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Background and objectives: Salmonella is one of the important food poisoning agents. The common method for its identification in foodstuffs is by using media cultures. This method is timeconsuming and does not have good precision. In the present study we compared PCR as an alternative, rapid and more precise method in identification of Salmonella Typhimurium serovar in milk purchased from the local supermarkets. Materials and methods: Six pasteurized milk sample bags were purchased and divided in 2 parts 3 were contaminated manually with different numbers of Salmonella typhimurium (10-1 –103), the other, non-contaminated, 3 being used as control. All were enriched in BPW (buffer peptone water) media and analyzed by both the PCR and common bacterial culture methods. Results: The PCR method could identify 10, 5, and 1 Salmonella typhimurium in the contaminated samples after 8, 12, and 16 hours of enrichment with BPW, respectively. Identification by the common culture media required a longer time (4-6 days) and was less precise. All the purchased milk samples were found to be free of any contamination with Salmonella typhimurium, using either both methods. Conclusion: These findings show that by using the PCR method it is possible to isolate and identify Salmonella typhimurium in milk in less than 24 hours with at least one bacterium in the sample, while with the culture media methods the time required is 4-6 days. Furthermore, in spite of good agreement between results obtained by the 2 methods, the PCR method has a higher precision and sensitivity.

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Background and objectives: Iron deficiency anemia is one of the most prevalent nutritional deficiencies in the world, as well as in Iran. A solution to this problem is fortification of foods with iron. In this study the possibility of milk fortification with microencapsulated iron was investigated. Materials and methods: Two kinds of iron salts were microencapsulated by two novel methods, and the efficiencies and optimum conditions of the methods were compared. Then, milk fat oxidation, color indices and sensory characteristics of the fortified milks during storage for 3 days at 4 OC were studied. Results: Maximum efficiency (ME) was obtained with microcapsules with a ratio of iron ion-to-lipid (0.04) and a 5 molar % of Tween 80 in the liposome method (ME=85.5%), and at ratio of polyglycerol monostearate-to-iron salt of 15 to 1 in the F.A.E. method (ME=81.8%). The minimum and maximum milk fat oxidation was observed in milks fortified with irons microencapsulated by F.A.E. and plain iron, respectively. From a sensorial point of view, there was no difference between milks fortified with iron microencapsulated by F.A.E. at a concentration of 7 mg L-1 and control. Conclusion: Based on the findings of the present study, it can be concluded that the F.A.E. method, due to its simplicity, low cost, reasonableness, rapidness of the process, as well as higher stability of the microcapsules obtained, is an appropriate method for iron microencapsulation and fortification of pasteurized milk.

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Background and objectives: Flat bread the main source of Iranian diet and the important carbohydrate supplier at food basket of our country. With regard to important of extension of shelf life and decrease of their wastage the objective of this study was to produce Iranian barbary bread with soymilk powder in an attempt to enhance its nutritional value and retard its staling. Materials and methods: Soymilk powder was substituted at 4 levels, namely, 3%, 5%, 7%, and 10%, for wheat flour to produce barbary bread a type of traditional, flat thick bread. The samples of soymilk powder, treated and control flours were analyzed for moisture, ash, protein, fat, fibre, pH, particle size, wet and dry gluten, falling number, and Zeleny value). Staling of bread samples was assessed by six trained panelists 1, 3, and 5 days after production. Results: Soymilk powder brought about statistically significant (p<0.05) increases in the ash, fiber, total fat, and protein contents, while it decreased wet and dry gluten, Zeleny value and falling number. pH of the treated samples was not significantly affected. Results of the sensory evaluation showed that a 10% substitution of wheat flour by soymilk powder created an unpleasant odor in the bread sample, though the least value was reported for the staling of this bread sample. However, addition of 7% soymilk powder had no undesirable effect on the sensory characteristics of bread in addition, the rate of staling was also acceptable for this sample. Conclusion: Substitution of soymilk powder (at 3%, 5%, and 7% levels) for wheat flour in making Iranian barbary bread not only will enhance the nutritional value of the bread, but it will also improve its shelf-life, without any undesirable effect on its sensory characteristics. Keywords: Soy milk powder, Barbary bread, Staling, Sensory evaluation

