نشریه پژوهش های علوم و صنایع غذایی ایران
سال دهم شماره 3 (پیاپی 29، پاییز 1393)

Traditional raw milk cheese is one of the most consuming cheeses in the world. Kurdish cheese is a semi-firm، traditionally made in the East of Iran. It is manufactured from raw sheep or cow milk and kept in goat’s skin bags during ripening period. As a result Kurdish cheese is often more complex in different varieties of microorganisms، which whose organoleptic properties make it highly esteemed. Changes in free fatty acid (FFA) and free amino acids (FAA)، could have great importance in Kurdish cheese final Characteristics. In this project، Changes in FFA and FAA contents of Iranian Kurdish cheese، in local condition، during 10، 30، 50 and 70 days of ripening periods were evaluated. Most FFA significantly increased throughout maturation (P)

Determination of the body composition weight due to the growing ostrich farms in Iran is a beneficial subject. It is so important for dependent industries to know the effects of sex and slaughter conditions on carcass quality. In present study، the mean value for hot yield (55. 93%) was higher than cold yield (54. 70%). Blood، feather and skin were evaluated as the maximum and the hide as the minimum body weight parts. Effect of sex on the body composition weight was insignificant (p>0. 05). The mean value for cooling loss in carcasses was 2. 2% that did not influence by sex significantly (p>0. 05). The average values for drip loss in 1 and 7 days of postmortem were 1. 52% and 1. 68% respectively. The mean value for cooking loss in male and female ostriches were calculated 31. 85% and 33. 55% respectively while this parameter in stunned ostriches were evaluated 33. 30% and in non-stunned one were 32. 10% (p>0. 05). Although drip and cooking losses increased during 14 days، there were no significant effects of ageing، sex and slaughter conditions (p>0. 05).

Biodetoxification is considered as one of the method for eliminating of aflatoxins including aflatoxin M1 (AFM1). In the present study، the ability of Lactobacillus acidophilus (La-5) in reduction of AFM1 in a simulated gastric model was studied. In this regard، two levels of bacterial suspension (3×109 and 3×1010 cfu/ml) were used to determine their ability to reduce three concentrations of AFM1 (0. 05، 0. 25 and 0. 5 ppb). The incubation times in the simulated gastric model were 0، 30، 60. 90 and 120 minutes. AFM1 concentration was determined by competitive ELISA. Results showed that the presence of Lactobacillus acidophilus (La-5) was more effective at higher concentration for removal of aflatoxin. Also، removal content for 0. 05، 0. 25، 0. 5 ppb AFM1 were 76. 09، 52. 26 and 76. 19 respectively.

Due to variation in economic value of different varieties of rice، reports indicating the possibility of mixing different varieties on the market. Applying image processing and neural networks techniques to classify rice varieties is a method which can increase the accuracy of the classification process in real applications. In this study، several morphological features of rice seeds’ images were examined to evaluate their efficacy in identification of three Iranian rice varieties (Tarom (Mahali)، Fajr، Shiroodi) in the mixed samples of these three varieties. On the whole، 666 images of rice seeds (222 images of each variety) were acquired at a stable illumination condition and totally، 17 morphological features were extracted from seed images. Fisher''s coefficient (FC)، Principal component analysis (PCA) methods and a combination of these two methods (FC-PCA) were employed to select and rank the most significant features for the classification. The so called LVQ4 (Learning Vector Quantization) neural network classifier was employed for classification using top selected features. The classification accuracy of 98. 87، 100 and 100% for Fajr، Tarom and Shiroodi، 100 and 100% for Fajr and Shiroodi، 100 and 100% for Tarom and Shiroodi and 97. 62 and 95. 74% for Fajr and Tarom were obtained، respectively. These results indicate that image processing is a promising tool for identification and classification of different rice varieties.

