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Protein digestion properties of Xinong Saanen goat colostrum and mature milk using in vitro digestion model
Author(s) -
Sun Yuxue,
Wang Cuina,
Sun Xiaomeng,
Guo Mingruo
Publication year - 2019
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.9852
Subject(s) - colostrum , digestion (alchemy) , casein , food science , chemistry , zoology , biology , chromatography , immunology , antibody
BACKGROUND Xinong Saanen goat milk is a raw material for goat milk‐based infant formula production. This study aims to analyze digestion properties of Xinong Saanen goat colostrum and mature milk by simulating infant gastrointestinal digestion. Zeta potential, particles size, protein profile and peptides composition of these two kinds of milk during the digestion process were studied. RESULTS Zeta‐potential values of the digested colostrum were lower than those of mature milk through the whole digestion. Absolute zeta potential of colostrum duodenal digestion samples showed a decrease from 16.63 ± 2.08 to 11.80 ± 2.03 mV while that of mature milk decreased sharply and then increased ( P < 0.05). Colostrum had a larger particle size than mature milk and both milks showed decreased particle size with increasing digestion time but an increase for the last 30 min. Colostrum showed more high molecular weight (MW) proteins which cannot be hydrolyzed completely compared with mature milk. Digested peptides (< 10 kDa) were characterized using liquid chromatography combined with tandem mass spectrometry (LC–MS/MS). The casein‐derived peptides identified in digested colostrum and mature milk accounted for 76.67% and 59.53%, respectively. β‐Casein was the most abundant in colostrum while that in mature milk was α s1 ‐casein. Enterotoxin‐binding glycoprotein PP20K, butyrophilin subfamily 1 member A1 (BTN1A1) and perilipin (PLIN) were only detected in digested mature milk. CONCLUSION Differences in digestion properties between goat colostrum and mature milk were mainly shown in duodenal digestion phase. Data may provide useful information about utilization of goat milk for infant formula formulation. © 2019 Society of Chemical Industry