Explore Gastric Lipolysis and Lipid Oxidation of Conventional versus Pasture-Based Milk by a Semi-dynamic In Vitro Digestion Model

• Published in: Journal of agricultural and food chemistry Vol. 69; no. 47; pp. 14241 - 14249
• Main Authors: Pinho, Susana C. M, Faria, Miguel, Casal, Susana, Sobral, M. Madalena C, Alves, Rui, Cabrita, Ana R. J, Fonseca, António J. M, Ferreira, Isabel M.P.L.V.O
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 01-12-2021
• Subjects: Animals; Cattle; Digestion; Fatty Acids; Female; Food and Beverage Chemistry/Biochemistry; Lactation; Lipolysis; Milk; Triglycerides; cow’s milk fat; UHT whole milk; human simulated gastric digestion; conjugated dienes and trienes; free fatty acid
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/acs.jafc.1c03150

Research on gastric lipolysis of commercial cow’s milk with different fatty acid (FA) compositions is scarce. Gastric lipase exhibits specificity for the sn-3 chain position of triacylglycerols, whose structure is influenced by milk FA composition. Therefore, during gastric digestion of conventional (C) vs pasture-based (P) milk, differences may occur on lipolysis, which has impact on free FA available, influencing their absorption/metabolism rate and physiological hormonal responses. Those two milk types were subjected to the INFOGEST semi-dynamic digestion model. Five gastric emptying points were analyzed for oxidative degradation of polyunsaturated fatty acids (PUFA) and individual free FA. The relative release of medium-chain FA (C8:0–C12:0) was higher than that of longer-chain FA (C14:0–C18:0), and a linear increase in markers of PUFA oxidative degradation occurred along gastric digestion. Quantitatively, C8:0, C18:2n-6, C18:3n-3, and CLAc9t11 were higher (P < 0.001) in P milk when compared with C milk.