Journal of Food Technology and Nutrition
Year:2017 | Volume:14 | Issue:3 (55)|Papers Count:11

Introduction: The medlar is a typical climacteric fruit which has gained a value commercially and in human consumption. A long list of recipes utilizing medlar fruits in jams, Jellies, marmalade and medlar vinegar have been known. Meldar is a nutritionally beneficial fruit due to its antioxidant and bioactive components.Materials and Methods: In this study the medlar sauce formulation was optimized using response surface methodology to analyse the effect of two independent variables, Persimmon juice (10, 30 and 50%) and salt as the additives (1, 1.75 and 2.5%), by using a central composite design with five control point. Viscosity, consistency, brix and the organoleptic evaluations concerned with thirteen different formulations were investigated. The relationship between sensory and device data were determined by using principal component analysis.Results: The results showed that by increasing the amount of Persimmon juice both the viscosity and brix increased and sauce consistency decreased. The effect of salt was not significant on the viscosity consistency of the samples but it has significant effect on the brix of sauces. Sensory analysis data indicated that there were not significant differences between color, smell and appearance of the samples. Samples containing 30% Persimmon juice received higher score in taste and overall acceptance from the assessors. Salt in the concentrations used did not have significant effect on sensory characteristics. The principal component analysis showed that there was a positive relationship between taste and overall acceptance.Conclusion: The highest score concerned with overall acceptability of formulated medlar sauce was obtained by using 30.17% Persimmon juice and 1% salt.

Introduction: Ice cream is one of the most popular dairy desserts and thus is an appropriate candidate to be fortified with blue-green microalgae Spirulina as a nutrient-dense food component. The main aim of the present study is to optimize the formulation ingredient of traditional Iranian ice cream enriched with Spirulina platensis using response surface methodology (RSM).Materials and Methods: The experiments were designed according to a 5-level-2-factor central composite design using RSM. The independent variable were formulation ingredients including Spirulina (0-5% w/w) and Carboxymethyl cellulose (0-0.5% w/w) and the responses of interest were the physical (viscosity, melting resistance and overrun) and organoleptic properties (flavor, color, texture and total acceptability) of ice cream.Results: The results indicated that while viscosity and melting resistance increased, overrun decreased by use of Spirulina (P<0.05). Carboxymethyl cellulose exerted the same effect on the physical characteristics of ice cream as did Spirulina, except for overrun on which it did not show a significant effect (P ≥0.05). The results of sensory analysis revealed that organoleptic properties of ice cream was adversely affected (P<0.05) by spirulina whereas, carboxymethyl cellulose did not have significant effect (P³0.05) on them. RSM described that incorporation of optimum concentration of 0.25% w/w Spirulina and 0.34% w/w carboxymethyl cellulose into the ice cream formulation would result in a health-promoting product with desired physical (melting resistance: 75.4; overrun: 55.27) and organoleptic properties (total acceptability score: 4.25 out of 5). The optimum sample showed significantly higher viscosity, melting resistance and overrun as compared to the commercial ice cream (P<0.05). The optimum and commercial samples both fulfilled the requirements of the sensory panel (P³0.05). The optimum sample had a higher microbial quality as compared to commercial sample Conclusion: It might be concluded that the incorporation of the optimum level of spirulina into the formulation of ice cream makes it possible to develop a functional product with desired physical and sensorial quality.

Introduction: The significance of medicinal plants as a source of active drugs emerged from the compounds that produces an obvious physiological action on the biological system. Phenolic compounds, alkaloids, tannins and flavonoids have been recognized as the most important bioactive compounds of plants. The present study is designed to evaluate the antioxidant ability of Datura innoxia petals in comparison with ascorbic acid.Materials and Methods: In this research, Datura innoxia petals were collected from Sabzevar city. Methanol extract was prepared by maceration method. Phytochemical screening and antioxidant activity of methanol extract was assessed by 1, 1-diphenyl-2-picrylhydrazyl (DPPH) assay.Results: Phytochemical screening revealed the presence of alkaloids, saponins, reluctant carbohydrates, cardiac glycosides, flavonoids, terpenoids, coumarins and free anthraquinones. The results indicated that the leaflets contained alkaloids, saponins, flavonoids, coumarins and tannin without cardiac glycosides, terpenoids, free and combined anthraquinone and steroids. The results also showed that the methanolic extract of Petal parts of the Datura innoxia has antioxidant activity with half percent inhibition of free radicals (SC50) that is equal to 31.183±0.302 mg/ml and 28.195±0.259 mg/ml for 60 and 90 minutes.Conclusion: The results indicated that the methanolic extract of Datura innoxia has antioxidant activity that is due to the presence of flavonoids and polyphenols.

