The Effects of the Lipex Finishing Diet Regimen on Pork Quality and Color Stability

The objective of this study was to determine the effects of the LIPEX finishing diet regimen on center cut pork chop Omega-3 and -6 content and color stability. Twenty-eight finishing pigs (PIC 359 × F1 Hermitage/NGT; initial BW 81.5 ± 2.55 kg) were subjected to a 49-d feeding trial. Treatments consisted of a 2×2 factorial design with Sex (n=14 barrows and gilts each) and Diet as main effects. Dietary treatments consisted of a two-phase standard finishing diet regimen or a two-phase LIPEX finishing diet regimen (EXL Milling, Lloydminster, SK, Canada). The LIPEX diet regimen added the EXL LIPEX.FA369^® additive during phase 1 and the EXL LIPEX.FA369^® and XFE Omega-3 Finisher during phase 2. Five-days postmortem, whole boneless pork loins were transported to the Kansas State University Meats Laboratory, aged 14 days, and halved immediately behind the spinalis dorsi. After blooming for 30 min, chops were evaluated for Japanese color score and National Pork Producers Council (NPPC) color and marbling scores. A 2.54-cm chop taken from the anterior portion of the loin was used for fatty-acid and proximate composition analyses. One 2.54-cm chop was cut from the posterior portion of the loin and was utilized for a 7-d simulated retail display analyses. Chops were placed on absorbent pads on Styrofoam trays, overwrapped with polyvinylchloride film, and placed in a constantly illuminated coffin-style retail cases set at 3±2°C. Spectrophotometric readings (L*a*, oxy- and metmyoglobin percentage) and visual panel evaluations (redness and percent discoloration) of the surface color of the chops were taken daily. There were no Sex ´ Diet interactions for all variables measured in the study (P>0.10). Sex did not affect all measures (P>0.07), except barrows had a greater (P<0.01) NPPC marbling score than gilts. The LIPEX finishing regimen increased loin chop Omega 3 content by 178%, Omega 6 content by 54%, and decreased the Omega 6:3 ratio by 41% (P<0.01). There were no Diet effects on pH , Japanese and NPPC color and marbling scores, and proximate composition (P>0.23). Finally, there were no two- or three-way interactions between Diet, Sex, and Day, or Diet and Sex main effects for L*a* values, surface oxy- and metmyoglobin percentages, or visual panel chop redness and surface discoloration scores (P > 0.14). Feeding the LIPEX finishing diet regimen increased center cut chop Omega-3 fatty acid content without negatively impacting fresh chop color stability.