Sodium alginate coating with plant extract affected microbial communities, biogenic amine formation and quality properties of abalone (Haliotis discus hannai Ino) during chill storage

Abstract

Due to hygiene and safety requirements, much attention is given to microorganisms and biogenic amine (BA) in aquatic food. This study investigated microbial communities, BAs, and quality properties in abalone (Haliotis discus hannai) treated with sodium alginate coating (SAC) and bamboo leaf extract (BLE) or rosemary extract (ROE) stored under chill condition. Results showed that SAC with ROE improved sensory properties, delayed pH change and decreased total volatile basic nitrogen (TVBN), but BLE did not show significant effect. Putrescine and cadaverine were main BAs in abalone while no histamine was detected. Total BA was approximate 75 mg/kg, lower than recommended limit. SAC with ROE reduced the accumulation of putrescine, cadaverine and tyramine. Total viable count, Pseudomonas sp., H2S-producing bacteria, Enterobacteriaceae and lactic acid count were inhibited by SAC, and ROE enhanced the inhibition. Principal component analysis showed clear separation of groups with different coating treatments. Close Pearson correlations between putrescine, cadaverine and aforementioned four microbial communities were observed. Results indicate that SAC combined with ROE could effectively modify microbial composition in abalone, which in return decides final BA composition and level, pH value, TVBN content. They can be used for improving hygiene status and safety of chill stored abalone.