Functional Properties and Metabolic Profile of National Fermented Products of Russia and South Africa

. Both Russia and South Africa have a long-standing history of fermented milk product consumption. Along with the products widely distributed around the world, such as yoghurts, in each of these countries there are a number of national products. An example of a widely demanded fermented milk product in Russia is Kefir.This productis used not only as a food source in the diet of children and adults, but also in medical institutions, since ithasa positive effect onhuman health when consumed regularly. South Africa is characterized by the consumption of products such as Amasi,which is produced commercially. Its consumption has also been shown to have beneficial effects on the digestive system. In this research, the metabolic profiles(fatty acid composition and volatile compounds) of these fermented milk products were analyzed and these showed significant differences. The results indicated that this metabolite composition reflected the different production protocols and microbial complexity of these dairy products. The functional properties of the studied drinks were also considered.The average content of L-leucine equivalents in Amasi was slightly higher (6.5-8.9mMol×L −1) than in Kefir (4.9-6.7mMol×L −1). Antioxidant and antihypertensive activity of the fermented products correlated with the depth of hydrolysis of the milk proteins. Amasishowed higher antioxidant and antihypertensive activities (600- 796µМolТE/ml and 1.3-1.5mg/ml, respectively) than Kefir (246-574µМolТE/ml and 2.0-4.3mg/ml, respectively). Keywords: fermented products, Kefir, Amasi,metabolic profile, antioxidant potential, antihypertensive properties

Biotechnological Aspects of Dietary Fiber Use in the Production of Fermented Dairy Products

This article presents research results of the chemical composition, physical and chemical properties and biotechnological potential of dietary fiber concentrates (DFCs) obtained from secondary raw materials for the production of carrot and pumpkin juices.It has been established that DFCs, along with dietary fibers (cellulose, hemicellulose, pectin, lignin), contain soluble sugars, nitrogenous substances and carotenoids, which determine their physiological activity and technological properties when used in dairy products fermented with probiotics.The effect of DFCs on the fermentation kinetics of dairy-vegetable mixtures with a starter containing lacto-, bifidobacteria and propionic acid microorganisms was studied. The optimal concentration and the degree of dispersion of carrot and pumpkin DFCs was determined. The findings can be used to ensureoptimal intensification of the fermentation process and the production of probiotic fermented milk drinks with a pleasant taste. Keywords: dietary fiber, secondary raw materials, functional dairy products, prebiotics, probiotics, enzyme kinetics, probiotic drinks

Fermented Milk Beverages Fortified with Soy Protein

Introduction. Fermented milk beverages with various vegetable additives expand the range of functional foods with probiotics, vitamins, and minerals. The research objective was to develop a new technology for fermented milk drinks fortified with soy protein. Study objects and methods. Heat-treated cow’s milk with Direct Vat Set bacterial starter served as the control sample, while the experimental samples featured fermented milk fortified with soy additives. The soy protein ingredient was obtained from powdered sprouted soybean. Soybeans were pre-germinated in a thermostat at 26°C for 24 h and blanched with steam for 15 min. After that, 1–9% of the soy substance was added to pasteurized milk and fermented at 38–40°C for 6–8 h. The resulting sample was tested for quality indicators and physicochemical composition. Results and discussion. The best sensory properties belonged to the sample with 5% mass fraction of the soy additive. As a result, the soy-fortified beverages entitled Bifivit and Immunovit had a better nutritional value: protein – by 1.92 and 1.79 g, fat – by 0.77 and 0.75 g, vitamin E – by 0.16 mg, choline – by 23.82 mg, potassium – by 149 mg, phosphorus – by 19 and 22 mg, calcium – by 25 and 24 mg, magnesium – by 22 and 23 mg, respectively. One portion (100 g) of these drinks contained over 15% of recommended daily intake of protein, vitamin B2, potassium, magnesium, calcium, and phosphorus. The content of lactic acid and bifidobacteria remained above the norm (1×108) both in fresh products and by the end of their shelf life. Conclusion. The article introduces a technology of new functional soy-fortified fermented milk drinks with improved chemical and sensory properties.

