were picked up at optimum maturity and damaged ones were separated. Edible coating solutions were prepared by dissolving different amounts of whey protein concentrate, sodium alginate and chitosan in to distilled water. Glycerol was used as plasticizer. The apricots were dipped in the prepared solutions with different concentrations for at least five minutes. Then they were stored for 35 days at 2°C. Some quantitative and qualitative characteristics of coated apricots, such as weight loss, acidity, color, texture, shrinkage, browning reactions, vitamin C, and microbial load were determined after 0 and 35 days of storage. The results were analyzed by response surface methodology based on central composite design with five replications at the central point.
Results & discussion. The statistical analysis of the results by central composite design (CCD) indicated that the different concentrations of whey protein did not have any significant effect on weight loss during storage. The weight loss decreased as the concentration of sodium alginate and chitosan increased. Chitosan and sodium alginate had an important role in maintaining firmness. The firmness of apricots were highest at the upper limit of sodium alginate (1%) and chitosan concentrations (2%). The b* (yellowness) and L* (lightness) values of the apricots were increased as the concentration of chitosan was increased and the concentration of sodium alginate decreased. No significant difference was observed between the a* values (redness) of apricots treated with different coatings. In addition, the acidity of the apricots was increased by increasing the concentration of chitosan and decreased by increasing the concentration of sodium alginate. Browning of the coated fruits was also increased as the concentration of chitosan was increased to 1%. Increasing the concentration of sodium alginate increased the shrinkage of the apricots at low concentrations of whey protein concentrate and decreased it at high concentrations of whey protein concentrate. It was also shown that increasing concentrations of chitosan would reduce microbial load. The optimization of the formulations with Design Expert software showed that the best formulation of edible coating for preserving apricots was 1.45% of chitosan, 1.25% of alginate, and 0 percent for Whey protein concentrate.
Research Article
Nasrin Malekizadeh; Seyed Hadi Peighambardoust; Aref Oladghaffari; Khashayar Sarabandi
Abstract
Introduction: Sumac is the common name of the Rhus genus, which contains over 250 individual species in the Anacardiaceae family. It is grown in temperate and tropical regions worldwide.Sumac is one of the most common spices used by people of the Mediterranean and Middle East regions. The sumac berries ...
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Introduction: Sumac is the common name of the Rhus genus, which contains over 250 individual species in the Anacardiaceae family. It is grown in temperate and tropical regions worldwide.Sumac is one of the most common spices used by people of the Mediterranean and Middle East regions. The sumac berries contain flavones, tannins, anthocyanins, and organic acids which provide antioxidant, antimicrobial and hypoglycemic activities. Due to spices maintenance problems caused by growth of microorganisms, flavor and color compounds losses, using spices extracts have recently been replaced. Although spices extract is sensitive to light, heat and oxygen and have a lower shelf life in poor storage conditions. Therefore, spices extract microencapsulation has been suggested by researchers. Spray drying is the most common and economical methods of microencapsulation. The aim of this study was to investigate the influence of different concentrations of maltodextrin and inlet air temperature on some properties of encapsulated sumac extract.
Materials and Methods: In the present study, the effects of three different inlet air temperatures (140, 160 and 180°C) and three different maltodextrin (DE=20-18) concentrations (10, 20 and 30%) on production efficiency, moisture content, water activity, solubility, hygroscopicity, wettability and color parameters of sumac extract spray dried powder were investigated. In all experiments, outlet air temperatures, atomizer rotational speed, feed flow rate and atomizer air pressure were kept constant at 80°C, 18000 rpm, 20 ml/min and 4±0.1 bar, respectively.
Results and Discussion: Production yield of the sumac powders varied from 44 to 57%. The addition of maltodextrin increased the product yield by preventing adhesion of the sumac extract on the dryer walls and also increasing the inlet air temperature caused an increase in product yield (P
Research Article
Raheleh Bazrafshan; Seyed Hadi Peighambardoust; Aref Oladghaffari
Abstract
Introduction: Cake is one of highly consumed products as a breakfast and snack. One of the common industrial concerns in the quality control of bakery products with high amounts of fat, such as layered cakes, is related to lipolytic effects of free fatty acids. Egg yolk due to its possible high free ...
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Introduction: Cake is one of highly consumed products as a breakfast and snack. One of the common industrial concerns in the quality control of bakery products with high amounts of fat, such as layered cakes, is related to lipolytic effects of free fatty acids. Egg yolk due to its possible high free fatty acids, phospholipids and lecithin is regarded as a main reason for possible high fat acidity content in the layer cakes. In addition, because of high cholesterol in the egg yolk, it may increase the possibility of health risk by cardiovascular diseases. Thus, the main objective of this research was to replace egg yolk with different industrial gel emulsifiers so called "Emulgels" to control the fat acidity content in the layer cake.
