Calcium binding affects in vitro gastrointestinal digestion of bovine α-lactalbumin under infant, adult and elderly conditions

• Published in: International dairy journal Vol. 154; p. 105943
• Main Authors: Wang, Zheng, Liu, Dasong, Hong, Xinhuizi, Tao, Xiumei, Zhang, Jielong, Zhang, Jie, Hou, Yanmei, Wu, Tong, Liu, Xiaoming, Zhou, Peng
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.07.2024
• ISSN: 0958-6946; 1879-0143
• DOI: 10.1016/j.idairyj.2024.105943

α-Lactalbumin bound with negligible, one and two Ca2+ ions (apo, holo-Ca and holo-2Ca La) were prepared, and thermal stability and gastrointestinal digestibility under infant, adult and elderly conditions were studied. Holo-2Ca La was prepared by adding 1.5 mol Ca mol−1 La to holo-Ca La solution. Almost complete release of bound Ca from holo-Ca La was achieved at pH 2.0. Bound Ca was limitedly released from holo-Ca La using citrate, and was readily released using EDTA especially at alkaline pH. Apo La was prepared by 5 stages of 4× ultrafiltration of holo-Ca La solution with 8 mol added EDTA mol−1 La at pH 8.0, where the bound Ca2+ ion remained at 0.03 mol mol−1 La. Thermal stability increased in order of apo, holo-Ca and holo-2Ca La. Infant gastrointestinal digestibility increased in order of holo-2Ca, holo-Ca and apo La. Digestibility of apo La increased in order of infant, elderly and adult conditions.