Food Biotechnology
Behrooz Alizadeh Behbahani; Mostafa Rahmati-Joneidabad; Mohammad Noshad
Abstract
IntroductionThe use of safe ingredients to preserve food is steadily increasing. The high time and cost of production and approval of synthetic food additives and the reduction of public acceptance of these compounds have caused serious problems in their utilization. Excessive use of synthetic preservatives, ...
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IntroductionThe use of safe ingredients to preserve food is steadily increasing. The high time and cost of production and approval of synthetic food additives and the reduction of public acceptance of these compounds have caused serious problems in their utilization. Excessive use of synthetic preservatives, which some of them are suspected to be toxic, has completely eliminated these additives and led to the use of natural alternatives to preserve or extend the shelf life of food products. Many plant-based bioactive compounds are good alternatives to synthetic antimicrobial and antioxidant supplements. Plant extracts have significant biological activity including antioxidant, antibacterial, and antifungal properties, which has increased their use in food products. In addition, plant-derived antimicrobial compounds have been considered in the pharmaceutical industry to control microbial pathogens. Natural antioxidant and antimicrobial compounds are receiving a lot of research and industrial 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.The plant Prosopis farcta grown in arid and semi-arid regions. In Iran, it is found in the southern regions of the country. In traditional medicine, this plant is used to prevent hyperlipidemia and hyperglycemia, to treat hemorrhoids, intestinal diseases and diarrhea, and leprosy, and to reduce abortion. In addition, antimicrobial and antioxidant properties of various species of Prosopis have been reported. Accordingly, in this study, after examining the of total phenols and flavonoids concentrations, the antioxidant and antimicrobial properties of ethanolic extract of Prosopis farcta were determined. Materials and MethodsThe ethanolic extract of P. farcta was obtained maceration method. Total phenol content (by Folin-Ciocalteu reagent method), total flavonoid content (by aluminum chloride method), antioxidant activity (by DPPH and ABTS free radical scavenging and beta-carotene bleaching methods), and antimicrobial effect against Escherichia coli, Shigella dysentery, Staphylococcus aureus, and Bacillus subtilis (by disk diffusion agar, well diffusion agar, minimum inhibitory concentration, and minimum fungicidal concentration) of the extract were evaluated. Results and Discussion farcta ethanolic extract showed high phenol content (145.58 ± 1.30 mg GAE/g), while its total flavonoid content was 72.37 ± 1.48 mg QE/g. Antioxidant activity of ethanolic extract of melon root using different methods of DPPH and ABTS free radical scavenging and beta-carotene bleaching inhibition were 62.60, 71.82 and 54.50%, respectively. Antibacterial activity of P. farcta ethanolic extract against Escherichia coli, Shigella dysentery, Staphylococcus aureus, and Bacillus subtilis according to disk diffusion agar and well diffusion agar methods showed that the antimicrobial activity of the extract was concentration dependent and Shigella dysentery and Staphylococcus aureus were the most resistant and sensitive bacterial strains to the extract respectively. The minimum inhibitory concentrations of ethanolic extract of P. farcta root for Escherichia coli, Shigella dysentery, Staphylococcus aureus, and Bacillus subtilis were 8, 8, 4 and 4 mg/ml, respectively; while the minimum bactericidal concentrations for these bacteria were 128, 256, 32 and 64 mg/ml, respectively. ConclusionIn the present study, ethanolic extract obtained from the roots of P. farcta was identified as a rich source of phenolic and flavonoid compounds. The ethanolic extract showed effective antimicrobial and antioxidant properties. The results greatly indicated the promising effect of P. farcta root extract against Gram-positive and Gram-negative bacterial species. As the microbial resistance is constantly increasing, ethanolic extract of P. farcta root can be considered as a suitable complementary option to tackle this problem. In addition, the identification of individual components of P. farcta ethanolic extract and their biological functions or their combination with common antioxidant and antimicrobial agents could be the subject of future research.
Food Biotechnology
Mostafa Rahmati-Joneidabad; Behrooz Alizadeh Behbahani; Mohammad Noshad
Abstract
IntroductionStrawberry and grapes are generally infected with pathogenic fungi (e.g., Aspergillus niger, Botrytis cinerea, Rhizopus stolonifera, etc.). Synthetic fungicides are commonly used as the first line of defense against post-harvest pathogens on packaging lines. However, disposal of toxic waste ...
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IntroductionStrawberry and grapes are generally infected with pathogenic fungi (e.g., Aspergillus niger, Botrytis cinerea, Rhizopus stolonifera, etc.). Synthetic fungicides are commonly used as the first line of defense against post-harvest pathogens on packaging lines. However, disposal of toxic waste is a costly process and the hazardous waste causes serious environmental problems. In addition, fungal pathogens have shown a worrying trend of resistance to these fungicides, thus shortening the shelf life of products. Compounds that can be equally effective in controlling pathogens, but preventing or minimizing the waste problems will be inevitable. The large volume of internationally processed agricultural products, as well as the increasing demand for organically produced fruits, emphasizes the need to replace synthetic fungicides with safer and biodegradable alternatives. Natural plant-derived products effectively meet this criterion and have great potential to influence modern agricultural research. Catechins and other polyphenols in green tea show strong antioxidant activity. Also, the antimicrobial activity of green tea extract against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Candida albicans has been reported. Therefore, the present study was performed to prepare the ethanolic extract of green tea and to determine the content of total phenol, total flavonoids, antioxidant activity, and its antifungal effect against Aspergillus niger, Botrytis cinerea, and Rhizopus stolonifer (causing rot in strawberry and grapes). Materials and MethodsFresh green tea leaves were dried at room temperature and then powdered. Then, ethanol (70%) was added to the powdered leaves (solvent to powder ratio of 10:1 v/w) and the mixture was refluxed for 120 min. The resulting mixture was filtered through a filter paper and then concentrated under vacuum and finally dried in an oven.Total phenol content (by Folin-Ciocalteu reagent at 756 nm), total flavonoid content (spectrophotometrically at 510 nm), antioxidant activity (by DPPH and ABTS radical scavenging methods), and antifungal effect (by disk diffusion agar, well diffusion agar, minimum inhibitory concentration, and minimum fungicidal concentration) of the extract were evaluated. Results and DiscussionThe extract contained 175.60 mg GAE /g total phenol and 47.53 mg QE/g total flavonoids and its antioxidant activity using DPPH and ABTS free radical assays was 78.89% and 86.57%, respectively. The results of antifungal activity showed that the diameter of the growth inhibition zone increased significantly with increasing the concentration of the extract, and Botrytis cinerea and Rhizopus stolonifer were the most sensitive and resistant fungal strains to the extract, respectively. The minimum fungicidal concentrations for the strains of Botrytis cinerea and Rhizopus stolonifer were 64 and 512 mg/ml, respectively. ConclusionThe results of the present study showed that the ethanolic extract of green tea could be considered as potential source of natural antioxidant and antifungal agents. The presence of phenolic and flavonoid compounds may be responsible for the antifungal and antioxidant effects of the extract. However, due to the fact that this study was performed with the crude extract of green tea, it is difficult to identify compounds responsible for antifungal and antioxidant activity. On this point, only the separation of the components of the extract allows the detection of antifungal and antioxidant compounds. This study provides a basis for further researches, in particular the use of these antioxidants and antifungal compounds. Green tea extract is especially suitable for products with high sensitivity to lipid oxidation and infection with molds.
Food Biotechnology
Ehsan Safari; Hassan Barzegar; Hossein Jooyandeh; Behrooz Alizadeh Behbahani; Mohammad Noshad
Abstract
Introduction
The addition of chemical preservatives increases the shelf life of food products, but prolonged and indiscriminate use of chemical preservatives increases the resistance of microorganisms and the health risks associated with theiruptake. Medicinal plants have a wide variety in the ...
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Introduction
The addition of chemical preservatives increases the shelf life of food products, but prolonged and indiscriminate use of chemical preservatives increases the resistance of microorganisms and the health risks associated with theiruptake. Medicinal plants have a wide variety in the world as well as in Iran. In recent years, the use of natural preservatives such as plant extracts and essential oils, due to their importance and role in controlling the growth of pathogenic microorganisms, has been proposed as an alternative to chemical preservatives. Black pepper is an aromatic medicinal plant. The specific properties of black pepper essential oil, such as its antimicrobial and antioxidant activity, have also been confirmed. Amphotericin B is one of the effective antibiotics for treating infections caused by pathogenic fungi. The mechanism of action of amphotericin B is to destroy fungal cells in such a way that by binding to ergosterol in the cell membrane of fungi, it creates pores and eventually destroys them. One of the most important and common antibiotics used in the treatment of infections caused by pathogenic bacteria is chloramphenicol. This antibiotic is effective against gram-positive and gram-negative bacteria due to its broad spectrum. The aim of this study was to identify bioactive functional groups, antioxidant potential, phenol and total flavonoid compounds and to evaluate the antimicrobial activity of black pepper extract against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus coagulans and Aspergillus niger.
