Effects of the anti-microbial peptide pardaxin plus sodium erythorbate dissolved in different gels on the quality of Pacific white shrimp under refrigerated storage

Pardaxin (33 amino acids; GFFALIPKIISSPLFKTLLSAVGSALSSSGGQE) is an antimicrobial peptide originally isolated from marine fish species (Pardachirus marmoratus). Pardaxin is a safe and natural peptide used as an anti-microbial agent. This study aimed to investigate (1) the optimal pardaxin concentration alone or in combination with various gums for coating on shrimp to maintain quality during storage at 4 °C, and (2) the potentials of pardaxin and sodium erythorbate (SE) to suppress bacteria growth and effect antioxidation, respectively. We found that 1% xanthan gum and 0.5% xanthan gum + 0.5% guar gum (mixed-XG) coating on shrimp yielded a film that countered oxidation and weight loss and maintained shrimp quality (including texture profile, sensory quality, and melanosis suppression) through inhibition of peroxide value and total volatile basic nitrogen. Subsequently, pardaxin alone or in combination with SE was added into mixed-XG for evaluating shrimp quality during storage at 4 °C. The results indicated that mixed-XG with 0.5% SE and 0.25% pardaxin could significantly suppress bacteria growth and potentially effect antioxidation. Overall, these findings indicate that storing fresh shrimp in specific conditions (mixed XG + 0.5% SE + 0.25% pardaxin) might serve as an effective post-harvest treatment for preserving the freshness of shrimp and prolonging shelf life.