The relationships between initial pH, reflectance and exudation in pig muscle.

Using data collected from several hundred pigs, the relationships of drip loss during storage, and reflectance, to pH(45) in the M. longissimus dorsi (LD) were both found to be biphasic. Muscles with a lower pH(45) lost more drip and were paler. Below pH 6·1, however, decreasing pH(45) had only a small effect on the weight of drip lost but a large influence on reflectance. In contrast, above pH 6·1, increasing pH(45) had a large influence on drip loss but only a small effect on reflectance. There was also a biphasic relationship between drip loss and reflectance with the discontinuity at 9·9% drip. Differences in pH(u) explained less than 15% of the variation in exudation and reflectance.