Materials and Methods
In this study, the antimicrobial effect of black pepper aqueous extract was investigated against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus coagulans and Aspergillus niger by disc diffusion agar, well diffusion agar, minimum inhibitory concentration, and minimum bactericidal concentration methods. Total phenol and flavonoid contents of the species were determined by Folin-Ciocalteu and AlCl3 assays, respectively. Three biochemical assays, namely 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azinobis 3-ethyl-benzothiazoline-6-sulfonic acid (ABTS) free radical scavenging and β- caroten/linoleic acid activity systems, were used to evaluate antioxidant activity. Identification of functional groups as well as the structure of organic compounds in black pepper extract was also performed by Fourier transform infrared spectroscopy (FTIR). To evaluate the synergistic effect of black pepper extract in combination with amphotericin B and chloramphenicol antibiotics, Sub-MIC was used.
Results and Discussion
The peaks observed in aqueous black pepper extract confirmed the presence of O-H (3000-3500 cm-1), C-H (2800-3000 cm-1), C=O (1613.62-1633.52 cm-1) and C-O (100.57-1038.82 cm-1) functional groups of bioactive compounds. The total phenol and flavonoids content of the extract were 45.12 mg GAE/g extract and its flavonoid content was 29.66 mg QUE/g extract which had an important role in its antioxidant activity. The aqueous black pepper extract had remarkable DPPH free radical scavenging activity (IC50=32.37 μg/ml), ABTS free radical scavenging activity (IC50=28.45 μg/ml) and beta-carotene bleaching inhibitory effect (46.45%), revealing the electron/hydrogen donating ability of the essential oil. The results of measuring the antimicrobial activity of extract by disk diffusion and agar well showed that black pepper extract showed more antimicrobial effect on gram-positive bacteria Staphylococcus aureus and Bacillus coagulans than gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa. This could be due to the difference in their cell wall structure. Aspergillus niger is the most sensitive species to aqueous black pepper extract. The minimum inhibitory concentrations of extract for Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus coagulans and Aspergillus niger were equal to 32, 16, 4, 8 and 4 mg/ml, respectively. The minimum bactericidal concentration of black pepper extract for two bacterial species, Escherichia coli and Pseudomonas aeruginosa was more than 512 mg/ml. Also, the minimum bactericidal concentration for Staphylococcus aureus and Bacillus coagulans was 128 and 256 mg/ml, respectively, and 128 mg/ml for Aspergillus niger. The results of interaction of black pepper extract with chloramphenicol antibiotic showed that the Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus were synergistic, but antagonism was observed for the gram-positive Bacillus coagulans.
Food Engineering
Behnaz Vafania; Milad Fathi; Sabiheh Soleimanian Zad
Abstract
The aim of this research was to investigate the efficiency of nozzle-less electrospinning for encapsulation of ajwain essential oil (as a hydrophobic bioactive) using two hydrocolloids (chitosan/gelatin) in order to enhance its antioxidant properties and stability for food applications. Nanofibers were ...
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The aim of this research was to investigate the efficiency of nozzle-less electrospinning for encapsulation of ajwain essential oil (as a hydrophobic bioactive) using two hydrocolloids (chitosan/gelatin) in order to enhance its antioxidant properties and stability for food applications. Nanofibers were spun using chitosan/gelatin in ratios of 1:6, 1:8 and 1:10 and ajwain concentrations of 20 and 40%. Solution properties (i.e. viscosity and electrical conductivity) were measured. Encapsulation efficiency and loading capacity data illustrated an enhancement with increasing of essential oil concentration. Fibers diameter and morphology were studied by scanning electron microscopy (SEM). The chitosan/gelatin nanofibers with ratio of 1:6 containing 40% essential oil had the highest encapsulation efficiency (99.9%), loading capacity (39.9%) and the smallest diameter (146 nm). Attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) proved that during electrospinning, no any chemical interaction was occurred between ingredients and differential scanning calorimetry (DSC) data showed that essential oil was well encapsulated in nanofibers. Antioxidant properties were analyzed by 2,2-diphenyl-1-picrylhydrazylradical and approved the efficiency of encapsulation for protection of antioxidants.
Food Biotechnology
Mostafa Rahmati-Joneidabad; Behrooz Alizadeh Behbahani; Mohammad Noshad
Abstract
[1]Introduction: Economic losses can occur due to the growth of fungi on foods that lead to food spoilage and plant diseases. Fruits and vegetables are often exposed to microbial activity, caused by pathogenic fungi, during post-harvest storage. Diseases of food origin are a growing public health problem. ...
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[1]Introduction: Economic losses can occur due to the growth of fungi on foods that lead to food spoilage and plant diseases. Fruits and vegetables are often exposed to microbial activity, caused by pathogenic fungi, during post-harvest storage. Diseases of food origin are a growing public health problem. Thus, food safety has become a major public concern as microbial contamination increases the risk of foodborne illnesses and shortens the shelf life of foods. Infection with fungi such as Aspergillus, Rhizopus, and Penicillium species is considered as the primary cause of rapid spoilage of fresh produce, which reduces their quality and shelf life. Synthetic fungicides have been applied to solve this problem for many years. Nonetheless, the adverse effects of synthetic chemicals on human health and the emergence of fungicide-resistant strains have motivated the scientists and food industries to find out safe preservatives to control postharvest rot/diseases. On this point, natural antimicrobial agents such as plant extracts and essential oils are gaining more and more interest. In this study, we used Levisticum officinale Koch essential oil, which its antimicrobial and antioxidant activity has been reported in literatures. Materials and Methods: L. officinale Koch essential oil was obtained by hydrodistillation method and its total phenol content, total flavonoids, antioxidant activity (based on DPPH and ABTS free radical scavenging and β-carotene bleaching tests) and its antifungal effect against fungi causing apple and orange rotting (Alternaria alternata, Penicillium expansum, Penicillium digitatum, Penicillium italicum, and Botrytis cinerea) were examined according to antimicrobial tests of disk diffusion agar, well diffusion agar, minimum inhibitory concentration, and minimum fungicidal concentration. Results and Discussion:L. officinale Koch essential oil contained 61.27 ± 0.34 mg GAE/g and 20.14 ± 0.21 mg QE/g total phenol and flavonoids, respectively. Its antioxidant activity, based on DPPH free radical scavenging, ABTS free radical scavenging, and β-carotene bleaching inhibition were 69.72 ± 0.65%, 78.54 ± 0.3% and 57.50 ± 0.41%, respectively. L. officinale Koch essential oil was effective against all fungal species and the highest susceptibility was observed for Penicillium expansum. According to the results, L. officinale Koch essential oil can be used as a natural antifungal agent to prevent post-harvest diseases of fruits and vegetables.
Food Technology
Zahra Sadri Saeen; Mohammadreza Khani; Vajiheh Fadaei Noghani
Abstract
[1]Introduction: Butter is a type of dairy product made of sweet cream or sour cream. It is a perishable food that can be spoiled due to chemical changes during storage. Rancidity is one of the main problems caused by lipolysis and oxidation of fatty acids, which cause off-flavor and reduce the nutritional ...
