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In this study, the optimum combination of major factors affecting the acceptability of whey-based Ricotta cheese i.e. fat at three levels (0, 5, 10%), salt at three levels (0, 1, 2%), and starter culture at two levels (0, 3%) was determined in a complete randomized design method with a factorial experiment. Ricotta cheese trials made by mixing whey and milk in a ratio of 5:1 were then organoleptically judged on the basis of the main attributes such as color, flavor, texture, and overall acceptability. The collected data were then statistically analyzed using a seven point hedonic method. The results show that the addition of fat had a significant effect on all sensory attributes (p< 0.05). The incorporation of salt in the formulation also had a significant effect on flavor, color, and overall acceptability (p< 0.05) as well as on texture (p< 0.01), whereas the addition of starter culture had a significant effect only on texture (p< 0.01) and overall acceptability (p< 0.05). It was concluded that a combination of 5% fat, 2% salt, and 3% starter culture gains a higher score and could be recommended as the preferred formulation for Iranian consumers.

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The objective of this experiment was to investigate the antimould effect  of 19 Lactobacillus plantarum strains isolated from different production stages of  Lighvan cheese (3, 8 and 8 strains from raw milk, curd and fresh cheese stages, respectively) a traditional raw milk cheese, on  Penicillium expansum  (PTCC 89046) as an indicator  in fruit juice spoilage. This antimould spectrum was determined by agar spot and well diffusion method, followed by determination the influence of different technological or physico-chemical factors including  temperature (80°C for 1 h, 100°C for 10 min, 100°C for 30 min and 121° C for 15 min) and pH( 2 to 7) and different dilution (Titre test) . Serial twofold dilutions were conducted to the CFE in order to assess of CFE Titre against mould indicator. Findings revealed that Lactobacillus plantarum strain C28 has the highest antimould properties in both antimicrobial methods (Agar Spot and Well Diffussion Assay) and antimould effect showed decreasing trend with pH increasing. In 121 ° C for 15 min, no antimould effect was observed. The Lactobacillus plantarum strain C28  showed the highest titre  factor of 160 (AU / ml) .  Finally, we can assume that these strains which isolated from different production stages of Lighvan cheese or their Cell Free Extract (CFE) can be used as biopreservative in food systems.  

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In this research different methods of DNA extraction from Aspergillus niger in tomato paste have been optimized and compared with each other. For this purpose classical optimization techniques and commercial Kit base methods were used. Mold spores of Aspergillus niger at different levels (10¹, 10³ and 10⁵ CFU/g) were added to the tomato paste. After mycelium growth DNA extraction was perfomed by five methods. Different methods employed by use the Liquid nitrogen, ultrasonic and lysis solution in the cell wall. These methods in terms of quality and quantity of DNA extracted were studied using spectrophotometer with NanoDrop. The absence of smear, protein contamination and no presecnce of PCR inhibitors determined with PCR that performed forward and reverse primers. Result of gel electrophoresis and PCR assay showed that Method 1 is the most appropriate method for DNA extraction is the mold of tomato paste.

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The objective of this study was to assess the microbial contamination of Razavi Khorasan (Iran) hot red pepper. The natural occurrence of aflatoxins and ochratoxin A in those samples was also investigated. For this purpose, 36 samples of this kind of pepper were collected from a farm and sun-dried. Standard and established methods were used for both microbiological analyses and mycotoxins identification. Total aerobic mesophilic counts of samples varied from 10² to 4×10⁶ cfu g^-1. Coliforms were present at high levels in all samples ranging from 1.9×10² to 3.52×10⁶ cfu g^-1that may indicate inappropriate hygienic quality of samples. 42% of the samples were of unsatisfactory quality due to the presence of E. coli. In all samples examined, sulphite-reducing clostridia (SRC) was below detection limit and Salmonella spp. was not detected. Fungi were found in all of the collected samples. Mold and yeast were generally high ranging from 2.4×10³ to 4.6×10⁶ cfu g^-1and the most predominant fungal genera were Aspergillus spp., Penicillium spp and Rhizopus spp. Considering the results obtained, the samples analyzed contain a high level of microorganisms and only two samples (6%) had acceptable levels for all microbial factors according to EU Commission Recommendation (directive2004/24/EC). 69% and 17% of samples were found contaminated with total aflatoxins and ochratoxin A, respectively, that might contribute to health hazards for humans. Overall, The Razavi Khorasan hot red pepper samples collected for this study were contaminated with microorganisms and mycotoxins, which suggests that hygiene practice pre- and post-harvesting must be improved if the region is to exploit fully the potential for this valuable product.

