Inroduction: Rice is one of the main food crops consumed by a huge global population. The by-‎products of rice after milling are germs, broken rice, and bran. Bran is the most favorable by-‎products of rice and wheat. Rice bran is a source of fiber with the balance level of soluble and ‎insoluble dietary fiber, high amount of minerals, and vitamin. Rice bran is rich in nutrients such ‎as protein (15%), fat (20%), and fiber (10%). It also provides a rich source of vitamins and ‎minerals such as thiamin, niacin, aluminum, chlorine, iron, magnesium, phosphorus, potassium, ‎and sodium. Also rice bran has some antioxidants such as ferrulic acid, tocopherol, oryzanol, ‎and tocotrienol. It contains lysine nearly 4 times higher than rice due to having the out layer of ‎rice. On the other hand, the use of probiotic foods, especially probiotic dairy products, in the ‎consumers community is much preferred rather than probiotic pharmaceutical products, ‎therefore, the development of probiotic food products seems necessary. Objectives: The aim of ‎this study was to produce a probiotic fermented dairy beverage containing Bifidobacterium ‎bifidum, Lactobacillus casei, and rice bran extract. Methods: Rice bran was obtained from a ‎rice milling complex in Amol and sterilized in an autoclave at 160°C for 1 hour. Then, 100 ‎grams of bran was mixed with acetate buffer solution with pH equal to 5, 200 ml of distilled ‎water along with 5% (weight/volume) of phytase enzyme and heated at 37 degrees Celsius for ‎‎60 minutes. The liquid phase was separated from the solid phase by filter paper and the bran ‎extract was separated by a centrifuge (6000 g, 15 minutes). Formulation of dairy drink ‎containing rice bran extract was prepared using the following components: 50% (v/v) skim milk ‎containing 5% (w/v) sucrose and 0.5% (w/v) pectin with low methoxylation degree, 20 % (v/v) ‎of cheese juice and 30% (v/v) of rice bran extract. In formula A, the bacterial culture only ‎contains starter cultures (Streptococcus thermophilus and Lactococcus lactis, 0.01% by ‎volume/volume), and in formulas B and C, it includes probiotic culture (Lactobacillus casei or ‎Bifidobacterium bifidum, 0.01% by volume/volume and The final population was 7 logcfu/ml). ‎The control sample was prepared without adding rice bran extract. After preparing the base ‎formulation and before adding the bacterial culture, the thermal process was performed at 90°C ‎for 5 minutes and cooling to 42°C. The starter culture was added and mixed, cooled to 37°C, ‎and then probiotic bacteria were added. The formulation was kept in a greenhouse at 37°C for 3-‎‎4 hours until the pH reached 4.5. In the next step, homogenization was done with a homemade ‎stirrer to break the clots. Drinks were stored in 250 ml glass bottles with lids at refrigerator ‎temperature (4±0.5 °C) for 21 days and tested at 7-day intervals.Survival of probiotic bacteria, ‎chemical and physical properties, the content of phenolic compounds (TPC), antiradical activity, ‎and sensory properties were evaluated. Results:The results showed that incorporating rice bran ‎extract in a dairy beverage containing probiotics increases the activity of bacteria to produce ‎acid and reduce pH. The activity of Bifidobacterium bifidum in acid production was higher than ‎that of Lactobacillus casei, and samples containing rice bran extract and Bifidobacterium ‎bifidum have lower pH and higher titratable acidity. The samples containing Bifidobacterium ‎bifidum showed lower total solids and viscosity than the samples containing Lactobacillus casei, ‎which indicates higher activity in the production of enzymes that decompose substrates in the ‎culture medium. TPC and free radical scavenging potential in probiotic beverages increased ‎during the storage period and its level was higher in the beverage containing Bifidobacterium ‎bifidum (74% radical scavenging) than the samples containing Lactobacillus casei (70% radical ‎scavenging). The addition of rice bran extract to the milk based medium improved the survival ‎of both probiotic bacteria by more than 20% due to the prebiotic activity of the extract. The ‎physical stability of the samples was checked using the precipitation formation technique ‎‎(coagulation technique). No significant difference was observed between the control samples ‎containing Bifidobacterium bifidum and Lactobacillus casei, but the amount of sediment formed ‎in the samples containing rice bran extract was slightly higher than the control samples .The ‎amount of precipitation increased slightly with increasing storage time, which could be due to ‎the presence of suspended bran particles in the product, despite the two-stage filtration of the ‎extract. Therefore, in order to solve the phenomenon of phase separation between the soluble ‎component and the insoluble component, stabilize the product and stabilize the colloidal ‎systems, an emulsifier or stabilizer such as carboxymethyl cellulose should be used.‎‏ ‏‎ ‎Conclusion: The results of this study showed that rice bran (agricultural waste) extract acts as a ‎prebiotic in the presence of probiotic bacteria‏ ‏‎ (symbiotic and synergistic effects are observed), ‎and this synbiotic product has a high potential to be presented to the consumer market as a ‎functional food due to its significant content of phenolic compounds, antioxidant activity and ‎high survival and activity of probiotics.‎

