In vivo digestion of bovine milk fat globules: effect of processing and interfacial structural changes. I. Gastric digestion

Abstract

The aim was to study the in vivo gastric digestion of fat globules in bovine cream from raw, pasteurised or pasteurised and homogenised milk. Fasted rats were gavaged once and chyme samples were collected after 30, 120 and 180 min post-gavage. Proteins from raw (RC) and pasteurised (PC) creams appeared to be digested faster and to a greater extent. Free fatty acids (FAs) increased throughout the 3h postprandial period. Short and medium chain FAs were released more rapidly than long chain FAs which were hydrolysed to a greater degree from PC. The size of the fat globules of all creams increased in the stomach. Protein aggregates were observed in pasteurised and homogenised cream chyme. Protrusions, probably caused by the accumulation of insoluble lipolytic products, appeared at the surface of the globules in RC and PC chyme. Overall, PC proteins and lipids appeared to be digested to a greater extent.

Keywords: ADPH; BTN; Bovine cream; CD; CLSM; Confocal microscopy; DIC; FA; FABP; In vivo gastric digestion; LCFA; MCFA; MFGM; MUC1; Milk fat globule membrane; PAS; PC; PHC; RC; Rd-DHPE; SCFA; SDS–PAGE; TEM; Transmission electron microscopy; WGA; XO; adipophilin; butyrophilin; cluster of differentiation; confocal laser scanning microscopy; differential interference contrast; fatty acid; fatty acid binding protein; long chain fatty acid; medium chain fatty acid; milk fat globule membrane; mucin1; pasteurised and homogenised cream; pasteurised cream; periodic acid Schiff; raw cream; rhodamine B 1,2-dihexadecanoyl-sn-glycero-3-phosphoethanolamine; short chain fatty acid; sodium dodecyl sulphate polyacrylamide gel electrophoresis; transmission electron microscopy; wheat germ agglutinin; xanthine oxidase.