Materials and methods: Six different formulations were used to prepare cake batters as follows: 1) Control cake with whole egg, 2) Batter with only egg white, 3) Batter with egg white plus Softex emulgel, 4) Batter with egg white plus Golden emulgel, 5) Batter with egg white plus Gilk 60 emulgel and 6) Batter with only egg yolk. In the aforementioned formulations three different industrial emulgels were replaced with egg yolk. Cake batter was prepared with single-stage method according to Gomez et al (2007). Physical properties of batter such as density were measured. Cake physical, chemical, textural and staling properties were analyzed during storage. For this reason, cake volume and height as well as loaf symmetry were characterized. To evaluate cake staling by instrumental method, crumb firmness was measured by universal testing machine (Instron). Cake moisture and water activity, fat acidity and peroxide value were also measured.
Results and discussion: Batter density is a measure of how much air bulbuls can be incorporated during mixing or creaming. Increasing air inclusion into the batter increases the batter volume, and thereby, leads to a decrease in batter density. Results indicated that formulation with all three industrial emulgels had the lowest batter density (1.0-1.25 g/cm3) compared to those (1.5–1.75 g/cm3) of control and treatments with only egg white and egg yolk. Cake formulations with all three industrial emulgels used in this study had the highest cake volume (502-525 cm3/200 g batter) and height (60-69 mm) and the most loaf symmetry (24-33) compared to those (449-491 cm3/200 g batter for volume, 48-57 mm for height, and 15-22 for symmetry) of control/only egg white/only yolk cakes. As mentioned before, application of emulgels increased air incorporation into batter during the mixing process leading to a decreased batter density and thereby, an increased cake volume. Cake with only egg white showed the firmest (1.0-3.5 N) structure compared to other formulations (0.1– 0.5 N). The absence of egg yolk as an emulsifier can results in formation of a firm structure. Meanwhile, cakes containing gel emulsifiers all had the softest crumb structure as measured by Instron. Cakes containing gel emulsifiers without egg yolk had softer texture than that of control. Between three different emulges used there was no significant difference in terms of their effect on cake firmness. Results also indicated that crumb firmness increased upon 60 days storage. Nevertheless, this increasing rate was not significant (p
Research Article
Hoda Ghayomi; Mohammad Ali Najafi; Mohammad Rahnama; Mohammad Soltani
Abstract
Introduction: The environmental problems of plastic materials have increased the importance of renewable edible films. In the manufacture of edible films, hydrocolloid compounds such as methyl cellulose and sodium caseinate are usually employed. Methyl cellulose is a biopolymer, soluble in water, and ...
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Introduction: The environmental problems of plastic materials have increased the importance of renewable edible films. In the manufacture of edible films, hydrocolloid compounds such as methyl cellulose and sodium caseinate are usually employed. Methyl cellulose is a biopolymer, soluble in water, and has substantial inhibitory properties against oxygen and lipids. Sodium caseinate has favorable mechanical properties and a high inhibitory effect on air transmission. Furthermore, it possesses good nutritional value. One of the most notorious pathogenic bacteria in food is the Listeria spp. which hastens food decay. Listeria monocytogenes is one of the most harmful species of bacteria that causes disease in humans. Lactic acid bacteria can inhibit the growth of cells that cause decay in food. The use of lactic acid bacteria in food has been made legal by the Food and Drug Administration of the United States of America (FDA). In this study, Lactobacillus casei PTCC1608 (L. casei 1608) was added directly to the film forming solution. The primary effect of L. casei 1608 and film type, i.e. sodium caseinate and methylcellulose polymers, were evaluated based on mechanical properties, water vapor permeability (WVP) and the opacity of films. Anti-listeria features of the films were studied under experimental conditions as the films were prepared against the growth of Listeria innocua IBRC-M10799 (L. innocua 10799). The L. innocua 10799 was selected because of its non-pathogenicity and its physiological similarity with Listeria monocytogenes.
Materials and methods: L. casei 1608 and L. innocua 10799 were purchased from credible organizations. The bacteria were prepared as lyophilization form. In order to propagate and prepare bacterial suspensions of L. casei 1608 and L. innocua 10799, the cells were inoculated in the de Man Rogosa Sharpe Broth (MRS Broth, Liofilchem, Italy) and Blood Heat Infusion broth medium (BHI, Liofilchem, Italy), respectively. The cultures were then incubated at temperatures between 30 and 37°C, respectively, for 24 hour. The cells were harvested after centrifugation for 15 minutes at 3500 rpm (Eppendorf 5810 model, Germany). The collected medium was washed twice with a saline buffer solution. The population growth curve of L. casei 1608 and L. innocua 10799 were obtained using the pour plate method and by using the UV-VIS spectrophotometer device (Cecil model, England) at OD= 600nm. In order to prepare the film formation solution of methyl cellulose (CAS 9004-67-5, Sigma-Aldrich, Madrid, Spain), four grams of powder and 1 g of glycerol were mixed with 100 ml sterilized distilled water. After homogenization and degassing, the film forming solution was transferred to the plastic container. To prepare the film formation solution of sodium caseinate, 5 g of sodium caseinate powder (CAS 9005-46-3, Sigma-Aldrich, Madrid, Spain) was added to distilled water along with 1.5 g of glycerol. The solution was planned to reach 100 ml and, after complete dissolution, the film formation solution warmed up to 85°C and then cooled. To prepare the bio-film, L. casei 1608 was added to the film forming solution until the number of L. casei 1608 in the dried film reached 106 CFU/cm2. The film formation solutions were transferred to plastic containers and were dried at 25°C for 24 hours. All films were placed in a desiccator at 25°C and 75% RH for one week. In order to evaluate the anti-listeria activity, the bio-films were put on tryptic soya agar (TSA) medium, inoculated with L. casei 1608 (102 CFU / cm2) for 12 days at 5°C. The number of pathogenic bacteria and L. casei 1608 were counted on days 0, 4, 8 and 12. Also, the prepared films were evaluated according to the ASTM D-882 (ASTM, 2001) as per the ASTM D-882 instruction manual (Testometric, Model M350-10CT, UK). WVP was determined according to the ASTM-96-95. The opacity of the films were assessed by using the spectrophotometric apparatus according to the method described by Nu nez-Flores et al. (2012). Comparing the mean values of data was based on a factorial experiment in a completely randomized design (CRD) with three replications, by the SAS software version 9.1. The chemical and microbial mean values were calculated using Duncan’s and Tukey’s tests, respectively.
