Abstract: This study investigated the effects of three non-thermal sterilization pretreatments, plasma activated water (PAW), ozonated water (OW), and slightly acidic electrolytic water (SAEW) on the quality characteristics and microbial community structure of Litopenaeus vannamei. After being soaked in PAW, OW, SAEW or tap water (TW, as the control) for 15 min, shrimp were evaluated for microbiological, physicochemical, and sensory indices, and the microbial community structures of different body parts were analyzed using 16S rRNA high-throughput sequencing. The results showed that all three pretreatments significantly reduced the total viable count, Staphylococcus aureus, Vibrio parahaemolyticus, and Pseudomonas counts, and inhibited the increase of total volatile basic nitrogen (TVB-N) value (P < 0.05). Among them, OW and SAEW pretreatments better maintained the water content, texture, and sensory quality of shrimp. Microbial community analysis indicated that Proteobacteria and Bacteroidota were the dominant phyla in each body part across all groups, but their relative abundances varied among treatments. At the genus level, all three pretreatments effectively inhibited conditional pathogens such as Vibrio and Photobacterium, thereby optimizing the microbial community composition. In conclusion, PAW, OW, and SAEW pretreatments can significantly inhibit bacterial growth in shrimp while improving its quality. This study provides scientific support for the purification, processing and industrial application of aquatic products.

Key words: Litopenaeus vannamei; non-thermal sterilization pretreatment; quality; microbial communities; 16S rRNA high-throughput sequencing