The Physicochemical Changes of Farm-Raised Pacific White Shrimp (<i>Litopenaeus vannamei</i>) as Influenced by Iced Storage

Abstract

Farm-raised Pacific white shrimp ( Litopenaeus vannamei ) freshly harvested was evaluated for differences in proximal composition (moisture, ash, fat, and protein contents), water activity ( a w ), water retention index (WRI), pH, colour and texture of up to 12 days of iced storage. Shortly after harvest, the proximate composition of shrimp appeared comparable across the farms. With ice storage, the pH significantly increased whereas fat content slowly decreased particularly between days 3 and 9 ( P < 0.05), after which it stayed unchanged ( P > 0.05). Expressly, the protein content of shrimp specimens gradually decreased after day 8 ( P < 0.05). In addition, the moisture content, water retention index (WRI) and water activity ( a w ) of shrimp specimens exhibited inconsequential differences during iced storage. While the lightness ( L *) was significantly affected from day 2 onwards, the yellowness ( b *) colour was so but only between days 6 and 10 ( P < 0.05). In addition, the adhesiveness and hardness textures of shrimp specimens registered peak values at day 11. Overall, the physicochemical differences in farm-raised shrimp during iced storage of this study provide valuable information for relevant stakeholders of the shrimp industry. Importantly, the data provided at this study can serve as baseline for comparison and evaluation of preservative treatments applied to shrimp.