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.

Background and Objective: Inactivated probiotics provide various health and technological benefits, making them appropriate for the production of functional dairy products. The aim of this study was to investigate effects of adding nonviable probiotics (Lactobacillus acidophilus LA-5 and Lacticaseibacillus casei 431) to doogh (a typical Iranian fermented milk drink). Material and Methods: Probiotics were inactivated by heat or sonication and added to the samples before or after fermentation. Various parameters such as pH, titratable acidity, redox potential, antioxidant capacity, color, viscosity, and phase separation, viability of traditional starter bacteria and probiotics and sensory characteristics were assessed during fermentation and refrigerated storage at 5 °C. Results and Conclusion: Sonicated probiotic-containing treatments included the highest pH decrease rate (0. 011 pH min-1) during fermentation, as well as the highest antioxidant capacity (16. 45%) and viscosity (35. 15 mPa. s), while heat-inactivated probiotic-containing treatments included the lowest viscosity (17. 60 mPa. s). Treatments with viable probiotics reasonably included the highest post-acidification rate during storage (4. 14 °D d-1), compared to those containing nonviable cells, as well as the minimum phase separation rate. The b* and L* values of color did not differ significantly within treatments, but the highest a* value was observed in the treatments with sonication. The highest populations of Lactobacillus delbrueckii ssp. bulgaricus (log 11, 891 cfu ml-1) and Streptococcus thermophilus (log 14, 977 cfu ml-1) at the end of the storage were observed in treatments with heated probiotics (compared to viable probiotics) and treatments with sonicated probiotics, respectively. In addition, Lactobacillus acidophilus was more susceptible than Lacticaseibacillus case and included lower viability. Taste, mouth feeling and total acceptance of all samples did not differ significantly within treatments. The present study suggests that inactivated probiotics can successfully be used for the production of fermented milk beverages with appropriate sensory characteristics and higher antioxidant capacity, compared to the control group. Conflict of interest: The authors declare no conflict of interest.

In recent years, water or sugar syrup, flavoring agents such as fruit juice or fruit juice concentrates and stabilizers have been added to the acidified dairy beverage composition. Nowadays, the popularity of low fat and defatted fruit yoghurt drinks are mainly growing. The purpose of this study was to diversify the acidified dairy products by determining the sensory, rheological and stability attributes of these kinds of dairy products with considering added elements and hydrocolloids as variables and then optimizing the formulation of fermented beverage, being directly flavored with the fruit concentrates. Moreover, mutual effects of total solid materials, concentrate, sweetener and stabilizer were inspected using Minitab software and response surface methodology. In this regard, consistency, viscosity, pH and acidity, sensory characteristics and yeast and mold counts were assessed. Surveys indicated that contrary to flow behavior index, the stability and straightness index increased with adding stabilizer and decreasing water content. According to sensory evaluation, white samples got lower score in comparison with black cherry ones. Furthermore, adding high amount of hydrocolloids negatively affected the total acceptance. Not only yeast but also mold was grown on the optimal sample after 28 day storage at refrigerator temperature. Generally speaking, it can be concluded that highly viscose and extremely sweet products as well as samples with high amount of stabilizer were rejected by panelists whereas the ones with high amount of concentrate were accepted. According to mentioned properties, the optimum amounts of ingredients are as follow: 13% total solid materials, 9.5% concentrate, 6.2% sweetener and 0.78% stabilizer. This sample with 2.3% of serum scored 7.93 in mouth feel, 8.25 in texture, 7.68 in acidic and 7.84 in fruit flavor, 7.89 in color, 7.78 in sweetness and 7.93 in total acceptance and also had 84.36% of total satisfaction.

