Effects of pH and Time of Grinding on Lipid Oxidation of Fresh Ground Pork

Experiments detected effects of pH on lipid oxidation of fresh ground pork. Pigs received antemortem epinephrine injections or postmortem carcass electrical stimulation to manipulate ultimate postmortem pH. High‐pH (>6.10) samples had lower TBA values than low‐pH samples. Nonsignificant difference in TBA values between high‐pH prerigor‐ and postrigor‐ground samples indicated that, at common high pH, time of grinding had no effect on lipid oxidation. Differences in TBA values between prerigor high‐ and low‐pH samples and postrigor high‐ and low‐pH samples indicated that, with identical grinding treatments, inhibition of oxidation occurred at high pH. Metmyoglobin was relatively high in both low‐ and high‐pH muscle and was not catalytically active at high pH.