Effects of mixed starter cultures and exogenous L-Lys on the physiochemical and sensory properties of rapid-fermented fish paste using longsnout catfish by-products

Fermentation is a good way to utilize fish by-products. In this study, the effects of mixed starter cultures and exogenous L-Lys on the physiochemical and sensory properties of fermented longsnout catfish minced meat were investigated. Fish pastes were divided into three groups, including a treated group (sample A), a mixed starter culture-treated group (sample B), and a L-Lys and mixed starter culture-treated group (sample C). The pH and total volatile base nitrogen in the sample C were the lowest among the tested samples. At the final stage of fermentation, the total acidity, amino acid nitrogen content, and free amino acid content in the sample C were the highest among the tested samples. No significant differences in the histamine content or antioxidant activities were observed among the three samples (p < 0.05). An electronic nose test showed that the odors of the samples B and C were similar, but different from those of the sample A. The sample C exhibited a strong umami and fermented flavor and had the best flavor. All the results demonstrated that the mixed starter cultures and L-Lys can improve the flavor and nutritive value of the fish pastes made with Chinese longsnout catfish byproducts by fermentation.