PREVENTION OF MELANOSIS AND QUALITY LOSS OF PACIFIC WHITE SHRIMP (LITOPENAEUS VANNAMEI) BY ETHANOL PERSICARIA ODORATA EXTRACT DURING FROZEN STORAGE

Ethanolic extract from Persicaria odorata leaf was applied to investigate the ability to preserve Pacific white shrimp ( Litopenaeus vannamei ) during frozen storage of 5 days at -21 o C in comparison with 1.25% sodium metabisulfite. From evaluating the effects of P.odorata extract concentration and immersion time on melanosis formation, shrimps treated with the extract at 1/15 (mg/mL, w/v) in 10 minutes showed the lowest degree of melanosis. Microbiological analyses showed that Pacific white shrimp treated with P. odorata extract possessed lower values in total plate count and Enterobacteriaceae count compared with the control (p<0.05). pH and total volatile base content saw a lower increase in samples treated with P. odorata crude extract (p<0.05). Freshness loss, protein degradation, and melanosis growth in shrimps with crude extract treatments were impeded. The results show that P. odorata extract can be used a potential source of melanosis inhibitors, and natural preservatives for shelf-life extension of Pacific white shrimp during frozen storage.