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In this study, Response Surface Methodology (RSM) was used for optimization of the conditions for hot air drying of pear slices with osmosis pretreatment. The effects of two parameters including drying temperature (50-70 °C) and drying time (240-360 minutes) as independent variables on moisture content, shrinkage percentage and rehydration ratio of pear slices as dependent variables (responses) were evaluated. The regression models for all responses were statistically significant at the 99% confidence level and lack of fit was not significant. All process variables had linear effect on all the responses (p <0.01). Also the quadratic term of drying temperature on rehydration ratio was significant. The optimum conditions obtained for minimum moisture content and shrinkage percentage and maximum rehydration ratio were: 39.60 °C as drying temperature and the drying time of 360 minutes. In optimized condition, the moisture content, rehydration ratio and shrinkage percentage of dried pear slices were 26.17%, 1.62 and 77.31 respectively.

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There is a global interest to study lactic acid bacteria (LAB) of artisanal fermented products like yoghurt for improving or replacing current strains used in commercial starter cultures. In this work, five traditional yoghurt samples were collected from different areas of Khorasan-e-Razavi. Grouping and identification of isolates were carried out on the basis of physiological and biochemical tests (non-molecular),as well as ARDRA technique and sequencing (molecular methods). Totally, 71 isolates including 33 Streptococcus thermophilus, 30 Lactobacillus delbrueckii (subsp. Bulgaricus and lactis), were identified as dominant strains in all yoghurt samples. Also 8 other isolates belonging to Lactobacillus helveticus, Pediococcus pentosaceus and Weissella cibaria were observed. Results of this research show the diversity of LAB population in collected samples.

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Rheological properties of chocolate are important in manufacturing process for obtaining high-quality products with well-defined texture and are directly influenced by composition and their refining time. Soy protein benefits from nutritional and functional properties to be used in different foods. Effects of different replacement levels of skim milk powder by soy flour, (from 0 to 100%) and ball mill refining time (105 and 135 minutes) on particle size and rheological properties of compound chocolate were investigated. Considering four rheological models, it was found that compound chocolate behaved as a Casson fluid .Overall, the results indicated that Casson plastic viscosity values ranged between 1.36 and 5.47 (Pa s) and replacing skim milk powder with soy flour led to a significant (P< 0.05) increase in Casson plastic viscosity in either of the refining time treatments. Casson plastic viscosity and apparent viscosity also increased for all the replacement levels with increase in refining time from 105 to 135 minutes. Values of Casson yield ranged from 11.23 to 38.88 (Pa). By replacing soy flour, Casson yield value increased significantly (P<0.05). Casson yield value also increased with increase in refining time in samples containing only skim milk powder, but it decreased in samples containing soy flour.

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Guar gum and whey proteins concentrate (WPC-35) were used as functional additives to improve the functional characteristics (hardness and meltability) of the Na-caseinate-based imitation cheese. Also, the alterations in the composition, sensory acceptance, color, and texture caused by these ingredients were evaluated. Imitation cheeses were formulated with three levels each of WPC (0, 1.5, and 3%) and guar gum (0, 0.3 and 0.6%) w/w in cheese formulation. Cheeses with higher guar and lower WPC were softer and melted to a greater degree. Use of the two food additives at increasing levels reduced the amount of protein significantly (P< 0.05). Unlike guar, WPC increased pH values. Color of the cheese was affected positively by guar and negatively by WPC (P< 0.05). The overall acceptability of the cheese was not affected by the levels of WPC, but it did improve with increasing level of guar used in the formulation. Taking into consideration the adverse impact of WPC on color and meltability and slight adverse effect of guar on the hardness of imitation cheese, use of WPC at 1.5% and guar at 0.3% level in the formulation of imitation cheese is recommended.

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In this study, the antibacterial effect of eucalyptus extract on different bacteria showed that the bulk of compounds present in the sap of eucalyptus leaves were formed by the phenolic compounds. starch was prepared for the production of starch film was used to improve the quality of film by 10 % of the volume of glycerol. ground beef production was evaluated by adding 0.5 and 1.5 percent of eucalyptus oil to the film, then ground mutton meat was packed with film, and microbial and chemical properties and transparency of meat after preservation in the fridge were studied in times 1, 3 and 6 days. according to the results, inhibition of DPPH increased with an increase in the amount of extract and the highest percentage was reported on day 3. also the results of TBA with a decrease in the amount of extract decreased and the maximum reduction rate was reported on day 3. according to the results, the total population count of microorganisms decreased with an increase in the amount of extract and the maximum reduction rate was reported on day 3, but did not have significant differences with the sample count on the day 6 with the spread of corruption. (P> 0.05) is based on the results that Staphylococcus aureus has decreased by increasing the amount of extract and the maximum reduction rate is reported on day 3. However, on the day 3 at 0.5 %  extract , its extracts and on the day 6 with the spread of corruption, the number of samples did not show significant differences. according to the results, the amount of transparency and color spectrum decreased with the increase of the extract and had significant differences with the sample. (p < 0.05)