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[1]Introduction: Butter is a type of dairy product made of sweet cream or sour cream. It is a perishable food that can be spoiled due to chemical changes during storage. Rancidity is one of the main problems caused by lipolysis and oxidation of fatty acids, which cause off-flavor and reduce the nutritional quality of butter. By adding low concentrations of antioxidant compounds, autooxidation can be prevented or delayed. It is also possible to increase the shelf life of butter by adding antioxidants. However, the carcinogenic effect of some synthetic antioxidants and consumer preference has led manufacturers to use more natural antioxidants. Chia seeds contain significant amounts of protein, fat, carbohydrates, minerals, and vitamins. Moreover, many bioactive compounds with high antioxidant potential are found in chia seeds such as phenolic acids, flavonoids, tocopherols, and sterols. Therefore, the present study was conducted to investigate the effects of chia seed extract in sweet cream butter to improve its chemical and sensory properties during refrigeration storage. Materials and Methods: For this purpose, the alcoholic extract of chia seed was prepared by adding chia seed powder to 70% ethanol (5% w/v) with stirring for 24 h, at room temperature. The filtered extracts were concentrated with a rotary evaporator. The concentrated mixture was dried in an oven at 40 °C and kept in an amber glass container in the refrigerator at 4 °C until the experiment was performed. Total phenolics content and antioxidant activity of chia seed extract were evaluated by the Folin–Ciocalteu colorimetric method using gallic acid as standard and for free radical scavenging ability by DPPH (2,2-diphenyl-1-picryl-hydrazyl) method, respectively. Then, chia seed extract was added to butter with different percentages (0.05, 0.1, 0.25, and 0.5%) and its effects on chemical properties including acidity, acid value, peroxide value, and thiobarbituric acid were evaluated for two months at 15-day intervals in refrigerated storage. Also, sensory properties including color, odor, taste, texture, and overall acceptance of butter samples were assessed using 15 untrained evaluators based on a 5-point hedonic test as above conditions. The results were reported as means± standard deviation and they were analyzed with analysis of variance using the software SPSS version 14. Statistical differences were analyzed by Duncan’s multiple range test (p<0.05). Results and Discussion: The results of total polyphenols content were 1108.78 ± 111.79 mg gallic acid per 100 g of extract and radical scavenging activity of chia seed extract in the concentration range of 4 to 20% was 35.17 ± 0.47 to 64.92 ± 2.95%. Also, the efficient concentration (EC50) of chia seed extract was 12.13 ± 0.59 mg/L in this study. It is known that the smaller the EC50, it will be the greater the antioxidant or free radical scavenging activity. According to the results, it was found that the concentration of chia extract has a significant effect on free radical scavenging (p<0.05) so that with increasing the concentration of the extract, its inhibitory properties increased. The results showed that the addition of different concentrations of chia seed extract and storage time were significant on the acidity and acid value of butter samples so that with increasing the amount of chia seed extract in treatments, the amounts of acidity and acid value increased significantly (p<0.05). Also, the acidity and acid value in all samples of butter increased significantly with increasing storage time during refrigeration (p<0.05). However, the amount of these two indices in treatments containing chia extract increased at a slower rate than the control sample during storage time, which could be due to the effect of phenolic compounds in chia seed extract in controlling the activity of lipolytic enzymes. Moreover, the results revealed that with increasing the concentration of the chia seed extract from the 15th day to the end of the storage period, the amounts of peroxide value and thiobarbituric acid of butter treatments significantly decreased compared to the control sample (p<0.05). This is due to the antioxidant effects of phenolic compounds in chia seed extract that delay the oxidation process. In this study, all chemical indices increased significantly during the storage time (p<0.05). All the samples in evaluated sensory properties were significantly different from the control sample (except odor) during 60 days of storage (p<0.05), in this way treatments had better sensory scores in color and taste properties compared to the control. In general, a concentration of 0.5% chia extract delayed oxidative damage, but in terms of sensory evaluation, a treatment containing 0.25% chia extract is selected and introduced as the most desirable treatment.
Food Chemistry
Seyed Hamidreza Ziaolhagh; Sima Zare
Abstract
Walnuts have a high nutritional value because of their high levels of essential compounds for human health. Phenolic compounds have beneficial properties, including anti-cancer and antimicrobial properties. In this study, the amount of the extracted antioxidants from different parts of walnut, ...
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Walnuts have a high nutritional value because of their high levels of essential compounds for human health. Phenolic compounds have beneficial properties, including anti-cancer and antimicrobial properties. In this study, the amount of the extracted antioxidants from different parts of walnut, including the walnut kernel, hard shell and green husk by ethanol and water was compared with those of the ultrasound-assisted extraction. This study was performed by determining the amount of polyphenols present and the free radical scavenging power of DPPH. The results showed that the effect of all factors was statistically significant at 99% statistical level. The highest rate of extraction of phenolic compounds (1.09 mg Gallic acid/g) and the highest rate of free radical scavenging of DPPH (6.86%) was related to the use of ethanol solvent for extraction. It was also shown that the hard walnut shell has the highest amount of phenolic compounds (1.1 mg Gallic acid per gram of extract) and the walnut kernel has the highest antioxidant properties (7.99%). Ultrasonic pretreatment increased the extraction efficiency of phenolic compounds and antioxidant properties so that this process increased the extraction of phenolic compounds from the green husk of walnut by 1.22 mg Gallic acid/g and increased the antioxidant properties of the kernel walnut by 13.51% compared to other parts.
Elnaz Saffari Samani; Hossein Jooyandeh; Behrooz Alizadeh Behbahani
Abstract
Introduction: Shirazi thyme is a perennial herbaceous plant related to Lamiaceae family growing in central and southern regions of Iran. This study aimed to assess chemical composition, bioactive functional groups, antioxidant potential, total phenol, and total flavonoids of Shirazi thyme essential ...
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Introduction: Shirazi thyme is a perennial herbaceous plant related to Lamiaceae family growing in central and southern regions of Iran. This study aimed to assess chemical composition, bioactive functional groups, antioxidant potential, total phenol, and total flavonoids of Shirazi thyme essential oil (STEO) and also to evaluate its cell toxicity effect against the colorectal cancer cell line (HT29). Materials and Methods: The chemical composition of STEO was identified by gas chromatography-mass spectrometry. The bioactive functional groups of STEO were measured by Fourier transform infrared at spectra range of 500- 4000 cm-1. The total phenol and total flavonoids of STEO were determined by folin- ciocalteu and aluminum chloride colorimetric method, respectively. MMT method was performed to measure the cell toxicity of STEO against the colorectal cancer cell line (HT29). The cells were cultured on DMEM high glucose medium supplemented with 10% fetal bovine serum and penicillin/streptomycin and incubated at 37°C with 95% relative humidity and 5% CO2 concentration. The antioxidant activity of STEO was evaluated by DPPH and ABTS free radicals scavenging assays. Duncan test at 5% probability and SPSS software (version 18) was performed to compare the means of obtained results. Results and Discussion: Based on GC/MS spectrometry, a total of 29 constituents were identified and quantified in the STEO representing more than 99% of total constituents. Thymol with 39.3% and Carvacrol with 30% were the most constituents of STEO. The other major compound of STEO were Benzene (8.52%), γ-Terpinene (5.27%), and Caryophyllene (2.97%). The presence of peak at a wavelength of 320- 1000 cm-1 demonstrates O-C bound that could be related to organic compounds such as alcohols, carboxylic acids, esters, and ethers. The peaks occurred at spectral range between 2800- 3000 cm-1 (particularly at 2869.6 up to 2960.8 cm-1) are related to the stretching mode of C-H bounds and are mostly associated with alcoholic compounds in the essence. The amount of total phenol and flavonoids of STEO were 64.05 mg gallic acid equivalent/g and 11.68 mg quercetin equivalent/g, respectively. Results obtained from antioxidant activity of STEO with DPPH and ABTS free radicals scavenging showed that by increasing of STEO, the inhibition level of free radicals was enhanced. The inhibition percent of free radicals by using DPPH and ABTS at 1000 ppm concentration were 63.69% and 64.33%, respectively. The cell toxicity results of different STEO concentrations against the cell line HT29 revealed that survival of HT29 cells at 1, 3.125, 6.25, 12.5, 25, 50, 100 and 200 ppm of STEO were 100, 70.15, 61.19, 59.33, 38.83, 25.68, 20.65 and 12.2%. According to the results of this study, as the concentration of STEO increased, its effect on the cell line HT29 enhanced and the cell percentage viability decreased. Some antioxidant activity of STEO could be interrelated to its phenolic compounds. Based on the results of antioxidant activity, the amount of total phenol and flavonoids and the effect of STEO on cell toxicity against the cell line HT29, it seems that the use of STEO is applicable in the pharmaceutical and food industries
Sara Forouzandeh; Mohammad Fazel
Abstract
[1]Introduction: Nowadays, various methods have been developed to transfer and improve the absorption of lipophilic compounds in food in the form of coating. Colloidal emulsion-based systems are widely used in commercial systems. Chia seed oil is an oil rich in unsaturated fatty acids, especially omega ...
