Slush-Ice Storage of Catfish Carcasses

Abstract

This study evaluated the effects of 24-h slush-ice storage of carcasses of channel catfish Ictalurus punctatus on subsequent fillet yield, shape, and color. Channel catfish were sorted into three size-classes based on carcass (unskinned, with head and viscera removed) weight: small (250–425 g), medium (426–550 g), and large (551–1,000 g). In each of three replicate trials, 40 carcasses from each size-class were processed immediately after being killed (immediately processed treatment) and 40 carcasses from each size-class were held in ice water slush for 24 h and then processed (slush-ice treatment). Slush-ice-treated fish had higher unskinned fillet yield (+1.7%), skinned fillet yield (+1.2%), shank fillet yield (+0.6%), and nugget yield (+0.7%) than immediately processed fish. Measures of fillet yield increased in both treatments as carcass size increased. Immediately processed fillets were shorter (maximum distance anterior to posterior margin) and deeper (maximum distance from dorsal to ventral margin), and had less surface area than slush-ice fillets 24 h after slaughter. Sensory panelists perceived fillets from the slush-ice treatment to be larger than immediately processed fillets in 74% of comparisons of fillet pairs of equal weight. No fillet color differences were detected between treatments. Commercial catfish processors could increase fillet yield by storing carcasses in slush ice before filleting. However, costs associated with chilling and holding carcasses and quality issues, such as fillet drip-loss, texture, and shelf life, need to be addressed to determine whether slush-ice storage of carcasses will be beneficial to commercial catfish processors.