The effects of a couple of factors (cooking period of wheat: 0، 1 and 3. 5 h and temperature of drying 70، 80 and 90 C) on drying behavior of Tarkhineh during hot-air drying has been investigated. Tarkhineh pill samples with 8 cm diameter and 11 mm thickness were dried to 0. 64 (d. b). Results showed that cooking of wheat led to higher water absorption of Tarkhineh dough، while increased drying rate. On the other hand، increasing drying temperature resulted in higher drying rate of samples. The effects of temperature on drying rate was pronounced in raw samples compared to cooked ones، which could be attributed to the cracking in the cooked samples during drying. Drying kinetics of Tarkhineh in raw samples unlike cooked samples presented a falling rate period followed by a constant rate period. The effective moisture diffusion coefficient of Tarkhineh varied between 1. 611E-10 & 7. 822E-10 (m2/s)) for the given temperature range) and corresponding activation energy was between 37. 928 and 17. 941 (kJ/mol) respectively.

Saffron is the most important Iranian non oil export. Improper conditions of saffron flower storage increases microbial contamination and decreases saffron quality. This study was done for prolonging the shelf life of saffron flower in modified atmosphere packaging and subsequent to producing a new method for exporting the fresh saffron flower as cut flower. Saffron flowers were packed in a polymer (Polyamide- Polyethylene bags) and three gas combinations of CO2، O2، and N2 (30%،5%،65%; 50%،5%،45% and 70%،5%،25% respectively). Samples and Control (without packaging) were kept at 0 c for 15 days. Every three days the concentrations of oxygen and carbon dioxide inside the packages، the yield of product، physical (weight loss، percent of the flowers welter، the length and diameter of fresh stigma) and chemical properties (percent of moisture and the amount of Crocin، Safranal and Picrocrocin of dried stigma) were measured. The existence of E. Coli and enumeration of yeasts and moulds also were done. The results showed that modified atmosphere packaging increased the shelf life of saffron flowers. The chemical and physical qualities of control were lost strongly during 9 days. There were no evident for E. Coli growth in the samples. Enumeration of yeasts and moulds showed that most treatments were seen the national standard of Iran (103cfu/gr).

The aim of present study was to investigate and compare antioxidant properties of green tea and rosemary extracts and determine the effect of their combination on the antioxidant properties. Results of total phenols، DPPH free radical scavenging assay، total antioxidant capacity، reducing power and their addition into soybean oil، showed that the green tea extract was significantly (p)

Wheat germ is a by-product of milling industry rich in fiber، tocopherol، unsaturated fatty acids، polyphenol، minerals and protein. In this study، effect of adding raw and stabilized wheat germ on the characteristics of cake batter such as specific gravity، viscosity and cake properties such as volume، apparent density، solid density، porosity، water activity، moisture and firmness was studied. Raw wheat germ was stabilized by steaming for 15 min and subsequent drying at 80 °C for 20 min. It was then ground and added to cake formulation at levels of 5، 10، 15 and 20 % (on flour wet basis). Results showed that adding wheat germ changed the characteristics of cake batter. With increasing amount of raw and stabilized wheat germ، specific gravity and viscosity of cake batter increased and reduced، respectively. Important difference was observed in the physical characteristics between wheat germ enriched and control cakes. Increasing wheat germ in cake formulation decreased cake volume and porosity، while apparent and solid densities were increased. Investigation of moisture content and firmness، in several days of storage، showed that the cakes enriched with raw germ had the higher moisture content than those enriched with stabilized germ. Cakes enriched with stabilized wheat germ had the highest firmness. Incorporation of stabilized wheat germ by controlling its detrimental effects relating to lipase activity which leads to fat rancidity، could favor production of a functional cake with improved nutritional properties.

Cellulose nanocrystal (CNC) is a type of nanomaterial which is produced by partial hydrolysis of cellulose and elimination of its amorphous regions. CNC has several advantages such biodegradability and safety toward human health. In this study، CNC was produced from cotton linters and methods such transmission electron microscopy which were used for confirmation of nanoscale size production of cellulose crystals. Due to the disadvantages of pure starch films، in the present research، for improving the properties of plasticized starch-PVOH films، from nanoparticles CNC and TiO2 are used together، then effects of nanoparticles and glycerol determined on physical properties by response surface methodology (RSM). CNC and GLY showed significant linear effects on ultimate tensile strength (UTS) of nanocomposit and there were significant interaction effects between TiO2 and CNC، and also between GLY and TiO2. The optimum levels of TiO2، CNC and GLY for obtaining maximum UTS were as 0. 118، 0. 6 g and 1. 06 ml، respectively. In addition، the TiO2 concentration had linear and quadratic effect on the contact angles of bionanocomposites and optimum levels of TiO2، CNC and GLY for obtaining maximum contact angles were 0. 112، 0. 299 g and 1. 06 ml، respectively. UV-visible spectroscopy studies in the wavelength range 200–800 nm showed that adding of CNC and TiO2 decrease the light transmission and increase the opacity، adding of glycerol increase the light transmission and decrease the opacity.