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Background and Objectives: One of the major defects in acidified milk–fruit juice mixtures is their physical instability due to low pH, low viscosity, and sedimentation of caseins. In the present study, the influence of some commercial and local gums on the stability, rheological, and sensory properties of milk–orange juice mixture was investigated. Materials and Methods: The effects of pectin, locust bean gum, guar gum, gum tragacanth, Persian gum, water-soluble fractions of gum tragacanth (tragacanthin) and Persian gum over a wide range of concentrations on the physical stability of milk–orange juice mixtures during storage at low temperature (4 C, 30 days) were determined. Moreover, the stabilization mechanisms were studied using rheological (rotational and oscillatory tests), zeta potential measurements, and microstructural observations. Finally, sensory evaluation was made on the physically stabilized samples. Results: Pectin, locust bean gum, guar gum, gum tragacanth, Persian gum, and water-soluble fractions of tragacanth and Persian gum effectively prevented phase separation for 30 days at concentrations of 0.5%, 0.5%, 0.4%, 0.3%, 2.2%, 0.175% and 1.0%, respectively. Furthermore, combinations of water-soluble fractions of gum tragacanth and Persian gum (ratios of 4:96 and 19:81) at a concentration of 0.37% or 0.53% caused stabilization. The best fitted rheological models for the control (milk–orange juice mixture without hydrocolloids), the pectin-containing one, and rest of the samples were Bingham, Herschel-Bulkley, and Power law, respectively. In terms of sensory properties, the mixture stabilized with a combination of water-soluble fractions of gum tragacanth and Persian gum (0.53% w/w) achieved the highest scores by the taste panels (p<0.01). Conclusions: Based on the findings of the present study, water-soluble fractions of gum tragacanth and Persian gum can be categorized as anionic hydrocolloids which are adsorbed on the surface of caseins which can prevent aggregation via steric and electrostatic repulsions by simulating a hairy layer. In addition, their insoluble fractions could promote physical stability of the mixtures due to making a gel-like network and increasing viscosity. Keywords: Milk, Orange juice, Stabilization, Hydrocolloids, Tragacanth, Persian gum, Rheology

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Background and Objective: Raw milk is a source of new strains of bacteriocin-producing lactic acid bacteria (LAB) with the potential to inhibit undesirable microorganisms. The aim of this work was to detect the bacteriocin-producing LAB from raw ewe's and goat's milks and characterize the isolated bacteriocins. Materials and Methods: A total of 100 samples of ewe's and goat's milks were screened for bacteriocin-producing lactic acid bacteria. Two strains were selected and identified phenotypically to genus level. The serums of cultures of the selected strains were treated with various enzymes to detrmine the nature of their antimicrobial substances. The inhibition potential of the substances was investigated by agar well diffusion assay and their stability at different temperatures and pH's were determined. The antimicrobial substances were partially purified by ammonium sulphate and poly-ethylene gltcol (PEG) and the titer determined. In addition, their molcular weights were determined by SDS-PAGE analysis and their resistance estimated during storage at 4 °C. Results: The two strains of Enterococcus, Le40 and Le50, exhibited a broad antimicrobial activity in several replicates. The sensivity of the inhibitory substances to proteolytic enzymes confirmed the production of enterocin-like substances (ELS) by these strains. Listeria monocytogenes and Staphylococcus aureus were inhibited by the ELSs. The ELSs were both stable at a wide pH range (pH 3-10) and the one isolated from Le50 was resistant to heat. Partial purification of both the ELSs increased their activity and titer. Their molcular weights were between 24 and 29 KD. Finally, the ELS's activity was maintained during storage at 4 °C for 28 days. Conclusion: Considering the desirable antimicrobial characteristics and biochemical properties of the isolated ELSs, further studies to explore the possibility of using them as biopreservatives in food processing is recommended. Keywords: Enterocin-like, Enterococcus, Milk, Staphylococcus aureus, Listeria monocytogenes

