Sabari Sarizan, Julmohammad Norliza, Jahurul Haque Akanda Md, Matanjun Patricia, Ab Wahab Noorakmar
Faculty of Food Science and Nutrition, Universiti Malaysia Sabah, Kota Kinabalu 88400, Sabah, Malaysia.
Department of Agriculture, School of Agriculture, University of Arkansas, 1200 North University Dr., M/S 4913, Pine Bluff, AR 71601, USA.
Foods. 2023 Feb 3;12(3):667. doi: 10.3390/foods12030667.
The model in vitro protein digestion technique has received greater attention due to providing significant advantages compared to in vivo experiments. This research employed an in vitro infant digestive static model to examine the protein digestibility of whey proteins isolate-lactose (WPI-Lac). The polyacrylamide gel electrophoresis (PAGE) pattern for alpha-lactalbumin of WPI at 60 min showed no detectable bands, while the alpha-lactalbumin of the WPI-Lac was completely digested after 5 min of gastric digestion. The beta-lactoglobulin of the WPI-Lac was found to be similar to the beta-lactoglobulin of the WPI, being insignificant at pH 3.0. The alpha-lactalbumin of the WPI decreased after 100 min of duodenal digestion at pH 6.5, and the WPI-Lac was completely digested after 60 min. The peptides were identified as ~2 kilodalton (kDa) in conjugated protein, which indicated that the level of degradation of the protein was high, due to the hydrolysis progress. The conjugated protein increased the responsiveness to digestive proteolysis, potentially leading to the release of immunogenic protein by lactose, and to the creation of hypoallergenic protein.
与体内实验相比，体外蛋白质消化模型技术具有显著优势，因此受到了更多关注。本研究采用体外婴儿消化静态模型来检测乳清分离蛋白 - 乳糖（WPI-Lac）的蛋白质消化率。WPI的α-乳白蛋白在60分钟时的聚丙烯酰胺凝胶电泳（PAGE）图谱中未检测到条带，而WPI-Lac的α-乳白蛋白在胃消化5分钟后被完全消化。发现WPI-Lac的β-乳球蛋白与WPI的β-乳球蛋白相似，在pH 3.0时不明显。WPI的α-乳白蛋白在pH 6.5的十二指肠消化100分钟后减少，WPI-Lac在60分钟后被完全消化。在结合蛋白中鉴定出的肽约为2千道尔顿（kDa），这表明由于水解过程，蛋白质的降解程度很高。结合蛋白增加了对消化蛋白水解的反应性，可能导致乳糖释放免疫原性蛋白，并产生低敏性蛋白。
