Abstract: The objective of this paper was to investigate the efficacy of radish seed protein extract (RSPE) in preserving the freshness of cold stored surgeon fillets. The antibacterial activity of RSPE against nine sturgeon spoilage bacteria was studied. Sturgeon fillets were treated with 64 (T1), 32 (T2) and 2 AU/mL (T3) RSPE solutions, respectively, and sterile saline solution was used as control. All samples were analyzed periodically for microbial counts (total viable counts (TVC), Enterobacteriaceae, Pseudomonas, Aeromonas and Psychrotrophs), Physicochemical properties (pH, color, total volatile basic nitrogen (TVB-N), thiobarbituric acid (TBA) and biogenic amines) and sensory characteristics. The results showed that the growth of nine sturgeon spoilage strains was inhibited by RSPE with inhibition zones larger than 17.5 mm in diameter. The shelf-lives of the control, T1, T2 and T3 groups determined by microbiological analysis were 7, 11, 9 and 7 d, respectively. Meanwhile, the accumulation of TVB-N, TBA and biogenic amines were significantly and concentrationdependently inhibited by RSPE as compared with the control. The results of sensory evaluation were consistent with the microbiological and physicochemical results. As a consequence, RSPE could effectively inhibit the growth of spoilage bacteria in sturgeon and reduce the spoilage rate of sturgeon during cold storage. Therefore, it has the potential to be used as a novel biological preservative for chilled sturgeon fillets.

Key words: radish seed protein extract, biopreservative, sturgeon, shelf-life