Effect of vacuum packaging on the shelf-life and quality of Hypophthalmichthys molitrix fillets during storage in refrigerator temperature

Vacuum packaging is one of the appropriate methods in packaging and storage of fish products. In this study, chemical changes including pH, thiobarbituric acid (TBA), total volatile basic nitrogen (TVN) and microbial counts such as coliform bacteria, fecal coliform, salmonella and Escherichia coli in vacuum packed fillet of silver carp (Hypophthalmichthys molitrix) was performed during 30 days storage at 4 ± 1 °C. Fresh silver carp fish samples (ranged 900 to 1200 g) were obtained and transported to the laboratory. Data were analyzed using SPSS 18 software. Results showed that the highest levels of TVN and pH were determined as 63.33 ± 1.82 mg/100 g and 6.81 ± 0.04 in the day 30, respectively. According to the results, TBA, TVN and pH values were increased during 30 days storage. Moreover, total bacterial count increased during the 30 days of storage. Results revealed that coliform counts were less than 2 log cfu/g during the 30 days of storage. Increasing trend of faecal coliform at the end of storage period was estimated as 2.38±0.01 log cfu/g. Considering the microbial populations and the chemical spoilage indicators (TBA and TVN), the shelf life of 15 days was established for the vacuum packaged fillet stored at 4±1°C.