Discoloration of Fresh Pork as Related to Muscle and Display Conditions

Pale, soft, exudative (PSE), normal, and dark, firm, dry (DFD) pork was held 7 days at 4°C under light or dark then color was evaluated instrumentally and visually. Change in reflectance (R630‐R580) was used to estimate color changes due to oxymyoglobin. PSE pork was lighter (high L*) than normal and DFD pork, but did not change over time. An increase in a* and R630‐R580 occurred the first day for normal and DFD, but not for PSE samples. A subsequent increase in hue angle and decrease in R630‐R580 (loss of redness) occurred in PSE and normal, but not in DFD samples. Changes in hue angle and R630‐R580 were more rapid in PSE than in normal samples. Light exposure accelerated all changes except L*. Visual redness inversely correlated with L* value.