Riddet Institute, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand.
School of Food and Advanced Technology, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand.
Molecules. 2021 Mar 4;26(5):1379. doi: 10.3390/molecules26051379.
This study investigated the effect of gel structure on the digestion of heat-set whey protein emulsion gels containing capsaicinoids (CAP), including the bioaccessibility of CAP. Upon heat treatment at 90 °C, whey protein emulsion gels containing CAP (10 wt% whey protein isolate, 20 wt% soybean oil, 0.02 wt% CAP) with different structures and gel mechanical strengths were formed by varying ionic strength. The hard gel (i.e., oil droplet size ~ 0.5 μm, 200 mM NaCl), with compact particulate gel structure, led to slower disintegration of the gel particles and slower hydrolysis of the whey proteins during gastric digestion compared with the soft gel (i.e., ~ 0.5 μm, 10 mM NaCl). The oil droplets started to coalesce after 60 min of gastric digestion in the soft gel, whereas minor oil droplet coalescence was observed for the hard gel at the end of the gastric digestion. In general, during intestinal digestion, the gastric digesta from the hard gel was disintegrated more slowly than that from the soft gel. A power-law fit between the bioaccessibility of CAP (Y) and the extent of lipid digestion (X) was established: Y = 49.2 × (X - 305.3), with = 0.84. A greater extent of lipid digestion would lead to greater release of CAP from the food matrix; also, more lipolytic products would be produced and would participate in micelle formation, which would help to solubilize the released CAP and therefore result in their higher bioaccessibility.
本研究考察了凝胶结构对含辣椒素（CAP）的热凝固乳清蛋白乳液凝胶消化的影响，包括 CAP 的生物利用度。在 90°C 下热处理时，通过改变离子强度形成了具有不同结构和凝胶机械强度的含 CAP 的乳清蛋白乳液凝胶（10wt%乳清蛋白分离物，20wt%大豆油，0.02wt%CAP）。具有致密颗粒状凝胶结构的硬凝胶（即油滴大小约为 0.5μm，200mM NaCl）导致凝胶颗粒的崩解和乳清蛋白在胃消化过程中的水解比软凝胶（即油滴大小约为 0.5μm，10mM NaCl）更慢。在软凝胶中，胃消化 60 分钟后油滴开始聚结，而在硬凝胶中，胃消化结束时仅观察到少量油滴聚结。一般来说，在肠消化过程中，硬凝胶的胃消化产物比软凝胶的胃消化产物崩解得更慢。CAP 的生物利用度（Y）与脂质消化程度（X）之间建立了幂律拟合关系：Y=49.2×（X-305.3），其中 = 0.84。更大程度的脂质消化会导致更多的 CAP 从食物基质中释放出来；此外，会产生更多的脂解产物并参与胶束形成，这将有助于溶解释放的 CAP，从而导致其更高的生物利用度。