Results & Discussion: Data analysis showed that the bio-caseinate film hosted the highest survival rate of L. casei 1608 on the eighth day of culture (123.8%) when L. casei was concurrently present with L. innocua 10799. Analysis of data by the bio-methyl cellulose film showed that the strongest inhibitory effect on the growth rate of L. innocua 10799 was observed on the fourth day of the 12-day experimental duration (P0.05). Laboratory evaluations showed that the presence of lactic acid bacteria in films significantly increased the transparency, WVP and amount of elasticity. Nonetheless, a significant decrease in tensile strength and modulus of elasticity was observed. The type of matrix had a significant effect on mechanical properties. By comparing the methyl cellulose matrix and the sodium caseinate, it was observed that the methyl cellulose matrix showed significantly greater elasticity, tensile strength and higher modulus of elasticity while having less WVP and less opacity (p
Research Article
Zahra Sheikholeslami; Mahdi Karimi; Toktam Hejrani; Mehdi GhiafeDavoodi; Hamed Fatemian
Abstract
Introductıon: Hydrocolloids have been employed for reduction of moisture migration from the crumb to crust, added to the formulation, improved texture, prevent ice Crystallization and delay staling (Ba´rcenas et al 2003, 2004, Hager, and Arendt, 2013). However, given the importance of their role still ...
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Introductıon: Hydrocolloids have been employed for reduction of moisture migration from the crumb to crust, added to the formulation, improved texture, prevent ice Crystallization and delay staling (Ba´rcenas et al 2003, 2004, Hager, and Arendt, 2013). However, given the importance of their role still trying to find new resources will continue to create the best quality. Today, researchers introduced new technologies such as modified atmosphere packaging, frozen technology and using different additives to produce bread with higher quality, longer shelf life and high nutritional value. Production of the part baked frozen bread is a method which interrupted baking process, the first stage is the crumb formation and the crust color is not developed. The aim of this study was to evaluate the effect of Ocimum Bacilicum and tragacanth at 3 levels (0, 0.3 and 0.5%) (W/W flour basis) on the quality of part-baked Barbari bread after frozen storage and re-baking.
Materials and methods: The Ocimum Bacilicum seeds were cleaned, then were firstly soaked in distilled water to obtain a water to seed ratio of 37:1 at 40˚C and pH 7. Separation of the hydrocolloid from the swollen seeds was achieved by passing the seeds through an extractor equipped with a rotating plate that scraped the gum layer on the seed surface. The extracted solution was then filtered and dried in an air forced oven at 60˚C and finally the powder was milled, sieved using a mesh 18 sifter, packed and kept at cool and dry condition (Karazhiyan et al., 2010, Sahraiyan et al., 2013). Tragacanth purchased from the local market as a tape shape after milling and sieve (70 mesh) were used. Bread prepared as part baked, freezing in -18°C and storage for 15 days, after this time samples were thawing and full baked. The test includes moisture content, specific volume, porosity, firmness, image analysis and sensory properties was measured. For Data Analysis used SPSS software and Duncan test, for mean comparisons.
Results and discusions: The results obtained from volume, texture, moisture content and sensory properties showed Tragacanth gum at 0.5 concentrations and Ocimum Bacilicum gum at 0.5 levels improved moisture content. Using tragacanth at 0.3% and Ocimum Bacilicum gums at 0.5 % concentration improved the specific volume, porosity, firmness, and sensory properties. The hydrocolloids are highly hydrophilic nature, it made hydrogen link between the water available in the system, prevent the movement of water from crumb and improved the firmness and improved the quality of bread (Manadala et al., 2008). The hydrocolloids capable to strengthen the gluten matrix surrounded cell gas as result maintenance them during part baked and frozen storage. Hydrocolloid, coalescence of gas cells as a result of expansion during the proofing step and increase the volume and porosity of bread (Shillini & Laxemi, 2007).