The microbiological and biochemical changes occurred during the fermentation of camel milk inoculated by three selected bacterial starter, were investigated as well as the sensory evaluation of the product. Milk samples were collected from camel herds of southeastern of Iran. Chr. Hansen ABT-10 starter including Lactobacillus acidophillus, Biphidobacterum biphidum and Sterptococcus thermophilus in ratio of 0.50 g per 100 mL of camel milk was added. This fermented product was examined at the 0, 3rd, 6th and 9th days for microbiological, biochemical and sensory evaluations. The results showed the number of starter bacteria was maintained at least 106 CFU mL-1 during nine test days. It was shown that it could be used as fermented-probiotic drink. The product did not show any microbial contamination. The acidity and protein amount of produced drink showed a significant (p < 0.05) increase in different test days. Fat, solids-not-fat and ash amount of the product showed significant differences at the ninths’ test day compared to the zero test day (p < 0.05). Organoleptic properties of product including flavor, color, odor, consistency, mouth feel and overall acceptance were significantly improved (p < 0.05). Therefore, the produced fermented-probiotic drink, in addition to keep maintenance and increased nutritional quantity value, was accepted by consumers in terms of organoleptic properties and it could be used as a healthy and functional drink.

The liver is extremely vulnerable to damage because of its role in metabolism. Toxin, metabolic syndrome, alcohol, microorganisms, and autoimmune diseases can be the cause of liver damage. While different etiologies can cause liver disease, pathophysiologically, there are similarities in the role of free radicals, inflammatory mediators, and gut microbiome during the disease development. Therefore, ingredients with antioxidant, antiinflammatory, and antidysbiotic properties have the potential to act as hepatoprotectors,and water kefir is one of them. Water kefir is a traditional fermented drink made from water kefir grains, sugar, and dried fruit. Water kefir is dominated by lactic acid bacteria and yeast as a fermented beverage, and several species of this group of microorganisms have been shown as probiotics. According to researches, water kefir has strong antioxidant, antiinflammatory, and hepatoprotective effects. Even so, there are still few researches reported about water kefir as a hepatoprotective agent. Several studies, on the other hand, showed promising results. This review discusses the relationship between the pathophysiology of liver disease and the pharmacological activity of water kefir and other probiotics in general, which leads to the potential prospect of water kefir research as a hepatoprotective agent.

