Functional properties and emulsion stability of wheat gluten hydrolysates produced by endopeptidases from Bacillus licheniformis and Bacillus amyloliquefaciens

Gluten hydrolysates (GHs) were prepared using endopeptidases, alcalase, and neutrase. Characteristics of both enzymes including UV spectrophotometry, protein content, enzyme activity, and productivity, temperature, pH, hydrolysis time, and the combination ratio of the enzymes were determined. The degree of hydrolysis (DH) and alcalase to neutrase ratio was determined 2:1 ratio with 97% product yield. A study on emulsification properties of gluten hydrolysates revealed that oil in water emulsions obtained by a combination of two enzymes and 8 hours’ hydrolysis time were more stable compared with the resulting hydrolysates with less or more than 8 hours. The molecular weight of the resulting peptides compared with natural gluten by sodium dodecyl sulfate-Polyacrylamide gel electrophoresis (SDS-PAGE) indicated 20-245 KDa for gluten and 45-55 KDa for gluten hydrolysates. Comparison of the effect of the combination of sodium caseinate (SC), sodium polyphosphate (SP), and xanthan gum (XG) with gluten hydrolysates on oil in water emulsion stability indicated that a combination of hydrolysates with sodium caseinate has been the best effect on emulsion stability.