Department of Biology and Biological Engineering-Food and Nutrition Science, Chalmers University of Technology, SE 412 96 Gothenburg, Sweden.
Department of Biology and Biological Engineering-Food and Nutrition Science, Chalmers University of Technology, SE 412 96 Gothenburg, Sweden.
Food Chem. 2022 Nov 1;393:133356. doi: 10.1016/j.foodchem.2022.133356. Epub 2022 May 31.
The degradation of trout and bovine hemoglobin (Hb) and their pro-oxidant activities in washed cod muscle mince (WCM) were studied using simple pH-shifts to simulate gastrointestinal (GI) conditions (pH 7 → 6 → 3 → 7), as well as full static in vitro GI digestion. Following gastric acidification to pH 6, metHb formation increased, especially for trout Hb. Subsequent acidification to pH 3 promoted Hb unfolding and partial or complete heme group-loss. During full GI digestion, polypeptide/peptide analyses revealed more extensive Hb-degradation in the gastric than duodenal phase, without any species-differences. When digesting WCM +/-Hb, both Hbs strongly promoted malondialdehyde (MDA), 4-hydroxy-2-hexenal (HHE), and 4-hydroxy-2-nonenal (HNE) formation, peaking at the end of the gastric phase. Trout-Hb stimulated MDA and HHE more than bovine Hb in the first gastric phase. Altogether, partially degraded Hb, and/or free hemin -both mammal and fish-derived- stimulated oxidation of PUFA-rich lipids under GI-conditions, especially gastric ones.
研究了用简单的 pH 转移模拟胃肠道 (GI) 条件（pH 7→6→3→7）以及全静态体外 GI 消化时，鳟鱼和牛血红蛋白 (Hb) 的降解及其在鳕鱼肌肉糜 (WCM) 中的促氧化剂活性。胃酸化至 pH 6 后，MetHb 的形成增加，尤其是对鳟鱼 Hb。随后酸化至 pH 3 促进 Hb 展开，并部分或完全失去血红素基团。在全 GI 消化过程中，多肽/肽分析表明胃阶段的 Hb 降解程度比十二指肠阶段更广泛，而无种属差异。当消化 WCM +/-Hb 时，两种 Hb 都强烈促进丙二醛 (MDA)、4-羟基-2-己烯醛 (HHE) 和 4-羟基-2-壬烯醛 (HNE) 的形成，在胃阶段结束时达到峰值。在第一个胃阶段，与牛 Hb 相比，鳟鱼 Hb 更能促进 MDA 和 HHE 的形成。总之，部分降解的 Hb，以及/或来自哺乳动物和鱼类的游离血红素，在 GI 条件下，尤其是在胃条件下，刺激富含多不饱和脂肪酸的脂质氧化。
