Asian green mussel treated with sous vide and chitooligosaccharide-catechin conjugate: Chemical, physical, microbiological, histological properties and quality changes during refrigerated storage

Abstract

Asian green mussel (Perna viridis) poses public health risks due to the contamination of pathogenic bacteria from its aquatic environment. It is highly perishable and deteriorates within 1–2 days. This study investigated the effectiveness of combining chitooligosaccharide-catechin (CC) conjugate treatment with sous vide (SV) cooking to enhance the safety, quality, and shelf life of half-shelled mussel (H-AM) edible portion (EP). H-AM samples were vacuum-packed and cooked in a water bath at 45 °C, 65 °C, and 85 °C. SV cooking at 45 °C for 30 min (SV 45/30) was the optimal condition, effectively inactivating vegetative microflora, preserving texture and protein patterns, and maintaining high edible portion yields with minimal disruption to collagen fibers, muscle, and connective tissues. When SV cooking at 45 °C was combined with 400 ppm CC (H-AM + CC + SV45/30), pathogenic and spoilage bacteria were significantly inhibited during refrigerated storage for 45 days. Untreated samples (day 5) showed increased total volatile basic nitrogen and microbial loads, while H-AM + CC + SV45/30 samples had no marked changes. Leuconostoc mesenteroides (92.27%) became predominant over Vibrio spp. and Pseudomonas spp. in the H-AM + CC + SV45/30 sample. Volatile organic compounds determined using HS-SPME-GC-EI/MS revealed that the abundance of alcohol and ketone was high in untreated samples, indicative of spoilage, while hydrocarbons were predominated in treated samples at the end of storage. Sensory evaluation confirmed acceptability of H-AM + CC + SV45/30 for up to 45 days. This study highlights the potential of CC pretreatment combined with SV cooking as an effective method to enhance microbiological safety, maintain quality, and extend the shelf life of mussels.