School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018, P. R. China.
Allergy Research Center, Zhejiang University, Hangzhou, 310018, China.
Food Funct. 2023 Jun 6;14(11):5342-5354. doi: 10.1039/d2fo03000d.
Advanced glycation end-products (AGEs) are a group of heterogeneous compounds formed during the Maillard Reaction (MR) and have been proven to be detrimental to human health. In addition to thermally processed foods, the digestive tract may be an additional site for exogenous AGE formation since the MR would possibly occur between (oligo-)peptides, free amino acids, and reactive MR products (MRPs) such as α-dicarbonyl compounds (α-DCs) along the digestion. In this study, through establishing a simulated gastrointestinal (GI) model consisting of whey protein isolate (WPI) and two typical α-DCs, , methylglyoxal (MGO) or glyoxal (GO), we first validated that co-digestion of WPI with α-DCs generated extra amounts of AGEs in a precursor-dependent manner, especially seen in the intestinal stage. At the end of GI digestion, the contents of total AGEs in WPI-MGO and WPI-GO systems were 4.3-242 and 2.5-73.6 times higher than those formed in the control system, respectively. Evaluation of the protein digestibility further showed that AGE formation along the digestion process slightly affected the digestibility of whey protein fractions. However, as sequenced and identified by high-resolution mass spectrometry, different types of AGE modifications were identified in peptides released from β-lactoglobulin and α-lactalbumin in the final digests, as well as changes in peptide sequence motifs. This suggested that the glycated structures formed during co-digestion affected the action of digestive proteases toward whey proteins. Overall, these results highlight the GI tract as an additional source of exogenous AGEs and provide new insights into the biochemical consequences of MRPs in heat-processed foods.
糖基化终产物（AGEs）是美拉德反应（MR）过程中形成的一组异质化合物，已被证明对人体健康有害。除了热加工食品外，由于 MR 可能在（寡）肽、游离氨基酸和反应性 MR 产物（MRPs）如α-二羰基化合物（α-DCs）之间发生，消化道也可能是外源性 AGE 形成的另一个部位。在本研究中，通过建立一个由乳清蛋白分离物（WPI）和两种典型的α-DC，即甲基乙二醛（MGO）或乙二醛（GO）组成的模拟胃肠道（GI）模型，我们首先验证了 WPI 与α-DC 的共消化以依赖于前体的方式产生额外量的 AGEs，尤其是在肠道阶段。在 GI 消化结束时，WPI-MGO 和 WPI-GO 系统中的总 AGE 含量分别比对照系统中的含量高 4.3-242 倍和 2.5-73.6 倍。对蛋白质消化率的进一步评估表明，消化过程中 AGE 的形成略微影响了乳清蛋白分数的消化率。然而，如通过高分辨率质谱测序和鉴定所示，在最终消化物中从β-乳球蛋白和α-乳白蛋白释放的肽中鉴定出不同类型的 AGE 修饰，以及肽序列基序的变化。这表明共消化过程中形成的糖化结构影响了消化蛋白酶对乳清蛋白的作用。总体而言，这些结果强调了胃肠道是外源性 AGE 的另一个来源，并为热加工食品中 MRPs 的生化后果提供了新的见解。
