The Hindu , 29 March 2006

New technique to enhance shelf life of fishes

Tuticorin: Fisheries College and Research Institute here has developed a new technique to enhance shelf life of commercially important fishes.

Its team of scientists led by G Jeyasekaran developed the technique, under a research project funded by Indian Council for Agriculture Research, using a combination of dry ice (generic name of carbon dioxide in its solid form), and wet ice as medium of preservation.

Explaining the technology, R. Santhanam, Dean, said that a certain quantity of fish, dry ice and wet ice were first taken on a 1: 0.2: 0.5 ratio.

"The dry ice packed in paper pouches and wet ice packed in polythene pouches were placed with fish in alternate layers and the whole consignment was wrapped in polypropylene bags, before keeping inside a Styrofoam box," he said.

The boxes were then sealed airtight with cellophane tapes and stored at ambient temperature.

The packed fish were studied periodically for changes in various parameters pertaining to microbiological, biochemical, sensory and physical qualities.

" Results indicated that the shelf life of fish stored in the new combination was found to be 33 to 50 per cent more than that packed in the traditional method of wet ice alone as a medium," he said.

He said commercially important fishes such as Tuna and Emperor had a shelf life of 36 hours in the `combined pack' against a shelf life of 24 hours in the wet ice packs.

Similarly, shrimps and seer fish recorded a shelf life of 24 hours each under the new storage combination vis--vis 18 hours under the conventional method.

Dr. Santhanam said the new technique would be of immense help to exporters to maintain the quality of fish exported by air.

"Moreover, the transportation costs would be reduced by 15 to 25 per cent since only 700 kg of dry and wet ice in toto were required for 1,000 kg of fish in the new method whereas the preservation using traditional method needed wet ice and fish on a 1:1 ratio."