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[1]Introduction: Nowadays, various methods have been developed to transfer and improve the absorption of lipophilic compounds in food in the form of coating. Colloidal emulsion-based systems are widely used in commercial systems. Chia seed oil is an oil rich in unsaturated fatty acids, especially omega 3 and omega 6, which can be used as the oily phase of nanoemulsions. The aim of this study was to investigate the fatty acid composition of chia seed oil and the effect of oil to water ratio and emulsifier on the properties of nanoemulsions of this oil. Materials and Methods: Clean chia seeds were purchased as a pack from Zistfa Company and all other chemicals were purchased from Marack, Pars Shimi and Dr. Majelli companies. By using the oil set machine, the seeds were treated by cold pressing method and oil extraction efficiency was calculated .Gas chromatography (GC) was used to identify and measure the fatty acid composition of chia seed oil. In this study, nanoemulsions were produced in three levels of oil to water (20%, 35% and 50%) and in three levels of oil emulsifier (5%, 10% and 15%).To produce nanoemulsions, the aforementioned ratios were first calculated and determined .Then, Weigh the tweens 20 and 80 with chia seed oil and water and mix the emulsifiers with the chia seed oil on the stirrer. Then a mixture of 20 and 80 tweens and oil was added dropwise to the weighed distilled water. The mixture was stirred gently by a magnet. After this step, the mixture is placed in the refrigerator to reduce its temperature. After this time, it was placed in an ice bucket and placed in an ultrasonic homogenizer for 9 minutes at a power of 300 watts to form nanoemulsions. Then, the properties of nanoemulsions including particle size and distribution, coating efficiency and antioxidant properties were evaluated. Vasco model DLS (Dynamic light scattering) was used for the particle size. The particle size of nanoemulsions was determined by this device using dynamic light diffraction method. DPPH method was used to measure the antioxidant activity of oils and nanoemulsions and the antioxidant activity was calculated by using the formula. To evaluate the efficiency of coating of nanoemulsions, the amount of surface oil and total oil was measured and the efficiency was calculated by using the formula. The release rate of nanoemulsions was evaluated for 7 weeks. The tests were performed in three replications. Experimental data were analyzed in a completely randomized design with factorial test and Duncan test was used to compare the mean data. Software (Excel, 2010) was used to draw the graphs Results and Discussion: According to the results obtained in this study, it can be said that chia seed oil contains a high percentage of unsaturated fatty acids and has a very high level of antioxidant properties (88.43%), which has antioxidant properties in the structure of nanoemulsions. Oil is better preserved in water. Other results showed that with increasing oil content of nanoemulsions, particle size, antioxidant properties and release increased and the coating efficiency decreased. Also, by increasing the ratio of emulsifier to oil in nanoemulsions, the coating efficiency and antioxidant properties increase and the particle size and release decreases. In the results obtained from these tests, the minimum particle size was 14.08 nm and the highest coating efficiency was 96.40%. The antioxidant activity of the samples was evaluated in the range of 5.61% to 21.43%. Also, the average release of samples at the end of 7 weeks of the study reached nearly 18%. During storage, the treatments were quite stable for five months, which could be due to the low particle size and low release of samples. Considering the mentioned advantages, using nanoemulsions of this oil is a suitable option for enriching beverages.
Food Biotechnology
Mostafa Rahmati-Joneidabad; Behrooz Alizadeh Behbahani
Abstract
Introduction: Apple fruit is highly susceptible to fungal spoilage by Penicillium, Botrytis, and Alternaria species. Currently, the use of synthetic fungicides is considered to be the most accessible method of managing and controlling post-harvest diseases of vegetables and fruits, especially apples. ...
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Introduction: Apple fruit is highly susceptible to fungal spoilage by Penicillium, Botrytis, and Alternaria species. Currently, the use of synthetic fungicides is considered to be the most accessible method of managing and controlling post-harvest diseases of vegetables and fruits, especially apples. However, increasing concern about environmental pollution, the toxicity, and the resistance of fungal pathogens to synthetic fungicides have resulted in an increased demand for less dangerous methods. In this regard, the use of compounds of natural origin that have potential antifungal activity (such as herbal essential oils), can be an effective solution to control and prevent post-harvest diseases of vegetables and fruits. In this study, the potential antifungal activity of Thymus daenensis essential oil was evaluated against fungi species causing apple rot (i.e., Penicillium expansum, Alternaria alternata, and Botrytis cinerea). The chemical compounds, total phenol and flavonoids content, and antioxidant activity of the essential oil were also determined. Materials and Methods: In this study, the essential oil of T. daenensis was extracted by the hydrodistillation method and its main chemical compounds were identified and quantified by gas chromatography coupled to mass spectrometry apparatus. Total phenols and flavonoids content of the essential oil were measured using the Folin-Ciocalteu and Aluminum chloride colorimetric methods, respectively. The in-vitro antioxidant activity of T. daenensis essential oil was evaluated based on the DPPH/ABTS free radical scavenging activity, beta-carotene bleaching, and ferric reducing antioxidant power (FRAP) assays. The antifungal effect of the essential oil against Penicillium expansum, Alternaria alternata, and Botrytis cinerea was investigated by the disk diffusion agar (DDA), well diffusion agar (WDA), minimum inhibitory concentration (MIC), and minimum fungicidal concentration (MFC). Results and Discussion: The T. daenensis essential oil was rich in thymol (69.88%), γ-terpinen (8.49%), p-cymene (8.20%), and carvacrol (3.55%). In addition, the total phenol and flavonoids content of the essential oil were 91.45 mg GAE/g and 42.28 mg QE/g, respectively, which had an important role in its antioxidant activity. The T. daenensis essential oil had remarkable DPPH free radical scavenging activity (IC50= 29.30 mg/ml), ABTS free radical scavenging activity (IC50 = 22.68 mg/ml), beta-carotene bleaching inhibitory effect (62.22%), and ferric reducing antioxidant power (30.10 μM QE/g), revealing the electron/hydrogen donating ability of the essential oil. Antifungal results showed that P. expansum was the most sensitive fungi species to the essential oil and lower concentrations of the essential oil were required to inhibit the growth of or kill the species, due to the presence of phenolic compounds (such as thymol and carvacrol) in the oil. Indeed, reactive aromatic nucleus and phenolic OH groups in the structure of phenolic compounds can form hydrogen bonds with –SH groups at the active sites of target enzymes, leading to the deactivation of the fungal enzymes. In addition, the lipophilic nature of the essential oils makes them to be highly absorbed by the lipophilic mycelia and consequently suppress the growth of fungi species. Based on the results, the T. daenensis essential oil could be used as a natural antifungal agent and synthetic fungicide substitute to prevent the growth of pathogenic fungi on apple fruit or other food products and increase their shelf-life.
Food Biotechnology
Rana Tahmasbi; Mahta Mirzaei; Mohammadreza Khani
Abstract
Introduction: Fermented foods, probiotic, prebiotics, and symbiotic, are among the most important groups of functional food that have attracted the attention of researchers during the last years. Proteolytic activity of lactic acid bacteria can lead to the production of peptides in the fermented product. ...
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Introduction: Fermented foods, probiotic, prebiotics, and symbiotic, are among the most important groups of functional food that have attracted the attention of researchers during the last years. Proteolytic activity of lactic acid bacteria can lead to the production of peptides in the fermented product. The produced peptides can exhibit different biological activities such as antioxidant, antihypertensive, etc. that are influenced by the type of protein source, type of bacteria, time and conditions of fermentation process. Fermentation of various cereals such as quinoa seeds with high sugar and protein content by lactic acid bacteria can lead to the production of antioxidant peptides and improving their nutritional properties. Materials and Methods: In this study, the role of Lactobacillus reuteri and Lactobacillus acidophilus and the combination of two bacteria on the progress of fermentation and antioxidant activity of quinoa extract was investigated. The fermentation process was started by separate and simultaneous inoculating of Lactobacillus reuteri and Lactobacillus acidophilus and continued for 72 hours at 37° C. Sampling was performed every 24 hours of fermentation and samples were kept at -20° C for further analysis. The parameters such as pH, acidity, amount of soluble protein, degree of hydrolysis, amount of phenolic compounds and DPPH and ABTS radical scavenging activity were determined. Results and Discussion: Lactobacillus acidophilus showed higher acidification capacity than Lactobacillus reuteri. The amount of acidity in the sample fermented by Lactobacillus acidophilus increased from 0.27 to 1.13 % after 72 hours, while this amount was measured as 0.80 % for sample fermented by Lactobacillus reuteri. The amount of soluble protein and the degree of hydrolysis increased in samples fermented by both species. However, the largest increase was related to the sample fermented by Lactobacillus reuteri, so that the amount of soluble protein increased from 0.72 to 0.88 mg / ml and the value of free amino groups increased from 20.28 to 58.14 µM leucin/ mg protein during 72 hours of fermentation. The DPPH and ABTS radical scavenging activity increased in all fermented samples. The highest antioxidant activity was observed in samples fermented by Lactobacillus reuteri, followed by a combination of two bacteria (50:50) and Lactobacillus acidophilus. The amounts of phenolic compounds increased in all fermented samples. However, the highest increase was related to the sample fermented by Lactobacillus reuteri, so that it increased from 0/73 to 16.21 mg Gallic acid / ml after 72 hours of fermentation. Therefore, the results showed that despite the higher acidifying power of Lactobacillus acidophilus in quinoa extract, but Lactobacillus reuteri exhibited higher proteolytic activity, more ability to produce antioxidant peptides and also release phenolic compounds during the fermentation process.Simultaneous use of the two bacteria did not intensify the proteolytic activity and antioxidant activity of peptides, and the greatest increase in acidity, proteolysis, and antioxidant activity occurred in the first 24 hours of fermentation. Fermented extracts showed higher ABTS radical inhibitory activity than DPPH radical inhibition, indicating the hydrophilic nature of most produced antioxidant compounds. The highest levels of antioxidant activity were observed in samples fermented by Lactobacillus reuteri, a combination of Lactobacillus reuteri and Lactobacillus acidophilus (50:50) and Lactobacillus acidophilus, respectively. The results showed that fermentation by Lactobacillus reutri has the greatest effect on the production of antioxidant peptides and the release of phenolic compounds. The results of this study confirm the effectiveness of fermentation methods on improving the healing properties of quinoa extract and Lactobacillus reuteri was a more effective bacterium in fermentation and production of antioxidant peptides compared to Lactobacillus acidophilus. Simultaneous use of two bacteria did not increase the intensity of fermentation and did not improve the antioxidant activity compared to single use of each bacteria. Finally, the results of this study showed that fermentation of quinoa extract improves its antioxidant properties and has the potential to be used as a fermented beverage.
