Proteolytic processes in cheese analogues ripening

Abstract

The research relevance is predefined by the theoretic basics of their production processes not being sufficiently studied, including the proteolysis despite the wide production of cheese analogues incorporating vegetable substances. The research aims to determine the effect of the content of cheese analogues, namely milk fat substitutes, soy protein isolates, and lactobacilli species Lactococcus lactis ssp. lactis and L. lactis ssp. cremoris, L. lactis ssp lactis bv. diacetilactis as well as Leuconostoc mesenteroides by the physical, chemical, and sensorial traits, and by amino acids content of cheese analogues. Determination of the physical and chemical parameters was fulfilled according to the standards: active acidity (рН) – DSTU 8550:2015; solids content (by weight) – DSTU 8552:2015 and ISO 5534:2004; non-casein nitrogen content (by weight) – ISO 17997-1:2004; total protein (by weight) – ISO 8968-1:2014 and ISO 8968-5:2001; casein content (by weight) – ISO 17997-1:2004. The fractional composition of proteins was determined using the Polyacrylamide Gel Electrophoresis. While in the cheese dough after analysing the differences in the spectrum of free amino acids between the variants were insignificant, in ripe cheese analogues the accumulation was significantly less than in the control cheeses, only one ripe cheese analogue showed the total amount of free amino acids and was almost equal to the control. During ripening, the content of these compounds increased in cheese analogues from 2.2 times to 3.3 times, in the control the content of free amino acids increased by 2.5 times, and individual free amino acids accumulated from 3-7 to 30-40 times. Active proteolytic processes led to the appearance of all ripe products of such essential amino acids as methionine and isoleucine, there was also an increase in the level of glycine. The practical significance of the study is determined by substantiating rationale proteolytic processes in the manufacture of cheese analogues to ensure consumer quality close to the quality of cheeses made of milk