Journal of Food Technology and Nutrition
Year:2013 | Volume:10 | Issue:1 (37)|Papers Count:12

Introduction: increasing awareness of the consumers during the last decades resulted in using safe additives specially antioxidants components in food products. Licorice root contains high levels of phytochemicals that have health-promoting properties. Some of these phytochemicals, such as Glycyrrhizin and phenolic compounds act as antioxidants, reducing the oxidative damage to cells, that can lead to cancer, heart disease and numbers of the pharmacological actions. The quality of plants in term of the antioxidant activity and potency might be influenced by numerous factors including harvesting time. Therefore investigation concerning the effect of harvest time might be essential to obtain the best quality of licorice root.Materials and Methods: Licorice roots harvested at two different periods (T1: 20 October 2010 and T2: 20 January 2010) were analyzed for their chemical composition and the antioxidant activity was assessed by DPPH reducing power and total antioxidant capacity assay.Results: Higher amounts of moisture were detected in T1 licorice root, whereas higher levels of sugar, protein, ash and phenolic compounds were determined in T2 licorice root. T2 licorice root was found to possess higher antioxidant activity.Conclusion: The environmental condition influences the growth of herbs and consequently affect the content of their active ingredients. Therefore picking of plant is cost-effective when the concentration of active ingredients reaches the optimum level.

Introduction: Yogurt is a fermented dairy product and due to its suitable sensory and functional properties, it is regarded as one of the most desirable dairy products. In recent years, suggestions have been made to consumers to use yogurts containing probiotics.Prebiotics are added to probiotic products to improve the sensory and technological properties of the food products. The yogurt products that contain both probiotic bacteria and prebiotic components are called symbiotic yogurt. The aim of this research work is to investigate the production and storage of symbiotic yogurt.Materials and Methods: In this study prebiotics including Lactulose, Inulin, and Oligofructose as single, double and triple mixtures, and lactobacillus casei were used to produce synbiotic yogurt. Sensory evaluations of the samples were carried out one day after production and the best sample was selected. In the next stage, the samples were compared with the control sample (probiotic yogurt without prebiotic) stored at 4oC for 21 days and their sensory properties and textural analysis (texture firmness) were carried out.Results: The results showed that the samples containing Inulin, Lactulose – Inulin, and Lactulose – Oligofructose had the best sensory properteis. These samples and the control were refrigerated for 3 weeks at 4oC. The results suggested that the sample contained Lactulose – Inulin had the best flavor and the control had the lowest score. The best score concerned with texture and texture firmness was the sample containing Lactulose- Oligofructose while the control sample had the lowest score in term of firmness. There were not significant differences between the samples' color. The results suggested positive effect of prebiotic in probiotic yogurt.Conclusion: The study showed that prebiotics might be used for improving sensory and rheological properties of synbiotic yogurt.

Introduction: Tea is one of the popular beverage all over the world. Among different types of tea, green tea is the richest source of natural antioxidants especially catechins, that is studied in detail due to their health effects. These valuable compounds, may loss their activity and oxidize to thearobigin during fermentation stage or black tea processing. Therefore the main objective of this research is to apply the mixture of antioxidants extracted from green tea on packaging materials of black tea bags and study the physical properties of the treated packaging and the amount of green tea antioxidants released into boiling water during immersion of the black tea bag samples.Materials and Methods: The green tea extracts were prepared by two step extraction process in water at 50oC and 80oC in four individual time periods, i.e.; (10 min: 10 min), (10 min: 20min), (20 min: 10 min), (20 min: 20 min). Final extract from each process was sprayed on the tea bag packaging material. The physical property and the air permeability of treated packages were analysed immediately and after 3 months storage. In addition, the activity and concentration of released antioxidants from treated tea bags were investigated by HPLC methods and sensory properties of the tea beverage samples were also studied.Results: The results showed that the concentration of antioxidants increase by 45-50% as compared to control (i.e. untreated black tea). Air permeability of packaging samples was not changed significantly, but their tensile strength decreased by 1-1.5% which was still in the standard range. Tea beverage samples were more astringent as compared to untreated black tea.Conclusion: Among different time/temperature conditions the best results were obtained from the third samples [(20 min, 50oC), (10 min, 80oC)] containing the highest concentration of antioxidants and lowest astringency.

