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The consumption of fermented milk products, including yogurt, has been increased dramatically as people become aware of the functional and health resources. Quinoa seeds have recently received more attention due to their favorite nutritional properties and high content of protein, amino acids, fatty acids, minerals, and essential vitamins. Therefore, in this study, the fortification of beneficial yogurt with quinoa and its effect on physicochemical and microbial and organoleptic properties of product were investigated. Flour of quinoa seeds were added to yogurt milk at three levels (2, 4, and 6%). A sample of each treatment is selected every week and were analysed with respect to physicochemical (texture, pH, acidity, dry matter, hydration, etc.), microbial (starter count and yeast mold), and sensory properties compering to control samples. Based on the results of physicochemical tests, addition of quinoa flour significantly reduced syneresis, pH, and increased acidity, dry matter, viscosity, fiber, fat, and ash contents. The evaluation of color of samples showed that L index decreased while a and b indexes increased significantly with increasing the percentage of quinoa flour. On the other hand, the starters counts increased in fortified samples due to the nutrients of quinoa. Sensory properties were not significantly different between fortified and control sample except of texture that was improved with quinoa addition. The results of this study showed that the use of quinoa flour in stirred yogurt can led to producing a product with desirable and functional characteristics [ABSTRACT FROM AUTHOR]

Today, the use of Lactobacill strains and their metabolites is the new strategies in control of diabetes and oxidative stress. Therefore, the present study aimed to investigate the antidiabetic and antioxidant properties of metabolites obtained from of Lactobacillus delbrueckii ssp. bulgaricus culture media. The samples were evaluated including cell free supernatant (CFS), cell free extracts (CFE), cell free supernatant of fermented milk (CFS -FM) and bioactive peptides separated from ultrafiltration (3,5,10 kDa). The ability of bacteria in proteolysis of protein of fermented milk (FM) was evaluated by O -phthaldialdehyde method compared with non -fermented milk (NFM). The antidiabetic activity was measured based on inhibition of α -amylase and α - glucosidase. The antioxidant activity was evaluated by inhibition of 2,2 -Diphenyl - 1 - picrylhydrazyl (DPPH) and 2,2 -azino -bis - 3 -ethylbenzothiazoline - 6 -sulfonic acid (ABTS). The results showed that the sample of CFS -FM inhibited α -amylase (25%) and α -glucosidase (26.6%) enzymes. Among the peptide fractions, fraction of >10 kDa with higher protein content (13.816 mg (had the highest inhibition of α -amylase (80.64%) and α -glucosidase enzyme (54%) (p<0.05). The inhibitory efficiency ratio (IER) showed that the 3 -5 kDa fraction had more inhibitory than other peptide fractions (p<0.05). Also, the CFS and CFE inhibited α -glucosidase enzyme by 50% and 25%, respectively. In case of antioxidant properties, it was observed that the free radicals scavenging of CFS -FM increased compared with NFM (p<0.05). Also, the peptide fractions of 3 -5 kDa (80.85%) and >10 kDa (43.63%) had the highest DPPH and ABTS free radicals scavenging. The antioxidant capacity of trolox equivalent from peptide fractions (µmTE/mg protein) showed that the <3 kDa fraction had the highest antioxidant activity (p<0.05). The ability to free radicals scavenging in CFS and CFE was observed. Results indicate the importance of Lactobacillus delbrueckii as a starter culture and its functional role. [ABSTRACT FROM AUTHOR]

Nowadays, Polysaccharides are used to improve the nutritional and physicochemical properties of dairy products. The identification of natural compounds such as polysaccharides with antidiabetic and antioxidant properties has become important due to the relationship between diabetes and oxidative stress. Therefore, the present study aimed to evaluate the influence of pectin on the antidiabetic and antioxidant activity of milk fermented by lactic acid bacteria (LAB) isolated from traditional Iranian dairy products. Pectin (1%) was added to the samples following milk fermentation by Lactobacillus helveticus and Lactobacillus para-casei strains, and antidiabetic activity was assessed by considering the inhibitory effects on α-amylase and α-glucosidase. The antioxidant activity was determined by evaluating inhibition of 2,2-Diphenyl-1-picrylhydrazyl (DPPH), 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and hydroxyl radicals. Samples included pectin solution (0.5-3.5 mg/ml and 0.5-10 mg/ml for evaluation of anti-diabetic and antioxidant activity, respectively), whey of fermented and non-fermented milk with (1%) and without pectin. The results indicated the role of pectin on inhibition of α-glucosidase enzyme activity (IC50=2.38 mg/ml), as well as scavenging the DPPH (44.57%), ABTS (28.7%), and Hydroxyl (38.85%) radicals (P<0.05) a concentration of 10 mg/ml. Pectin added to the whey of non-fermented milk sample boosted antioxidant properties and the maximum rate of free radical scavenging activity (35%) was obtained for DPPH radicals. Furthermore, adding pectin to the whey of milk fermented with Lactobacillus helveticus strain improved the activity of the product on inhibition of α-glucosidase enzyme (29%), scavenging of DPPH (41.26 %), ABTS (2.5%), and hydroxyl radicals (7.64%) (P<0.05). The results indicated the potential of pectin to be used in the formulation of beneficial food products due to its ability to improve the antioxidant and anti-diabetic properties of fermented milk products. [ABSTRACT FROM AUTHOR]

