Abstract: In order to study the mechanism of action of cold plasma in preserving the quality of shrimps during storage, changes in the microflora and quality (microbial diversity, total viable count, total volatile basic nitrogen (TVB-N) content, elasticity, chewiness and microstructure) of Solenocera crassicornis treated by cold plasma was detected during chilled storage at (4 ± 1) ℃. The results showed that Pseudomonas and Shewanella were the dominant spoilage bacteria in untreated samples, whose relative abundance reached 49.01% and 28.6% on day 6, respectively. The dominant strain in treated samples was Aeromonas, whose relative abundance was 43.16% on day 6. The TVB-N content of the control group reached (28.03 ± 1.98) mg/100 g on day 4, while that of the treatment group just approached the maximum limit (30 mg/100 g) set by the national standard of China on the day 8. The elasticity and chewiness of the treated group decreased more slowly compared with the untreated group. As observed under an electron microscope, a flocculent structure appeared in the space among muscle fibers in the untreated group on day 4, while the muscle microstructure of the treated group was not significantly different from that in the fresh state. It is concluded that cold plasma treatment can effectively delay the microbial spoilage of Solenocera crassicornis, and significantly change its microscopic morphology, being beneficial to maintain the product quality during storage and transportation. The results from this study can provide a theoretical reference for the application of this new technology to aquatic product preservation.

Key words: Solenocera crassicorni; cold plasma; microbial diversity; quality characteristics; microstructure