Background: Probiotic bacteria are live microorganisms which have beneficial effects on the host body, if consumed at sufficient amounts. Some positive effects of such bacteria are as follows: reduction of lactose intolerance, inhibition of colon, intestine, liver and breast cancers, reduction of blood cholesterol, improving and boosting the immune system, infection prevention, treating and inhibiting from acute diarrhea, reduction of intestinal inflammation, reduction of food allergies or Eczema in children, improving the absorption of minerals and vitamins, and prevention of the growth and replication of harmful bacteria. In addition to longer shelf life, fermented foods have flavor and odor characteristics which are directly or indirectly associated with the fermenting microorganisms. In many cases, the vitamin content of fermented foods and the digestibility of raw materials are increased. Moreover, fermentation decreases the toxicity of some food ingredients. Functional food products such as yoghurt and Doogh could be appropriate carriers for the transfer of such bacteria to the intestinal epithelial cells. The purpose of this research is to examine the viability of the probiotic strains of Lactobacillus delbrueckii and Pediococcus pentosaceus in Doogh as well as investigating their effects on the chemical, microbial and sensory properties of this dairy product during storage. material and methods: In this study, the probiotic strains of L. delbrueckii and P. pentosaceus were used to produce Iranian traditional Doogh. pH was measured on the 1 st th th, 7, 14 st and 21 day using the Lab827 pH meter (Metrohm, Switzerland). For microbial count, 25 ml of the sample was mixed with 225 ml of sterile sodium citrate 0. 2% and considered to be 10-1 dilution after homogenization. The dilution series up to 10-7 were prepared by adding 1 ml of the content of each test tube to 9 ml of the sterile ringer solution. For the microbial total count, plate count agar was applied at 37°, C for 48 h. For the yeast and mold count, yeast extract glucose chloramphenicol was utilized at 25°, C for 5 days, and for the coliform count, violet red bile agar was employed along with incubation at 37°, C for 48 h. Various properties of the Doogh samples were determined using 9-point hedonic scale during storage. A number of 20 panelists were chosen according to the degree diagnosis or quality level test. A number of 20 samples were prepared from each treatment and given to the panelists with a form scaled with 9 points (9=desirable, 1=undesirable) to fill it out considering their own tastes and comments. The sensory properties were as follows: mouthfeel, flavor, odor and overall acceptability. Results and discussion: The results revealed that L. delbrueckii reduced the pH about 1 unit after 21 days of storage at 25°, C, while the reduction of pH in the Doogh stored at 4°, C was about 50% of this value. For P. pentosaceus, the pH reduction was equal to 0. 9 and 0. 5 after 21 days of storage at 25 and 4°, C respectively. During the 21 days of storage of the samples at 4°, C, no growth of molds and yeasts was observed. Although molds and yeast could grow in the samples stored at 25°, C for 21 days, application of L. delbrueckii and P. pentosaceus could decrease their growth relative to the control. On the 21 st day, L. delbrueckii reduced two logarithmic cycles of the molds and yeasts (compared with the control), while P. pentosaceus decreased one logarithmic cycle. The results also showed that no coliform growth was observed in the samples stored at 4°, C. Coliform growth depends on the food nature and its storage conditions. In general, coliforms grow slowly at temperatures under 6°, C. In the doogh samples stored at 25°, C, the decreasing effects of L. delbrueckii and P. pentosaceus were significant on the coliform growth, compared with the control. In this study, the microbial total count was also performed on different days and the results demonstrated that Doogh storage at 4°, C caused a decrease in the number of the inoculated bacteria during storage. One of the reasons behind this could be the storage temperature. Refrigerated storage is not suitable for the growth and replication of mesophilic bacteria. Therefore, a decrease in the microbial population was observed after some days and the greatest reduction occurred in the fourth week. In the Doogh samples stored at 25°, C, the number of bacteria increased in the second week relative to the first one. In the third week, a slight reduction was observed in the bacterial count, compared with the second week. This could be ascribed to the increase in the sample pH and the inability of the bacteria to replicate and grow. The largest reduction in the number of the bacteria was observed on the 21 st day of storage which was about two logarithmic cycles lower than the second week. The results of the sensory evaluation showed that the Doogh samples inoculated with L. delbrueckii and P. pentosaceus achieved higher scores in terms of mouthfeel, flavor, odor and overall acceptability in comparison with the control. Conclusion: L. delbrueckii was more potent in reducing the samples pH. In addition, its protective effect was more pronounced in preventing the growth of coliforms, molds and yeasts. On the sensory properties, including mouthfeel, flavor, odor and overall acceptability, the effects of the probiotic Doogh samples were significant compared with the control. As a result, the probiotic bacteria used in this research not only did not have undesirable effects on the chemical, microbial and sensory properties of Doogh, but also improved them. In conclusion, L. delbrueckii and P. pediococcus could be appropriate candidates for industrial uses in this area after complementary experiments.

Phenylketonuria (PKU) is an inborn genetic disorder, there is no cure and all PKU patients must use a special diet none or low in Phenylalanin (Phe) for preventing the onset of symptoms and intension of the retardation of the children. Therefore, production of foods containing no or very low Phe is essential. In the present study, nutritionally a suitable dairy drink suitable with high acceptability was produced for these patients. The drink was prepared on the basis of the permeate of the milk containing Glycomacropeptide (GMP) as the protein source with the addition of Corn Germ Oil as the source of essential fatty acids, flavoring agent, stabilizer and emulsifier. GMP was added at three different concentrations of 2.5, 3 and 3.5wt%. Protein, pH, fat, sugar (total reducing sugars and sucrose), ash and total solids of the samples were determined. The HPLC was used to determine the Phe content of the samples. Cacao flavor was used for increasing the acceptability of the prepared drinks and sensory evaluation was conducted. The results showed that increasing GMP increased the protein content, total solids and pH. Moreover, the results showed that the GMP content had no significant effect (P> 0.05) on the sensory characteristics of the prepared drinks and the samples with the cacao flavor were desirable drinks considering organoleptic properties. Results of Phe determination showed that prepared dairy drink had very low Phe levels (almost 0.58 mg/ml). It can be concluded that the diet dairy drink produced by this method is recommended for Phenylketonuria patients.