Conclusion: Addition of Ocimum Bacilicum and tragacanth to bread recipe improved the crumb texture of the bread that obtained from part-baking, frozen storage and re-baking. In addition, the presence of gums improved the specific volume, texture and the overall quality of the product during frozen storage, removing the negative effects of that process conditions. The Ocimum Bacilicum in comparison of tragacanth had the greater concentration effect on PBF Barbari bread on improved the quality. The interaction of tragacanth and Ocimum Bacilicum (0.3 and 0.5 %) respectively had the best result to improving the all parameters that investigated in part baked and freezing storage of Barbari bread. This study provides insights into the complexity of interactions between tragacanth and Ocimum Bacilicum as a new source of hydrocolloids and their combined influence on bread characteristics, thereby serving as a guide for future research on the other bread
Research Article
Tooraj Mehdizadeh; Hossein Tajik; Ali Mojaddar Langroodi
Abstract
Introduction: Meat is sensitive to microbial spoilage and chemical oxidation, so it is favorable to use a natural preservative with antioxidant and antimicrobial effects. The objective of this study was to prepare composite films from chitosan and starch containing pomegranate peel extract (PPE) and ...
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Introduction: Meat is sensitive to microbial spoilage and chemical oxidation, so it is favorable to use a natural preservative with antioxidant and antimicrobial effects. The objective of this study was to prepare composite films from chitosan and starch containing pomegranate peel extract (PPE) and Thymus kotschyanus EO alone and in combination to evaluate their effects on shelf-life characteristics, including physico-chemical (pH, aw and lipid oxidation), sensorial (color, odor and general appearance) and microbial (lactic acid bacteria, aerobic mesophiles, pseudomonas) on meat at 4°C for 21 days.
Materials and methods: Fresh pomegranate fruits (Punica granatum) were purchased from a local hypermarket. After separation, the peels were washed and dried. Thus 700 ml alcohol and 300 ml distilled water were added to 250g of powdered peel. The mixture was left in a shaker for 24 hr. After cooling and filtration using a paper filter, the solvent was removed in a rotary evaporator and the extract was stored at 4 °C until use. The Thymus kotschyanus was purchased a local market in Urmia. Hydrodistilation of dried parts of plant was performed in a Clevenger-type apparatus for 3 hr. Sodium sulfate was used for dehydration of the oil, then oil was filtered using 0.22 μm filters and stored in colored glass tubes in the dark at refrigerated temperature. Chitosan film solution was prepared by dissolving 1.5% (w/v) of chitosan in 1% (v/v) of glacial acetic acid solution with constant agitation using a magnetic stir plate during 24 h at room temperature. As a plasticizer, glycerol was added in the proportion of 30% (w/w) to chitosan powder, and the system was agitated for 5 min to complete homogenization. Starch solutions with concentrations of 3.5 % (w/v) were prepared by dispersing 27% amylose corn starch (Sigma-Aldrich Chemie GmbH, Steinheim, Germany) in distilled water and heating the mixtures on hotplates 95 ˚C during 30 min with stirring until it gelatinized, and then cooling to 40 ˚C. Composite films were prepared by mixing 100 mL of 2% chitosan solution with 100 mL of 3.5% starch solutions. For the films incorporated with the essential oils, tween 80 at a level of 0.2% w/v of essential oil was used as emulsifier. EO or hydro-alcoholic extracts were incorporated to the system at the level of 1% (v/v) of film form solution and homogenized in magnetic stir plate during more 5 min at room temperature. For microbial tests ten grams of each sample was diluted in 90 ml sterile 0.1 % ml peptone water (Merck, Darmstadt, Germany) and homogenized using shaker for 3 min at room temperature. Then, 0.1 mL of serial dilutions (0.1 % peptone water) of beef meat homogenates were transferred to agar plates. Pseudomonas were counted on Pseudomonas agar supplemented with CFC at 25 °C for 48 h (CFC, Merck, Darmstadt, Germany). Lactobacillus were enumerated on MRS agar (Merck, Darmstadt, Germany, Oxoid) incubated at 30 °C for 48 h. Finally, total mesophilic counts were determined using Plate Count Agar (PCA, Merck, Darmstadt, Germany), after kept for 2 days at 30°C. Level of lipid oxidation was investigated using thiobarbituric acid reactive substances (TBARS) method as described by Pikul et al (1989). Ten grams of sample was homogenized with 1 mL BHT (1 mg/mL) and 35 mL trichloroacetic acid (5%) in a blender. The mixture was filtered using Whatman no 1. Five mL TBA solution (0.02 M) of filtrate solution was added to 5 mL of filtrate solution and kept in a water bath at 100°C for 60 min to expand the malondialdehyde–TBA complex. After cooling the tube, the absorbance of the samples were determined at 532 nm. The pH values were determined using a digital pH meter. A 5 g of beef meat sample containing 25 ml of distilled water was homogenized for up to 1 min. The sensory analysis of meat samples was carried out with 10 trained PhD students. After preparation of treatments, the samples were offered to each panelist separately. Fresh beef meat was used as a control. Panelists were asked to evaluate texture, color, flavor and odor and overall acceptance on a nine-point Hedonic scale, with 9 being so good and 1 being so poor.
