The changes in digestibility of TG-treated myofibrillar protein (MP), soybean protein isolate (SPI) and mixed proteins were evaluated by measuring liberation of primary amino groups, monitoring structural changes and investigating peptide fingerprints. TG treatment generally increased gastric digestion of treated proteins, possibly due to the structural changes occurred during TG treatment. In contrast, the initial intestinal digestion was suppressed by TG treatment. Compared with MP, the digestibility and peptide composition of SPI were affected by TG treatment to a larger degree, possibly due to the higher level of glutamine in SPI. Peptidomics analysis indicated that the changes in peptide composition of digests of TG-treated samples were related with the loss of Lys residues during TG treatment. Larger quantities of bioactive peptides KIEFEQFLPM, EVHEPEEKPRPK and TVKEDQVFPMNPPK were released after digestion of TG-treated MP. These results highlighted the complex and substantial influence of TG treatment on the digestibility of dietary proteins.

通过测量伯氨基的释放、监测结构变化和研究肽指纹来评估经 TG 处理的肌原纤维蛋白 (MP)、大豆分离蛋白 (SPI) 和混合蛋白的消化率变化。TG 处理通常会增加处理过的蛋白质的胃消化，这可能是由于 TG 处理期间发生的结构变化。相比之下，TG 处理抑制了最初的肠道消化。与 MP 相比，SPI 的消化率和肽组成受 TG 处理的影响更大，可能是由于 SPI 中谷氨酰胺含量较高。肽组学分析表明，TG 处理样品消化物肽组成的变化与 TG 处理过程中赖氨酸残基的损失有关。消化 TG 处理的 MP 后，释放出大量的生物活性肽 KIEFEQFLPM、EVHEPEEKPRPK 和 TVKEDQVFPMNPPK。这些结果突出了 TG 处理对日粮蛋白质消化率的复杂而实质性的影响。