Journal of Food Technology and Nutrition
Year:2019 | Volume:16 | Issue:1 (61) |Papers Count:12

Introduction: Lippia Citriodoraplantis is a rich source of flavonoids that can reduce the microbial and oxidative deteriorations of food in general and therefore can extend the shelf-life of the food systems.Materials and Methods: For evaluation of the antimicrobial activity of essential oil and extract, the treated food emulsions by 1% and 2% essential oil and aqueous-alcoholic extract at the pH of 5, 7 and 9 were employed. Peroxide value, anisidine value, conjugated dienes, as oxidative parameters, and also total counts of microflora were measured during eight days of storage.Results: Essential oil and aqueous-alcoholic extract showed good antimicrobial activities under the experimental conditions. There were not significant differences (p£0.05) in the results concerned with DPPH and FRAP between essential oil and aqueous-alcoholic extract. The results of antimicrobial and antioxidant activities of essential oil and aqueous-alcoholic extract in model food system showed that both essential oil and extract decreased the total counts of microorganisms and the amounts of oxidative rancidity as compared to the control during 8 days of storage. Antimicrobial and antioxidant activities of essential oil and extract showed a direct correlation with the pH, therefore the mentioned activities were higher at lower pH values.Conclusion: The results of this study showed that the essential oil and extract of Lippia Citriodora can be used as antioxidant and antimicrobial agents in food products.

Introduction: In gluten-free pasta there is a need to use materials that can partially simulate viscoelastic properties of gluten in the dough and have the ability to replace gluten. The aim of this study is to investigate the potential of replacing gluten in cassava starch-based pasta formulation by using cress seed gum and pectin and evaluate the qualitative and organoleptic properties of gluten-free pasta and finally optimize pasta formulation.Materials and Methods: In this study, pectin at three concentrations of 1%, 2% and 3% and cress seed gum at concentrations of 0.5%, 1% and 1.5% were employed. Weight after cooking (baking numbers), the percentage of solids in the cooking water (glazing), adhesion, color, moisture and sensory evaluation were investigated. Statistical analysis of the result was carried out by response surface method (RSM).Results: The results indicated that the addition of pectin and cress seed gums concerned with the weight after cooking (cooking number), total soluble solid in cooking water (glazing), adhesion, color were significant at 0.05% level. The sensory evaluation based on hedonic method showed significant level at 0.05% level as concerned with taste, odour, texture and over all acceptability.Conclusion: It was concluded that the addition of pectin and cress seed gums caused increases in moisture and cooking number. The results of glazing and adhesion indicated that by increasing the concentration of pectin, glazing is decreased linearly and by increasing the concentration of cress seed gum glazing is in increased linearly in the case of gluten free pasta. The application of Hunter lab regarding the evaluation of colour L * is decreased while a * and b * is increased nonlinearly by the addition of both cress seed and pectin gums. The results concerned with the organoleptic test showed that both pectin and cress seed gums changed the taste and odour. The assessors gave the highest score to the samples containing 1% cress seed and 2% pectin gums concerned with colour, texture and overall acceptability.

Introduction: Growth of food pathogenic microorganism is one the major obstacles in the food industry. Nano technology has a broad application in all parts of food industry. The development of bacterial resistance to antibiotics and antimicrobial effect of silver nanoparticles, has caused the attention of researches to this subject. In this study, biosynthesis of silver nanoparticles and the effective parameters concerned and the antimicrobial effect of them against some food pathogens for use in antimicrobial packaging has been discussed.Materials and Methods: Silver nanoparticles were synthesized by the leaf aqueous extract of Kelussia odoratissima Mozaff. In order to achieve Silver nanoparticles with a uniform shape and minimum size, effective parameters on synthesis such as: pH of reaction, extract volume, concentration of Ag+ and reaction time, were studied and optimized by UV-Vis spectrophotometry. After characterization of nanoparticles using TEM and XRD techniques, their antimicrobial activities were investigated against Staphylococcus aureus, Bacillus cereus, Escherichia coli, Salmonella tifimurium, Listeria monocytogenes4b, Aspergilus Flavus, Penicillium expansum, Clavicpes purpureaby Agar Well Diffusion and MIC, methods.Results: Silver nanoparticles that had been biosynthesized with the approximate size of 20-25nm, had high antimicrobial activity against all of microorganisms and this activity was dependent on the concentration of silver nanoparticles, therefore in very low concentrations, they prevented the growth of microorganisms.Conclusion: Biosynthesis of silver nanoparticles, made nanoparticles with minimum size and better performance. Currently these nanoparticles can be use in food industry as food disinfectant filters, food coatings and packaging and cleaning the food pruduction lines.

