Resumen

β-Casein (β-CN) is a major protein component of cow milk, and numerous genetic variants have been described, including the most common A1 and A2 types. These two genetic variants differ in terms of the inclusion of either proline in A2 β-CN or histidine in A1 β-CN at position 67 in the peptide chain. Due to the presence of histidine in the A1 variant, digestive enzymes act on it, releasing the bioactive opioid peptide β-casomorphin-7 (BCM-7), while A2 variant releases much less and probably minimal amounts of BCM-7 under normal gut conditions. Nowadays, there exists a controversial debate on the benefits of drinking milk containing A2 β-CN (A2 milk), since recent studies suggest a correlation between the consumption of milk containing A1 β-CN (A1 milk) and gastrointestinal digestive discomfort and the incidence of certain human diseases. For this reason, farmers of different zones of the world are being stimulated to select the A2 genetic variant of β-CN in their dairy cows, reducing the A1 allele frequency. From a physicochemical viewpoint, it has been demonstrated that A2 β-CN has a lower hydrophobicity and forms smaller micelles compared with A1 β-CN, modifying the technofunctional characteristics of milk. Further, recent studies have shown that the selection of a defined β-CN genotype seems to alter other milk proteins genotypes (i.e., κ-CN) and then the physicochemical and functional properties of milk. The aim of this chapter is to examine the influence of A1 and A2 β-CN genotypes on bovine milk production and composition and the impact of these protein variants on the milk technological quality and human health. The current state of the market for dairy products made with A2 milk and the analytical techniques used for their identification will also be reviewed.

Idioma originalInglés
Título de la publicación alojadaCasein: Structural Properties, Uses, Health Benefits and Nutraceutical Applications
Subtítulo de la publicación alojadaStructural Properties, Uses, Health Benefits and Nutraceutical Applications
EditorialElsevier
Páginas99-121
Número de páginas23
ISBN (versión digital)9780443158360
ISBN (versión impresa)9780443158360
DOI
EstadoPublicada - 1 ene 2024

Huella

Profundice en los temas de investigación de 'β-Casein type A1 and A2'. En conjunto forman una huella única.

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