Sammendrag
Despite the fact that the fishing fleet has the best conditions in order to process the fish correctly through the whole catch and production process, errors occurs and with a quality and value reduction as a result. Common mistakes are bad bleeding cut, too short bleeding time, poor cleaning and cutting errors. Even though the long line caught fish has a generally good quality there still are potential for improvement, the quality is not uniform and error occurs. Long line caught fish has traditionally been the preferred quality of salted and dried fish companies, but the lessons of the recent past is that the quality difference between the long line caught and trawl caught fish may have become less. Quick cooling and constant refrigeration chain is crucial for the quality of the fish. The faster cooling down to 0 ° C, the longer shelf life has the fish (Lynum 2005). On board fishing vessels seawater is used in bleeding and bulk tanks. Temperature in seawater varies widely with seasons and affects the quality of the fish in the different seasons.
Correct catch processing is important from a quality perspective as well as for the profitability of the crew, the ship owner and the salt cured and dried fish industry. Loss of quality can’t be corrected in a later stage in the process. Therefore it is important to handle fish gently through the whole catch and the production process. Wrong handling of the fish often leads to complaints and reduced profitability. A growing problem has been gaping errors and to soft fish flesh when producing to salt- cured and dried fish. This has led to downgrading of end products. Cooling down the fish before freezing reduces the enzymatic degradation of fish flesh at the same time as one get a more rapid freezing of the fish, which can provide better quality and less gaping of the salt-cured and dried fish. So how the situation is at present time, with poor purchasing power in the European markets, the consumer sets more stringent standards of quality when they first buy salt-cured and dried cod. If the companies in this period of time produce an improved quality, they probably also will be able to take a bigger share of market.
The aim of the project is to further develop methods for cooling and bleeding that ensure good quality of long line caught cod for the application in the salt-cured and dried, salt-cured fish production, by testing of different operation of the line and temperature regimes in the production on board the M/S Loran. Further, it is investigated how the operation of the line and the different temperature regimes has affected the quality of the raw materials and the manufactured dried and salt-cured cod.
The results of the experiments in this project showed that when cooling process water using ice slurry in the bleeding-and bulk tanks on board, had a positive impact on the quality of the manufactured salt-cured and dried cod. Also by increasing water flow in bleeding tank provided higher quality of salt-cured and dried fish due to less blood error/color error. The results also indicate that there may be an advantage by raising the temperature of the raw material before salting. In one of the series that was produced in the project, the fish was thawed in 7-8 ° C seawater and this fish, when salt-cured and dried, came out with 5% higher yield than cod thawed at 0-0.5 ° C, but this series also had a higher percentage of gaping errors in fish flesh. Further research is necessary to provide better information on how thawing temperature affect quality and yield of salt-cured and dried cod.
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