Results and discussion: The incorporation of PPE and EO into composite film showed that aerobic mesophiles and lactic acid bacteria were the most sensitive and resistant groups to films by 7.11 and 6.92 log cycles reduction after 21 days’ storage, respectively. In addition, meat wrapped by 1% PPE films had the lowest degrees of lipid oxidation (1.11 mg MDA/kg samples) which was 61% lower than the control samples (2.90 mg MDA/kg samples). This study showed that starch-chitosan composite films containing of pomegranate peel extract and Thymus kotschyanus EO was significantly antibacterial properties, while shows the higher antioxidant effect. PPE also improves some physical properties of the film. Our results indicated that incorporation of pomegranate peel extract (PPE) and Thymus kotschyanus EO as a natural antibacterial agents have a potential to prolong the shelf-life of meat.
Research Article
Hassan Sabbaghi; Aman Mohammad Ziaiifar; Mahdi Kashani-Nejad
Abstract
Introduction: Color is the most important feature of food appearance, since it strongly affects consumer acceptance. The abnormal color is closely related to degradation of food quality or food spoilage. Various factors affecting color of the product include the composition and surface properties of ...
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Introduction: Color is the most important feature of food appearance, since it strongly affects consumer acceptance. The abnormal color is closely related to degradation of food quality or food spoilage. Various factors affecting color of the product include the composition and surface properties of the foodstuff, process conditions (temperature and time), and the type of pretreatment processes. Therefore, for the design of a new process, kinetic modeling is essential for extracting basic kinetic information in a system to predict changes. Intermittent irradiation is the novel processing method in food industry which the surface temperature of product is kept constant. Darkening process occur in the fruit slices during drying, resulting in undesirable color changes. Undesirable color variations can be attributed to Millard's browning reactions between sugar and amine compounds or ascorbic acid oxidation. Thermal degradation kinetic models define maximum maintenance conditions for qualitative factors to produce a safe food. Color descriptive models are known as zero order, first order, and fractional conversion model. The fractional conversion model represents the response rate required at a given time to complete a phenomenon. This modeling is necessary for designing online quality control systems for thermal processing in the food industry and preserving the apparent quality of the product by optimizing the most important drying parameters. In this study, the kinetic of color changes in apple slices was investigated, in order to maintain appearance quality of product during simultaneous infrared dry-blanching and dehydration with intermittent irradiation.
Materials and Methods: Apple slices (Golden Delicious Variety) were dried in three thicknesses of 5, 9 and 13 mm using three constant surface temperatures of 70, 75 and 80 ° C. Image acquisition of apple slices was made use of a flatbed scanner with an interval of 15 minutes during processing. The treated samples were placed on the scanner and then a black box was utilized so as to prevent the interferences of the peripheral lights. The images featured a 300 dpi quality and were saved in TIFF-24 bit format. The color analysis of the images was carried out in color space of L*a*b* by the use ImageJ software, version 1.6.0. The lightness parameter (L), redness (a), yellowness (b), the intensity of the color changes (∆E), chroma (Cr) and browning index (BI) were described during product processing using fractional conversion model. Equilibrium color parameters (Cf) were also used as an indicator to compare different process conditions. The fitting of the model was done using the curve fitting toolbox in the 2009 version of the MATLAB software with 95% confidence level (P
Research Article
Maryam Ravaghi; Anna Maria Fadda
Abstract
Introduction: Curcumin is the main ingredient of turmeric spice, derived from rhizome of the Curcuma longa. It is a hydrophobic material with low bioavailability which is rapidly removed from the body due to its instability under physiological conditions and inadequate absorption. Curcumin is a polyphenol ...
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Introduction: Curcumin is the main ingredient of turmeric spice, derived from rhizome of the Curcuma longa. It is a hydrophobic material with low bioavailability which is rapidly removed from the body due to its instability under physiological conditions and inadequate absorption. Curcumin is a polyphenol and one of the most widely explored natural pharmacological agents in nanomedicine due to its high in vitro activity and low systemic bioavailability in vivo. In recent years, many efforts have been made to increase its therapeutic potential for disease prevention and health promotion, by using specific nano-delivery systems. Delivery and accumulation of curcumin in the intestine may represent an attractive strategy to improve its systemic absorption and bioavailability. The incorporation of curcumin in phospholipid vesicles (liposomes) may modulate its accumulation and be released, but do not improve its stability in the gastrointestinal environment due to the phospholipid degradation. An appropriate combination of phospholipid and polymer may provide a suitable strategy to protect the vesicles, resulting in an amelioration of curcumin intestinal deposition and bioavailability. In the present work, the potential use of Eudragit and hyaluronan to complex phospholipids was investigated, thus forming gastroresistant vesicles able to deliver the curcumin to the low intestine.
