Background and Objective: Edible film is one of the solutions for food packaging that carry antimicrobial and antioxidant compounds, usually found in Medinilla speciosa fruits. The objective of this study was to assess effects of Medinilla speciosa fruit extract on physical, chemical and bioactivity of edible films as well as effects of coating on sausage quality during storage. Material and Methods: The edible film included 2% w w-1 chitosan, 2% w w-1 sorbitol and Medinilla speciosa fruit extract. Variations of Medinilla speciosa extract included 0, 2.5, 5 and 10% (w w-1), while the storage temperature included 4 and 27 oC. Seven parameters of edible film characteristics were assessed, including tensile strength, elongation, water vapor permeability, antimicrobial and antioxidant activities, surface microstructure and Fourier-transform infrared response. Parameters assessed in storage treatment included total plate count, yeast mold count and thiobarbituric acid reactive substances. Data were analyzed using Kruskal-Wallis test. Organoleptic characteristics were analyzed using Friedman test and SPSS Software. Results and Conclusion: Results showed that the higher the concentration of Medinilla speciosa extract was, the higher the value of tensile strength, water vapor permeability and antioxidant activity and lower the elongation value were. The film control with 0% Medinilla speciosa extract was the only film that met Japanese standard for the water vapor permeability value, including 6.74 gm-2 h-1. Furthermore, shelf life of sausages coated with edible films revealed that the higher the concentration of Medinilla speciosa extract was, the lower the total plate count, yeast mold count and thiobarbituric acid reactive substances values were. Study demonstrated that the Medinilla speciosa extract edible film inhibited microbiological and oxidative damages. ​Oon Day 15 of storage, sausages coated with edible films with 10% Medinilla speciosa extract included lower total plate count, yeast mold count and thiobarbituric acid reactive substances values, respectively including 2.4 ±0.02 log CFU g-1, 1.3 ±0.08 log CFU g-1 and 13.38 ±0.22 mg malonaldehyde kg-1 sausage, compared to the control film. Organoleptic assessment showed no major differences in consumer acceptance. In conclusion, edible film with 10% Medinilla speciosa extract is the best physical, chemical and bioactivity film. Moreover, this film extends the sausage shelf life. Conflict of interest: The authors declare no conflict of interest.

Background and Objective: Increasing concerns over the use of antibiotics in aquaculture have emerged researchers to focus on short chain fatty acids and other biocompatible molecules as alternatives for disease prophylaxis and treatment. Polyhydroxyalkanoates well studied as biopolymeric materials for using in packaging and biomedicine were not focused much for their abilities to act as antimicrobial agents in aquaculture until recent years. Application studies of polyhydroxyalkanoates as aquafeed additives have highlighted their promising roles as eco-friendly alternatives for commercial antibiotics with strong immunomodulatory effects in fish-es and shrimps. The major aim of this review was to explore up-to-date scientific research studies on use of polyhydroxyalkanoates as aquafeed additives and their immunomodulatory effects. Results and Conclusion: Up-to-date, limited scientific literatures have been published on the use of polyhydroxyalkanoates and their copolymers as alternatives to antibiotics in aquaculture. This research field includes a great scope of development due to the promising immu-nomodulatory and antimicrobial activity of polyhydroxyalkanoates against common pathogens in aquaculture, as reported in literatures. Although several hypothesis and research data for explaining the mechanisms behind their immunostimulatory effects were suggested by various researchers, genetic and molecular bases underlying these phenomena are yet to be explored. Further research and development in this area can introduce these biopolymers as the most promising eco-friendly alternatives for antibiotics in aquaculture. Conflict of interest: The authors declare no conflict of interest

Background and Objective: Milk agar is recommended for enumeration of microorganisms in dairy products. Most of the commonly used media are imported to Nigeria and hence available in-house substitutes are necessary. In this study, microbial growth enhancement values of compounded milk agar were compared to imported milk agar using two milk brands. Dawadawa (fermented locust beans), yeast powder and peptone in the proportions of 1: 3: 5, respectively, were used as nutrient sources. Material and Methods: Growth enhancement values of the compounded media were assessed on three bacterial species of Staphylococcus aureus, Escherichia coli and Lactobacillus plantarum. Furthermore, imported milk agar served as the control. Results and Conclusion: Significant differences were seen in nutritional contents of the compounded milk agar and imported milk agar as well as the elemental compositions of compounded milk agar and imported milk agar. No significant differences were seen between the total viable counts of Staphylococcus aureus and Lactobacillus plantarum on compounded milk agar and imported milk agar. However, significant differences were reported in the total viable counts of Escherichia coli on compounded milk agar and imported milk agar. Media containing Cowbell milk powder recorded the highest total viable counts (1.3 ´ 105, 1.8 ´ 106 and 2.0 ´ 106 CFU ml-1) for Staphylococcus aureus, Escherichia coli and Lactobacillus plantarum, respectively. In conclusion, the Cowbell milk powder in combination with yeast extract and peptone is the best milk of choice for compounding milk agar when using local resources. Conflict of interest: The authors declare no conflict of interest.