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Background and Objective: Tofu (soybean curd) is one of the most important soya protein products. It has a low-energy content and is a very suitable replacer for cheese and meat for persons who are sensitive to lactose, cholesterol and saturated fatty acids contained in these animal products. In this research, the effects of a hydrocolloid, namely, carrageenan, at a concentration of 0.1% and 0.2% (w/w of soya milk) and two coagulants, namely, glucono-Delta-lactone (GDL) and calcium chloride (CaCl2), on the quality characteristics of Tofu were investigated. Materials and Methods: Soya milk, carageenan and the 2 coagulants, GDL and CaCl2 ,were used in the formulation of Tofu. Soya milk samples were heated at 100C and then carageenan and coagulants were added and mixed to obtain soya curd. This was followed by removing the serum phase of the soya curd specimens and measuring the quality parameters (yield, color, texture and sensory properties) of the final product.. Results: Addition of carageenan brought about increases in the yield, lightness (L*- hunter parameter), softness and flexibility of the Tofu produced by using GDL and CaCl2. The CaCl2-Tofu specimens showed more hardness (fracture force) than the GDL-Tofu samples. The results of sensory evaluation showed that addition of carageenan caused decreases in hardness and elasticity and increases in freshness and moisture of the samples, the effects being more pronounced in the GDL-Tofu specimens. Conclusion: The types and amounts of hydrocolloids and coagulants, as well as interaction between them, in making Tofu can have important effects on its yield and quality parameters. In this study, carageenan (at a level of 0.1%) and GDL showed the best results. Keywords: Tofu, Carageenan, Rheological properties, Physical properties, Tofu (soybean milk)

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Background and Objective:Frozen yogurt is obtained by freezing a mixture containing milk fat, milk solids-non-fat (MSNF), sweeteners, stabilizers, and yogurt. Increased milk solids-non-fat is one way to avoid undesirable changes in texture observed in low-fat products. Thisincrease in MSNF also helps greatly improve health properties of these products. Since frozen yogurt is considered a low-fat dessert, in this study the effects of milk solids-non-fat content on its physical, chemical and sensory characteristics were investigated. Materials and Methods:Ingredients included milk (2.5% fat and 8% solids-non-fat), skim milk powder (98% solids-non-fat), cream (30% fat), starter yogurt (DVS Lat 1/63, including Streptococcus salivarius subsp. thermophilus and Lactobacillus delbrueckii subsp.bulgaricus), sugar, vanilla powder, and panisol ex. All samples contained 8% fat, 13% sugar, 0.3% stabilizer and 0.09% vanilla. To produce test samples,the milk solids-non-fat content was adjusted at 13%, 16% and 19% levels with skim milk powder. Statistical analysis of the data was performed by completely randomized two-factor design with 3 replications using the MSTAT-C software, and analysis of variance was done with Duncan’s multiple range test (p<0.05). For drawing diagrams the Excel software was used. Results: Titratableacidity, pH, viscosity, overrun capacity and melting characteristics of ice cream were influenced favourably significantly (p<0.05) by increasing MSNF. Increasing the MSNF content significantly (p<0.05) decreased pH, overrun capacity and resistanec to melting of ice cream, while it increased titratable acidity and viscosity. The dataalso showed that samples with 13% MSNF resulted the highest scores in texture and total acceptance (p<0.05). Conclusion:Increases in milk solids-non-fat content of frozen yogury affects favourably its properties. Based on the findings in this study, 13% MSNF is suggested for producing concentrated frozen yogurt. Keywords: Frozen yogurt, Milk solids-non-fat, Physiochemical

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Background and Objective: Phenylketonuria is a hereditary disease caused by a lack or deficiency of the enzyme phenylalanine hydroxylase, its most severe clinical manifestation being irreversible mental retardation. Presently, the only therapy available is the dietary restriction of phenylalanine. The objective of this study was to produce laboratory-scale low-phenylalanine milk to be used as a dietary supplement by phenylketonurics. Low-phenylalanine milk can be used to make a variety of palatable, low-phenylalanine foods and beverages. Materials and Methods: Three milk hydrolysates were prepared enzymatically (1g of enzyme/100 g of substrate), using a protease from Aspergillus oryzae and papain, separately and in combination (0.5 g of either enzyme/100 g of substrate), followed by adding different amounts of activated carbon (0.3, 0.9, and 1.5 g) to them to remove phenylalanine. Results: The combination of Aspergillus oryzae protease and papain, along with the use of 0.9 g activated carbon in the post-hydrolysis process, resulted in the lowest final phenylalanine content. Conclusion: The best condition for removing phenylalanine from milk was use of a combination of Aspergillus oryzae enzyme(0.5g of enzyme/100g of substrate) and papain (0.5 g of enzyme/100 g of substrate) with 0.9 g activated carbon in the post-hydrolysis process, resulting in removal of 99% of the phenylalanine. Keywords: Low-phenylalanine milk, Activated carbon, Enzymatic hydrolysis, Second derivative spectrophotometry

