Effect of pomegranate peel extract on the melanosis of Pacific white shrimp (Litopenaeus vannamei) during iced storage

Shrimp is a highly perishable product with limited shelf life due to melanosis and biological composition. The effect of pomegranate peel extract (PPE) at different concentrations (0, 7.5 and 15 g L-1) on the melanosis formation and quality of Pacific white shrimp (Litopenaeus vannamei) was investigated in the present study. The melanosis formation was significantly inhibited and sensory quality was significantly improved in Pacific white shrimp treated with various concentrations of PPE, compared with the control. The increase of pH, total volatile basic nitrogen content and thiobarbituric acid reactive substances was also significantly inhibited in Pacific white shrimp treated with various concentrations of PPE, compared with the control. The melanosis score, total volatile basic nitrogen, thiobarbituric acid reactive substances and pH values of Pacific white shrimp treated by 15 g L-1 of PPE was lower than that treated by 7.5 g L-1 of PPE during 10 days of ice storage. However, the effect of PPE treatment on inhibition of melanosis formation and the improvement of quality of shrimp was less than that of 12.5 g L-1 sodium metabisulfite. These results suggested that PPE could be used as an effective natural alternative to synthetic antimelanosic agents to inhibit postmortem melanosis in shrimp.