A liquid nitrogen (LN2)-based chilling system is an environmentally friendly, energy-efficient method for preserving fish on fishing vessels. It can quickly and evenly chill or freeze fish, preventing the formation of large ice crystals and reducing cellular damage, which helps maintain product quality during storage and transport. In this study, an LN2-based refrigerant chilling system installed on board the ICAR-CIFT fishing vessel ‘Sagar Harita’ was used to store and assess the quality of black pomfret fish (Parastromateus niger) caught during the fishing operation. The refrigerant was replenished every three days to ensure a constant supply and maintain the temperature of 2° C throughout the 21-day storage period.
Various parameters, including microbial counts such as Total Plate Count, Psychrophilic counts, Pseudomonas sp., and biochemical characteristics like TBARS, TVB-N, and TMA, as well as the freshness indicator (K-value), were monitored throughout the storage period. The findings were compared with those of fish stored on ice.
In microbial analysis, there was no significant difference between samples in the total Plate Count and Psychrophilic counts. However, the Pseudomonas sp. count exceeded the acceptable limit on the 21st day of storage in both samples. Similarly, the biochemical parameter, such as the TBARS value, exceeded the limit at the end of storage in both samples. The K-value indicated the samples’ freshness, and it increased as storage days progressed. Overall, the study reveals no significant difference between LN2 and ice storage conditions, suggesting that LN2 storage can provide a similar preservative effect with minimal storage space and energy requirements.
It could be one of the best options for the fishing industry to replace traditional icing, chilling, and freezing techniques onboard fishing vessels, owing to its advantages, including high efficiency, rapid freezing or chilling, energy savings, environmental benefits, and reduced volume.