Oyster sauce,a traditional Chinese condiment,is widely popular for its distinctive umami-sweet taste and marine flavor.While enzymatic hydrolysis is now mainstream owing to its efficiency and flavor control,current re...Oyster sauce,a traditional Chinese condiment,is widely popular for its distinctive umami-sweet taste and marine flavor.While enzymatic hydrolysis is now mainstream owing to its efficiency and flavor control,current research relies on a narrow selection of commercial enzymes,resulting in product homogenization and impeding the development of distinctive flavors.This study developed a natural protease from Aspergillus oryzae ZA304 for oyster hydrolysis,exhibiting neutral protease and aminopeptidase activities of 50,134 U/g and 12,533 U/g,respectively.It demonstrated optimal activity at 50℃,with effective operation between 30 and 60℃,and high salt tolerance.The Natural Protease hydrolysis degree reached 34.91%,the resulting hydrolysate contained more low-molecular-weight peptides and free amino acids,and exhibited a distinct flavor profile compared to com-mercial enzyme preparations.GC-MS analysis identified 2-pentylfuran,1-octen-3-ol,3-octanone,ethyl butyrate,ethyl benzoate,(Z)-4-heptenal,and 2-methylbutanol as key volatile flavor compounds,highlighting their critical role in shaping the distinct flavor profiles of raw oyster homogenate and four enzymatic hydrolysates.Metab-olomic investigations revealed that the primary differential metabolites before and after enzymatic hydrolysis included amino acids,peptides and their derivatives,along with lipid metabolites.This substantiates that the enzymatic hydrolysis process primarily influences flavor development through two parallel mechanisms:(1)proteolytic cleavage-driven amino acid and peptide metabolism,and(2)concomitant activation of lipid oxidation networks during hydrolysis.This study provides a theoretical foundation for exploring highperformance enzyme preparations and their industrial application technologies in oyster processing,thereby facilitating the green and low-carbon transformation of oyster processing systems.展开更多
基金funded by the National Key Research and Devel-opment Program of China(Grant No.2023YFD2100200).
文摘Oyster sauce,a traditional Chinese condiment,is widely popular for its distinctive umami-sweet taste and marine flavor.While enzymatic hydrolysis is now mainstream owing to its efficiency and flavor control,current research relies on a narrow selection of commercial enzymes,resulting in product homogenization and impeding the development of distinctive flavors.This study developed a natural protease from Aspergillus oryzae ZA304 for oyster hydrolysis,exhibiting neutral protease and aminopeptidase activities of 50,134 U/g and 12,533 U/g,respectively.It demonstrated optimal activity at 50℃,with effective operation between 30 and 60℃,and high salt tolerance.The Natural Protease hydrolysis degree reached 34.91%,the resulting hydrolysate contained more low-molecular-weight peptides and free amino acids,and exhibited a distinct flavor profile compared to com-mercial enzyme preparations.GC-MS analysis identified 2-pentylfuran,1-octen-3-ol,3-octanone,ethyl butyrate,ethyl benzoate,(Z)-4-heptenal,and 2-methylbutanol as key volatile flavor compounds,highlighting their critical role in shaping the distinct flavor profiles of raw oyster homogenate and four enzymatic hydrolysates.Metab-olomic investigations revealed that the primary differential metabolites before and after enzymatic hydrolysis included amino acids,peptides and their derivatives,along with lipid metabolites.This substantiates that the enzymatic hydrolysis process primarily influences flavor development through two parallel mechanisms:(1)proteolytic cleavage-driven amino acid and peptide metabolism,and(2)concomitant activation of lipid oxidation networks during hydrolysis.This study provides a theoretical foundation for exploring highperformance enzyme preparations and their industrial application technologies in oyster processing,thereby facilitating the green and low-carbon transformation of oyster processing systems.