Materials and Methods: Soy phosphatidylcholine S75 (purity of 70%) and P90G (purity of 94%) were purchased from Lipoid GmbH (Germany). Sodium hyaluronate or hyaluronan with low molecular weight (200–400 kDa) was purchased from DSM Nutritional Products AG Branch Pentapharm (Switzerland). Eudragit S100 and L100 with molecular weight about 125 kDa were provided by Evonik Industries
AG (Germany). Curcumin and other chemicals were analytical grade and procured from Sigma-Aldrich (Italy). This paper was aimed to find a liposome type formulation to immobilize the phospholipid structures, and to protect liposomes and enhance curcumin stability from simulated gastrointestinal conditions. To this purpose, phospholipid (P90G and S75), sodium hyaluronate and Eudragit (S100 and L100) were combined to obtain immobilized liposomes and drug. Liposomes were formed by hydration, combined with sonication using a high intensity ultrasonic disintegrator (Soniprep 150 plus, UK). The average diameter, polydispersity index (PDI) and zeta potential were determined using a Zetasizer nano-ZS (Malvern Instruments, United Kingdom). Entrapment efficiency (EE%) was calculated as the percentage of the drug amount found after dialysis (Spectra/Por® membranes, 12–14 kDa MW cut off, 3 nm pore size, The Netherlands) versus that initially used. Curcumin content was estimated spectrophotometrically at λmax=424 nm by a Perkin Elmer UV/visible spectrophotometer (Lambda 25, USA) after disruption of liposomes. Vesicle formation and morphology were checked by cryogenic electron transmission microscopy, using a Tecnai F20 TEM (FEI Company, The Netherlands). The average diameter, PDI, zeta potential and EE% of the vesicles produced using Eudragit S100 and L100 were measured after 1 month incubation at 4°C to determine their stability. Vesicle behaviour was also measured in fluids at pH 2 and 7 and high ionic strength immediately after dilution, at 2h and 6 h. Data are expressed as mean±standard deviation (n=3 independent samples). Analysis of the data was made using SAS statistical software (version 9.0). Comparison among the means was carried out by Duncan’s multiple range test at p800 nm) and polydispersed (>0.8). In this work, the Eudragit was dispersed in ethanol with the curcumin, leading to a homogeneous, yellow transparent solution, and the curcumin and hyaluronan were dispersed in water. After freeze drying and rehydration with water, the vesicle size and polydispersity decreased, leading to the formation of more suitable systems. Liposomes of Eudragit were spherical or oval, multi-lamellar or large uni-lamellar vesicles with some smaller vesicles inside. These liposomes had high entrapment efficiency (>80%) immediately after production without significant decrease after storage. Liposomes of Eudragit S100 had smaller vesicles (287±31 nm) compared to those of Eudragit L100 (407±33 nm) after preparation Moreover, vesicles containing Eudragit S100 showed better stability during storage. Immobilization of liposomes in polymeric network of hyaluronan-Eudragit increased their stability against the mimicking conditions of gastrointestinal tract such as high ionic strength and pH variation. The present study indicated that the combination of P90G, Eudragit S100 and hyaluronan results in the production of innovative delivery systems with suitable dimensions and adequate stability, capable of protecting the curcumin from the pH variation during the stomach to colon transit, and favoring the local accumulation of the drug. Finally, a more detailed research according to ICH and WHO guidelines should be performed in a more advanced development step.
Research Article
Fatemeh Bahrami Maghsudbeki; Hajar Abbasi; Mohammad Goli
Abstract
Introduction: Legumes are suitable sources in nutraceutical properties due to existence of anticancer, antioxidant and also significant antimicrobial substances. Different processing such as soaking, peeling and germinating improves nutritional value and bioavailability of minerals such as calcium, iron ...
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Introduction: Legumes are suitable sources in nutraceutical properties due to existence of anticancer, antioxidant and also significant antimicrobial substances. Different processing such as soaking, peeling and germinating improves nutritional value and bioavailability of minerals such as calcium, iron and phosphorus content of legumes and based on the literature review, germination is the best method among the others. The results of previous researches demonstrated significant improvement of nutraceutical and farmoceutical properties of products due to germination. In legumes, sprouted lentil has higher nutritional value such as minerals and essential amino acids than others. Cereal based products, especially products of wheat flour such as bread, pastries, biscuits and etc are used generally as a staple food around the world. Cake is one of the widely used confectionary cereal based product that its nutritional quality is important in public health. According to deficiency of wheat flour from many essential amino acids and important minerals such as iron, the aim of present study was to employ natural enrichment of cake with sprouted lentile and improving the qualitative characteristics of products using active gluten and hemicellulase enzyme. Due to the existence of problems in enrichment of wheat flour with iron due to difficulties in uniform distribution of particles and creation of unsuitable organoleptic properties in the products, currently, iron enrichment is limited to whole flour in Iran. Therefore, the results of the present research could an alternative way for flour enrichment with iron and other nutrients.