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Background and Objective: Prevention of physical instability of chocolate milk is an important challenge in the field of food science, particularly dairy technolohy. In this study, the effects of high-intensity ultrasound treatment on stability of cocoa particles in chocolate milk, with or without the presence of stabilizers, was investigated. Materials and Methods: Chocolate milk was exposed to ultrasound (maximal nominal power 600 W at 20 kHz) at various levels of power intensity (24, 72 and 120 W), exposure times (2, 6 and 10 minutes) and temperatures (25, 45 and 65ºC) for 30 days. κ-carrageenan at concentrations of 0.000, 0.010, 0.015 and 0.020 %, with or without sugar (7.0% and 0.0%), was added to the samples. Results: Increasing power intensity and exposure time led to a significant increase in physical stability of the milk samples − the milk phase volume decreased and the cacao phase increased. Moreover, the phase separation and cacao particle sedimentation were effectively prevented in the treated samples (ultrasonic power 120W, exposure time 2 min, temperature 45ºC, κ-carrageenan 0.02%, and sugar 7%) after 30 days of storage at 4ºC, while phase separation and cacao particle sedimentation occurred in the control sample (containing 0.040% κ-carrageenan). The findings also showed that sugar improved cacao milk stability. The milk phase volume in the presence of 0.02% κ-carrageenan, kept at a temperature of 45 ºC for 30 days, was less than that of samples kept at other temperatures. Conclusion: Based on the findings of the present study, it seems that ultrasound can increase the stability of cacao particles in milk. In addition, ultrasound treatment possibly degrades the κ-carrageenan network, particularly at higher temperatures. Furthermore, cavitation, probably due to entrapment of air in the κ-carrageenan network, may weaken the gel network. Keywords: Cacao, Chocolate milk, Ultrasound, Stabilization, Hydrocolloids, Carrageenan

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Background and Objective: Date syrup, as a native and nutritious additive, is one of the best choices for milk flavoring. In this study, some of the rheological, physical and sensory properties of date milk made from three different concentrations of two types of Iranian gum tragacanth, as a substitute for imported gums, were determined. Materials and Methods: Rheological properties of samples of date milk containing three different concentrations (0.1%, 0.2%, 0.3% w/w) of two types of gum tragacanth (Astragalus.gossypinus and Astragalus.rahensis) were measured using a rheometer at 3○C, and at three different time periods (one, two and three days) after production. Particle size distribution was determined by laser diffractometry, and colorimetric assays were done by using reflection spectrometer. Sensory analysis was performed by 25 semi trained panelists, using a 5-point hedonic scale. Results: Findings showed that flow behavior parameters, particle size and color parameters (L*, a*,b*) were significantly affected by concentration of the gum tragacanth and the impact severity was influenced by the type of gum. Based on sensory evaluation, samples containing 0.3% A.gossypinus and 0.2% A.rahensis showed higher desirability than others. Conclusion: Using an appropriate type and concentration of gum in date milk formulation can improve the milk texture and mouthfeel by affecting the particle size and flow behavior. Keywords: Date milk, Date syrup, Gum tragacanth, Rheology, Sensory evaluation

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Background and Objective: Inadequate intake of Calcium and vitamin D is one of the common health problems, especially among the children in developed as well as developing countries, including Iran. Fortification of foodstuff, specially milk and dairy products, is being used as a major strategy to combat this problem in many countries. This study aimed to evaluate sensory desirability and compliance with vitamin D and Calcium-fortified milk, among 9-11 year-old schoolchildren in the city of Tehran. Materials and Methods: This cross sectional study was conducted in two phases including sensory evaluation and compliance with vitamin D and Calcium fortified-milk in schoolchildren. The first phase was performed by a panel of 212 schoolchildren from both sexes using a 5- point hedonic questionnaire with both images and words. And, the second phase was carried out on 200 children using an 8-item questionnaire. Results: In sensory evaluation 44.4% of the students described the taste of the fortified milk as bad, while in the compliance study 85% of children were satisfied with the taste of vitamin D and Calcium - fortified milk. Only less than half of the students agreed with the continuation of the fortification program. Conclusion: Calcium and vitamin D fortification, resulting in unpleasant changes in the taste of milk, can challenge fortified milk distribution program for children. Further study is needed to provide a formulation that would result in a higher compliance among schoolchildren. Keywords: Compliance, Vitamin D and Calcium fortified milk, School age children, Sensory evaluation

