Examination of the effect of ageing and temperature at rigor on colour stability of lamb meat

•Colour stability of lamb meat was compared between fresh and aged meat.•There was no effect of ageing period or vitamin E level on stability.•Stability declined with display time.•Stability increased with increasing temperature at pH 6.0.

A study of factors (ageing period, rigor temperature and vitamin E level) impacting on the colour stability of lamb m. longissimus thoracis et lumborum (LL) during 3 days of simulated retail display was undertaken. The LL were taken from 84 lambs from 3 slaughters. Slices of LL were measured fresh (24 h post-mortem) or after ageing for 5 days in vacuum packaging. The oxy/met ratio (630/580 nm), declined with display time, and increased with increasing temperature at pH 6.0. Redness (a*) values also declined with display time and a reduction in redness values was observed as LL pH at 24 h post-mortem and/or pH at 18 °C increased. There was no effect of ageing period or vitamin E level on the oxy/met ratio or a* values when the vitamin E level averaged 3.76 mg/kg LL. These results suggest that maximising vitamin E levels in lambs and achieving a moderate rate of pH decline will optimise colour stability irrespective of ageing period.