Control of melanosis and spoilage during chilled storage of pacific white shrimp (Penaeus vannamei ) using sulphite alternatives

Abstract

Effect of various additives viz., sodium metabisuphite (SMS), combination of SMS, sodium citrate (SC) & ethylene diamine tetra acetic acid (EDTA); and pomegranate peel extract (PE) in controlling melanosis and quality deterioration in ice stored Penaeus vannamei was investigated. Shrimp was dip treated in: A) water without any additive (control), B) 1.25% SMS (w/v), C) 0.5% SMS, 0.5% SC and 200 ppm EDTA, D) 0.5% SC and 200 ppm EDTA and E) 0.5% PE for 5 min. The samples stored in ice were evaluated at 0, 12, 24, 36, 48 and 54 h for melanosis score, total volatile base nitrogen (TVB-N), pH and aerobic plate count (APC). Treatment, (E) and (D) significantly delayed melanosis development compared to control (A) followed by (B) and (C) combination. At the end of 54 h, melanosis score reached 8; 5.5; 5; 4 and 5, respectively for A, B, C, D and E samples. The APC of (E) and (D) combination of SC+EDTA was relatively lower compared to other treatments and control samples. The APC at the end of 54 h of chilled storage was 2.2 x105; 1.23x105; 4.5x105; 2.3x104 and 2.2x104 cfu g-1, respectively for A, B, C, D and E samples. TVB-N and pH of PE treated samples remained lower compared to other samples. The results indicated that pomegranate peel extract and chemicals like sodium citrate and EDTA can be used in combination with sodium metabisulphite to control development of melanosis in farmed shrimps during chilled storage.