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Background and objectives: Nowadays there is an increasing tendency to natural foods with low calorie and high keeping quality. Stevia is a kind of natural sweetener with antioxidant activity, zero calorie and sweetness of 250-300 times than that of sugar. Compared with artificial sweeteners it does not lead to health problems. The aim of this study was to assess the effect of using stevia sweetener on peroxide value of chocolate milk in order to have an extend shelf-life product. Materials and Methods: This study was carried out on 9 treatments with 3 replications. Stevia was substituted with sucrose in two portions of sucrose to stevia 50:50 and 0:100. Inulin, as a thickening agent, in four levels of 0%, 2%, 4% and 6%, was added to the treatments with 50% and %100 of stevia. The control sample contained no stevia and no inulin, such as commercial ones. After the homogenization process, the samples were exposed to the temperature of 74°C for 15 seconds to be pasteurized and then were cooled to 4°C. Peroxide value was measured in day 0, 3 and 5. Data analysis was implemented by ANOVA at the significant level of 0.05, using SPSS software ver. 17. Results: Sugar replacement with stevia caused significant increase in peroxide value of samples (p<0.05). Increasing the concentration of stevia resulted in decreasing the peroxide value. Samples containing 100% stevia had lowest values of peroxide. In day 0 and 3 there were no significant difference among the samples, but in day 5 significant differences were revealed. Conclusion: The present study showed that stevia sweetener can have a good effect on promoting shelf-life of the product by reducing the peroxide index. Keywords: Chocolate milk, Dietary, Stevia, Inulin, Peroxide value

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Aflatoxins are hazardous fungal toxin that produces in sufficient moisture, heat and preservation unfit condition and could brought about serious hazards to consumer health. The aim of this study was systematic review on the Aflatoxin M1 level in raw, pasteurized and UHT milk in Iran. Articles, guidelines and specific databases such as SID, PubMed, Scirus, Elsevier, Science Direct, WHO were searched for related topics cited since 2000. Early season definition, and other variables such as sample size, study location and comunity, means and range contamination were analyzed. According to the results, there was a lack of methodological consistency and standard inconsistent unit in the literature, and draw conclusions were difficult. Results about Aflatoxin M1 level higher than standard in type of milk were different. Contamination in cold season was higher than heat season. Milk is one of the most complete foods and its contamination is serious risk for public health. Notify Aflatoxin M1 reduction methods in milk and dairy products are necessary. Keywords: Aflatoxin M1, Raw milk, Pasteurized milk, UHT milk, Iran

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Cancer is a leading global cause of death and disability in the world. Observational evidence suggests that approximately 30–40% of cancer cases are potentially preventable via modification of nutritional factors and food consumption patterns Milk is considered to be the only foodstuff that contains approximately all different substances known to be essential for human nutrition. In terms of cancer risk, dairy foods have been reported occasionally as harmful. The indusive effects of milk and dairy products on risk of cancers and the role of indigenous and exogenesis ingredients have been discussed in this review article. Pubmed, Science direct, Springer and Google scholar databases were searched in order to achieve the desired articles. Cellular, animal as well as human studies that have been conducted from 1980 till 2012 were recruited in this investigation. However, the results of some previous studies indicated that some indigenous and specially exogenesis ingredients of milk and dairy products may affect in increasing risk of some types of cancer. But, the proven health benefits of dairy foods greatly outweigh the unproven harm. In fact, there is certainly no evidence that milk consumption might increase death from any condition. Despite the occasional reports about the probable causative effect of milk or milk product consumption on some types of cancer, such as prostate cancer, there are ample convincing evidences through thousands of years of consumption that shows their definite impact on health, health maintenance, survival and longevity. Moreover, the probable harmful effect of milk and dairy product consumption related to cancer is dose-dependent. The Cancer Council and USDA recommend 3 servings dairy of milk and milk products. It is generally acceptable that high consumption of milk and dairy products with low hygienic standards and with relatively high levels of contaminants and toxins, or their consumption by the special patients that are susceptible to some dairy ingredients could enhance the risk of emerging/progressing cancers. As an overall conclusion, normal consumption of dairy foods products with high hygienic standards should be encouraged as part of a varied and nutritious diet. Keywords: Milk, Dairy products, Cancer, Inducing risk factor

