Sodium erythorbate, stable chlorine dioxide, and gellan gum glazing for shelf life extension of commercial peeled shrimp (Litopenaeus vannamei) during frozen storage

The combined effect of sodium erythorbate, stable chlorine dioxide, and gellan gum glazing on quality of peeled shrimp was investigated during frozen storage, and compared with traditional water-ice-glazing treatment. Data revealed that the growth of total aerobes, Escherichia coli, and Staphylococcus aureus was significantly inhibited in the combined treatment, compared to the water-ice-glazing group. Examination of tissue texture and microstructure verified that the combined glazing effectively maintained springiness and chewiness of the shrimp muscle, and this treatment showed a positive effect on stability and integrity of tissue microstructures. Myofibrillar protein content and Ca2+-ATPase activity in muscle treated with combination were significantly higher than the water-ice-glazing treatment. SDS-PAGE results confirmed that this treatment markedly slowed the degradation of muscle proteins. Additionally, the combined treatment significantly decreased the amount of protein carbonyls and dityrosine, which was mainly governed by the anti-oxidization effect of incorporated sodium erythorbate. Practical applications Ice-glazing is a surface coating process and is especially useful in the field of shrimp preservation, which prevents incidence of surface drying and dehydration, freezer burn, oxidation, and/or rancidity. However, the traditional water-ice-glazing can lead to cracking and sublimation during long period of frozen storage. The bacterial contamination cannot be completely suppressed or inactivated by the single ice-glazing treatment. Among glazing processes, chitosan-based glazings have been most widely studied to maintain quality of shrimp products. However, chitosan is water-insoluble, relatively expensive, and highly viscous, which greatly limits its practical applications. For these reasons, alternative treatments that can form a stable and uniform glaze on surface of shrimp should be considered to minimize bacterial contamination and inhibit quality deterioration of frozen products. Outcome of the current study provides information regarding an optimum glazing formulation for shelf-life extension of shrimp during frozen storage.