How are fishes stored after harvesting?
Whenever we are out at market, we need to know on which day we have got the fish. To understand the day initially we need to know on what temperature the fish is kept. The quality and temperature of the fish represents whether the fish is consumable or not. The consumability of the fish is relative to the conditions in which it is stored prior to cooking.
What is available in market?
Direct cooking for consumption as soon as the fish is caught out of water and killed is the best way of having the fish at its best form. In such a condition, all the biochemical parameters in the fish are at its excellent level. But it’s difficult to get the fish in such a fresh condition always to a customer residing in a town or city. There are different cases or situations at which the fish reaches the customer hand prior to cooking.
Figure on top represents the relationship between temperature influence and days. (From www.fao.org)
The different situations are as follows:
Case 1: If the fish is harvested and stored at a temperature of 15°c, the fish need to be consumed within 1 day, the 2nd day it becomes partially consumable and the 3rd day need to be discarded.
Case 2: If the fish is harvested and stored at a temperature 0-5°c, the fish remains fresh and chilled condition up to 3 days. When this fish is kept in chilled condition all the minerals and nutrients present in the fish muscle remain in it’s original from i.e., fresh. On the 4th day onwards, it begins to reduce the quality and simultaneously becomes not fit for consumption on the 6th day and need to be discarded.
Case 3: If the fish is harvested and stored at temperature 0°c it is said to be in semi-frozen condition. In frozen stage the fish whole body becomes slowly frozen and becomes hard and stiff in due course of time. And the fish can be stored as fresh for much longer period i.e., up to 6 days. In the frozen condition also, the nutrients present in the fish muscle remain in its original but will get frozen as a result when thawing is done to the frozen product, the water-soluble nutrients present in the fish will gets out of fish along with water which will impact in the texture and flavour of the fish. While consuming a frozen fish we are consuming a meat with limited nutrient value needed for the human body.
Case 4: If the fish is harvested and stored at temperature below -18°c it is said to be in frozen condition. There are commercially different methods to keep the fish in frozen condition with glazing provided. This kind of method is adopted for long term preservation of the fishes. The shelf life of frozen fish can extend up to 2 years depending on the type of freezing and kind of preservatives added in freezing. The quality parameters are the similar to the case of case 3 that will periodically degrade the texture and flavour of the product.
What VTF provides to customer?
VTF provides customers with fish and fish products in fresh and chilled condition. This allows customers to consume the fish fillet at its ever-best form for consumption. The customer can consume fish fillet at the Extra grade quality with all the fish nutrient enriched in the fillet. The texture and flavour in the fish is retained as such for a period of 3 days from processing.
Prepared by - Abin.S.N
(MSc Industrial fisheries & Fish Biologist)