Study of the performance of acid protease from Aspergillums hennebergii in solid- state fermentation of wheat

Traditional solid- state fermentation is multi- dimensional variability fermentation system including microbial diversity, enzyme diversity, substances diversity, metabolic diversity etc.Acid protease plays an important role for hydrolyzing protein, increasing microbial biomass and forming flavour compounds during the whole fermenting process. In this study, wheat was used as raw materials for solid- state fermentation, and the performance of extracellular acid protease from Aspergillus hennebergii was investigated.The results showed that, compared with the control samples without any addition of acid protease, the addition of acid protease could increase hydrolysis degree of wheat protein by 28.26%, increase amino acid contentration of fermented grains by34.21%, promote S. cerevisiae biomass of fermented grains by 37.09%, increase total acids content of fermented grains by 36.17%, enhance alcohol content by 38.29% in fermented grains, and increase wheat protein hydrolyzate ( less than 300u) to 14.1 % which could promote the metabolism of aromatic amino acid and produce more flavour compounds.