Особенности процесса ферментации молочно-соевой смеси

Abstract

The plant milk market is actively developing at the moment, as many consumers suffer from lactose and casein intolerance, while vegetarianism is being popularized. The use of soy milk is becoming popular in the technology of fermented dairy plant products, as it is a lactose-free analog of cow milk and source of native protein, polyunsaturated fatty acids, vitamins, minerals, and other micronutrients. However, the fermentation of dairy and plant compositions is quite complex and has not been fully understood yet, and therefore the goal of this study was to conduct a comparative analysis of the fermentation of milk and soy mixtures with different compositions (cow milk: soy milk in the ratios of 55:45; 70:30; 85:15). The tests were conducted at the Laboratory of Agricultural Product Processing. To obtain milk and soy mixtures, a plant protein drink – soy milk – was prepared from soybeans of the Sentyabrinka variety selected by the Federal State Budgetary Scientific Institution Federal Research Center All-Russian Research Institute of Soybean. The fermentation of milk and soy mixtures was performed using the acid-rennet method with bacterial starter cultures No. 1 (Lactobacillus lactis, Lactococcus diacetylactis, Lactococcus cremoris, Streptococcus thermophilus) and No. 2 (Lactococcus lactis ssp. lactis, Lac. lactis subsp. diacetilactis, Leuconostoc lactis and/or mesenteroides subsp. cremoris, Lactobacillus plantarum, Lactobacillus helveticus, Streptococcus thermophilus). The acid formation of fermented milk and soy clots was studied in time at intervals of 1 hour, and their active and titratable acidity levels were analyzed in the course of work. Fermentation completion was determined based on the organoleptic indicators of fermented clots and their acidity levels. The following was established as the result of the tests: composition of the milk-soy mixture – 70:30; technological fermentation process parameters and modes – 328–346 minutes at a temperature of 34 °C, with the production of a fermented milk and soy clot having the best organoleptic quality indicators – well-formed, with a stable texture, pleasant, sour-milk taste, light soy aftertaste and smell. The analytical dependences of the titratable and active acidity indicators on the duration of fermentation process were calculated based on an analysis of acid formation in experimental clot samples.