Abstract:In this study，enzymatic hydrolysate was prepared from sea cucumber viscera，and multi-strain fermentation was applied for the deodorization of the hydrolysate. The experimental group was the hydrolysate supplemented with complex strains including Lacticaseibacillus paracasei，Hansenula polymorpha，Pediococcus pentosaceus，Lactobacillus acidophilus and Lactiplantibacillus plantarum，while the hydrolysate without strain inoculation served as the control group. Characteristic metabolites were screened and a fishy odor evaluation model was established based on receiver operating characteristic （ROC） curve analysis. The deodorization effect was analyzed using sensory scores combined with data from electronic nose and headspace-solid phase micro-extraction/gas chromatography-mass spectrometry （HS-SPME/GC-MS）. The antioxidant activity was determined by 1，1-diphenyl-2-picrylhydrazyl （DPPH） radical scavenging rate，superoxide anion （O2-·） scavenging rate and tyrosinase inhibition rate，so as to screen the optimal deodorization method.The results showed that the fishy odor evaluation model of sea cucumber viscera hydrolysate constructed with characteristic metabolites screened by ROC analysis presented satisfactory fitting degree and predictability. The predicted fishy odor value output by the model could effectively replace the sensory fishy odor score for the evaluation of fishy odor in the hydrolysate. Compared with the control group，the multi-strain fermentation group significantly decreased the contents of fishy odor substances such as unsaturated aldehydes，alcohols and ketones in the hydrolysate （P＜0.05），and reduced the abundance of acids and esters. The response values of sulfur compounds（W1W），short-chain alkanes （W5C） and long-chain alkanes （W3S） were all lower than those of the control group，indicating effective mitigation of fishy odor. Partial least squares discriminant analysis （PLS-DA）showed significant inter-group differences in the predicted fishy odor values of the multi-strain fermentation groups （P＜0.05），and the fermentation groups containing Lacticaseibacillus paracasei exhibited lower predicted fishy odor values. Under the same fermentation conditions （40 ℃，10 h），the optimal strain ratio was obtained in group SFG_3 with Lacticaseibacillus paracasei∶Hansenula polymorpha∶Pediococcus pentosaceus=2∶1∶2 （by volume）. Compared with the control group，the DPPH radical scavenging rate，superoxide anion radical scavenging rate and tyrosinase inhibition rate were increased by 26.17%，39.18% and 40.67%，respectively. In conclusion，multi-strain fermentation can significantly reduce the fishy odor of sea cucumber viscera enzymatic hydrolysate.