Materials and method: In order to prepare sprouted lentil flour, the “official” lentil variety was prepared and treated at ambient temperature (24°C) and suitable humidity (90%) in dark place in order to germinate and increase the shoot height to 1.5 cm. The sprouted lentils were dried at room temperature in shadow. Then, they were milled and sieved in order to achieve suitable particle size. At the beginning step, sprouted lentil flour and wheat flour were evaluated in terms of protein, moisture, ash, fat and minerals such as iron, calcium, potassium and phosphorus. After numerous pre-tests by experts in cereal technology, the usable quantities of sprouted lentil flour according to organoleptic characteristics of the product, was considered 25% of batter’s flour. Improving the textural characteristics of products due the negative effects of germinated lentils flour was considered using independent variables of present study (hemi-cellulase enzymes at 0, 25 and 50 ppm levels and active gluten powder at %0, %1/5 and %3). Sprouted lentil flour was treated for 30 minutes with enzyme before using in batter formulation. Prepared samples with 25% replaced sprouted lentil with wheat flour and hemicellulase (0, 25, 50 ppm) and active gluten (%0, %1.5, %3) were investigated in terms of volume, bulk density, color properties of crust and crumb, moisture content, textural properties (hardness, cohesiveness and springiness) and also sensorial properties. Prepared product based on optimized formulation according to the results of chemical, physical and sensorial analysis was evaluated in staling rate, the quantities of fat, protein, ash, fiber and minerals such as iron, calcium, phosphorus, potassium and its results were compared to control. Data was analyzed according to the factorial experiments based on completely randomized design by SAS software (version 9.2), and the means were compared by LSD test at 5 significance percent level. Statistical evaluation of sensorial properties was also done based on qualitative method of Kruskal-Wallis.
Results and Discussion: In chemical composition of wheat and sprouted lentil flour, there were significant differences between two samples in terms of protein, ash, and minerals content such as iron, calcium, phosphorus and potassium. But, there was no significant difference in fat content. The quantity of iron in lentil flour was five times more than that of wheat flour, calcium was double, potassium was seven times and phosphorus was six times more than that of wheat flour. Also, sprouted lentil flour showed higher protein content than wheat flour. Addition of sprouted lentils to batter formulation increased moisture content of the sample than the same one prepared only with wheat flour. Gluten and hemicellulase had significant effects on reducing the apparent density of samples and improving the physical, sensorial and textural characteristics of the product. In this regard, the hardness of sample’s crumb were decreased and theirs cohesiveness and springiness were increased significantly. According to the results of the present study, the addition of gluten and hemicellulase enzyme was improved color properties, especially in crust position. Therefore, independent variables were effective in improvement of qualitative properties of products. Finally, the optimal sample based on physical, textural and sensorial evaluation was introduced a sample with 25% sprouted lentil flour, 3% active gluten and 50 ppm hemicellulase enzymes. The optimum sample was closed to wheat control sample in the case of the qualitative characteristics. Comparison of textural characteristics of optimum and control samples during storage was indicated the similar characteristics of them. Sprouted lentil flour was a rich material in fiber with high water binding capacity in technological point. Therefore, it improved moisture retention and softness of texture. As well as, comparison the textural qualitative characteristics of the selected and control samples (prepared with wheat flour completely without additives) was shown a very high affinity in them. The products made with sprouted lentil had significantly higher nutritional value in protein, ash, crude fiber and minerals such as iron, calcium, potassium and phosphorus content than control. The iron content of optimum sample was more than twice of the control. Therefore, the results of the present research are effective in production of the functional product with improved nutritional characteristics. Due to the unique nutritional value of grain, more sprouted bean is recommended to use in food product formulation, and at the same time suitable additives are used for reducing their impact on the textural and sensorial properties of product.
Research Article
Nazanin Abdi; Neda Maftoonazad; Amir Heidarinasab; Fujan Badii
Abstract
Introduction: The date palm (Phoenix dactylifera), is one of the most important plants of arid desert area of the western and southern Asia and northern Africa for over 5000 years. Date fruit has a great importance in nutrition due to being a main source of carbohydrates, but it is low in fat and protein. ...
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Introduction: The date palm (Phoenix dactylifera), is one of the most important plants of arid desert area of the western and southern Asia and northern Africa for over 5000 years. Date fruit has a great importance in nutrition due to being a main source of carbohydrates, but it is low in fat and protein. Also it is a good source of many minerals and high amounts of antioxidants which prevent some diseases. This fruits is an important element in economy of date growing countries. Some factors such as variety, environmental impact of growing regions and large quantities of the produced date causes postharvest losses resulting in lower quality fruits. These amounts of fruit which are not consumed directly as fresh may have been used as raw materials to formulate some products like date syrup, powder, jam, etc. Date powder is a highly nutritional quality sweetener obtained from date for sucrose substitution in confectionary, bakery or ice cream industry. Stickiness is a problem in production of fruit powder during drying, transportation and storage. Stickiness in fruit powder is mainly due to the presence of low molecular weight sugar such as fructose, glucose, sucrose and organic acids in fruits. These compounds are very hygroscopic in the amorphous state and have low glass transition temperature and leads to increase stickiness and decrease stability of the product in room temperature. This research consisted of two major objectives: i) determination of an optimum proportion of date paste, silicon dioxide and maltodextrin and the most suitable temperature of drying; ii) characterization of physicochemical and thermal characteristics of date powder.
