This study was conducted at a commercial beef slaughter plant to determine the effects
of carcass washing, intermittent spray chilling and carcass fatness on carcass weight yields
and on moisture content of cutaneous trunci muscle and s.c. adipose tissue (AT) samples
excised from two carcass locations. Beef steer carcasses (n = 36) initially had 12.8% moisture
in AT. Immediately following washing, AT from the sirloin region had more (P < .01)
moisture (24.5%) than AT from the fifth-rib region (15.6%). Fat (n = 20) and lean (n - 20)
carcasses were selected, and their right and left sides were allotted alternately to either a
non-spray chill cycle or to an intermittent cold water spray-chilling cycle lasting either 3 or 6
h. After 20 h of chilling, carcasses subjected to the 6-h spray had 12.9% more (P < .01) AT
moisture and possessed 2.6% more moisture in the cutaneous trunci muscle than similar
samples from the non-spray chilled counterparts. In comparison, AT samples that were
subjected to the 3-h spray had 3.9% more (P < .65) moisture, and the cutaneous trunci
muscle had 2.0% more moisture, than their dry-chilled counterparts. After chilling, the
spray-chilled AT had substantially higher (P < .01) moisture in the fifth-rib region (26.1%)
than in the sirloin (14.8%). Spray-chilled sides in the 6-h cycle gained .3% of their hot
carcass weight, whereas the corresponding non-spray sides shrank 1.2%. Spray-chilled sides
subjected to the 3-h cycle shrank .4%, and their dry counterparts shrank 1.1%. Carcass
washing and length of spray cycle had a greater influence than carcass fatness on surface
tissue moisture retention. Modulation of these factors will help control post-chilling fluctuation
of carcass weights in excess of USDA regulations and yet maximize carcass weight
yields.
