Determination of the influence of raw milk β-casein polymorphism on the efficiency of making cottage cheese

The positive functional features of A2 milk and the increase in the percentage of animals with the A2A2 genotype will contribute to expanding the choice of dairy products, in particular, cottage cheese. It is expected that determining the influence of the protein composition of raw milk on the quality and yield of cheese will allow for effective selection of dairy breeds of cows. The object of the study is the technological process of producing cottage cheese, produced by the classical acid method of coagulation of milk proteins from cows with different β-casein genotypes (A1A1, A1A2, A2A2). Subject of the study: physical and chemical characteristics of raw milk (A1A1, A1A2, A2A2); yield and quality of cottage cheese. It was experimentally established that the milk samples have a typical composition and comply with DSTU 3662:2018. The average dry matter content in milk from cows with the A1A1 genotype was 12.73 %, with the protein-to-fat ratio varying within 0.76–0.83. In raw material samples from animals with the A1A2 genotype, the average dry matter content was 12.72 %, and the protein-to-fat ratio was 0.66–0.68. For milk from cows with the A2A2 genotype, the average dry matter content was 13.14 %, and the protein-to-fat ratio was in the range of 0.62–0.82. A study of the quality indicators of cottage cheese samples showed that the genetic variation of β-casein does not affect the sensory properties of the final product. The moisture, protein, and fat contents in cheese from milk from cows with the A1A1 genotype were on average 72.27 %, 9.77 %, and 15.47 %, respectively. In samples of cheeses from cows’ milk with A1A2 genotype, the average moisture content was 67.17 %, protein – 18.30 %, fat – 14.37 %. For cheeses from cows’ milk with genotype A2A2, the average moisture content was 67.47 %, protein – 15.30 %, fat – 15.40 %. It was found that the efficiency of cheese production from cows’ milk with A2A2 genotype is the highest and on average is 141.26 %, which exceeds similar indicators for A1A1 milk by 13.18 % and A1A2 by 2.21 %.