High-resolution mass spectrometer-based identification of β-Casein variant (A2/A1) in the milk of Indian Holstein Friesian crossed cows

Abstract

Foodomics tools are ameliorating the compositional and quality analysis part of various domains of food products. The use of proteomics in the polymorphic product investigation of beta-casein (β-Cn) is intriguing because of the fast and reliable results from the accurate mass spectrometry. This study delineates the LC-MS/MS-based sequential analysis of gel fractionated β-Cn of eighteen Holstein Friesian (HF) crossed cow milk for the identification of A2 milk. The probe of genetically induced polymorphism of β-Cn milk protein in the crossed animals is essential for the quality concern and fulfilling the demand of the consumers. Several in-vivo studies have shown that proteolytic digestion of the A1 milk secreted an opioid, i.e., β-casomorphin-7 that can cause many types of non-communicable diseases. SDS-PAGE was done on 15% resolving gel and an orbitrap mass spectrometer equipped with UniProt database search was used for the detection of the genetic variants in the HF crossed cows have shown ten animals are lactating milk with A2 β-Cn (Pro67), whereas only eight animals have A1 β-Cn (His67). The high number of HF-crossed cows are producing A2 milk. Among the molecular biology methods, top-down proteomics is the most efficient, accurate, and sustainable technique of milk protein genetic variant analysis.