Background and ObjectiveFish tissue and liver and some microalgae are some of the richest sources of omega-3 (ω3) fatty acids in nature. Annually, more than 4.2 billion tons of algae are cultivated with various goals. Therefore, development of novel ways to extract more ω3-fatty acids from microalgal tissues is a valuable target. In this study, comparisons were carried out between various methods of extraction and purification of ω3-fatty acids from a native species of microalgae.Material and MethodsCombination method (urea complex and winterization) used as a method for extraction of ω3-fatty acids. For the optimization of combination method, three factors, including temperature of winterization, time of winterization and frequency of extraction with hexane were studied at fourvarious levels and 15 examinations using Design Expert 10.0 software.Results and ConclusionResults of optimization included 10 h for time of winterization, -20 °C for temperature of winterization and six times of extraction with hexane. In optimized conditions, the highest quantity of ω3-fatty acids derived from Chlorella vulgaris at the moisture of 65% was 43.6 mg g-1fatty acids.

Background and Objective: Enzyme-assisted hydrolysis of the proteins from food sources is an effective way to generate peptides with various bioactive properties. Furthermore, enzyme immobilization is a way to recycle enzymes for the future uses. The objective of this study was to investigate the effects of neutrase and thermolysin immobilization on the enzyme properties and in vitro anti-diabetic properties of intestinal digests achieved by the simulated digestion of egg white protein hydrolysates. Material and Methods: Neutrase and thermolysin were immobilized on cellulose-coated magnetite nanoparticles. Then, enzyme activity, thermal resistance, reusability and optimum conditions of the egg white protein hydrolysis were assessed. Egg white protein hydrolysates were then digested in vitro and inhibitory activities of the intestinal digests against dipeptidyl peptidase IV (DPP-IV) and α-glucosidase were investigated. Results and Conclusion: Enzymes immobilization resulted in increases in the thermal stabilities of them. Optimum temperatures for the egg white protein hydrolysis increased by 4.0 and 3.2 °C for neutrase and thermolysin, respectively. Digests from the hydrolysates of free neutrase effectively inhibited DPP-IV and α-glucosidase by 17.9 and 29.7%, respectively. These values for the hydrolysates released by the free thermolysin were higher (37.2 and 35.1%, respectively). The enzyme immobilization resulted in a 4.4% decrease in DPP-IV inhibitory activities of the digests for the hydrolysates from neutrase and a 28.6% decrease for those from thermolysin. Decreases in α-glucosidase inhibition due to the immobilization included 9.8% for neutrase and 12.2% for thermolysin for the digests from the hydrolysates. Based on the results from the current study, hydrolysates from the egg white proteins achieved by the free and immobilized neutrase and thermolysin can be used in formulations of the functional foods and nutraceuticals with multifunctional properties.

Background and Objective: Diabetes mellitus is the fifth leading cause of death in the world. Damaging effects of diabetes include advanced metabolic complications and various organ lesions. More than 90% of diabetic cases belong to type 2 diabetes. For decades, medicinal fungi such as Trametes versicolor have been considered as treatments for diabetes. The fungi exopolysaccharides show α-glucosidase activity in the intestinal membrane. Material and Methods: In this study, Iranian Trametes versicolor was cultured in various media based on soy milk, cow milk and soy protein extraction. After selecting appropriate culture media for biomass and exopolysaccharide production, response surface method with Box-Behnken design was used to investigate effects of independent variables of glucose (g l-1), soy milk (v v-1) and pH on biomass and exopolysaccharide production and optimization of these products. An animal (rat) model of streptozotocin-induced diabetic rats was used to investigate effects of exopolysaccharides on diabetes. Rats were treated with exopolysaccharides for 21 days. Results and Conclusion: Results showed that the culture media containing soy milk was appropriate for the growth and production of fungal products. Productions of biomass and exopolysaccharides increased to 2.87 g l-1 and 1.37 g l-1 respectively. Based on the analysis of response surface method, pH with p-value of 0.0004 and pH and soybean interaction with p-value of 0.0129 included significant effects on exopolysaccharide production. In optimum condition of the culture media with pH 4.67, 13.01 g l-1 glucose and 75% v v-1 soybean milk, biomass and exopolysaccharides reached 21.80 g l-1 and 9.6 g l-1. In diabetic rat model treated with exopolysaccharides, a 50.38% decrease in blood glucose was seen while triglycerides, cholesterol and low-density lipoproteins included 89, 20 and 21.67%, respectively. Furthermore, high-density lipoproteins increased by nearly 2.5%.

