Institute of Bioanalytical Chemistry, Faculty of Chemistry and Mineralogy, Universität Leipzig, Germany; Center for Biotechnology and Biomedicine, Universität Leipzig, Leipzig, Germany.
Food Chem. 2017 Apr 15;221:489-495. doi: 10.1016/j.foodchem.2016.10.092. Epub 2016 Oct 22.
Thermal treatment preserves the microbiological safety of milk, but also induces Maillard reactions modifying for example proteins. The purpose of this study was evaluating the influence of consumer behaviors (storage and heating) on protein glycation degrees in bovine milk products. Lactosylation and hexosylation sites were identified in ultra-high temperature (UHT), lactose-free pasteurized, and lactose-free UHT milk (ULF) and infant formula (IF) using tandem mass spectrometry (electron transfer dissociation). Overall, 303 lactosylated and 199 hexosylated peptides were identified corresponding to 170 lactosylation (31 proteins) and 117 hexosylation sites (25 proteins). In quantitative terms, storage increased lactosylation up to fourfold in UHT and IF and hexosylation up to elevenfold in ULF and threefold in IF. These levels increased additionally twofold when the stored samples were heated (40°C). In conclusion, storage and heating appear to influence protein glycation levels in milk at similar or even higher degrees than industrial processing.
热处理既能保持牛奶的微生物安全性，又能引发美拉德反应，从而改变蛋白质等物质。本研究旨在评估消费者行为（储存和加热）对牛乳制品中蛋白质糖化程度的影响。采用串联质谱法（电子转移解离）鉴定了超高温（UHT）、无乳糖巴氏杀菌和无乳糖 UHT 牛奶（ULF）和婴儿配方奶粉（IF）中的糖基化和己糖基化位点。总的来说，鉴定出了 303 个乳酰化和 199 个己糖基化肽，分别对应于 170 个乳酰化（31 种蛋白质）和 117 个己糖基化位点（25 种蛋白质）。从定量的角度来看，在 UHT 和 IF 中储存会使乳酰化增加四倍，在 ULF 和 IF 中储存会使己糖基化增加十一倍，加热（40°C）会使这些水平进一步增加两倍。综上所述，储存和加热似乎会以与工业加工相似甚至更高的程度影响牛奶中的蛋白质糖化水平。
