Relationship of β-casein genotypes (A1A1, A1A2 and A2A2) to the physicochemical composition and sensory characteristics of cows’ milk

Abstract

This study determines the relationship between β-casein CSN2 genotypes (A1A1, A1A2, A2A2) and milk’s biochemical and sensory traits. Ninety-six cow’s milk from the same herd was investigated. Animals were grouped according to the β-casein genotype variants A1A1, A1A2 and A2A2, with thirty-two animals each. A1A1 milk had higher monounsaturated fatty acids MUFA (<0.001) and lower levels of saturated fatty acids SFA (<0.001) fatty acids content. A1A2 milk had higher amino acids and higher SFA (<0.001) fatty acid content in the milk. Furthermore, A1A2 milk had the highest lightness index (L*) (<0.001), which we found correlated to increased redness index (a*) (<0.001) and yellowness index (b*) (<0.01) values. A2A2 milk was higher in polyunsaturated fatty acids PUFA (<0.001), omega-3 (0.001) and omega-6 (<0.001) and lower saturated fatty acids SFA (<0.001) fatty acids content. We concluded that the amino acid content, fatty acid content and colour of the milk could be influenced by CSN2 genotypes A1A1, A1A2 and A2A2. As a result, the selective breeding of genotypes with preferred qualities may improve milk and dairy products.

Keywords

• Cow’s milk
• fatty acid composition
• β-casein
• CSN2
• amino acid composition