The effect of electron beam irradiation combined with slurry ice on physicochemical parameters and bacterial communities of shrimp (Litopenaeus vannamei) during refrigerated storage

Abstract

Litopenaeus vannamei (L. vannamei) has high moisture, protein, and strong enzyme activity, which makes the shrimp susceptible to spoilage and deterioration after death. The study investigated the effects of different refrigerated conditions on the sensory quality, physicochemical indicators, and bacterial communities of L. vannamei, including crushed ice (CI, −0.5 °C), freshwater slurry ice (FI, −1 °C), seawater slurry ice (SI, −1.7 °C), and electron beam irradiation combined with seawater slurry ice (ESI, −1.7 °C), of which CI was the control group. All samples were stored in a freezer at −2 °C to keep the experimental conditions consistent. The results of sensory and physicochemical indexes showed that, compared with the other groups, the ESI group effectively inhibited the activities of polyphenol oxidase, significantly slowed down the growth of pH, TVB-N, and TVC values, and maintained the good organoleptic quality of the shrimp. High-throughput sequencing analyzes showed that the relative abundance of Vibrio and Photobacterium decreased significantly after irradiation, while the uniformity of the microorganisms increased. After 16 days of refrigeration, the relative abundance of Pseudoalteromonas, Photobacterium, and Alistipes in the ESI group was lower compared to the CI group, and the colony structure appeared to be more uniform. Therefore, the combination of electron beam irradiation and seawater slurry ice technology is promising for extending the shelf life of shrimp.