Evaluation of Freshness of Farmed Two-Year-Old Acipenser persicus during Storage in Ice

Abstract

Chilled fish is considered a fresh product and helps to ensure the development of world trade. So, the present study aimed to investigate the freshness of two-year-old farmed A. persicus by chemical, microbial, sensory, and physical experiments, and determine its shelf life during ice storage. 20 fish samples were maintained in chilled seawater tanks for 12 days. The ratio of ice powder to fish is of 2 : 1. The fish were separated by layers of ice with a thickness of about 5 cm. The temperature was maintained throughout the storage period at 0-1°C. The fish had an average weight and length of 3.50 kg and 70 cm, respectively. Total bacterial counts, Staphylococcus, and Enterobacteriaceae were acceptable (6.78, 2.96, and 3.99 log CFU·g−1, respectively) for 10 days. Coliform, Escherichia coli, Pseudomonas aeruginosa, Vibrio parahaemolyticus, and Aeromonas hydrophila were not detected during storage. pH (6.89), peroxide value (4.32 meq O2 kg oil−1), thiobarbituric acid (0.96 mg·kg−1), free fatty acids (10.86 g 100 g−1), and total volatile nitrogen bases (19.83 mg 100 g−1) were normal during 10 days. Texture (2.56), odor (2.50), the appearance of gills (2.59), eyes (2.67), belly cavity (2.58), skin (2.49), and outer surface (2.90) of A. persicus displayed a decrease throughout storage ( $p<0.05$ ). Sensory characteristics were acceptable for 10 days. Ash was 1.88–2.13% during storage ( $p>0.05$ ). Unlike moisture (79.05–81.06%), fat and protein showed a decrease of 1.16−2.33 and 15.65–16.74%, respectively, during storage ( $p<0.05$ ). According to the results of the present study, to maintain the economic value of sturgeon and for the expansion of their business, and to preserve the freshness of sturgeon during handling and the effect of freshness on the consumer’s opinion, it is recommended that fisheries use ice for sturgeon transport for 10 days.