University of Alberta, Edmonton, AB, Canada.
J Appl Microbiol. 2022 Jul;133(1):120-129. doi: 10.1111/jam.15346. Epub 2021 Nov 5.
This study aimed to quantify α-amylase/trypsin inhibitor (ATI) CM3 and glutathione (GSH) during wheat sourdough breadmaking.
Breads were made with two wheat cultivars and fermented with Fructilactobacillus sanfranciscensis, F. sanfranciscensis ΔgshR or Latilactobacillus sakei; chemically acidified and straight doughs served as controls. Samples were analysed after mixing, after proofing and after baking. GSH and CM3 were quantified by multi-reaction-monitoring-based methods on an LC-QTRAP mass spectrometer. Undigested ATI extracts were further examined by SDS-PAGE.
GSH abundance was similar after mixing and after proofing but increased after baking (p < 0.001), regardless of fermentation. In breads baked with cv. Brennan, the samples fermented with lactobacilli had higher GSH abundance (p < 0.001) than in the controls. CM3 relative abundance remained similar after mixing and after proofing but decreased after baking (p < 0.001) across all treatments. This trend was supported by the SDS-PAGE analysis in which ATI band intensities decreased after baking (p < 0.001) in all experimental conditions. The overall effect of baking exerted a greater effect on the abundances of GSH and CM3 than fermentation conditions.
This is the first report to quantify ATI over the course of breadmaking by LC-MS/MS in sourdough and straight dough processes.
本研究旨在定量测定小麦酸面团制作过程中的α-淀粉酶/胰蛋白酶抑制剂（ATI）CM3 和谷胱甘肽（GSH）。
使用两种小麦品种制作面包，并分别用嗜酸果糖杆菌、缺失谷胱甘肽合成酶的嗜酸果糖杆菌或清酒乳杆菌发酵；化学酸化和直接面团作为对照。在混合后、发酵后和烘焙后分析样品。使用基于多反应监测的 LC-QTRAP 质谱法定量测定 GSH 和 CM3。未消化的 ATI 提取物进一步通过 SDS-PAGE 进行检查。
无论发酵与否，混合后和发酵后 GSH 丰度相似，但烘焙后增加（p<0.001）。在使用 Brennan 品种烘焙的面包中，与对照相比，经乳酸菌发酵的样品具有更高的 GSH 丰度（p<0.001）。混合后和发酵后 CM3 相对丰度相似，但烘焙后降低（p<0.001），所有处理均如此。SDS-PAGE 分析也支持了这一趋势，其中 ATI 条带强度在所有实验条件下烘焙后均降低（p<0.001）。与发酵条件相比，烘焙的总体效果对 GSH 和 CM3 的丰度产生了更大的影响。
这是首次通过 LC-MS/MS 在酸面团和直接面团工艺中定量测定 ATI 在面包制作过程中的含量。