In recent decades، as the result of industrial life، consuming fried and fast foods have increased significantly. Excessive use of fat، especially saturated fats and trans fatty acids is one of the important factors that increases heart diseases، weight gain، and cancers. Therefore، using effective methods for decreasing fat absorption not only retains desirable features but also seems essential. In this study، the effect of subtituting wheat flour with lentil flour on the batter formulation (in different level of 10، 25 and 50 percent) on the rheological properties of batter، amount of moisture and oil content، and color of fried crusts investigateded by using a deep-fried crust model at three temperature (140، 160 and 180oc) and for 90، 180، 270 and 360 s frying times. Consistency index showed a significant increase by increasing subtitution of lentil flour in batter formulation. Moreover، all the batters showed shear-thinning behaviour. The findings indicated that Batter formulations، temperature and frying time significantly (p < 0. 05) affected moisture content، oil content and color of fried Crusts. Results of the study indicated that as frying time increased، the amount of moisture content reduced and increased the oil content of the final product. Also، with increasing substitution of lentil flour، moisture removal decreased and therefore، oil uptake decreased. 50% lentil flour substituted samples was found to be an effective formulation in decreasing oil content of fried crusts at all the times. Conrol sampel showed the lowest moisture content and highest oil content among all the formulations. 50% lentil flour substituted samples was found to be an effective formulation in decreasing oil content of fried crusts at all the times. Conrol sampel showed the lowest moisture content and highest oil content among all the formulations. Temperature leaded to an increase in moisture removal and an increase in oil content. By increasing frying time، temperature and subtitution of lentil flour in battre formulation، L*parameter decreased and a* and b* increased.

Pasta products are known in all countries of the world and the quality of them are dependent on the technology and type of flour. At the present، these products are producing with wheat flour and old technology، or semolina and modern technology. The goal of this study was the Assessment of spaghetti''s quality that are producing in Iran، for this purpose Samples were taken from all factories in the Khuzestan province that have produced spaghetti via old method and characteristics of them based on the standard methods، compared with spaghetti produced by modern technology. The analysis showed، the cooking، chemical، sensorial and microbiological characteristics have significantly different (p≤ 0. 05) in types of spaghetti. So that the amount of protein and cooking time of these samples were fewer and cooking loss of them was more than the control samples. On the other hand، the panelists were evaluated the appearance، color and taste of controls better than others samples. The results also showed that the amount of the microbial contamination، except coliform، were in the standard range، however، the content of the infection in these samples were more than the controls.

In this study، response surface methodology and face central composite design in order to investigate decolorization and clarification extraction of Kaluteh date was used for the production of liquid sugar. The optimum amount of bentonite (1-3 g/l) and gelatin (0/02-0/08 g/l) was determined that the desired amount of bentonite and gelatin، 3 and 0/05 (g/l)، respectively. To determined the optimum conditions for maximum activity of these two compounds for clarification with regard to fixed amount of bentonite and gelatin، three factors determine the temperature (30-70 °C)، pH (4-6) and time (40-120 min) was implemented. Parameters consists of the colors، ash and absorbance. Bentonite and gelatin at low temperature and pH with over time، more active and reduce the mount of impurities. The least amount of this responses for the color at 420 (nm)، ash and absorbance at 660 (nm)، 4302 Icumsa، 0/421 % and 0/059، respectively. By comparing amounts in the optimum point the clear syrup by bentonite and gelatin، the initial syrup، it was found that this technique able to reduce the mount syrup color، ash and absorbance، 68/25 %، 8/7 % and 89/46 %، respectively.