Introduction: The high nutritional and medicinal values and the increasing production and demands, it is important to control the factors affecting the quality of pomegranate fruit during storage. Regarding the understanding of how to store pomegranate fruit, it would be possible to offer this product at local and international markets for a long duration with high quality.Materials and Methods: In this study, the effect of nano silicate-based polyethylene and polypropylene on the storage life of pomegranate fruit (cultivar Malas-e-Saveh) has been studied in a completely randomized factorial design. The treated fruits were stored in common storage for two and four months period. Qualitative and quantitative characteristics of fruits were measured using the standard methods of analysis.Results: The results showed that the nano-based polyethylene and polypropylene could maintain the highest amount of moisture in the skin (75.72% and 73.14%, respectively) as compared to the control (26.64%) at the end of storage period. These coating treatments also maintained the highest amount of aril moisture (76.88%) as compared to the control (71.09%). After storage period, the nano-based polypropylene showed the highest concentrations of phenolic compounds (883.54 mg GAE/100 ml), flavonoids (487.71 mg GAE/100 ml) and anthocyanins (11.69 mg C3GE/100 ml) as compared to the control (649.76 and 437.56 mg GAE/100 ml, and 7.9 mg C3GE/100 ml, respectively); although the normal coating treatments showed less influence. Nano-based coating treatments also decreased the changing rate of ascorbic acid but did not have any significant influence on pH and EC.Conclusion: The application of nano-based polyethylene and polypropylene treatments is recommended to improve the keeping quality of pomegranate fruit during storage.

Introduction: The aim of this study was to determine the effect of short-term supplementation of two different amounts of colostrum powder on the lactate, blood glucose- and anaerobic power in male wrestler.Materials and Methods: In this applied and quasi experimental study, 26 wrestlers (age 21.48 ± 1.93 years, height 174.64 ± 6.05 cm, weight 71.96±10.23 kg, body fat percent 9.78 ± 3.66 %) in a randomly and double-blind design were allocated in three equal groups: control (placebo: Dextrose), experimental group 1 (colostrum: 30 g/day) and the experimental group 2 (colostrum: 50 g/day). The training protocol of the present study was to conduct two Wingate tests (30 second) and simulated wrestling with 30 minutes of rest between the two tests. After two weeks of supplementation, the test was repeated under the first phase. Four blood samples before and after two weeks of supplementation (5 ml) were analyzed by ELISA. The result and the parameters (mean and standard deviation) of the four stages were repeated using ANOVA and post hoc tests Bonferuni analysis. All statistical analyses were performed using the SPSS-22 software. The significance level was set at p<0.05.Results: Blood glucose and lactate levels in two experimental groups 1 and 2 and stage one and two were similar to the control group. However, Investigation showed that the mean difference of phase two and four of blood lactate in experimental group 1 and 2 significantly decreased as compared to the control group (P<0.05). There was also, a significant difference in the level of anaerobic power in the experimental group 1 and 2 in the post-test (P<0.05).Conclusion: Two weeks of supplementation of colostrum powder can increase anaerobic power and decrease the blood lactate in wrestlers.

Introduction: Natural preservatives that have been employed for many years are employed to keep the quality of foods characteriestics. In this investigation the application of natural preservatives in the form of Nano-Encapsulated grape seed extracts have been studied to increase the shelf life of rainbow trout fillets.Matherials and Methods: Rainbow trout fillets were prepared after be heading, gutting, deboning and washing and prepared with grape seed extract with two doses of 2 and 4% of free (normal) and Nano-encapsulated (NEn) forms separately, and refrigerated at 4°C for 15 days. Chemical and microbiological characteristics consisted of total volatiles nitrogen, peroxide value and Thiobarbituric acid, total mesophyll count (TC) and psychrophilic count (TPC) were evaluated.Results: The results showed that all treated samples which contain samples in both free and NEn forms had better quality; therfore the shelf life increased considerably (p<0.05). The results also showed that the effect of grape seed NEn on the TPC bacteria is the same as the free form while has different and independent effects on the TC community and some other indices such as TVB-N, PV and TBA (p<0.05).Conclusion: According to the results, it can be claimed that rainbow trout fillet might be preserved for 12 days by the application of grape seed extract when kept in the refrigerator.

