Microbial transglutaminase mtgase

Lentil protein concentrate (LPC) with a protein content of 78% (w/w) was used. Alcalase (extracted from Bacillus licheniformis) and Flavourzyme (extracted from Aspergillus oryzae) were purchased from Novozymes Co. Microbial transglutaminase (MTGase) was prepared from Ajinomoto Co. Angiotensin‐I‐converting enzyme (ACE, extracted from rabbit lung) and the ACE synthetic substrate hippuryl‐l‐histidyl‐l‐leucine (HHL) were purchased from Sigma‐Aldrich Canada Ltd. Porcine pancreatic α‐amylase (Cat no. A3176) and rat intestinal α‐glucosidase (Cat no. I1630) were provided by Sigma‐Aldrich Co. All chemicals used in the present study were prepared by Sigma‐Aldrich Co. and had an analytical grade.

Lupine protein isolate (LPI) with protein content of 85% was produced according to the alkalization and precipitation method (Rezvankhah et al., 2021a (link)). Alcalase as an endopeptidase (the commercially called Alcalase 2.4 L), company reported activity of 2.4 anson units per gram (AU/g) with a density of 1.18 g/mL that has been originated from Bacillus licheniformis, and Flavourzyme as an exopeptidase (the commercially called Flavourzyme 1000 L), company reported activity of 1000 leucine amino peptidase units per gram (LAPU/g) with a density of 1.28 g/mL that has been originated from Aspergillus oryzae were provided from Novozymes Co. (Bagsværd outside of Copenhagen). Alcalase and Flavourzyme were used to produce peptides or single amino acids. Microbial transglutaminase (MTGase) with the activity of 100 U/g was prepared from Ajinomoto Co. Gum Arabic (GA) was provided from Ingredion Co. Trinitrobenzenesulfonic acid (TNBS) was purchased from Sigma Company. All other chemicals used were of analytical and HPLC (high performance liquid chromatography) grade.