Food Technology
Fahimeh Hajinia; Alireza Sadeghi; Alireza Sadeghi Mahoonak; Morteza Khomeiri; Yahya Maghsoudlou; Ali Moayedi
Abstract
Introduction: Bread is the main source of nutrients and it is a cheap staple food in the daily diet of people in many parts of the world. One of the most important ways to improve the quality of bread is to ferment cereals and use fruit resources. Cereal fermentation has a well-known potential to improve ...
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Introduction: Bread is the main source of nutrients and it is a cheap staple food in the daily diet of people in many parts of the world. One of the most important ways to improve the quality of bread is to ferment cereals and use fruit resources. Cereal fermentation has a well-known potential to improve the nutritional properties of the baked goods. It stabilizes the levels of various bioactive compounds, retards starch retrogradation and increases mineral bioavailability. A diet rich in cereal and fruit-based products could improve human health. Oat grain has a high functional potential due to its composition. This grain is known to be an excellent source of dietary fiber, antioxidants and a well-balanced protein fraction. Jujube fruit is also getting popularized due to the high content of vitamins, phenolic, polysaccharides and natural colorant agents. The quality of available commercially jujube depends on the contents of its bioactive compounds and micronutrients. There is no report about simultaneous application of fermented oat and jujube powder in processing of wheat bread. Accordingly, the aims of this study were to produce a supplemented wheat bread containing these ingredients, and evaluate the textural and antioxidant properties of the product. Materials and methods: In the present study, controlled fermented oat containing selected LAB isolated from oat sourdough (as starter culture) was used to produce supplemented wheat bread. Crumb hardness, porosity, specific volume, overall acceptability and antioxidant activity in wheat bread containing fermented oat, jujube powder and their mixture were investigated in comparison with the control (wheat bread). All the experiments were done in triplicates. A complete randomized design with the least significance difference (LSD) post-hock was also used to statistical analysis of the data at p < /em>< 0.05 by SPSS (version 20) software. Results and Discussion: The highest amount of crumb hardness was observed in the sample containing mixture of controlled fermented oat and jujube powder, meanwhile the lowest amount of hardness was belonged to the control sample. The results of specific volume showed an inverse relationship between the values of hardness and specific volume, and the lowest specific volume was observed in sample containing controlled fermented oat along with jujube powder. The highest amount of specific volume was also observed in the control sample. The porosity of all the produced breads was also significantly (p < /em><0.05) higher than the control sample, and the highest porosity was observed in the sample containing controlled fermented oat. The amount of produced gaseous compounds and carbon dioxide during fermentation affect the porosity of the produced bread. Furthermore, water retention capacity is also involved in increase in bread specific volume. Water reduces the stiffness of protein structures and allows better air to enter the dough texture and more specific volume of the product. Wheat breads containing controlled fermented oat + jujube powder and jujube powder (alone) had the highest antioxidant activity, and the control sample had the lowest antioxidant activity. During fermentation, the amount of phenolic compounds or flavonoids increases, and fermentation also causes the synthesis or release of various compounds that have antioxidant properties. Characterization of wheat bread containing the optimal formulation of controlled fermented oat and jujube powder didn’t show significant effect on the overall acceptability of the product. The presence of fiber in fortified breads is likely to increase water uptake, which in turn increases water retention capacity, reduces dough stability and increases overall acceptability. Fruits and whole grains are rich in phytochemicals such as phenolic compounds. Application of phenolic compounds in bread processing, in addition to improve antioxidant properties, affects the physicochemical properties of the dough and the quality characteristics of the produced bread due to various interactions with flour compounds such as gluten and starch. Accordingly, the combined use of plant-rich resources such as jujube powder and fermented oat, which are rich in minerals and micronutrients, can be used to improve the nutritional and quality characteristics of the supplemented wheat bread as a simple and efficient method. Due to the adverse effects of chemical additives and improvers, the importance of providing natural alternatives such as fermented substrates and plant resources in wheat bread processing is quite necessary. The best alternatives for this purpose include sourdough and fiber-rich plant. Wheat bread containing a mixture of controlled fermented oat and jujube powder had the highest crumb hardness and the lowest specific volume. Antioxidant activity in all samples was significantly higher than the control sample and wheat bread containing a controlled fermented oat and jujube powder with 90.52% had the highest amount of antioxidant activity. According to the results, controlled fermented oat and jujube powder, as functional ingredients, may be successfully incorporated into the wheat bread with positively effects on its quality characteristics.
Food Chemistry
Mohammad Taghi Golmakani; Gholam Reza Mesbahi; Nasireh Alavi; Azita Hosseinzade Farbudi
Abstract
Introduction: Food wastes and losses are produced during all phases of food life cycles. The highest wastes belong to the processing of fruits and vegetables. Bioactive compounds have the potential to be extracted from the by-products of fruits and vegetables which can be used in the food processing. ...
