Vol. 12, Special Issue 8 (2023)

Author(s):
Ashlesha Ranade, Pradeep Kumar Singh, Ranvijay Singh, Surbhi Yadav, Neeraj Shrivastav and Namrata Agarwal

Abstract:
Milk is considered as an important source of nutrients for human population; specially good quality proteins, carbohydrates and some micronutrients. Casein is the major milk protein present in milk and remaining proteins are constituted by whey proteins and others. Beta casein is an important component of casein protein which has role in nutritional contribution of infant as well as adult; as milk is an important part of daily food habit consumed as fluid milk & different milk products in various parts of the country. However, it has been found that mutations in bovine beta casein gene resulted into several genetic variants. Out of the genetic variants reported till date, A1 and A2 are the most prevalent one. The basis of A1 and A2 milk is the difference in beta casein at 67^th amino acid position where histidine is present in A1 and proline in A2 milk; this has been observed as a result of single nucleotide difference in beta casein gene. In gastrointestinal tract the proteolytic digestion of A1 variant of β-casein leads to formation of a bioactive peptide, beta-casomorphin (BCM-7). Different age groups consuming milk can be affected by BCM-7 leading several health implications. Initial studies have revealed that frequency of A1 allele is more common in cattle of exotic origin while native cattle and buffalo populations have only A2 allele; considered as a source for healthy and safe milk.