Identification of β‐casein phenotypes (A¹/A²) in the milk of the Indian Jersey crossbreed bovine using the high‐resolution accurate mass spectrometer

Abstract

SummaryFoodomics is an emerging probing method of phenotype investigation of the different milk proteins and their subtypes. The polymorphic nature of the β‐casein (β‐Cn) protein has shown fourteen different protein variants to date in bovines. The analysis of the β‐Cn genetic polymorphism from the milk of the crossbred dairy animals is crucial for the quality assurance of the consumers from the various health concerns, especially those linked with the A1 phenotype which yields β‐casomorphin‐7 on in‐vivo digestion. Jersey‐crossed Indian cattle have been widely utilized in dairy because of their better milk production and survival performance trait. In this investigation, an SDS‐PAGE coupled with a high‐resolution accurate mass spectrometry‐based proteomics approach has been applied to identify the presence of specific phenotype of the β‐Cn protein in the milk of the 24 Indian crossbred (Jersey crossed) animals. Amino acid sequential analysis has been done using different search modules, as MS Amanda and Sequest HT showed 17 cows are producing A2 β‐Cn (Pro~67) while only seven animals yielded the A1 variant (His~67). The maximum number of Indian Jersey‐crossed animals are lactating milk having A2 β‐Cn. The A2 milk from the crossbred animals is free from the negative impact on health caused by β‐casomorphin‐7 (BCM‐7) released during digestion of the A1 phenotype. Among the molecular biology techniques, top‐down proteomics has been an intriguing technique for the identification of protein genetic polymorphic products.

BCM-7: Opioid-like Peptide with Potential Role in Disease Mechanisms

“…In a different study, a specific phenotype of β-casein was determined from 24 different crossbred (A1/A2) Jersey breeds. As a result of this study, which is a proteomic approach, proline and histidine residues were highlighted in the proteome database of A1 and A2 β-casein [10]. Originally, the β-casein protein comprised 209 amino acid chains in the A2 variant.…”

“…β-casein possesses balanced amino acid nutritional ratio and is useful in maintaining a healthy cycle within the body. β-casein occurs in 13 different variants, with the most commonly known variants being A1 and A2 [8][9][10]. Milk can be classified according to its casein type, primarily due to its various physicochemical properties.…”

Functional chocolate: exploring advances in production and health benefits

“…One significant difference between the A1 and A2 variants of bcasein is the type of digestive products they produce. When the A1 variant is digested through gastrointestinal proteolysis, it creates a bioactive peptide called b-casomorphin-7 (BCM-7), which activates l-opioid receptors of the body (Singh et al, 2023). These International Journal of Food Science and Technology 2024 receptors regulate the body's response to pain.…”

Metabolomics applications in food science, technology and nutrition

“…Singh and his coworkers (2023b) identified β‐casein (β‐Cn) protein genetic polymorphism from the milk of the crossbred dairy animals, especially those linked with the A1 phenotype which yields β‐casomorphin‐7 on in vivo digestion for the quality assurance of the consumers from the various health concerns. They indicated that 17 cows produced A2 β‐Cn (Pro~67) while only 7 yielded the A1 variant (His~67).…”