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Introduction: Food wastes and losses are produced during all phases of food life cycles. The highest wastes belong to the processing of fruits and vegetables. Bioactive compounds have the potential to be extracted from the by-products of fruits and vegetables which can be used in the food processing. Extraction of flavor compounds, phenolic compounds, enzymes, and organic acids from wastes of fruits – pomace, peel, and seeds of citrus fruits, pomace and leave of apple, seeds of grape, and peel of kiwifruit – and vegetables – pomace of carrot, husk of garlic, skin of onion, peel of potato, and skin of tomato – have been reported (Sagar et al., 2018).Sour orange, Citrus aurantium, is one of the species of citrus fruits. Sour orange seeds contain fats, protein, and bitter compounds which affect citrus processing (Ye et al., 2017). Naringin, neohesperidin, flavon, caffeic acid, p-coumaric acid, ferulic acid, and sinapic acid have been detected in methanolic extract of sour orange seeds (Bocco et al., 1998).Bioactive compounds are recovered from food wastes through various conventional and novel extraction techniques. Microwave-assisted extraction is one of the most used novel and environmentally friendly extraction methods. Advantages of microwave-assisted extraction over conventional extraction techniques include automated operation, more effective and selective heating, and less extraction time (Vinatoru et al., 2017).The objective of this study was optimization of microwave-assisted extraction of sour orange seed coat extract in terms of microwave power level, extraction time, sample quantity, and solvent volume on yield, bioactive compounds (total phenolic content and total flavonoid content), and antioxidant activity (free radical scavenging activity, ferric ion reducing antioxidant power, cupric ion reducing antioxidant capacity, and ferrous ion chelating). Also, optimum conditions of microwave-assisted extraction was compared to that of conventional magnetic stirrer-assisted extraction method. Materials and methods: Sour orange seeds were purchased from Limondis Company (Beyza, Fars province, Iran). Microwave-assisted extraction conditions including microwave power level (100, 200, and 300 W), extraction time (5, 10, and 15 min), sample quantity (5, 10, and 15 g), and solvent (methanolvolume 100, 150, and 200 mL) were optimized. Yield, bioactive compounds (total phenolic content (Habibi et al., 2015) and total flavonoid content (Habibi et al., 2015)), and antioxidant activity (free radical scavenging activity (Habibi et al., 2015), ferric ion reducing antioxidant power (Rekha et al., 2012), cupric ion reducing antioxidant capacity (Pascu et al., 2014), and ferrous ion chelating (Oyetayo et al., 2009)) of sour orange seed coat extract were evaluated. After determining the optimum conditions of microwave-assisted extraction, yield, bioactive compounds (total phenolic content and total flavonoid content), and antioxidant activity of sour orange seed coat extract were compared to those of conventional magnetic stirrer-assisted extraction method. Design Expert software (Version 10, Stat-Ease, Minneapolis, MN) was employed for analyzing four variables – microwave power level, extraction time, sample quantity, and solvent volume – at three levels consisting 30 experimental runs. Response surface methodology concerning central composite design (6 center points, quadratic model, and face center = 1) was applied. Results and discussion: Optimum conditions of microwave-assisted extraction were microwave power level of 200 W, extraction time of 12 min, sample quantity of 5 g, and solvent volume of 200 mL. Under optimum conditions, yiled, total phenolic content, total flavonoid content, IC50, ferric ion reducing antioxidant power, cupric ion reducing antioxidant capacity, and ferrous ion chelating were11.57%, 15550.50 µg gallic acid equivalent/g, 1476.22 µg quercetin equivalent/g, 11.33 mg/mL, 7.12 mg ascorbic/g, 6.44 mg ascorbic acid/g, and 0.43 mg EDTA/g, respectively. Intermediate microwave power level (200 W) can be more suitable from an industrial perspective and energy consumption (Jokić et al., 2012). Further increase in microwave power level, i.e. higher than 200 W, causes thermal degradation of bioactive compounds (Dahmoune et al., 2013), decreasing total phenolic content, total flavonoid content, and antioxidant activity of sour orange seed coat extract. The highest extraction time gives the bioactive compounds a chance to diffuse and release from the cell matrix to the surrounding environment (solvent). The highest solvent volume was selected as the optimum extraction condition. By increasing solvent volume up to 200 mL, meaning a greater gradient in bioactive compound concentration, mass transfer was also improved (Dahmoune et al., 2013). Also, the minimum sample quantity (5 g) was determined in optimum conditions. Increasing sample quantity (while the solvent volume remained constant) reduces the surface area available for the solvent to penetrate the sample matrix. As a result, higher sample quantity caused lower extraction of bioactive compounds (Ballard et al., 2010). There were no significant differences between yield, bioactive compounds, and antioxidant activity of extract obtained by conventional-assisted extraction method in comparison with those of microwave-assisted extraction. In conclusion, microwave-assisted extraction, as a green and fast method, can be proposed as a suitable and practical method for extraction of bioactive compounds from sour orange seed coat.
Food Biotechnology
Sahar Roshanak; Behrooz Alizadeh Behbahani; Fakhri Shahidi; Farideh Tabatabaei Yazdi; Alireza Vasiee; Neda Hashemi
Abstract
Usage of natural products like herbals, provide unlimited opportunities for novel and suitable additives. Mocheh can be used in fresh form or as an ingredient in soup and salad. This study was aimed to determine the antimicrobial and antioxidant activities of Mocheh (Lepidium draba) extract. The antimicrobial ...
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Usage of natural products like herbals, provide unlimited opportunities for novel and suitable additives. Mocheh can be used in fresh form or as an ingredient in soup and salad. This study was aimed to determine the antimicrobial and antioxidant activities of Mocheh (Lepidium draba) extract. The antimicrobial activity of Mocheh extract was tested against Bacillus subtilis, Pseudomonas aeruginosa, Staphylococcus aureus and Aspergillus niger. The extract showed a strong antimicrobial activity with a concentration dependence and a broad antimicrobial spectrum for all tested microorganism species. The results showed that MIC of leaf extract of Lepidium draba on Aspergillus niger, Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus was 128, 128, 128 and 128 mg/mL respectively. The results showed that MBC/MFC of leaf extract of Mocheh on the examined microorganisms was 256, 256, 256 and 256 mg/mL respectively. The values obtained for total flavonoid content and total phenolic contents were 22.13 µg/mL and 18.88 mg/mL, respectively. Measured value in the radical scavenging activity was IC50= 168/21 µL/mL. The results showed that Mocheh leaf aqueous extract is a novel source of natural antimicrobial and antioxidant agents for the food and pharmaceutical industries.
Food Biotechnology
Bahareh Majdi; Mohammad Amin Mehrnia; Hassan Barzegar; Behrooz Alizadeh Behbahani
Abstract
Introduction: Antioxidants by Quenching free radicals and preventing lipid oxidation, retard spoilage, discoloration and rancidity of foods. Due to adverse effects of synthetic antioxidants such as carcinogenicity and liver injury, consumers’ attention toward natural antioxidants are increasing. ...
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Introduction: Antioxidants by Quenching free radicals and preventing lipid oxidation, retard spoilage, discoloration and rancidity of foods. Due to adverse effects of synthetic antioxidants such as carcinogenicity and liver injury, consumers’ attention toward natural antioxidants are increasing. Turmeric (Curcuma longa) is a medicinal plant frequently used in food industry and pharmacology. In this research, chemical composition, structure and type of bond, antioxidant capacity, total phenol, flavonoid and cytotoxic effect of Turmeric essential oil (TEO) on colorectal cancer cells (HT29) were investigated. Materials and methods: TEO was extracted using Clevenger apparatus by aqueous distillation method. To identify chemical composition, 1 µl essential oil was injected in gas chromatography-mass spectrometry and essential oil composition and quantity were determined by comparing with standards. Functional groups and qualitative identification of turmeric essential oil were done using Fourier-transform infrared spectroscopy (FTIR) in range of 500 – 4000 cm-1. Antioxidant capacity of TEO was determined suing ABTS, DPPH and β-carotene/linoleic acid bleaching assay. Total phenol and flavonoid were measured by colorimetric methods. MTT test was used to find cytotoxic concentrations of TEO on colorectal cancer cell line (HT29). Results and discussion: The 18 compounds identified in TEO accounted for 97.91% and the highest compound was turmerone by 40%. The other compounds were curlone, zingiberene and benzene with 34, 8.30 and 4.18% respectively. Infrared spectrum in range of 3600-3400 cm-1 (specially 3516 cm-1) and peaks at 2930, 1621, 1515 and 1447 cm-1 were due to stretching vibration of O-H, C-H, C=O, C=C bonds of aromatic ring and aromatic groups of curcuminoids. 1515 cm-1 peak was due to stretching vibration of C=O bond of sesquiterpenes (turmerone). Observed peaks at 1378 and 1308 cm-1 confirmed the presence of alkanes or bending vibrations of CH3 groups in curcuminoids (curcumin). Antioxidant potential of TEO according to DPPH and ABTS methods and β-carotene bleaching assay was 25.15, 93.90 and 72.76 %, respectively. Total phenol and flavonoid content of TEO were 38.91 mg GAE/g and 87.9 mg QE/g. The results showed that by increasing essential oil concentration from 3.125 to 200 mg/mL survival rate of HT29 changed from 66.76 to 9.88%.
Mohammad Hojjati; Behrooz Alizadeh Behbahani
Abstract
Introduction: There is a remarkable interest in developing natural antimicrobial compounds of essential oils and plant extracts origin, due to the increase of bacterial resistance to common antibiotics. On the other hand, lipid oxidation in raw or processed materials leads to food rancidity and deterioration. ...
