Bioaccessibility of docosahexaenoic acid in naturally and artificially enriched milk

Abstract

This study aimed to compare the bioaccessibility of docosahexaenoic acid (DHA) in naturally and artificially enriched milk and investigate the potential mechanisms involved. The results indicated that the DHA in naturally enriched milk (NEM) had a higher bioaccessibility (76.9 %) and a lower digestive loss rate (18.1 %) compared to artificially enriched milk (ArEM). Moreover, NEM contained a higher proportion of DHA-containing glycerophospholipids and sn-2 DHA, with fewer long-chain fatty acids and more saturated fatty acids adjacent to DHA in the same lipid molecule. During simulated intestinal digestion, NEM had a higher free fatty acid release and lipid digestion rate than ArEM. These findings suggested that the bioaccessibility of endogenous DHA in milk was superior to that of externally added DHA due to its more easily digestible and absorbable chemical binding form and lower digestive loss rate. The easy digestibility of milk lipids in NEM also contributed to its high DHA bioaccessibility.

Keywords: Chemical binding forms; DHA bioaccessibility; DHA-enriched milk; In vitro digestion; Milk fat digestion properties.