The effect of dehydrogenase enzyme activity in glycolysis on the colour stability of mutton during postmortem storage

This study investigated the influence of activities of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and lactate dehydrogenase-B (LDH-B) on the colour stability of mutton. From 60 sheep (Bayannur mutton sheep), 15 longissimus dorsi (LD) muscles were selected on the basis of colour stability (R630/580 and a* value) during the storage and classified into three groups (5 for each group) as high colour stability (HCS), intermediate colour stability (ICS) and low colour stability (LCS). The activities of GAPDH and LDH-B, muscle colour attributes, nicotinamide adenine dinucleuotide (NADH) concentration and lactate concentration were measured. The samples in HCS had higher activities of GAPDH and LDH-B than the samples in the LCS, and the samples in the HCS group also possessed higher NADH and lower lactate concentration. The higher activity of dehydrogenase enzyme may result in higher NADH concentrations and colour stability in muscle tissue. The results suggest that the activity of GAPDH and LDH-B may also play a role in maintaining colour stability.