Color stability and sensory characteristics of fresh and enhanced pork loins from immunologically castrated barrows

Abstract

Our objective was to evaluate color changes during storage of fresh pork chops and enhanced and nonenhanced loin quality from anti-gonadotropin-releasing factor (Improvest) immunologically castrated (IC) barrows. In study 1, treatments evaluated were IC barrows, IC barrows fed ractopamine (IC+RAC), physically castrated (PC) barrows, intact males (IM), and gilts. Fresh loins were evaluated for sensory characteristics and instrumental tenderness including both Warner-Bratzler Shear force (WBSF) and star probe force. In study 2, treatments evaluated were IC barrows fed 0.55% and 0.65% standard ileal digestible (SID) lysine and PC barrows fed 0.55% SID lysine. Loin chops were displayed for 7 d, and color was evaluated. The remaining loin was halved, and one half was enhanced with a 3.5% salt and phosphate solution. Enhanced loins were evaluated for sensory characteristics and instrumental tenderness. In both studies, pen served as the experimental unit for all traits measured. Data from individual animals were averaged by pen and analyzed, per study, as a 1-way ANOVA using the MIXED procedure of SAS. In study 1, there were no differences (P > 0.05) between treatments for juiciness, tenderness, chewiness, or off-flavor. Intact males had the most intense (P < 0.05) boar aroma. Gilts had the most intense (P < 0.05) pork flavor, whereas IM had the least intense pork flavor; all other treatments were intermediate. Tenderness (WBSF) was similar between treatments at 1 d of aging; however, at 7, 14, and 21 d of aging, loins from IC barrows were more tender (P < 0.05) than those from gilts, IM, and IC+RAC but were similar (P > 0.05) to those from PC. In study 2, discoloration of fresh loin chops during storage was similar (P = 0.42) between PC and IC barrows. Chops from enhanced loins were more tender and juicy but had more off-flavor than nonenhanced loins (P < 0.01). Star probe and WBSF were also reduced (P < 0.01) in enhanced loins compared with nonenhanced loins. Sensory characteristics and tenderness were not different between treatments of IC and PC barrows (P > 0.05), and there were no interactions of enhancement with castration treatments. These data suggest that immunological castration does not negatively impact the color stability, sensory characteristics, or tenderness of enhanced or nonenhanced pork loins.