51A-28

J. L. SILVA and J. E. Figueroa. Food Science and Technology, Mississippi State University, Box 9805, Miss. State, MS 39762

Channel catfish (Ictalurus punctatus) are usually processed into fillets upon live receiving at the plant. This process sometimes results in an unsmooth fillet cut, lower yields, shrinking, and sometimes a mushy texture. This is the result of processing prior to rigor onset of the fish. A technology used to process sea harvested finfish is to behead and eviscerate on board, hold on ice or salted ice/brine, and then process.

The objective of this project was to see if beheaded and eviscerated fish held on ice in a refrigerated chamber for up to 30 hours, would yield a quality fillet with a low microbial load.

Catfish were beheaded, eviscerated, packaged in HDPE bags, placed on ice chests with ice and held at 4°C. The fish were then filleted after 0-30 hours of holding. This process was done on June 1998, and February, March, April, May and September 1999. Fillets were analyzed for Hunter color, surface pH, moisture loss, shear and compression force.

Hunter ‘a’ and ‘b’ values were higher (p£ 0.05) for winter harvested fish, while ‘b’ values were higher after 26 hours of holding time. Shear and compression force were lower (p£ 0.05) on summer harvested fish and varied with holding time. The pH and moisture of summer fish were lower (p£ 0.05) than those of winter fish, with few changes during holding. Winter fish had lower (p£ 0.05) PPC and these decreased (p£ 0.05) with holding time.

Holding beheaded eviscerated fish for up to 22-26 h on ice results in similar or better quality than freshly processed fillets. Fillets of winter harvested fish become stiff (rigor onset) very quickly after death while those from summer fish are pliable for up to 22-26 h after holding.