Introduction: Lactic acid bacteria (LAB) are a heterogeneous group of gram-positive and catalase negative bacteria that produce lactic acid during fermentation of carbohydrates. These probiotic bacteria with the ability to produce industrial valuable biopolymers have a significant impact on the improvement of taste and texture of dairy products. A number of methods have been introduced to screen and identify bacteria. Among different methods, some are less reliable and some are expensive. Introduction of a reliable, cost-effective and time-saving method to identify bacteria is of great importance.Materials and Methods: In order to identify milk probiotic LAB, donkey's milk microbiota was investigated. LAB was identified and characterized with basic microbiological methods as well as Fourier Transform Infrared Spectroscopy (FTIR). Principle Component Analysis and cluster analysis were used to validate the FTIR data.Results: The results of this experiment showed that LAB isolates were mostly belonging to either Enterococcus faecalis or Streptococcus devriesei species. Furthermore, PCA and cluster analysis confirmed that FTIR data are reliable to identify LAB genera and species from milk.Conclusion: It is recommended to use FTIR method for mass screening of LAB from different sources before applying other complex and expensive methods such as DNA sequencing. The FTIR is a cost-effective and quick method that could distinguish bacteria at the genus and even species level. Two bacteria species were found and confirmed by both culture-dependent and FTIR methods and one of which Streptococcus devriesei is being introduced for the first time in Iran.

Introduction: Regarding the increase of hydrocolloids application in food industry and high price of commercial gums, the use of local hydrocolloids might be considered quite important. Therefore the study of local gums and its comparison with the commercial gums in different operations in industry might be considered essential.Materials and Methods: In this research, the rheological behavior and apparent viscosity of Qoudomeh shahri gum was investigated at four different concentrations (0.5-2%), temperatures (30–40oC with 5 degree intervals), and rotational speeds (up to 200 rpm) and was compared with commercial Xanthan gum and also for modeling and fitting the experimental data tow Power law and Bingham models were applied.Results: The results showed that by increasing the temperature and rotational speed the apparent viscosity of both gums decreased and by increasing the concentration of both gums the apparent viscosity increased. Consistency index in Qodumeh shahri gum solutions was lower than Xanthan gum solutions and in a constant concentration, the Xanthan gum solution has a higher consistency index. Evaluation of the rheological models showed that the power law model described the rheological behavior of the xanthan solutions with high determination coefficients, R2 and low SE, while the Bingham model described the rheological behavior of the Qodumeh shahri solutions with high determination coefficients, R2 and low SE Conclusion: The rheological characteristic of Qodumeh shahri gum is quite similar to commercial xanthan gum, therefore this gum might be applied as a commercial xanthan gum.

Introduction: Kefir is among the probiotic fermented beverages that has been taken into consideration by people since the past. The health effects of this product include decreasing blood cholesterol, improving digestion, preventing gastrointestinal diseases. This study attempts to improve the quality of this product by using alginate gum and transgulataminase enzyme and investigate the physicochemical characteristics of the product.Materials and Methods: Initially different concentrations of alginate and transgulataminase were selected in such a way that the sums of two stabilizers became 0.1 percent in the formulation. Evaluations concerned with pH, acidity, viscosity, organoleptic analysis and color were conducted on the first, seventh, fourteenth and twenty first days and free fatty acid profile measurement was carried out at the end of the maintenance phase.Results: The results of this study indicated that transglutaminase enzyme caused an improvement in the texture of the product but did not affect the pH of the product and the sample containing 0.1 % of alginate had the lowest pH. Special sensory test results showed that the simultaneous consumption of alginate with transglutaminase was effective in the establishment and maintenance of the taste. The predominant fatty acid was palmitic acid and different concentrations of alginate and transglutaminase did not affect the free fatty acid profile.Conclusion: The combination of transglutaminase with alginate gum could be effective in the improvement of sensory characteristics of kefir.

Introduction: Rowing is one of the oldest sports and its competition has been held every four years at the Olympic games and is considered as one of the greatest world championship. The aim of this study is to investigate the effect of acute beta-alanine supplementation on the Tmax, record of 6 minutes on rowing ergo-meter and Vo2max and blood lactate responses in the Iranian national team members of rowing.Materials and Methods: 15 elite male rowers (age: 22.5±4.9, Height: 186.8±8.3cm, weight: 80.3±4.9 kg body fat: 8.8±2.7 percent) voluntarily participated in this study. Rowers were in training camp and preparing for competetion. The subjects were randomly divided into two groups: placebo (control) and supplement groups (experimental). Subjects were supplemented every 4 hours, 3 hours and 2 hours with10 mg per kg of body weight with betaalanine or placebo (glucose) in a cross-over design before the 6-minute and Tmax test on rowing ergo-meter with free rhythm. Tests concerned with rowing ergometer and Tmax and blood lactate before and after 6 minutes test were carried out. Independent t-test and SPANOVA were used for statistical analyses.Results: The results did not show differences among the groups for all the variables (p>0.05), except, Tmax that increased significantly in beta-alanine group. This study showed that acute beta-alanine administration could increase Tmax significantly.Conclusion: According to the results, beta-alanine supplementation could improve rower’s record and postpone their fatigue and improve rower’s stamina to increase the time for exhaustion.

Introduction: Nowadays, the growing demands for low fat foods consumption has resulted in more intensive researches on the preparation of these foods that resemble the original products. The aim of the present study is to optimize the formulation of the ultrafiltrated low-fat Iranian white cheese using fat replacers.Materials and Methods: The experiments were planned on the basis of 3-level-3-factor box-Behnken design throughout Response Surface Methodology. The fat content (3-10%), Persian gum (0-0.2%) and almond gum (0-0.2%) were considered as independent variables and texture characteristics of the cheese samples were regarded as responses.Results: The results indicated that as the amounts of fat (p<0.01) and Persian gum (p<0.05) in the low-fat cheeses increased, softer cheeses were produced and hardness, cohesiveness, springiness, gumminess and chewiness decreased where as adhesiveness increased significantly (p<0.05). Although the addition of almond gum had similar effects on the mentioned textural parameters but these were not considerable. Microstructure analysis of the cheese samples using scanning electron microscope (SEM) showed that full-fat control and optimized samples had a much more open network structure and consequently were weaker than low-fat control cheese.Conclusion: Response surface optimization showed that desired rheological and textural properties for low-fat Iranian UF-Feta cheese were obtainable using 10% fat, 0.2 Persian gum and 0.14% almond gum. Based on the optimization results, it was revealed that textural defect related to fat reduction might be improved by using local gums, such as Persian and almond gums, in cheese formulation.

Introduction: Strawberry is a perishable fruit, vulnerable to mechanical damage, microbial spoilage and physiological disorders. Temperature of field and heat of respiration are two important factors affecting the postharvest quality of many fruits. The fruits must be cooled after the harvest in order to improve the quality and shelf-life of the product. The purpose of this experiment is to evaluate the effects of precooling on the microbial and physicochemical properties of two strawberry cultivars during storage.Materials and Methods: Immediately after harvesting and packaging of strawberries “Queen Elisa and Kurdistan”, half of the packed was put in the field and the other half was subjected to the precooler. Finaly all of them, were transferred to the cold storage (1oC, 90% RH).Microbial stability, physiochemical characteristics (weight loss, ascorbic acid, anthocyanin, total phenol contents, antioxidant capacity, titratable acidity, total soluble solids and pH) of precooled and non-precooled strawberries were evaluated every 4 days after harvesting up to 20 days of storage. This experiment was performed in a completely randomized design.Results: Precooled strawberries significantly showed lower microbial load, weight loss and destruction of ascorbic acid than that of non-precooled fruits up to 20 days of storage (p< 0.05). Titratable acidity, total soluble solids, anthocyanin content, total phenol and antioxidant capacity for precooled strawberries were significantly increased as compared to non-precooled (p<0.05).Conclusion: Application of precooling technique in Queen Elisa strawberry cultivar as compared to Kurdistan strawberry cultivar was significantly more effective in reducing the microbial load, weight loss and loss of biochemical characteristics.

Introduction: Wheat is the only grain that due to its nature containing gluten has important application in the production of various type of bread. Wheat quality and the bread produced have direct and positive correlation with environmental factors. Applications of organic matters on land have improved the quality of wheat, dough and the bread produced.Materials and Methods: This study was conducted with five fertilizer treatments on the spring wheat in Mahidasht Research Station of Kermanshah in the year 2013. The rheological and extensographic evaluations of dough as well as tests concerned with the quality and size of produced Barbary and Baguette breads regarding staling and sensory evaluation after 1st, 2nd and 5th days of baking were carried out.Results: Combined treatments of organic and chemical fertilizers produced higher quality bread. This was concerned with flavour, volume and staling of bread produced as compared to the control.Conclusion: The results of this study indicated that high quality of flour and bread were produced as the result of chemical and organic fertilizers treatments. The mentioned treatment produced maximum amount of gluten in the wheat, improved the rheological properties of dough and bread volume. The other roles of the treatment were sustainable agriculture cycle, conservation of fertile land and production of healthy and natural products.