89A-37

D. MANTILLA¹, H. G. Kristinsson¹, W. S. Otwell¹, M. O. Balaban¹, and F. A. Chapman². (1) Dept. of Food Science & Human Nutrition, Univ. of Florida, 130-B Aquatic Foods Pilot Plant, PO Box 110370, Gainesille, FL 32611-0370, (2) Dept. of Fisheries & Aquatic Sciences, Univ. of Florida, 7922 N.W. 71st St., Gainesville, FL 32653-3071

Carbon monoxide (CO) is used in the seafood industry in order to stabilize the red color of fish muscle. Currently the application of CO into fish muscle via euthanasia is being performed by tilapia processors. There is a lack of information on how application of CO with euthanasia will affect fish quality compared to conventional applications. The objective was to investigate the color retention and quality of fillets from euthanized tilapia, compared to a conventional post-mortem gas treatment. Live tilapia was (a) euthanized in water saturated with CO; or (b) killed following industry guidelines. Half of the (b) fillets were treated with 100% CO for 30 minutes and the other half used as control. Fillets were kept in bags of high air permeability for 12 days at 4C. Color changes (L*, a* and b* values) in red and white muscle were analyzed every 2 days for a period of 12 days using a color vision machine system. Heme proteins were extracted from white and red muscle to determine their oxidation/ligand binding state. Both treatments led to a significant increase in the red color (a*values) of the fillet white and dark muscle. This distinctive cherry red color was maintained for a long period of time for both treatments while a brown color developed for the controls. There was no significant difference in a*values between the gas treated and the euthanized fillets. The UV-Vis spectra confirmed the intake of CO by heme proteins by both methods and also demonstrated improvements in heme protein stability. These results suggest both treatments have a positive effect on color and heme stability. The similarity of results between the treatments imply that the industry could adopt this new method of processing which has advantages such as less stress to the fish, shorter processing and less product handling.

Session 89A, Aquatic Food Products: General
2:00 PM - 5:30 PM, Tuesday PM Room Hall I-2

2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana