Dynamics of Milk Material Fermentation with Whey Protein Hydrolysate

Abstract

Using the whey protein hydrolysate (WPH) in yogurt manufacture contributes to the development of a number of fermenting microorganisms and accelerates the fermentation process, which would ultimately reduce production costs and the overall cost of the product. The objective of the presented study was a comparative analysis of the fermentation processes in buttermilk and skimmed milk caused by starter microorganisms in the presence of WPH. The authors were looking to create a probiotic product with typical consumer characteristics. WPH hydrolysate with a high degree of hydrolysis (DH not less than 60%) was used as a functional food ingredient to improve the nutritional value of the product. Samples of skimmed milk and buttermilk without WPH were used for control. Standard physical and chemical methods for studying the composition and indicators of dairy raw materials were applied. The titrated and active acidity were analyzed by indicator and potentiometric methods respectively. The osmotic concentration was determined with using an osmometer-cryoscope. The synthesized lactate and the degree of acid formation increase have been calculated. Qualified experts have bee detected the organoleptic evaluation of raw materials in control and experimental samples. The processes of lactic acid fermentation of skimmed milk and buttermilk both containing from 1-3 wt% of WPH and monostrain and monospecies multistrain starter microorganisms were studied. The main attention in the study was paid to the organoleptic as well as physical and chemical parameters of fermented milk clots, the characteristics of fermentation processes, and the influence of WPH on the development of microorganisms have been revealed. WPH using in the studied types of milk materials helps to increase the protein content, raise the biological value, and ensure a normalized amount of starter microbiota including probiotic bacteria. So, it has been found that using skimmed milk or buttermilk with added WPH as a basic material in the starter, probiotic cultures should be used in combination with thermophilic lactic streptococci to develop a fermented milk product for dietary prophylactic purposes.