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 (aw), 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 (aw) 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.

Effect of ice water pretreatment on the quality of Pacific White Shrimps (Litopenaeus vannamei)

“…Due to an abundance of polyphenol oxidase in shrimp, it reacted effortlessly with DOPA substances to produce melanin (Bartolo & Birk, 1998). The observation seemed to agree with the color data reported by Okpala (2015) regarding the pink shrimp (Parapenaeus longirostris) that were processed onboard the shrimp under iced storage conditions. The observation seemed to agree with the color data reported by Okpala (2015) regarding the pink shrimp (Parapenaeus longirostris) that were processed onboard the shrimp under iced storage conditions.…”

Effect of low‐temperature preservation on quality changes in Pacific white shrimp, Litopenaeus vannamei: a review

“…The increase in pH reflected the production of alkaline bacterial metabolites in spoiling shrimp muscle . The pH of the fresh L. vannamei ranged from 7.20 to 7.33 and the shrimps were of good quality before the pH reached 7.7 . The pH of L. vannamei increased to 7.6 at the seventh day of storage under 4 °C, 7.48 at the ninth day during chilled storage, and 7.6 at the eighth day of storage at −0.8 °C .…”

Effect of severing skeletal muscle at different stage of rigor on the quality of pacific white shrimp (Litopenaeus vannamei)

“…The increase in the moisture content during ice storage may have been due to absorption from the melting ice. Annamalai et al () and Okpala () also reported some increase in the moisture content in L. vannamei during ice storage. In the current study, however, moisture content did not show any significant difference between the treatments.…”

“…Water holding capacity of the shrimp of this study in all the treatments decreased with storage time (Table ). This decrease in WHC indicates the denaturation/degradation of the protein during the storage (Okpala, ). The initial higher value (96.61%) of water holding capacity was observed in T 1 and lowest initial value (96.19%) was found in T 2 .…”

“…Different methods used to maintain the quality of shrimp during transportation and storage of which icing remains the best choice because unlike processing methods like freezing, drying, and canning, icing appears not to alter the meat quality so drastically. Quality of meat is also affected by harvest method (Fu, Chen, & Wang, ; Okpala, Choo, & Dykes, ; Okpala, ). Various studies have been conducted about the effect of rigor on the quality of meat in land animals like beef, pork and poultry (Marsh, Woodhams, & Leet, ; Babji, Froning, & Ngoka, ; Chow, Ockerman, Cahill, & Parrett, ; Dzudie & Okubanjo, ).…”