Flavor and quality enhancement of miiuy croaker (Miichthys miiuy) surimi by co-fermentation with Monascus purpureus and Actinomucor elegans

Co-fermentation technology is expected to improve the flavor and quality properties of fermented surimi products. Effects of fermentation with Monascus purpureus ( M. purpureus ) and Actinomucor elegans ( A. elegans ) at different inoculation ratios on the volatile profiles and physicochemical properties of surimi were investigated. Generally, fermentation resulted in significant surimi protein hydrolysis as indicated by increased amino acid nitrogen, TCA-soluble peptide, and free amino acid contents, simultaneously accompanied by decreases in hardness, gumminess, and chewiness of surimi. Co-fermentation effectively improved the volatile profiles of surimi. Comparatively, a higher inoculation ratio of M. purpureus was favorable for the production of esters and ketones, whereas a higher proportion of A. elegans reduced the aldehyde contents, especially nonanal with fishy odor. Taken together, a 1:1 inoculation ratio of M . purpureus and A. elegans was more conductive to improve the aroma profiles of surimi, with a 77.2% reduction of aldehyde compared to unfermented surimi.