College of Food Science and Engineering, South China University of Technology, 381 Wushan Road, Guangzhou 510640, China.
Department of Food Science, Aarhus University, Blichers Allé 20, 8830 Tjele, Denmark.
Molecules. 2018 Mar 21;23(4):712. doi: 10.3390/molecules23040712.
α-Dicarbonyl compounds, which are widely generated during sugar fragmentation and oil oxidation, are important precursors of advanced glycation end products (AGEs). In this study, the effect of glycation derived from glyoxal (GO), methylglyoxal (MGO) and diacetyl (DA) on the in vitro digestibility of bovine serum albumin (BSA) was investigated. Glycation from α-dicarbonyl compounds reduced digestibility of BSA in both gastric and intestinal stage of digestion according to measurement of degree of hydrolysis. Changes in peptide composition of digests induced by glycation were displayed, showing absence of peptides, occurrence of new peptides and formation of peptide-AGEs, based on the results obtained using liquid chromatography electron-spray-ionization tandem mass spectrometry (LC-ESI-MS/MS). Crosslinked glycation structures derived from DA largely reduced the sensitivity of glycated BSA towards digestive proteases based on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) results. Network structures were found to remain in the digests of glycated samples by transmission electron microscope (TEM), thus the impact of AGEs in unabsorbed digests on the gut flora should be an interest for further studies.
α-二羰基化合物广泛存在于糖的分解和油脂的氧化过程中，是晚期糖基化终产物（AGEs）的重要前体。本研究探讨了由乙二醛（GO）、甲基乙二醛（MGO）和二乙酰（DA）糖化生成的化合物对牛血清白蛋白（BSA）体外消化率的影响。根据水解度的测定，α-二羰基化合物的糖化降低了 BSA 在胃和肠道消化阶段的消化率。基于液相色谱-电喷雾串联质谱（LC-ESI-MS/MS）的结果，糖化诱导的消化肽组成发生变化，表现为肽缺失、新肽出现和肽-AGEs 的形成。根据十二烷基硫酸钠聚丙烯酰胺凝胶电泳（SDS-PAGE）的结果，DA 衍生的交联糖化结构大大降低了糖化 BSA 对消化蛋白酶的敏感性。通过透射电子显微镜（TEM）发现网络结构仍存在于糖化样品的消化物中，因此未被吸收的消化物中 AGEs 对肠道菌群的影响应该是进一步研究的关注点。
