Abstract:

In order to resolve the problem of Pacific white shrimp spoilage and food safety issues caused by chemical preservatives, a compound biological preservative composed of chitosan, tea polyphenols and Nisin was developed. The formulation of the preservative was optimized using orthogonal array design. Meanwhile, the optimized preservative formula was tested for its fresh-keeping effect on Pacific white shrimps. The optimal composition was 1.5% chitosan, 0.1% tea polyphenols and 0.02% Nisin. The total volatile basic nitrogen (TVB-N) in Pacific white shrimps treated with this biological preservative on 8th day of storage at (4 ± 1) ℃ was still less than 30 mg/100 g, the total bacterial count (TBC) was only 5 × 105 CFU/g on the 9th day, and in the first 6 days, the sensory quality kept better than that of untreated Pacific white shrimps and the shelf-life was prolonged from 4 to 7－8 days. This compound preservative has promising applications in the fresh-keeping of Pacific white shrimp due to its low cost.

Key words: compound boilogical preservative, preservation, Pacific white shrimp, shelf-life