Background & Aims: High concentrations of selenite have carcinogenetic, cytotoxic and genotoxic effects. Therefore, removal of this toxic pullutant from the environment has a particular importance in maintaining public health. In this study, with the aim of optimization of selenite removal process, the design Box-Behnken method was used to estimate the simultaneous effect of variables on removal efficiency and to determine the optimal values of variables on selenite removal with the probiotic bacterium Lactobacillus sp. Tra CHEESE 6.Methods: An experimental method using a three-level Box-Behnken method for testing the effects of four factors including concentrations of selenite ion, cell biomass, NaCl and agitation was investigated. Statistical Data Analysis was performed using Analysis of Variance (ANOVA) method. Regression coefficients of the second-order polynomial model were estimated. Then, by integrating the results and drawing a multivariate quadratic equation, the optimal point was precisely determined. Design-Expert software was used for data analysis.Results: Optimum removal of selenite was obtained at initial concentration of Selenite 49.5 mM, biomass concentration of 56 g/l, NaCl concentration of 4.2% (w/v) and agitation at 100rpm. Under these conditions, the optimal selenite removal was 77.12% after a 24-h reaction under the resting cells of Lactobacillus sp. Tra CHEESE 6.Conclusion: In the current study, Response Surface Methodology based on Box-Behnken design was successfully applied for improving selenite removal with the probiotic bacterium Lactobacillus sp. Tra CHEESE 6.

Processed or melted CHEESEs are producing in variation kinds because of variety in material blends. using ultrafiltered feta CHEESE and milk protein co-precipitate in this processed CHEESE is possible. also, creamy texture of this product is a good and cheaper competitor and substitute for ultra filtered feta CHEESE that because of creamy texture, more increased its prod. and consumption. Also because of using amount of milk protein co-precipitate, decreased its prod. cost and because of hot process, has long shelflife and formability for many of packaging methods. Using %25-30 protein co-precipitate with kinds of CHEESE can produce good product from view point texture, consistency, spreada bility and flavour that because of dry matter recovery in protein co-precipitate is more than %16 from rennet curd (fresh CHEESE) and ultra filtered CHEESE yield is %20 more than usually CHEESE yield, these samples are cheaper from usually commercial products. It is also because of using %5-15 very ripened CHEESE that because of high proteolysis is unsuitable for human direct consumption.

Background and Objectives: Local CHEESE made from raw milk is one of the most commonly consumed dairy products in the world. Mycotoxin contamination of foodstuff and its transmission to consumers are extremely important public health issues. The purpose of this survey was to determine the level of aflatoxin M1 (AFM1) residues in Koupeh CHEESE, a traditional fermented Iranian CHEESE produced in spring and summer. Methods: We randomly collected 48 local CHEESE samples produced in Mahabad (northwest of Iran) during spring and summer. The level of AFM1 was measured by enzyme-linked immunosorbant assay using commercial kits and a microplate reader. Results: All samples contained measurable amounts of AFM1. Cow milk CHEESE samples contained higher level of AFM1 compared to sheep milk CHEESE samples. The level of AFM1 in the samples from both animals was lower in summer. There was no significant difference between the mean level of AFM1 in summer and spring. Moreover, 33. 3% of cow milk CHEESE samples collected in spring and 16. 6% of the samples collected in summer contained toxin levels higher than the maximum allowed concentration set by the European Commission (250 ng/Kg) and by the Institute of Standards and Industrial Research of Iran (200 ng/Kg). Conclusion: The results of this study show that the level of AFM1in Koupeh CHEESE is influenced by the livestock type and production season, in a way that the level of contamination is higher in spring.

Objective: To determine the levels of aflatoxin M1 (AFM1) in produced CHEESEs by different plants in province of Tehran.Design: Cross- sectional study.Sample: Eighty CHEESE samples.Procedure: Chromatography was used for determining the presence of AFM1.Statistical analysis: One- way analysis of variance and Tukey test.Results: AFM1 was found in 83.8% out of 80 CHEESE samples. The range of contamination levels varied among different months. AFM1 in June, September, December, and March ranged from 197 to 1423, 177 to 1274, 179 to 1506 and 219 to 2918 ng/ kg, respectively. However, the mean values were 549.7, 503.9, 602.1 and 749.6 ng/ kg, respectively. Moreover, the highest mean concentration of aflatoxin M1 (AFM1) was registered in samples March (2918 ng/ kg). The lowest mean concentration of aflatoxin M1 was registered in samples of September (177 ng/ kg). Statistical evaluation showed that there were no significant differences (P>0.05) among the mean concentrations of AFM1 in CHEESE samples of June, September, December and March. However, mean concentrations of AFM1 in CHEESE samples of spring and summer was significantly lower than autumn and winter (P=0.004).Conclusion: It can be concluded that the high occurrence of AFM1 in CHEESE is probably due to the presence of aflatoxin in the feed. This condition should be considered as a probable hazard for human health.

