Slaughtering processes for farmed Pangasius in Vietnam. Consultancy surveying Pangasius fillet quality and by-products handling in Vietnamese industry

Sammendrag

In a consultancy for the DANIDA project SEAQIP II, a survey of the slaughter processes for farmed Pangasius has been performed in the Mekong delta from April 16th to May 20th 2005. Five processing factories were visited for discussions and survey of the processes run at each factory. In principle the factories followed the same procedures in slaughter and production of the frozen fillets from Pangasius. The big success in several markets for the product, is a proof of the high quality. In addition the price is right. The factories have high capacity, receiving around 100 tons, (from 50 to 300 tons) of live fish every day. The common method for transferring fish from the well boat to the factory is to transport in baskets without water, up to 20 minutes before the fish is killed. This is a stressful situation and should definitely be ended. Slaughter operation at the river bed or transport in water (containers or pumping) to factory should be considered as an improvement. The colour of fillets is variable due to farming condition and season (feed and water quality?). It is no obvious explanation to why some fillets are very yellow, while others are white. The reason for this must be looked into, finding the component giving the discolouration. The pinkish colour must come from poor bleeding, and procedures can be improved, introducing new bleeding methods, type of cut, bleeding time, fish:water ratio, temperature. It is advised to develop a colour card system, in order to objectively grade fillets from white towards yellow and red. The variation in quality due to different farming conditions, is a challenge for factories that plan to process products with high and consistent quality. It is advised that a pricing system may be developed in order to promote production of high quality Pangasius. The utilization of by-products can be improved. It is proposed that the factories co-operate in this effort since the quantities are big and they are located in the same area. Possible use is as feed and special products. A feasibility study in this area should be discussed. A general recommendation is to put even more effort into management of the health situation for the fish, in order to avoid development of diseases and focus more on welfare of fish. The quality of “home-made” feed is a variable that should be controlled in a better way.