Background and Objective: Oxidative stress, due to free radicals, brings injury to the body by attacking large molecules and cell organs, and is the main reason of many diseases. Fermentation of foods containing large amount of proteins such as milk by special species of lactic acid bacteria is a potential way in enhancement of the antioxidative activity of foods. This study aimed at evaluating non-common starter species isolates of Lactobacillus helveticus for their capability to produce fermented milk enriched in antioxidant peptides. Materials and Methods: Reconstituted skim milk (11%) was inoculated with 7 wild isolates of Lactobacillus helveticus , and after 24 h fermentation at 37oC, the samples were kept 4oC and for 14 days. Viable cell number, acidification and proteolysis degree in the milk fermented by each isolate were assessed in 1, 7 and 14 days. Development of antioxidant activity was measured using DPPH and ABTS●+ radial scavenging activities during the storage period. Results and Conclusion: Though some slight strain-dependent differences were observed in growth, acidification and proteolysis, all the samples showed considerably strong antioxidant activity (at least 62.32±3.66% and 57.64±1.42% measured using DPPH and ABTS●+ radicals, respectively) through the whole storage period. In vitro simulated gastrointestinal digestion indicated that DPPH radical-scavenging activity of the antioxidative peptidic supernatants was not affected significantly by consecutive pepsin-pancreatin hydrolysis in most of the samples. These evidences support Lactobacillus helveticus as a promising functional culture able to promote health benefits in dairy-based functional foods. Conflict of interest: The authors declare that there is no conflict of interest.

The effects of Allium sativum on yogurt formation and subsequent storage (4°C, up to 28 days) on proteolysis, microbial activity, and inhibition of α-amylase, α-glucosidase and angiotensin-I converting enzymes were investigated in vitro. Allium sativum yogurt showed higher rates of pH reduction and increment of titrable acid than control during the incubation at 41°C. Highest proteolysis was observed on day 7 in Allium sativum yogurt (62.7±0.80 mgmL-1), which was 2-flod higher than the control (31.0±0.96 mgmL-1). Bacterial counts in Allium sativum yogurt were higher for Lactobacillus spp. but lower for Streptoccus thermophilus (p<0.05) compared to those in the control throughout refrigerated storage. Highest inhibitory activities for α-amylase were recorded on day 14 of storage for Allium sativum and the control yogurt while highest inhibitory activities for α-glucosidase were recorded on day 7 of storage for Allium sativum and the control yogurt respectively. The highest angiotensin-I converting enzymes activity was observed on day 7 of the refrigerated storage in Allium sativum yogurt, and being more potent than the control. Allium sativum enhanced the fermentation of yogurt in favor of the population of Lactobacillus sp, stimulated proteolysis of milk proteins, and increased the in vitro inhibition of key enzymes associated with diabetes and hypertension.

Bioactive food components (such as phenolic compounds, carotenoids, anthocyanins, tochopherols, ascorbic acid, flavonoids, minerals, enzymes and pectin) are active ingredients in food or dietary supplements, which proven to have an important role in health, and are safe for human consumption. These compounds exert their antioxidant effects by different mechanisms such as single electron transfer or hydrogen atom transfer, and their efficiencies can be evaluated by several methods such as ferric reducing ability of plasma, oxygen radical absorbance capacity assay, total radical trapping antioxidant parameter, total oxidant scavenging capacity, conjugated dienes, lipoxygenase activity inhibition assay, chemiluminescence, deoxyribose, tocopheroxyl radical attenuating ability, and nitric oxide radicals trapping. In this review, these mechanisms and methods will be discussed in details.