In the present study, effects of Entroccocus faecium, Lactobacillus agilis, Lactobacillus plantarum, Strepoccucus thermophilus and a mixed culture from 3 former isolates were investigated on organoleptic characteristics of Iranian white CHEESE. The isolates used in this study that had been isolated from the Iranian Lighvan CHEESE, collected from central labrotory of Gorgan University. Ten CHEESEs were manufactured according to method of making of white Iranian CHEESE using ewe’s and cow’s milk which had been bought from Gorgan city. Organoleptics test performed by 8 trained panelists revealed that there is significant difference at 5 % significant level in organoleptics scores between Lighvan and manufactured CHEESE so that lighvan CHEESE and CHEESE prepared with ewe’s milk and mixed culture had most and least sensory score respectively. However, there was no significant difference between other prepared CHEESEs but the CHEESE prepared with cow’milk and mixed culture had the most score of organoleptic test. Results of organoleptic test showed that, type of milk has very important role in the development of organoleptic charectrestics of CHEESE. Also different speices of lactic acid bacteria associate in its flavor development.

Introduction: CHEESE has a complex structure with differences within the same variety that depends on the compositional factors and the changes occurring during ripening. Whitebrined CHEESE, its production and some physical, chemical, rheological and textural properties were evaluated during six months ripening in this research study.Materials and Methods: Standard methods were used to examine the influence of ripening period (at the end of each month during six months) on the characteristics of White-brined Golpayegan CHEESE (36 samples). The rheological and textural properties of the CHEESE were evaluated using a rheometer (the frequency sweep test) and a texture analyzer (the uniaxial compression test).Results: During ripening pH, total solid, protein and total nitrogen in total solid (TN/TS) of White-brined CHEESE were decreased while the amount of titratable acidity, fat in total solid, water soluble nitrogen in total nitrogen (WSN/TN) and non-protein nitrogen in total nitrogen (NPN/TN) were increased significantly (p<0.05). On the basis of the small amplitude oscillatory test and the uniaxial compression test during maturation, the storage modulus (G'), loss modulus (G"), fracture stress (sf) and firmness have been increased (p<0.05) while the loss tangent (tand) has been decreased (p<0.05). The fracture strain ( ef) was kept constant (p>0.05).Conclusion: The results showed that ripening time significantly affected the physicochemical, chemical, reological and textural properties of White-brined CHEESE.

Background and Objectives: This study is the first research on the physiochemical characteristics, microbial population and microstructure of Poosti CHEESE over 90-days of ripening. The main difference between Poosti CHEESE and other types of traditional CHEESE is the skin, which is used for its storage.Materials and Methods: Physicochemical characteristics including moisture, salt, pH, acidity, fat, and rate of water-soluble nitrogen to total nitrogen were measured during the ripening. Total population of mesophilic and psychrotrophic bacteria, Escherichia coli, Coliform, lactic acid bacteria, yeasts and moulds were determined during the aging. Micro-structural properties of Poosti CHEESE were evaluated by scanning electron microscopy (SEM). Three-dimensional (3D) images, binarised micrographs and surface plot were obtained by analyzing the two-dimensional (2D) SEM micrographs by Image J software.Results: The results showed that the moisture content, pH and fat percentage were decreased during the aging; however, salt, acidity, and ratio of water-soluble nitrogen to total nitrogen were increased during this time. Besides, the total count of bacteria was decreased during the aging. Finally, the SEM images indicated that the density of casein network, the number and depth of pores, and also roughness of the structure were increased during the ripening.Conclusions: According to this study, physicochemical characteristics of Poosti CHEESE were changed during the aging (salt and fat were increased, while pH and moisture were decreased) as a result of ripening in the skin and high microbial population of raw milk. The microstructure of Poosti CHEESE was changed during the ripening due to water and salt movement, and the fermentative activity of microbial population.