Traditionally fish is preserved for limited periods by reducing the temperature to less than 4C but above 0C and in India ice blocks and crushed ice are often used to transport fresh fish over long distances. Refrigerated transport containers are now available in India for distribution of freshly harvested fish consignments to different parts of the country. Modified Atmosphere Packing (MAP) first pioneered for perishable fruits to extend their life has become an accepted technology for all perishables. Reducing the O2 tension and increasing CO2 concentration with in the confined space of a container or a storage room provide an hostile atmosphere for most of the microorganisms that can cause spoilage. Recently further extension of shelf life of fish has been achieved by combining low temperature and modified atmosphere.
"However, the authors found that the use of the combination of superchilling and MAP incorporating a CO2 concentration of 90 per cent and a g/p ratio of 2.5 resulted in the longest shelf-life of 22 days as compared to 11 days in a control sample. The lowest salmon shelf life was 16 days, and the highest 22 days, values that are representative for the samples with the lowest and highest CO2 concentration and g/p ratio, respectively," .
The increased shelf life achieved is adequate for safe shipment spanning a travel time of less than 15 days between destinations. Probably India can gainfully utilize this technology for fish exports to nearby countries through land routes or across oceans. Quality of fish distributed within the country can also be expected to be better when this combination technology is deployed.