Evaluation of exogenous lactic acid bacteria, yeasts and staphylococci for flavor improvement of channel catfish frame hydrolysate

This study aimed to evaluate and select high aroma-producing strains for aroma improvement of a novel new fish sauce from channel catfish. Preliminary screening in the synthetic broth and secondary screening in fish frame hydrolysate were conducted for nine exogenous strains, including Lactiplantibacillus plantarum (LP), Pediococcus pentosaceus (PP), Latilactobacillus sakei (LS), Pichia fermentans (PF), Zygosaccharomyces rouxii (ZR), Wickerhamomyces anomalus (WA), Staphylococcus xylosus (SX), Staph. saprophyticus (SS) and Staph. carnosus (SC). In the broth, LP, PF, and SS exhibited superior growth, higher acid and alcohol tolerance than others in the same group (lactic acid bacteria, yeasts and staphylococci). Secondary screening in the fish frame hydrolysate demonstrated LP, PF, and SS displayed better performance in acid generation and reducing sugar consumption. HS-SPME-GC-MS analysis showed that the mixed culture of the three strains produced more alcohols and esters than other combinations. Sensory analysis revealed that the three-strains combination obviously improved the flavor profile of the fish frame hydrolysate relative to combinations with two strains and commercial fish sauce, especially the fruity and cheesy flavor. In summary, LP, PF, and SS can better adapt to the new fish sauce environment and have aroma enhancement potential.