In this study, milk fermentation capability by 6 isolates of lactic acid bacteria, proteolytic activity of lactic acid bacteria in milkby ortho-phthaldialdehyde (OPA)reagentand antifungal property of lactic acid bacteria in MRS broth and skim milk against Aspergillus flavus and Candida albicanswere studied. L. brevis KMJC1, L. acidipiscis KMJC2, L. curvatus KMJC3 and L. plantarum KMJC4 isolated from Jug cheese, L. helveticus KMCH1 isolated from camel doogh (Chal) and Lac. lactis KMCM3 isolated from camel milk were used. The results showed thatamong the isolates,L. plantarum KMJC4after 48 h, Lac. lactis KMCM3 after 16 hand L. helveticus KMCH1 after 60 hhad milk fermentation capability. The measurement of proteolysis rate performed infermented milk by mentioned isolates using OPA reagent indicated that the proteolytic activity of L. helveticus KMCH1, Lac. lactis KMCM3 and L. plantarum KMJC4 were 0.34, 0.26 and 0.22 mg/ml, respectively. In study of the antifungal effect of supernatant resulting from the activity of lactic isolates, it was found that supernatant obtained from culture in MRS broth had a more inhibitory effect (MIC= 25 and 50 mg/ml) than the supernatant obtained from the culture in the skim milk, as the MIC was not observed for the supernatant obtained from fermented milk. In the end, it can be concluded that Lac. lactis KMCM3 was able to ferment lactose in milk in comparisonwith other isolates in shorter time (16 h). The highest proteolytic activity of the isolates in milk was related to the isolate of L. helveticus KMCH1 (0.34 mg/ml). L. plantarum KMJC4 isolated from Jug cheese was as the best isolate for the preparation of supernatant resulting from MRS broth with the antifungal property. [ABSTRACT FROM AUTHOR]

Today, consumption of milk and its products is one of the signs of development of human societies. Milk is a healthy, nutritious, delicious and thirsty drink that is consumed by a large group of people, especially children. Therefore, the aim of this study was using grape syrup as a flavoring in probiotic milk containing Bacillus coagulants and investigating effects of grape syrup on physicochemical and microbial properties of probiotic milk. For this purpose, two quantitative factors including grape syrup concentrations (0.17, 1, 3, 5 and 5.83 %) and storage time (0.96, 2, 4.5, 7 and 8.04 days) in five levels were evaluated by using a central composite design. The results showed that different concentrations of grape syrup and storage time on pH, acidity, dry matter, fat and viability of B. coagulation of probiotic flavored milk were significant (P<0.05). Optimum condition was obtained based on maximum pH and viability of B. coagulation and minimum acidity. The optimum condition was 1% grape syrup and 2 days’ storage time, which its total desirability was 95%. [ABSTRACT FROM AUTHOR]

Kefir is one of the fermented milk products that plays a major role in nutrition and human health. The aim of this study was to investigate the effect of adding asparagus extract and green tea extract on survival of probiotic bacteria, antioxidant activity and sensory properties of kefir. Different concentrations (0.5, 1 and 1.5%) of asparagus extract and green tea extract were used in kefir and the samples were stored at 4 ̊C for two weeks.The results showed that addition of herbal extracts decreased pH and increased acidity and antioxidant activity of the samples (p≤0.05). The highest antioxidant activity was related to the sample containing 1.5% green tea extract. During storage time, pH of the samples decreased, but acidity increased significantly (p≤0.05). There was no significant difference between samples in terms of viability of Bifidobacterium lactis and Lactobacillus acidophilus (p>0.05). The viability of probiotic bacteria decreased significantly (p≤0.05) during storage but in all samples, the number of bacteria was more than 108 CFU/ml until the end of the storage period. The sample containing 1.5% asparagus extract had the highest score of overall acceptance. Therefore, this sample was selected as the best treatment. [ABSTRACT FROM AUTHOR]