Introduction: Probiotic products have tremendous effects in improving the health of consumers and the medicinal herbs have shown to exhibit antioxidant, anticancer and other properties. The aim of this research work is to study the possibility of yoghurt production using hydro-alcoholic extract of jujube fruit and Lactobacillus acidophilus probiotic bacteria and evaluate the effect of extract on the organoleptic characteristics of product and the survival of Lactobacillus acidophilus in the probiotic yoghurt.Materials and Methods: Low-fat raw milk was heated to 85-90ºC for 5min. Traditional yoghurt starter, Lactobacillus acidophilus and jujube extract (0, 0.2, 0.4, 0.6, 0.8 gr/Lit) were added at 40ºC. All the treatments were incubated at 37ºC to reach the acidity of 80-85 ºD, followed by storing at refrigeration temperature. The population of Lactobacillus acidophilus was evaluated with standard methods on the 1, 7, 14 and 21 days after production. All samples were examined for sensory evaluation by a test panel on the 21th day after storage. The data were analyzed using by SPSS-19 software.Results: In all the treatments the growth of Lactobacillus acidophilus was reduced during 21 days of storage and the concentration of jujube extract did not have significant effect on this decline (P>0.05) and none of treatments showed the number of probiotic bacteria less than 106cfu/gr. The best quality was obtained in the yoghurt containing 0.6 gr/Lit of jujube extract and in terms of organoleptic properties and survival of probiotic bacteria this treatment showed the highest score.Conclusion: The results of this research showed that we can use 0.6gr/Lit of jujube extract with Lactobacillus acidophilus in the production of probiotic yoghurt as a new functional product.

Introduction: Today, the consumption of frozen fruits and vegetables has been increasing due to the ability of these products to persuade the consumers to maintain nutritional value, time-saving and other practical reasons. The aim of this study was to investigate some physicochemical properties of two groups of corn kernels, single and attached to the cob, after heat processing and storage at -18 ° C.Materials and Methods: In this study, sweet corn in two forms of single kernels and corns on the cob were cooked for 4, 8 and 12 minutes and stored for 10 weeks at -18 ° C. The effects of heat treatment on the drip loss, color changes, total phenolic content, antioxidant activity, peroxidase activity, hardness and microstructure were investigated every two weeks.Results: The amount of drip loss increased significantly (p<0.05) during freezing, and therefore the hardness decreased, in which the corns on the cob were more effective in maintaining their water structure as compared to the single kernels. The peroxidase activity, total phenolic content and antioxidant activity were significantly (p<0.05) decreased with heating process. The reversibility of peroxidase activity was observed during the freezing storage. In terms of the radical scavenging capacity, there was no significant difference between single corns and the ones on the cob. The amount of phenolic compounds increased until the fourth week and then decreased significantly (p<0.05) during storage at -18 °C.Moreover, the corns on the cob also showed more color changes than the single ones.Conclusion: Heat Treatment has significant effect on some physicochemical properties of corn during storage at -18 ° C.

Introduction: Probiotics are microorganisms that if administered in adequate amounts would have beneficial effects on the host's health.Bacillus coagulans is a probiotic bacteria which sometimes mistakenly called Lactobacillus sporogenes. B. coagulans is a gram positive and facultative aerobic and anaerobic, catalase positive, oxidase negative and endospore forming bacteria. The aim of this study is the rapid molecular detection ofB. coagulans in various probiotic products.Materials and Methods: PCR test was optimized by using B. coagulans standard strain.Limit of detection (LOD) and specificity of this test were investigated by using related species of DNA. Samples of probiotic products which contain B. coagulans were collected from the Iranian market and various methods of DNA extraction were optimized for these products.Results: Amplicon with the size of 450bp was amplified by PCR test and observed by electrophoresis method. In specificity test none were positive using DNA for intended organisms.B. coagulans species were identified in all the samples by PCR method.Conclusion: According to the results of this study B. coagulans was detected in all samples.It was concluded that PCR is a reliable and accurate method to identify these products that might contain B. coagulans probiotics bactria.

Introduction: Application of ionizing radiation as a new method in the preservation of agricultural products has been introduced since 35 years ago. Gamma irradiation has been introduced as a new technique to preserve the foods.Materials and Methods: Kiwifruit cultivar (Hayward) has been used and the samples with 0 (Control), 0.5, 1 and 2 kGy cobalt-60 were gamma irradiated then refrigerated at 3±1°C for a duration of 0, 30.60 and 90 days. In this study Response Surface Methodology and input parameters consisted of irradiation dose and storage time for optimal conditions for storage of irradiated kiwis were determined. Finally, using regression and neural network methods output prediction and response surface method were compared.Results: The optimal conditions for storage of irradiated kiwis were determined. The optimum point for shelf-life, radiation dose, weight, color parameters L*, a* and b*, ascorbic acid content and pH value, were proposed respectively, (two months, 1 kGy, 48.13 and 45.86, 11.03 and 12.79, 29.916, 3.2545). By increasing storage time and radiation dose, the weight of stored samples reduced. By increasing irradiation dose and duration of storage a* parameter decreased. By increasing irradiation dose also the b* parameter reduced but by increased storage time, L* increased. Similarly, by increasing storage time and radiation dose, pH value increased and ascorbic acid content reduced.Conclusion: The neural network and regression analysis have been employed to predict the changes in color, weight, pH value and ascorbic acid content.