Introduction: Many ingredients are being used and employed in order to improve the texture, nutrient and color quality and properties of meat products. Carboxy Methyl Cellulose might be regarded as one of these ingredients.Materials and Methods: In this study, Carboxy Methyl Cellulose was used as the replacement of Poly Phosphate in German sausage formulation, at different concentrations (0.07, 0.14, 0.21 and 0.28 percent). Samples were prepared in 3 batches and each was heat treated in order to cook at 80oC for 45 minutes. Chemical and textural analysis were carried out on the finished product. Data were analysed according to Mini Tab software and Glm design.Results: Chemical analysis indicated that all of the evaluated properties, were correlated to the defined standards. The results also indicated that there were not significant differences between cutting forces and energy needed for cutting for all the samples examined. However the cutting force for the treatments containing 0.14 and 0.28% CMC and energy needed for cutting for the treatments with 0.14 and 0.21% CMC were at the highest amount.Conclusion: Textural analysis showed that treatment with 0.14 % Carboxy Methyl Cellulose, was superior to others.

Introduction: The first discovery of the presence of acrylamide (AA) in heat treated food products rich in carbohydrates, led to a worldwide concern about the potential toxicity and probable carcinogenic effects of this compound. The presence of acrylamide in cereal products such as biscuit through baking process and recipe formulation has attracted many researchers to investigate this subject thoroughly. Therefore in this research the effect of invert sugar and sucrose on the formation of acrylamide in biscuit in industrial scale is studied and correlations between color and acrylamide contents were also investigated.Materials and Methods: Biscuit samples were prepared in batches of 100 kg with three recipe formulations with three levels of inverted sugar syrup (9, 7, 5%) and three levels of sucrose (15, 13, 11%). The amount of acrylamide concentrations in biscuits were determined by the application of gas chromatography equipped with electron capture detector (GC-ECD).Results: The least concentration of acrylamide (118 ppb) was found in samples made with 5% invert sugar and 15% sucrose, baked at 340oC and the highest concentration of acrylamide (526 ppb) was observed in samples made with 9% invert sugar and 11% sucrose, baked at 320oC. In this study, digital colour images of biscuits were analyzed to determine the relation between acrylamide levels and colour formation. A significant correlation (r=-0.08) was found between the L* factor and acrylamide concentrations in biscuits. The products prepared with sucrose had lighter colour intensity due to the lack of reducing sugars. The sensory evaluations of the samples were carried out according to the multiple comparison.The results showed that there were not significant differences between the samples.Conclusion: The result has indicated that acrylamide content was effectively decreased by replacement of invert sugar with sucrose.

Introduction: Lime mud due to the lack of insufficient works and studies is disposed as a waste material in sugar factories. This will cause the sugar industries a considerable cost.The removal of organic matter in the mud by the application of aerobic microorganisms can provide easier separation of calcium carbonate. Therefore this study is concerned with this matter.Materials and Methods: The effect of different pH values (7.4 and 9) and four dilutions (control, 25%, 50% and75%) in respect of time (two and four weeks) on the activities of Bacillus migulanus concerning the reduction of organic matter, increase of calcium carbonate purity, change of electric conductivity and color of filter cake were investigated.Results: The results showed that, although the amount of organic matter is decreased and the purity of calcium carbonate is increased, but there are no significant differences in any of the variables; time, concentration, pH and their interactions. Color of filter cake, altered to yellow, gray and light gray. The electrical conductivity and soil salinity increased and there are significant differences in dilutions, pH values and their interaction effects on electrical conductivity.Conclusion: By provision of a suitable location for the filter cake without the addition of water or pH changes, one might be able to reduce the organic matter and produce calcium carbonate with a high purity and quality for a short period.

