Optimisation of parameters for obtaining milk-plant concentrates

A priority direction in the dairy processing industry is the development of innovative resource-saving technologies that enable raw material conservation, increased yield, and expanded product range. In particular, there is a growing demand for plant-based milk analogs in mixtures for producing milk-plant concentrates using accelerated technologies. The study aimed to determine the optimal parameters of the thermoacid coagulation process for milk-plant protein mixtures to obtain milk-plant concentrates and analyse their impact on the yield and qualitative characteristics of the final product. Milk-plant concentrates were obtained by thermoacid precipitation of proteins from a milk-plant mixture. The Box-Wilson central composite design method was used to optimise the parameters of concentrate production. It was established that thermoacid precipitation of proteins in a milk-plant mixture containing 35% whey-plant suspension with a water-to-solid ratio of 1:3 and a self-pressing duration of 30 min ensured a 36% transition rate of both milk and plant proteins into the concentrate. These parameters were 8-12% higher than those for protein precipitation from a mixture of skim milk and whey-plant suspension (20%) with water-to-solid ratios of 1:5 and 1:7. The addition of a 20% whey-plant suspension with a water-to-solid ratio of 1:7 and a curd self-pressing duration of 10 min resulted in the least protein destabilisation and the highest moisture content (78%) in the milk-plant concentrates. Analysis of the active acidity (pH) of the concentrates revealed a general trend: as the proportion of whey-plant suspension in the mixture increased from 20% to 40% and its water-to-solid ratio changed from 1:7 to 1:3, the pH decreased linearly. The lowest impact on water-holding capacity (72%) was observed under the following conditions: 20% whey-plant suspension, 1:7 water-to-solid ratio, and 10 min self-pressing duration. The obtained results allow for the regulation of qualitative indicators of milk-plant concentrates depending on their intended use, enabling the diversification of protein products with controlled moisture content, water-holding capacity, and active acidity