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

Abstract

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.

COPPER INDUCED LIPID OXIDATION DURING SALTING OF COD (GADUS MORHUA L.)

“…The mechanisms by which pH controls lipid oxidation in fish muscle is unclear. However, it has been suggested, in studies on porcine and beef meat, that this may be the pH effect on the metal catalysts present (Owen and Lawrie 1975;Yasosky et al 1984;Liu 1970).…”

Meat lipids

“…l72 The relative roles of haem and non-haem iron in meat are also indicated by a study on fresh ground pork with a difference in the natural pH. 173 Meat with a high pH, produced either by mincing prerigor or by preslaughter treatment of the pigs with epinephrine, had low TBA numbers compared with normal meat after storage. High pH meat has also been reported to be more stable under conditions of frozen storage.…”

Lipid Oxidation in Retail Beef, Pork and Chicken Muscles as Affected by Concentrations of Heme Pigments and Nonheme Iron and Microsomal Enzymic Lipid Peroxidation Activity

“…The pH values of the muscle samples used in Experiment 11 @H not determined in Experiment I) were 6.33 and 5.79 for chicken dark and white muscles, respectively, 5.76 for the pork LD, and 5.40 for both beef LD and SM muscles (data not shown in tabular form). It is known that lipid oxidation in meat animal tissues decreases with increasing pH (Watts and Peng 1947;Chen and Waimaleongora-Ek 1981;Yasosky et al 1984).…”