Effect of vacuum packaging on the shelf-life of silver carp (Hypophthalmichthys molitrix) fillets stored at 4 °C

- Silver carp fillets were vacuum packaged at 30 kPa and 50 kPa and stored at 4 °C.
- Different vacuum levels significantly improved the shelf-life of silver carp fillets.
- 30 kPa samples returned higher freshness value at the end of the experiment.
- E-nose and sensory evaluation are effective fish freshness indicators.

This study was carried out to evaluate the chemical changes, microbial load and sensory attributes of silver carp (Hypophthalmichthys molitrix) fillets when packaged at two vacuum levels (30 and 50 kPa) and stored at 4 °C for 14 days. The fillets packaged at 30 kPa had significantly lower pH values and total volatile basic nitrogen (TVBN) contents than those packaged at 50 kPa and normal atmospheric pressure (control). The increase in viable bacterial population was significantly lower in samples packed at 30 kPa and the control. The results of sensory evaluation and electronic nose (E-nose) analyses showed good agreement with the results obtained from chemical and microbial analyses. Both vacuum levels combined with refrigerated storage resulted in an extension of the shelf-life of fillets; up to 11 days at 30 kPa, 9 days at 50 kPa compared to 6 days in control samples. The headspace vacuum level of 30 kPa combined with storage at 4 °C was found to significantly slow down the undesirable chemical changes, retard the lipid oxidation, improve the sensory attributes and extend the shelf-life of silver carp fillets.