Antimicrobial effects of the phenolic compounds of Mentha piperita L on Streptococcus thermophilus and Lactobacillus bulgaricus and impacts on the quality of an alicament steamed yoghurt

This study contributes to the evaluation of the antibacterial effect of hy-droethanolic extract of peppermint (Mentha piperita L.) rich in phenolic compounds on the growth of reference bacterial strains Streptococcus ther-mophilus (ATCC19258) and Lactobacillus bulgaricus (ATCC11842) as well as the consequences of its addition at a dose of 6% on the quality of a steamed yoghurt. The phenolic compounds of peppermint collected in Algeria were extracted from the ground leaves of the plant in a hydroethanolic solution. The antimicrobial activity of peppermint extract and the quality of yoghurt were assessed by the following measures: bacterial growth test, disc diffu-sion test, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), pH, acidity, viscosity and the organoleptic tests (taste, odor, color and freshness). The results revealed that hydroethanolic extract of M. piperita L. had 25 mg GAE/ml of extract of total phenolic compound and a content of 8.28 mg QE/ml of extract of flavonoids. This extract had a bactericidal against S. thermophilus and a bacteriostatic inhibitory effect against L. bulgaricus. The addition of phenolic compounds of M. piperita L. at 154.02 mg GAE/100ml significantly reduced (p<0.05) acidity, viscosity, and the germ increase of S. thermophilus and L. bulgaricus in steamed yogurt prepared with 6% of hydroethanolic extract of the studied plant compared to the control. However, the fermented milk treated with the 6% of pepper-mint extract was very well appreciated by the tasting jury, just like the yo-ghurt control.

Fat content in fermented milk beverages: determination by the Gerber method

Fermented milk beverage is a product containing milk, whey and/or other ingredients, fermented by specific microorganisms and/or added with fermented milks. Fat determination in this product is important to quality control and inspection. The Gerber method is used worldwide as a simple and rapid method for fat content analysis in raw and processed milks. In Brazil, Roese-Gottlieb is the official method for analysis of fat content in milk beverages. However, the use of Gerber method for fat content determination in fermented milk beverages is widespread throughout the industry in the country. Several authors have tested the use of Gerber method for some dairy products, but there is no report on this evaluation for fermented milk beverages. In this context, the objectives of this work were to determine the fat content of fermented milk beverages by the Gerber method and evaluate the performance of this test, using Roese-Gottlieb as a reference method. Thirty samples of fermented milk beverages were analyzed by both methods. The fat contents ranged from 1.25 to 2.40% by the Gerber method and from 1.24 to 2.50% by the Roese-Gottlieb method. There was no difference (p > 0.05) between the methods. The Gerber method can be used to determine the fat content of fermented milk beverages, without prejudice to the results obtained.

Lactobacillus casei-fermented milk as an inhibitor on selected foodborne pathogens

The aim of this study was to reduce the growth of vanB resistant Enterococcus faecium, vanA resistant Enterococcus faecalis, Staphylococcus aureus ATCC 43300 and methicillin-resistant Staphylococcus aureus- MRSA ATCC 25923, which are foodborne pathogens that cause the death of a significant number of people every year, by the presence of Lactobacillus casei. For this purpose, the development of pathogens (104 and 106 log cfu/ml) in milk fermented with L. casei (106 log cfu/ml) was followed under in vitro conditions for 72 hours. Moreover, the generation times of each pathogen and the lactic acid content of fermented milk were determined. It was determined that the development of all pathogens could be suppressed by the presence of L. casei considering the change in generation times and the number of pathogens during the 72 hour fermentation period. This effect was greater in samples containing 104 log cfu/ml pathogen compared to samples containing 106 log cfu/ml.