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Folate is a term used for a set of compounds with similar biological activities. Folate (polyglutamates) naturally contains all forms of vitamins in this family. In other words, folic acid is a form of folate that is oxidized, this compound is stable and can be absorbed by humans (monoglutamate)[1]. There are several methods for measuring folate, but due to the fact that in this study, the production of extracellular folate (Quatrofolate) was examined, so the microbial assay method was used as the main method. Lactobacillus. Rhamnosus (ATCC7469), which is used as a sensing organism. [2,3] This method can also measure all forms of folate. In this study, 47 medical strains isolated from traditional dairy products were Special Khorasan. traditional yogurt (12 strains of Streptococcus.thermophilus and 15 strains of Lactobacillus delbrueckii subsp. Bulgaricus, 13 strains of Lactobacillus delbrueckii subsp. Lactis, 3 strains of Lactobacillus helveticus) were studied. The results of this evaluation showed that both strains (25 and 26) of Lactobacillus delbrueckii subsp. Bulgaricus produced significant high folate concentrations (133.23 μg / mL and 102.34 μg / mL), as well as K73 strain of Streptococcus.thermophilus, strain 73 from the strains of  Lactobacillus delbrueckii subsp. Lactis and strain No.87 from the three strains of Lactobacillus helveticus (90.29 μg / mL, μg / mL39.71, μg / mL 17.94), were also able to produce high amounts of quatrofolate. According to this study, it was found that the examined previously isolated strains have a potential ability to produce extracellular folate, and the microbial assay method for measuring a sensitive vitamin such as folate in all its forms is considered an efficient and accurate method.
 

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One of the most important steps in the refining process for edible oils is the coloring step. Decolorization is an absorption process that involves the use of acid-activated clay to remove undesirable components of oil. Therefore, it is necessary to optimize the parameters of decolorization, mainly temperature, time and concentration of decolorizing soil in order to prevent adverse changes of the oil in the next stages and during storage. In this research, corn oil was selected and the effect of changing the dyeing parameters on the chemical properties of the oil was studied in order to optimize the process. For this purpose, the effect of time (15, 25, 35, 45 and 55 minutes), temperature (80, 90, 100, 110 and 120 degrees Celsius) and the concentration of soil-dye remover (0.4, 0.6, 0.8) , 1 and 1.2 percent) was investigated using the statistical design of the response level in 5 levels by the Central Composite Design method with the aim of reducing the consumption of soil-dye remover. The effect of decolorization parameters on oxidative stability (peroxide number, anisidine number, totox number, free fatty acid amount, Rancimet test and specific absorption at 232 nm and 270 nm), decolorization efficiency (carotenoid amount) and bioactive compounds (sterols amount) in Corn oil was studied. The results showed that after optimizing the best conditions for the decolorization stage in corn oil in order to minimize impurities, preserve bioactive compounds, and minimize the consumption of decolorizing soil, the time of decolorization was 35.59 minutes, the temperature was 103.61 degrees Celsius, and the soil concentration The dye was 1%, which was able to meet 57% of expectations. The practical results did not show any significant differences with the theoretical values ​​and confirmed these results.

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The bleaching process is important in the refining operation of edible oils. In this study, bleaching parameters were changed to evaluate the best condition for optimizing of bleaching in corn and sunflower oils. For this purpose, the effect of time (15, 25, 35, 45, and 55 min), temperature (80, 90, 100, 110, and 120 °C), and bleaching clay concentration (0.4, 0.6, 0.8, 1, and 1.2%) was evaluated using response surface methodology as statistical design in 5 levels by Central composite design with the aim of reducing the consumption of bleaching clay. The studied factors were including carotenoids, sterols, tocopherols, pigment and cations. After optimization, the best conditions for bleaching of corn and sunflower oils was different. For corn oil, the best conditions was time 39.59 min, temperature 103.61 °C, and bleaching clay concentration 1%, which meet 67% of our expectations. For sunflower oil with the aim of reducing the consumption of bleaching clay, the best conditions were time 37.49 min, temperature 97.53 °C and bleaching clay concentration 1%, which satisfied 70% of our expectations. The practical results did not show any significant differences with obtained theory values ​​using response surface methodology and confirmed these results.
 

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Production and use of biodegradable films with appropriate physical and mechanical properties and replacing them with synthetic materials is an effective solution to reduce many environmental pollutions. In this study, with the aim of producing biodegradable consistent structure and durable composite films, starch, zein and PVA were mixed with different proportions according to mixture design and ternary composites were prepared.Physical and mechanical properties were compared and optimum formulation were determined. According to the results, adding PVA to starch improved the mechanical properties and adding zein to it reduced the water solubility of the composite films. The optimal formulation of the three-component composite was determined as 85% starch, 15% zein and 5% PVA with a desirability level equal to 98%.The x-ray diffraction patterns of optimal film showed two specified peak at 2θ = 17-19 ° and 2θ = 22-24°, this pattern indicated the amorphous and crystalline structure of the composite film. Finally, differential scanning calorimetry showed that the highest weight loss of composite film is 285/3-340°C equal to 48/2%.