Preliminary observations on the colour variability of breast meat ('magrets') in force-fed ducks

Abstract

Fifty-eight force-fed mule ducks were used to evaluate the variability of 'magret' (breast meat) colour. Trichromatic coordinates in the CIELAB system (L*, a*, b*) were measured at 4 and 24 h post mortem and after 6 days of storage at +4°C under an oxygen-permeable film. At 24 h post mortem, the colour of breast meat was visually assessed and the 'magrets' were assigned to one of three colour groups (normal, intermediate, pale). At 24 h post mortem, 22% of the magrets were classified as very pale, and showed higher L* and b* than those classified as normal. These differences were maintained over the 5 days storage but their magnitude was not increased. The L* and b* values were significantly and positively correlated with the content of intramuscular fat (r = 0.50, P < 0.01 and r = 0.29, P < 0.05, respectively). The different measurements could not clearly demonstrate that the abnormal colour was due to myoglobin and lipid oxidation and/or colour defects such as those encountered in PSE (Pale, Soft, Exudative) meat. These preliminary observations showed a high variability of breast meat colour in force-fed ducks. Further research is needed to elucidate the underlying mechanisms.