Materials and methods: Kabkab date was purchased from local market of Kazeroun, Fars, Iran. Moisture, ash, protein, fat, total sugar and dietary fiber contents were determined by AOAC methods (AOAC, 1997). Date flesh was minced by a kitchen meat grinder to make a smooth paste. Three different proportions of maltodextrin (35, 45 and 55% w/w) and three proportions of silicon dioxide (0, 0.75 and 1.5% w/w) were added to date paste to produce date powders. The mix was then spread to a thickness of about 5 mm on a Teflon coated tray and kept inside an oven dryer at 50, 60 and 70°C. The dry product was then ground in a hammer mill to produce date powder. The powder was immediately collected in plastic pouches and kept in desiccators to avoid moisture absorption from the air. Laboratory test sieves were used to collect date powder with particle size less than 1mm in diameter. Some physical and thermal characteristics of the powders were measured. Response surface methodology with central composite design was applied to minimize total number of experimental runs and to optimize the proportions of maltodextrin and silicon dioxide and also drying temperature. The dependent variables were density, moisture and color parameters. A completely randomized design was applied to analyze the effect of maltodextrin on thermal properties (glass transition temperature and specific heat) of date powder. Significant terms were found using ANOVA (P
Research Article
Ryhaneh Moghaddasi; Sara Movahhed; Hossein Ahmadi Chenarbon
Abstract
Introduction: The rheological properties of a bread dough describe its behavior under different process conditions. They are also central to its formulation, optimization, quality control, and better process capacity. A number of additives can improve the rheological properties of dough and breads. Fiber-based ...
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Introduction: The rheological properties of a bread dough describe its behavior under different process conditions. They are also central to its formulation, optimization, quality control, and better process capacity. A number of additives can improve the rheological properties of dough and breads. Fiber-based compounds and prebiotics in addition to gluten and starch, which have a large tendency to absorb the flour water, can affect the moisture distribution across the dough structure. Inulin and resistant starch are two types of prebiotics. Inulin is a water-soluble dietary fiber that is not absorbed by the enzymes at the upper section of he the digestive system and is partially fermented and metabolized by the microbial flora of the colon. Digestion-resistant starch is another prebiotic that acts as a food fiber and adds to the nutritional value. It can also improve the structure of the final product. In recent years, the rise in consumer awareness about health benefits of prebiotics has increased interests in functional foods particularly in bakery products. The present study qualitatively analyzed the effect of the prebiotics (i.e. inulin and resistant starch) on rheological properties of baguette bread doughs.
Materials and Methods: The study treatments are: Baking dough w/o inulin and resistant starch (Control); baking dough w 2.5% inulin (based on flour weight); baking dough w 5% inulin (based on flour weight); baking dough w 2.5% resistant starch (based on flour weight); baking dough w 5% inulin (based on flour weight); baking dough w 2.5% inulin + 2.5% resistant starch (based on flour weight); baking dough w 2.5% inulin + 5% resistant starch (based on flour weight); baking dough w 5% inulin + 2.5% resistant starch (based on flour weight); baking dough w 5% inulin + 5% resistant starch (based on flour weight). The treatments were rheologically tested by farinograph and extensograph after preparation. Study data were then analyzed using the completely randomized design. Means of data were also compared by Duncan's multiple-range test (α = 5%) in SPSS 16.
Results and Discussion: According to the results, the different levels of prebiotics (inulin and resistant starch) significantly improved dough water absorption compared to the control samples. This can be due to the presence of hydroxyl groups in the structure of the prebiotics, which increased the number of hydrogen bonds and thus water absorption in all treatments compared to the control. Moreover, these additives led to significantly higher dough development time than the control. This can be due to the hydroxyl groups in the structure of inulin and resistant starch, which increased the number of hydrogen bonds and thus cross-bonding with water. These additives also significantly increased the dough stability time compared to the control.This is a result of hydrogen attachments and hydroxyl bonding between gluten proteins (made up of glutenin and gliadin) and the prebiotics (inulin and resistant starch) that in turn improved the stability and strength of the doughs. As the dough stability increased, the dough softening degree after 10 and 12 minutes was also reduced, which was due to the hydrogen bonds resulting from hydroxyl cross-links of gluten with inulin and resistant starch. Note that the quality index increased when the stability and strength were improved compared to the control dough. According to the results, by adding different levels of inulin and resistant starch, the dough energy rised higher than the control sample after 45, 90 and 135 minutes. This is again due to (OH) hydroxyl bonds with hydrogen attachments between glutens and the prebiotics. In this regard, the highest resistance to extension after 45, 90 and 135 min was recorded for the treatments containing inulin and resistant starch whereas its lowest value was recorded for the control. This is due to the stable continuous lattice made by amylose in resistant starch granules, which led to the higher strength of other treatments than the control. Additionally, the increased dough resistance to extension can be due to the interaction of inulin and resistant starch with flour proteins. Regarding extensibility, significant differences were observed between the treatments and the control within all three time intervals. Accordingly, after 45, 90 and 135 min, the control treatment had the highest extensibility whereas the treatment with 5% inulin + 5% resistant starch (based on flour weight) had the lowest level of this parameter within these times. The increases in strength and stability of the doughs were caused by strong links between glutens and these prebiotics, which reduced the dough extensibility. The results showed that the highest dough ratio number after 45, 90 and 135 min belonged to the treatment with 5% inulin + 5% resistant starch (based on flour weight). The lowest ratio number was recorded for the control in these time periods. The gluten was the main factor behind dough stability. The large amount of hydroxyl groups in the structure of inulin and resistant starch led to formation of a better structured three-dimensional gluten lattice. In general, by taking all parameters into account, the treatment with 5% inulin + 5% resistant starch was selected as the best treatment.
