Open AccessImprovement of Functional Properties of Wheat Gluten Using Acid Protease from Aspergillus usamii
Author(s) -
Lingli Deng,
Zhaoxia Wang,
Sheng Yang,
Song Jun-mei,
Fei Que,
Hui Zhang,
Fengqin Feng
Publication year - 2016
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0160101
Subject(s) - hydrolysis , chemistry , gluten , hydrolysate , enzymatic hydrolysis , protease , chromatography , wheat gluten , response surface methodology , food science , biochemistry , enzyme
Hydrolysis parameters (temperature, E/S ratio, pH, and time) for acid protease (from Aspergillus usamii ) hydrolysis of wheat gluten were optimized by response surface methodology (RSM) using emulsifying activity index (EAI) as the response factor. A temperature of 48.9°C, E/S ratio of 1.60%, pH 3.0, hydrolysis time of 2.5 h was found to be the optimum condition to obtain wheat gluten hydrolysate with higher EAI. The solubility of wheat gluten was greatly improved by hydrolysis and became independent of pH over the studied range. Enzymatic hydrolysis resulted in dramatically increase in EAI, water and oil holding capacity. Molecular weight distribution results showed that most of the peptides above 10 kDa have been hydrolyzed into smaller peptides. The results of FTIR spectra and disulfide bond (SS) and sulfhydryl (SH) content suggested that a more extensional conformation was formed after hydrolysis, which could account for the improved functional properties.