Food ingredient development for fermented beverages productio

The aim of the study is to develop a food ingredient composition based on a consortium of lactic acid bacteria and bifidobacteria strains for the production of fermented beverages. The study was conducted in the Laboratory of Biotechnology of Organic Acids, Food and Feed Additives at the AllRussian Research Institute of Protein Biotechnology. The objects of the study were lactic acid bacteria strains from the institute’s collection: L. delbrueckii ssp. bulgaricus D16, L. plantarum 578/25, L. helveticus 842(D)2, L. lactis subsp. lactis M12, St. thermophilus B92 and bifidobacteria B. longum B2, as well as a starter culture for specialized dairy products (PILEGE, France) as a comparison. The studies were conducted on a hydrolysate of diluted curd whey with 7 % whey protein concentrate. Fermentation processes were monitored using the following parameters: dry matter content, titratable acidity, and bacterial biomass accumulation assessed by measuring optical density. The consortium composition was selected based on the technological properties of the strains and the 2 : 1 ratio of lactic acid bacteria to bifidobacteria. Technological regimes were developed to achieve the following cell titer after 15 hours of growth: probiotic lactobacilli – 64,5·108 CFU/cm3, lactic acid bacteria – 15·109 CFU/cm3, bifidobacteria – 6,8·109 CFU/cm3. The bacterial mass was isolated using an OPN16 centrifuge at 10,000 rpm (4 °C) for 15 min, and concentration was performed through a UPM20 polysulfonamide membrane at 20 °C. The resulting concentrate was frozen and lyophilized. The titer of microorganisms was determined by plating on selective agar media. The food ingredient contains a lyophilized bacterial product with a titer of 59,9·109 CFU/g, dietary fiber in the form of the prebiotic inulin, and the sweeteners erythritol and sucralose. The resulting complex food ingredient can be recommended as a component of dietary supplements or for the production of fortified foods as a source of bifidobacteria, probiotic lactic acid bacteria, and prebiotics. To create the base for the fermented beverage, the food ingredient was used as a source of probiotics, achieving a biomass accumulation of 1.4∙107 CFU/cm3 on soy whey after 24 hours of growth.