Dear Kevin, Hector, and other Listers
After that build-up by Hector, and being mentioned in the original message, I feel I have to add my bit. I agree with Hector in the points he makes. There is not a certain answer to the question of whether to gut or not. If you compare the spoilage of a particular species of fish gutted or not under comparable icing conditions, the usual limit to the good quality storage life of the ungutted fish is the results of autolysis of the gut, especially the pyloric caecae. This results in belly burst and in the diffusion of bitter flavours from the gut cavity into the flesh. On the other hand the gutting process allows the invasion of the flesh by spoilage bacteria through cut surfaces and through the vascular system. In fisheries where fish is landed following short voyage times, in the order of a day or two, it is probably preferable not to gut the fish at sea and to land and market ungutted fish. This is common practice in many countries. Gutting at sea developed in long distance fisheries where the vessels are away from port for more than a few days.
If the fish are to be gutted then of course the gutting should be carried out competently. It is important that the guts be removed completely and the belly cavity washed to remove traces of guts. Residues of guts will just be a focus for spoilage, but I agree with Hector that the few experiments that have been reported on hygienic versus not hygienic gutting and filleting are equivocal about the effects on spoilage. The original message from Kevin referred only to the presence of blood in the cavity and not to imperfect gutting. Personally I do not think the blood would have any effect on the rate of spoilage. I have no experience of handling mahi-mahi but it is possible that the fish had been well gutted and washed originally, but blood had subsequently leaked from the vascular system into the belly cavity. If the fish were smelly they were spoiled, blood or no blood, and Kevin should look to stowage practices on the fishing vessel rather than gutting/washing practices. I go along with Hector in emphasising the importance of rapid processing on board the vessel and in good icing practices. Imperfect gutting and bleeding are minor effects compared with the effects of delays in icing and of inadequate icing.
Personally I would not consider the presence of blood to be a CCP in a HACCP plan though I would consider it warrants action in a quality assurance programme. The presence of blood, other than in small amounts possible due to leaking as I have mentioned above, would suggest to me poor quality control on the fishing vessel and could point to the possible presence of other defects. Certainly smelly condition in fish is a reason for rejection, and the quality specifications should require that the fish should show no signs of spoilage.
Peter Howgate
----- Original Message -----
From: kevin lyman
To: seafood@ucdavis.edu
Sent: Tuesday, April 06, 2004 11:02 PM
Subject: Poor workmanship in removing blood from fish bellies
Attn: Peter Howgate & everyone else:
When fish such as mahi mahi are gutted and cleaned, does a poor job of washing the blood out of the bellies, contribute to foul odors, bacteria growth, and reduced shelf life. We had some mahi come in which had a lot of blood in the belly cavities and became extremely smelly. My theory is that the poor job of removing belly blood after removing the internal organs, contributed to this condition, and that the product should have either thouroughly cleaned or rejected at the time of inspection. Any scientific expertise responses will be appreciated. I am HACCP certified but lack the scientific knowledge and expertise to know if my observation of this poor workmanship is the cause of the problem we had. Thanks for your help.
Kevin Lyman
John Nagle Company
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