Measuring pork color: effects of bloom time, muscle, pH and relationship to instrumental parameters

To evaluate factors affecting pork color, the gluteus medius (GM), longissimus lumborumetthoracis (LT), semimembranosus (SM), biceps femoris (BF), and triceps brachii (TRI) muscles from pork carcasses of varying ultimate pHs were allowed to bloom for 30 min. L*, a*, and b* values, hue angle, chroma and visual color were determined. Color was evaluated using HunterLab (illuminants A, C, D(65) and F) and Minolta (illuminants C and D(65)) Spectrocolorimeters. LT had the highest L* value (51.31; TR=39.93) and hue angle (59.36; TR=46.94), and the lowest a* (7.52; TR=12.88) value. L* value was unaffected by bloom time; hue angle stabilized after 5 min, a* and b* values after 10 min and chroma after 20 min. Using the Minolta/illuminant D65, visual color best correlated with b* and L* values (r=-0.94 and -0.89) of LT. Using the Hunter/illuminant C, visual color correlated with L* value of LT, GM, BF and SM (r >-0.90 for each). Overall, the instrumental measure that best related to visual color was L* value.