Kefir is a kind of dairy drink with unique and exotic flavor that is traditionally produced from fermented milk with kefir grains included a mix of bacteria and yeasts. The phase separation during storage of kefir results in an unfavorable appearance, which is known as a defect, which can be controlled by making the cross- links between the milk proteins. In this research, the addition of the microbial transglutaminase enzyme (m-TG) to diminish the syneresis and its effect on the aromatic compounds of kefir was investigated during one-month storage at a refrigerated temperature using a solid phase microextraction method combined with a gas chromatography-mass spectrometer. The results showed that the adding of the m-TG to kefir significantly affected the syneresis of kefir and caused reduce in phase separation of kefir during storage. In total, 51 volatile compositions were isolated and identified from kefir samples using SPME-GC/MS. Most of the identified compounds include acids, alcohols, ketones, esters, and aldehydes, respectively. The results indicated that the storage time significantly affected the amount of all volatile compositions, so that some volatile compounds increased, while some volatile compounds decreased during storage. The m-TG had no effect the content of the volatile constituents except for alcohols. The findings of this study revealed that the total amounts of alcoholic and acidic compounds as well as carbon dioxide were increased during storage. On the other hand, total amounts of ketones, aldehydes and esters in kefir decreased during storage.Based on the findings of this study, it could be concluded that the use of m-TG without significant effect on the properties of aromatic compounds of kefir reduces its syneresis during storage. [ABSTRACT FROM AUTHOR]

Free radicals are a major cause of many diseases, such as cancer, by damage to the cells. The use of probiotic strains in fermented dairy foods has expanded due to the health-promotion effects of the consumer. Regarding antioxidant potentials of probiotic bacteria, the aims of this study were compared the antioxidant activity of probiotic species L. acidophilus LA5 and B. animalis subsp. lactis BB12 used in foods and investigate effects of incubation temperature, Initial ph, fermentation time, yeast extract concentration and linoleic acid concentration on their antioxidant activity in enriched cheese whey and milk permeate. The results showed that fermentation time, incubation temperature and concentration of yeast extract were the most important factors that had a significant effect on both DPph free radical inhibitory activity and hydroxyl radical scavenging activity (p <0.05). DPph free radical inhibitory activity and hydroxyl radical scavenging activity increased with increasing incubation temperature and yeast extract concentration, respectively. Antioxidant activity was observed in the first 24 hours of fermentation process, which was proportional to bacterial growth. Hydroxyl radical scavenging activity and DPph free radical scavenging activity, as a result of the probiotic culture activity and their effect on the substrate, increased and decreased, respectively, in the first 24 hours of fermentation time, by destruction the polymers. This study showed that the fermentation bioprocess by L. acidophilus LA5 and B. animalis subsp. lactis BB12 in the cheese whey as a medium had high antioxidant activity. [ABSTRACT FROM AUTHOR]

Yogurt is the most widely used fermented milk product, which, like any other dairy product, is subject to corruption and degradation. The effort to improve the production process and improve the quality and durability of this product is essential. Plants such as Allium iranicum that contain natural compounds and have medicinal properties, taste and appetite, have great importance in food products. These plants can delay the degradation of foodstuffs and are used as seasonings, flavors, preservatives and antioxidants in food industry. In this study, the effects of Allium iranicum adding to yogurt were studied to improve the quality and shelf-life of the product. Allium iranicum powder was used in 3 levels of 0.5 %, 1.25% and 2% in the production of stirred yogurt. Two quantitative factors such as concentration of Allium iranicum powder and storage time were investigated using a growing factorial design with central points. After collecting data, analysis of variance and linear regression were used to investigate the effects of factors and their significance. After data modeling, the effects of powder percent and storage time on physicochemical properties (pH, acidity, WHC, antioxidant activity, syneresis, dry matter, viscosity, color properties and sensory properties) were investigated. The results showed that with increasing the percent of Allium iranicum powder, the acidity of the samples increased during storage and the dry matter increased with increasing the concentration of Allium iranicum powder. Viscosity, WHC, synergy and sensory and colorimetric properties were desirable in lower levels of Allium iranicum powder. Antioxidant activity increased with increasing powder percent and decreased during storage time. The highest total acceptance of yoghurt samples was for samples containing powder (1.25%) and 2% showed a negative effect on sensory function. According to the results, it was found that the Allium iranicum powder at 1/25% level could improve the properties and durability of yogurt samples. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effects ofconsumption of different amounts of fermented milk by L.casei on serum lipid trends including total cholesterol, LDL-C, HLD-C, VLDL-C and triglyceride in the serum of rats fed 1 and 2% cholesterol enriched diet. For this purpose 49 male albino wistar rats with a body weight of 200±15 gr were randomly allocated to seven groups each containing 7 rats and adapted to new conditions during a week. Rats in the first group (control group) received commercial diet and water for 30 days, the second to fourth groups received diet enriched with 1% cholesterol and rats in the fifth to seventh groups received diet enriched with 2% cholesterol. Each rat in the fourth and seventh groups (double dose receiving treatment groups) consumed fermented milk containing 4×108 CFU bacteria per day, rats in the third and sixth groups (single dose receiving treatment groups) consumed fermented milk containing 2×108 CFU bacteria per day and in the second and fifth groups (sham group) consumed sterilized milk instead of fermented milk. According to the statistical tests, one way analysis of variance and Tukey at a level of α= 0.05, mean levels of total cholesterol and LDL-C of rats in the double dose receiving treatment groups and single dose receiving treatment groups were significantly lower and mean level of HDL-C was significantly higher than sham group (p