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Introduction: There is a remarkable interest in developing natural antimicrobial compounds of essential oils and plant extracts origin, due to the increase of bacterial resistance to common antibiotics. On the other hand, lipid oxidation in raw or processed materials leads to food rancidity and deterioration. In this way, synthetic antioxidants such as butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA) are used to prolong the storage stability of food products. Nevertheless, the toxicologists and nutritionists have documented the side effects and potential toxic effects of synthetic antioxidants. Herbs contain a wide variety of phenolic compounds such as phenolic acids, flavonoid, tannins and so forth. These bioactive compounds could be therefore used as natural antioxidants and antimicrobial agents to suppress lipid oxidation and food spoilage. In this context, Allium jesdianum extracts were obtained and their antioxidant and antimicrobial activities were investigated. Materials and methods: A. jesdianum was exposed to methanolic and aqueous maceration-based extraction methods to extract its bioactive compounds with positive biological activity. The extraction yield, total phenolic compounds, antioxidant activity (based on DPPH and ABTS radical scavenging activity), and antimicrobial activity (based on disc diffusion agar, minimum inhibitory concentration, and minimum bactericidal concentration methods) of the methanolic and aqueous extracts were evaluated and compared to each otherr. Results and discussion: The methanolic extract of A. jesdianum had higher extraction yield of 7.1±0.2% compared to the aqueous extract with 4.6±0.28% extraction yield, mainly due to the ability of methanol to extract both nonpolar and semi-polar compounds. The total phenolic compounds of the methanolic extract were also remarkably higher than the aqueous counterpart (88.28% vs. 68.29% mg gallic acid/g dried extract), indicating that the solvent type plays a significant role in extracting bioactive compounds. However, the aqueous extract was able to significantly scavenge DPPH and ABTS radicals compared to the methanolic extract. This means that the presence of phenolic compounds is not the only factor affecting the antioxidant activity of plant extracts. The bioactive extracts of A. jesdianum were able to suppress the growth of or kill the examined bacteria P. aeruginosa, E. coli, E. aerogenes, L. innocua, and S. pyogenes; and this effect was more pronounced in the methanolic extract. Therefore, A. jesdianum methanolic and aqueous extracts could be used as natural preservatives to improve the oxidative stability of food products rich in unsaturated fatty acids, and to inhibit the growth of spoilage and pathogenic microorganisms, treat infections, and increase the safety of food products.
Forouzan Jalali-zand; Mohammad Goli
Abstract
Introduction: Microencapsulation is represented as a technology of packaging solids, liquids, or gaseous materials in miniature sealed capsules that can release their contents at controlled speeds under specific conditions. The packaged materials can be pure materials or a mix, which are also called ...
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Introduction: Microencapsulation is represented as a technology of packaging solids, liquids, or gaseous materials in miniature sealed capsules that can release their contents at controlled speeds under specific conditions. The packaged materials can be pure materials or a mix, which are also called coated material, core material, actives, internal phase (Fang & Bhandari, 2010). Selenium is a micronutrient essential element for human health, which is toxic in high concentrations. Selenium is a component of selenoproteins that plays an enzymatic and structural roles in human biochemistry. Selenium is known as an antioxidant and catalyzer for active thyroid hormone production. The aim of this study was to optimize the microencapsulation of sodium selenite (100-900 mg per 20 mL final spray solution) using a combination of Arabic gum (25-29% per 20 mL final spray solution) and Persian gum (1-5% per 20 mL final spray solution) as capsule wall applying modified solvent evaporation method to produce microcapsules with the highest encapsulation efficiency (EE) and the smallest possible particle size using the response surface method (RSM) with central composite design (α = 2 with 6 central points and 2 repetition in axial and factorial points). Materials and Methods: In this research, production of encapsulated sodium selenite at different concentration (100, 300, 500, 700 and 900 mg/20 cc) with Arabic gum (25%, 26%, 27%, 28% and 29%) and Analogous Farsi gum (5%, 4%, 3%, 2% and 1%) as wall materials by solvent evaporation method was studied. The optimization of microcapsules based on the highest encapsulation efficiency and smallest microcapsules size was studied using RSM. Based on the mentioned parameters, 2 optimum conditions were chosen. The first one was a condition where the samples produced with 135 mg sodium selenite in 20 ml sprayed solution, 27% and 3% Arabic and Farsi gum, respectively. In this condition the encapsulation efficiency was 79.63% whereas the microcapsules size was 49.98 µm. The second condition was followed by producing samples with 109 mg sodium selenite in 20 ml sprayed solution, 28% and 2% Arabic and Farsi gum with result of 95.10% encapsulation efficiency and the size of 46.71 µm. Finally 390 ppm capsules of the first condition and 480 ppm capsules of second condition (equal to 8.6 ppm sodium selenite salt), synthesized BHA (200 ppm) and sodium selenite salt (8.6 ppm) were added to a free anti-oxidant soybean oil and were kept at 55°C at 0, 23 and 46 days which was equal with 20°C at 0, 180 and 360 days. In this condition, peroxide value, acidity, Thiobarbituric acid, Anisidine value, Totox value and anti-oxidant activity of free anti-oxidant soybean oil were evaluated using SPSS software. Results & Discussion: The results achieved by RSM showed that sodium selenite concentration had reverse relation on encapsulation efficiency whereas there was direct relation with Arabic and Farsi gum concentration. Also the size of microcapsules with had direct relation on sodium selenite concentration whereas Arabic and Farsi gum concentration had reverse relation. The result of SPSS analyses showed that with presence of the encapsulated sodium selenite anti-oxidant and synthesized BHA anti-oxidant in soybean oil, peroxide value, acidity, Thiobarbituric acid, Anisidine value, Totox value decreased whereas anti-oxidant activity of soybean oil increased. Based on anti-oxidant characteristics in soybean oil, recommended treatments in this research are: condition 2 ˃ condition 1 ≥ BHA ˃ sodium selenite salt ˃ control sample without anti-oxidant. The results of this study recommend the incorporation of encapsulated sodium selenite (condition 1 and 2) for increasing the shelf life of soybean oil as an alternative to synthesized BHA.
Azadeh Mardani Ghahfarokhi; Reza Farhoosh; Ali Sharif
Abstract
Introduction: Hydroxybenzoic acids are a large family of phenolic acids capable of inhibiting one of the most destructive reactions called lipid oxidation. Their antioxidant activities are markedly influenced by the number and position of phenolic OH groups. Increasing the number of electron-donating ...
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Introduction: Hydroxybenzoic acids are a large family of phenolic acids capable of inhibiting one of the most destructive reactions called lipid oxidation. Their antioxidant activities are markedly influenced by the number and position of phenolic OH groups. Increasing the number of electron-donating groups in the molecule and their placement at the ortho and/or para positions of the phenolic ring, could lead to the increased ability of H atom abstraction or electron donating capacity. Gentisic (3,5-dihydroxybenzoic acid) and Alpha-resoecylic (2,5-dihydroxybenzoic acid) acids are dihydroxybenzoic acids wildly dispersed in the plant tissues with some valuable biological and pharmacological properties for human health. These compounds are different in structure and position of hydroxyl groups in phenolic ring, that may had a strong influence on their antioxidant properties. In addition of structural property, environmental interference can play an important role in the antioxidant potency. Antioxidants are found to behave differently when used in different media.
Materials and methods: Partition coefficient (log P) of Gentisic acid and Alpha-resorcylic acid was measured between 1-octanol and acetate buffers. Antiradical and antioxidant activity of compounds was investigated in different medium (solvent system, purified bulk olive and soybean oils and their O/W emulsions). DPPH radical scavenging activity of gentisic acid and alpha-resorcylic acid was measured in the methanolic solvent. Progress of lipid oxidation in olive oil and soybean oil containing 200 ppm of the antioxidants at 80 oC was followed by monitoring the changes in peroxide value (PV). PV was measured spectrophotometrically at 500 nm using a UV– Vis instrument. Oxygen depletion in emulsion systems in the absence and present of the antioxidant (200 ppm) was measured using a YSI Model 5300A biological oxygen monitor at 37oC. The effectiveness of the antioxidants in bulk oils and emulsions was estimated on the basis of the induction period (IP).
Results and discussion: The obtained results indicated that the effectiveness of the Gentisic and - resorcylic acids in free radicals scavenging, was greatly affected by molecular structure of these antioxidants and environmental conditions.
Ortho position of hydroxyl group with respect to the carboxyl group in Gentisic acid, caused higher antiradical potency of Gentisic acid than α-resorcylic acid, with meta-structure, in different used mediums.
In addition, it was found that the environment plays an important role in the free radical scavenging activity of phenolic compounds. Gentisic acid with more hydrophilic structure showed better antioxidant activity in bulk oil hydrophobic systems, than emulsion systems, while -resorcylic acid with less hydrophilic structure showed better activity in O/W emulsions. Both antioxidants showed low antioxidant performance in solvent system. The polar medium of the methanol used in DPPH assay, with enhanced intermolecular hydrogen bonds, decreased the radical scavenging potency of antioxidants.
Makan Delfanian; Mohammad Hossein Hadad Khodaparast; Seyed Mohammad Ali Razavi; Reza Esmaeilzadeh kenari
Abstract
The central composite rotatable design by response surface methodology was applied for optimization of ultrasonic extraction conditions of Bene hull (Pistacia atlantica subsp. Mutica) polyphenols. The sonication time, temperature and ethanol-water ratio were independent parameters studied for the extraction ...