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Cancer is a leading global cause of death and disability in the world. Observational evidence suggests that approximately 30–40% of cancer cases are potentially preventable via modification of nutritional factors and food consumption patterns. Milk and milk products are recognized as functional foods, suggesting their use has a direct and significant effect on health outcomes and their consumption correlates with a reduced risk of numerous cancers. The preventive effects of milk and dairy products on risk of cancers and the role of indigenous and exogenesis ingredients have been discussed in this review article. Pubmed, Sciencedirect, Springer and Google scholar databases were searched in order to achieve the desired articles. Cellular, animal as well as human studies that have been conducted from 1980 till 2012 were recruited in this investigation. Various studies have shown that dairy consumption is associated to reduced risk of cancer due to the presence of compounds such as vitamin D, linoleic acid, calcium, proteins such as casein, whey , lactoferrin, which are potential anti-cancer properties. Also, the uses of functional dairy products or fermented products have contributed to the escalation of this property. There are ample convincing evidence through thousands of years of consumption of dairy products that shows their definite impact on health, health maintenance, survival and longevity. As an overall conclusion, normal consumption of dairy foods products with high hygienic standards should be encouraged as part of a varied and nutritious diet as they are essential to maintain good bone and dental health to counter osteoporosis, major cardiovascular disease risk factors, hypertension, type-2 diabetes, metabolic syndromes, as well as some cancers Keywords: Milk, Dairy products, Cancer, Prevention

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Freeze concentration is a process of concentrating liquid products by freezing the water content and subsequently removing the so-formed ice crystals from the food system. In dairy processing, this technology offers the advantage of minimizing the heat abuse of sensitive milk components, such as proteins and flavors. It thus provides an opportunity for producing dairy ingredients with enhanced functional and organoleptic qualities. By freeze concentration, skim milk has been concentrated up to 40wt% total solids (TS) and whole milk up to 44wt% TS. Lactose and lipids are more concentrated in the ice fraction than in the concentrated fraction. Proteins (casein and whey protein) decrease the ice growth rate and the high viscosity is a limiting factor for the freeze concentration of both skim milk and whole milk. In this study, the most important studies relating to the suspension, block and layer freeze concentration of milk are summarized, analyzing results and indicating how freeze concentration process efficiency of dairy products can be improved. Keywords: Freeze concentration, Dairy products, Whey, Skim milk, Whole milk

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Casein possesses important physiological and biological properties with regard to promotion of health, as well as prevention of diseases. Anticarcinogenic activities, reduction in the risk factors of cardiovascular disease and anticariogenic features have been associated with casein. In addition, casein is known as a source of bioactive peptides. Casein-derived peptides have been found to have a variety of specific properties, such as antihypertensive and ACE inhibitor activity, antimicrobial, opioid, immunomodulatory traits. In this article some health- related aspects of casein are reviewed. Pubmed, Science direct, Springer and Google scholar databases were searched in order to achieve the desired articles. Cellular, animal as well as human studies that have been conducted from 1980 till 2012, were recruited in this investigation Researches indicate the biological benefits of casein and casein-derived peptides on health- related aspects. Several studies demonstrate impacts of casein on prevention of tumor incidence and growth as well as inhibition of carcinogenesis. Casein and casein hydrolysate products also reduce the risk of cardiovascular disease via the reduction of blood cholesterol level and prevention of hypertension. Furthermore, Casein and its bioactive peptides prevent from dental caries by inhibiting the activity of cariogenic bacteria, stabilizing the amorphous calcium phosphate as well as reducing the hydroxyapatite dissolution. In addition, casein derived peptides regulate the immune responses through the regulation of proliferation and activity of immune cells. Collectively, with regard to the broad biological functions of casein in association with health conditions as well as prevention and treatment of diseases, consumption of these proteins in healthy subjects and patients could be beneficial. More human studies about health benefits of casein are necessary to achieve to substantial evidences. Keywords: Milk proteins, Casein, Bioactive peptides, Biological effects

