Influence of transglutaminase treatment on the digestibility of pork longissimus dorsi proteins.

This work aimed to investigate effect of TG treatment on the in vitro digestibility of pork longissimus dorsi proteins. Based on measurement of liberated -NH₂, TGase treatment promoted the release of -NH₂ by 9.6-30.2% after the gastric digestion, due to changes in advanced structure of protein. However, the released-NH₂ was reduced by 19.4-28.0% and 10.2-24.5% in the initial 15min of gastric and intestinal digestion respectively by TGase treatment due to the formation of Lys-Gln crosslinked structures and loss of Lys residues. Compared with controls, more undigested bands in the molecular range of 5-15 kDa were found in the digests of sample treated with 20 U TGase. Peptidomics analysis indicated that the changes in peptide composition of the digests of TGase-treated samples were largely related to the loss of Lys and Gln residues during TGase treatment. The relative abundances of potential bioactive peptides, including VDDLEGSLEQEK, EDQVFPMNPPK, LFDKPVSPL...