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The central composite rotatable design by response surface methodology was applied for optimization of ultrasonic extraction conditions of Bene hull (Pistacia atlantica subsp. Mutica) polyphenols. The sonication time, temperature and ethanol-water ratio were independent parameters studied for the extraction optimization. Total polyphenols and antioxidant potentials of extracts in terms of ferric reducing antioxidant potential (FRAP), DPPH scavenging activity and oxidative stability index (OSI) were determined. The obtained data were well consistent with the polynomial equations by significant variation in linear, quadratic and interaction impacts of the process factors. The optimized extraction conditions were sonication time, 26.91 min, temperature, 50.42 °C and ethanol concentration, 55.84%. The total polyphenols, DPPH, FRAP an OSI of optimal extract were 304.47 mg GAE/g, 72.47%, 54.04 mmol/100g and 8.55 h, respectively. High performance liquid chromatography (HPLC) analysis of optimal extract detected presence of epicatechin, chlorogenic, sinapic, caffeic and gallic acids.
Hassan Mirhojati; Parvin Sharayei; Reihaneh Ahmadzadeh Ghavidel
Abstract
The acidified ethanol extracts of dried barberry which have a relatively high anthocyanin content (376.28± 1.45 mg c3g/Kg dmp) were freeze dried using maltodextrin (MDX), polyvinyl-pyrrolidone (PVP) and mixture of MDX and calcium alginate (MDX-CaAlg) as a carrier and coating agents. The qualitative ...
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The acidified ethanol extracts of dried barberry which have a relatively high anthocyanin content (376.28± 1.45 mg c3g/Kg dmp) were freeze dried using maltodextrin (MDX), polyvinyl-pyrrolidone (PVP) and mixture of MDX and calcium alginate (MDX-CaAlg) as a carrier and coating agents. The qualitative attributes of the powders were characterized by their productively encapsulation efficiency, moisture content, bulk density, colour values (L*, a*, b*, C and H° ), particle size, total phenolic compounds (TPC), free radical scavenging activity of DPPH (RSA), ferric reducing-antioxidant power (FRAP) and minimized 50% of radical- scavenging activity (IC50). Scanning electron microscope was used for monitoring the structures of the powders. To determine the stability and half- life period of microencapsulated pigments, samples were stored under different storage temperatures (4◦C and 25◦C) at relative humidity 75%. Results showed that the encapsulated powder containing PVP 8% as wall material represented the best powder quality (p
Akram Arianfar; Fakhri Shahidi; Rassoul Kadkhodaee; Mehdi Varidi
Abstract
Introduction: Tea (Camellia sinensis), is the most widely beverage after water across the world. The most important chemical composition in tea is phenolic compounds (catechins) that have antioxidant and anticarcinogenic properties and are benefited for cardiovascular disease. There are two major kinds ...
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Introduction: Tea (Camellia sinensis), is the most widely beverage after water across the world. The most important chemical composition in tea is phenolic compounds (catechins) that have antioxidant and anticarcinogenic properties and are benefited for cardiovascular disease. There are two major kinds of tea, black tea and green tea. Green Tea, is originated in China and dates back to several thousand years ago. In the production of green tea, young leaves are rolled and oxidized to decreasing oxidation but in production of black tea, tea leaves are oxidized (fermented) for 90-120 min after rolling and then catechins are converted to complexe compounds (theaflavins and thearubigins). The conventional method for extraction of green tea polyphenols compounds are heating, boiling, cold and heathing refluxe extraction, with long extraction periods and low extraction efficiency. In this study 3 techniques for extraction of polyphenol compounds from Green tea leaves were investigated and compored together.The main objective of this study was to determine the effects of differrent extraction conditions, temperature ( 40, 60, 80 and 100° C), different time ( 15, 30, 45 and 60 min ), microwave power (300, 600 and 900 % ) and ultrasound amplitude (40, 60, 80 and 100 W) on Green tea polyphenol content and antioxidant activity in three methods including Heat Reflux Extraction(HRE), Microwave Assisted Extraction(MAE) and Ultasound Assisted Extraction(UAE).Materials and Methods: Dried green tea leaves (supplied from Lahijan (Iran))were grinded for increasing the contact surface area between the solvent and solute. 1 g of green tea was extracted with 100 mL of water at various methods, Heathing Reflux Extraction(HRE), Microwave Assisted Extraction(MAE), by microsynth laboratory system (Milestone-ACT-36-Rev01) at 50 Hz and output 2450 MHz with adjustable power output (100-1000 W), temperature 180° C and Ultrasound Assisted Extraction (UAE) in double jacket vessel by using a 25 kHz ultrasonic system (model VCX 750, Sonics & Materials, Inc., USA), at a maximum nominal power output of 750W. All measurements were carried out in triplicate. The results were analysed statistically using the minitab 16 Program to determine the average value and standard error. Variance analysis, with a significant level of α= 0.05% was performed to determine the effect of time, temperature, microwave power and ultrasound amplitude on polyphenols content and antioxidant activity. Total phenol were determined spectrophotometerically by Folin-Ciocalteu method at 765 nm )Hewlett- Packard spectrophotometer model 8452A, Rockville). The antioxidant activity evaluated with the DPPH test spectrophotometrically at 517 nm. Results and Discussion: These results showed that polyphenol content is increased with increasing the time, temperature, ultrasound amplitude and microwave power of extraction. By increasing temperature to 80°C , time to 45 min, ultrasound amplitude from 40 to 80 and microwave power from 300 to 600, polyphenol content and antioxidant activity was increased and after that was constant. These results showed that, H.R.E require long extraction time and have low efficiency. Polyphenol compounds are thermally unstable and maybe degredate in thermal processing. Also, the best method for extraction was MAE, because of higher yield, higher contents of pol-yphenol and shortend time and this method was very efficient in the extraction of polyphenl compounds. The efficiency of extraction by UAE method is higher than HRE and lower than MAE method. Conclusion: UAE method compared to HRE method is enhanced the extraction of polyphenol, facilating solvent peneteration and increase the product releasing from intracellular. This method agitated the solvent to material and increased the contact surface between material and solven, and peneteration of solvent in to the green tea leaves. UAE canbe carried out at a lower temperature than HRE and decreased thermal damage.
Sahar Lashgari; Majid Javanmard
Abstract
Nowadays, the use of natural antioxidants as alternative antioxidants is more acceptable than synthetic antioxidants mainly for negative effects such as carcinogenicity and toxicity. This has led to an increasing interest in the search for natural antioxidants. The objectives of this study were to measure ...
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Nowadays, the use of natural antioxidants as alternative antioxidants is more acceptable than synthetic antioxidants mainly for negative effects such as carcinogenicity and toxicity. This has led to an increasing interest in the search for natural antioxidants. The objectives of this study were to measure total crude phenolic compounds and in sorghum grain as natural antioxidant sources, to determine antioxidant effect of extracted compounds in various concentrations on sheep tail fat and to compare antioxidant effect of crude extract with synthetic antioxidant (TBHQ). The crude phenolic compounds in the whole sorghum grain were extracted using the organic solvents (acetone and methanol) and its constituents were measured by HPLC method. Antioxidant effect of extracted compounds at three concentrations (500,1000 and 2000 ppm) was determined by measurement of peroxide value, Thiobarbitoric Acid Substances(TBAS) and induction period (rancimat) compared with control (sheep tail fat without extract) after 48 and 96 hours incubation at 80ºC. The antioxidant effect of crude phenolic extract at optimum concentration (1000 ppm) and TBHQ at 100 ppm was also determined by measurement of later factors compared with control at 4-day intervals during 20 days of storage at 80ºC. Total crude phenolic compounds were 1700 (mgGA/100gr) Phenolic acids (Gallic acid, Vanillic acid, Ferulic acid and Caffeic acid), flavonoids and anthocyanins were measured as main crude phenolic compounds that determined by HPLC. Anthocyanins were the main components of flavonoids. The most antioxidant effect on sheep tail fat was achieved by adding of 2000 ppm of crude phenolic extract from sorghum after 96 hours at 80ºC. The most effective concentration of crude phenolic extracts on sheep tail fat was determined 2000 ppm. Crude phenolic extract at 2000 ppm increase induction period significantly. Synthetic antioxidant (TBHQ) exhibits constant and higher antioxidant effect compared with crude phenolic extract during 20 days of storage. This antioxidant increase induction period of sheep tail fat more than crude phenolic extract. The results indicated that crude phenolic extract present in the sorghum grain may be introduced as natural antioxidant source with out any harmful effects on human health. But the presence of high amounts of anthocyanin as red pigment in crude phenolic extract and its negative effects on oil colour may limit use of this antioxidant.