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Background and Objective: Full-fat dairy products have been reported as a major disease risk factor, particularly for cardiovascular diseases, due to their high cholesterol and saturated fatty acid contents. In this study, Iranian brined white cheese samples were prepared using olive and canola oils, known to contain essential unsaturated fatty acids, and compared with cheese made with full-fat milk. Materials and Methods: Iranian brined white cheese samples were prepared by substituting milk fat with olive and canola oils (at a level of 50% or 100% w/w) known to contain essential unsaturated fatty acids. A full-fat cheese (FFC) sample was prepared as the control. Physicochemical properties, lipolysis patterns, total fatty acids, total count of lactic acid bacteria starters, and sensory characteristics of all the samples were determined during 80 days of storage (ripening) at 20-day intervals. Results: Results showed that white brined cheeses made with vegetable oils had significantly (P<0.05) lower contents of saturated fatty acids and higher levels of unsaturated fatty acids compared to FFC control. The moisture contents and pH were also significantly (P<0.05) higher in the experimental cheeses than in the control cheese during ripening. Further analysis of the data showed that lipolysis index significantly (P<0.05) increased in all the experimental and control samples during the ripening period. Total counts of Lactococcus bacteria increased during the first 40 days of ripening but then decreased slightly, whereas the total count of Lactobacillus bacteria decreased during the first 40 days but increased afterwards Conclusion: It can be concluded that Iranian white brined cheese can be successfully made by substituting milk fat with vegetable oils, such functional cheese being nutritionally more acceptable and healthier. Keywords: Milk fat, Functional cheese, Fatty acids, Olive oil, Canola oil

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Background and objective: Milk pasteurization and sterilization processes prolong its shelf-life and also promote the safety of dairy products. On the other hand, these processes can also have adverse effects on the nutritional quality and safety of milk and dairy products. Formation of cross-linkages between amino acids in the protein molecules may produce undesirable compounds, e.g., lysinoalanine (LAL), resulting in reduced availability of some of the essential amino acids, as well as nephrotoxicity effects. The aim of this project was to determine the LAL content of pasteurized and sterilized milks consumed in the City of Tehran. Materials and Methods: Determination of protein in milk samples was done by the Kjeldahl method. Hydrolysis of milk proteins was done using 6N hydrochloric acid and placing the samples in the oven at 110 0C for 22 hours. The hydrolyzed protein samples were then dissolved in distilled water and the pH was adjusted to 9 by addition of 12N sodium hydroxide. For derivitization of the liberated LAL, dansylation was done by adding dansyl chloride (10mg/ml isopropyl alcohol) at 40°C for 60 minutes. LAL then measured in the samples by high performance-liquid chromatography. Results: The LAL content of raw milk samples obtained from a milk processing plant and dairy shops was zero and 5 mg/kg, respectively, while it was 35-86mg/kg in the pasteurized, and 110-233mg/kg in the sterilzed, samples. In addition, the data showed that the LAL content of sterile milk samples would increase gradually at days 1, 7, 15, 30 and 60 during storage at 25°C. Conclusion: The findings of this study show that lysinoalanine is prsesent in both pasteurized and sterilized milks, it being higher in the latter. In addition, the lysinoalanine contents of pasteurized and sterilized milks consumed in Tehran are higher than those in other countries. Considering that both children and adults consume milk daily in Tehran, controlling lysinoalanine content in pasteurized and sterilized milks marketed (by contolling time amd temperature) is of utmost importance. Keywords: Milk, Pasteurization, Sterilization, Lysinoalanine, HPLC

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Background and Objectives: The effect of the different proteins and polysaccharides on the characteristics of low-fat cheese has been a topic of recent study. The release of aromatic compounds from the cheese is affected by the addition of texture improvers. The present study investigated the addition of polysaccharides and proteins on the hardness, microstructure and ester release of low-fat brined cheese. Materials and Methods: The addition of 0.01% xanthan or milk protein concentrate to low-fat milk was studied by compression testing with a texture analyzer and scanning electron microscopy. To determine the release of aromatic compounds, 0.1% ethyl acetate, ethyl butyrate, and ethyl hexanoate were added to cool pasteurized milk and the amount of aroma released was evaluated using SPME-GC-MS. Results: The hardness and density of the casein aggregates of low-fat cheese decreased in the presence of xanthan and increased in the presence of milk protein concentrate. The release of esters from low-fat brined cheese was affected by the addition of xanthan and milk protein concentrate this could be related to the affinity of polysaccharides and proteins to bind to aromatic compounds and to changes in the hardness of the cheese. Conclusion: The release of aromatic compounds was affected by the texture improver added to low-fat brined cheese. This effect should be considered when selecting a texture improver as a replacement for fat. Keywords: Milk protein concentrate, Texture, Low-fat brined cheese, Xanthan