Cost effective household procedure of the production and packaging of dry fish with good odour and improved flavour and longer shelf life

摘要

A novel cost effective process for the preparation of dry fish with better aroma and flavour has been developed. In this process, fish samples were cleaned, dressed, beheaded and the elementary canals were removed followed by washing in 15% saline and air dried for 3 hr. Fish samples were then treated with 3% bleaching powder solution for 30 min to inhibit active enzymes and bacterial growth to prevent auto-decay. The fish samples were then rinsed with clean water to remove the traces of chlorine residues. The samples were soaked with hypertonic 15% sodium chloride (common salt) solution for 1 hr to plasmolyse the samples. The surface of the fish samples were covered with grounded ginger, garlic, tulsi leaves (Ocimum sanctum) individually to develop the particular flavour on the fish material. The fish samples were then oven dried at 75°C till 10% moisture retains. Dried fishes were packaged in commercially available transparent 70µm thick polythene pouches made of virgin polyesters, which were pre sprayed with nitrogen gas to remove the moisture and then sealed for preserving them for longer duration. When the fish samples were cooked, it gave the flavour and aroma of the respective plant materials used during the preservation process. The bleaching powder solution treatment was found to be very effective to inhibit the enzymes and microbial growth involved in auto decaying process and hence it was not found to be developing the usual unpleasant smell of any dried fish. The treatment with saline solution inhibited the growth of harmful microbes, hence no considerable growth of pathogenic microorganisms was observed when tested. The flavour of the herbs and plant materials used were found to be enhancing the taste and flavour of the odourless dried fish. Pre-treatment of the storage bags with dry nitrogen gas which dehumidifies the bags to provide better storage conditions for commercial use as well as prevents the growth of microbes. The aroma and flavour developed by the procedure is believed to be commercially appealing and also use of the above procedure enhances the shelf life by six to nine months without altering the flavour and aroma.