Submitted to: North American Journal of Aquaculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/12/2005
Publication Date: 12/29/2005
Citation: Bosworth, B.G., Wolters, W.R., Silva, J., Chamul, R. 2005. Slush-ice Storage of Catfish Carcasses. North American Journal of Aquaculture. 68:53-62. Interpretive Summary: Most meat animals are processed after a period of cold storage primarily because immediate processing (prior to rigor) results in excessively tough meat. Catfish are usually processed immediately after slaughter because excessive toughness is typically not a problem with catfish fillets. However, the amount of time between slaughter and processing may also affect fillet yield, shape, and color. Channel catfish processed either immediately after slaughter or after 24 hour storage in slush-ice were compared for fillet yield (percent of whole weight that is saleable meat), fillet shape, fillet color, and fillet size as perceived by a sensory panel. Compared to immediately processed fish, slush-ice treatment fish had higher fillet yield, longer fillets with larger surface area, and fillets appeared larger to a sensory panel. There was no difference in fillet color between fish that were immediately processed and those stored in slush-ice prior to processing. Catfish processors could improve fillet yield and alter shape and perceived size of fillets by storing fish in slush-ice prior to processing. However, the costs associated with slush-ice storage of fish, logistics of product flow, and influences on fillet texture and shelf-life need to be addressed to determine the overall benefits storage of catfish in slush-ice prior to processing.
Technical Abstract: The objectives of this study were to determine the effect of rigor-state at processing on channel catfish fillet yield, shape, and color. Fish were divided into 2 samples, 1 sample was immediately processed on a commercial catfish fillet machine and the other sample was placed in slush-ice for 24 h prior to processing (slush-ice treatment). Percent yield (relative to deheaded eviscerated carcass weight) was determined for skin-on fillets, skin-off fillets, trimmed shank fillets, and nuggets (belly meat). Instrumental color values (‘L’,’a’, and ‘b’) were measured on fillets and fillet length and surface area were measured from recorded digital images. Pairs immediately processed and slush-ice fillets of equal weight were displayed and sensory panelists were asked if they were different in size. Compared to immediately processed fish, slush-ice processed fish had higher yield for all fillet measures and nugget, longer fillets with larger surface area, and fillets appeared larger to the sensory panel. There were no differences in fillet color among treatments. Commercial catfish processors could realize meat yield gains from slush-ice storage prior to processing, but the costs associated with slush-ice storage and delays in product flow during processing need to be considered.