Introduction: Lipid oxidation is a process, which results in rancidity and deterioration of fats posing a major problem in food industry. Many synthetic antioxidants are used in food systems to inhibit lipid oxidation. Restriction on the use of synthetic antioxidants is being imposed because of their toxicity properties, therefore there is a tendency towards the use of natural antioxidants of plant origin to replace these synthetic antioxidants.Materials and Methods: In this study, the antioxidant activities of Fennel (Foeniculum vulgare) seed extract at different concentrations (0, 100, 150, 200, 250 and 300 ppm) on the stability of sunflower seed oil were evaluated by means of peroxide value, anisidine value and totox value determinations. The oxidation stability of the samples were measured by Metrohm Rancimat apparatus. The antioxidant activities were compared to synthetic antioxidants such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) at 75 ppm concentration.Results: The results indicated that the antioxidant activities of the seed extracts at 250 and 300 ppm on the sunflower seed oil were better than BHA and BHT and the antioxidant activity was increased as the concentration of the extract was increased.Conclusion: Fennel seed extract might be employed as a natural antioxidant to replace the synthetic antioxidants namely BHA and BHT.

Introduction: The quality of irrigation water and methods might have some effects on the oil yield and fatty acid composition of the oil extracted from sunflower seed. In order to study the effects of different integrated irrigation methods with salin water and well water particularly the oil yield and fatty acid composition, this project was carried out at Islamic Azad University, Shahr-e-Qods agricultural research station during 2010.Materials and Methods: The experimental design with three replications and four treatments consisting of treatment 1 (25% salin water: 75% well water), treatment 2 (50% salin water: 50% well water), treatment 3 (75% salin water: 25% well water) and treatment 4 (consisting of 100% well water as a control) were carried out.Results: The results indicated that there are significant differences concerning the oil yield.Treatment 3 had the highest oil concentration in the seed (49.8%) while treatment 4 with the yield of 1659 kg/ha seed obtained the highest amount of oil.Conclusion: The fatty acid composition of the oil extracted from the seed did not vary and significant differences between the treatments were not observed.

Introduction: Proteinous components of Lactobacillus spp have strong antagonizing activity against many microorganisms. The object of this study was the optimization of the production of proteinous components by three isolated Lactobacillus spp from local yoghurt and screening its influence on L. monocytogenes as a food spoilage organism.Materials and Methods: The strains were isolated from 20 samples of local yoghurt. In order to optimize antimicrobial production conditions, strains were kept at four different temperatures. The effect of oxygen, carbon dioxide and three media; Skim milk, MRS agar, MRS with yeast extract, with added minerals were evaluated on the production of bacteriocin.Lowry method was employed to determine soluble protein. By the application of ammonium sulfate, dialysis and SDS-PAGE, bacteriocin was extracted, purified and the molecular weight was determined and the effect of bacteriocin extract on the L. monocytogenes was evaluated.Results: Totally three isolations against L. monocytogenes were highly active. Maximum activity was shown at 30oC after 23 h in MRS medium with yeast extract. Results of incubation in candle jar with 5%CO2 and ordinary incubator were the same. Addition of mineral components had no effect on bacteriocin production. The best strain wasLn10 with the recorded inhibition zone at 23 millimeter. The results of SDS-PAGE showed a single protein band with molecular weight of 50-58 KDa.Conclusion: In this study, the maximum bacteriocin production was obtained in logarithmic growth phase while the productions of these compounds in three standard strains were observed at the beginning of stationary phase.

Introduction: Brucellosis is a zoonotic disease caused by gram-negative bacterium Brucella that are pathogenic for a wide variety of animals and human beings. Brucellosis is easily transmitted via raw milk. Despite its control in many countries, it remains endemic in Iran.The transmission of brucella from infected animals to humans occurs either by occupational contact or the consumption of contaminated animal products, especially milk, cream and fresh cheese. The purpose of this study was to evaluate the prevalence of cow raw milk contamination by Brucella abortus in Ilkhchi region (south west of Tabriz).Materials and Methods: A total of 50 cow’s raw milk samples were collected randomly (cluster random sampling) from Ilkhchi milk collection centers from Mehr to Azar 1388.Samples were monitored for Brucella abortus antibodies using Milk Ring Test (Razi Vaccine and Serum Research Institute) and indirect antibody ELISA kit (Pourquier, France).Results: The prevalence of Brucella abortus was 10% in Ilkhchi region.Conclusion: The results indicated that the contamination rate is high in Ilkhchi region and serious steps must be taken to overcome this serious problem.