The significance of diet, slaughter weight and aging time on pork colour and colour stability.

The objective of the present study was to investigate the effect of a diet with a low content of digestible starch, slaughter weight and subsequent aging time on meat colour and colour stability. Pork colour was determined as the extent of blooming of M. longissimus thoracis (LT) and M. semimembranosus (SM) after 1, 2, 4, 8 and 15 days postmortem and as colour stability during a subsequent storage period in air for 6 days. Compared to the control diet, the experimental diet resulted in a significantly lower postmortem muscle temperature (1°C; p<0.0001). Moreover, high slaughter weight (110kg) resulted in a higher postmortem temperature in LT (p<0.001) compared to low weight (85kg). Independent of feeding strategy and slaughter weight, the extent of blooming decreased during the first 2-4 days of aging in LT, however, the effect was more pronounced in meat from experimentally fed pigs and pigs with high slaughter weight. This effect was not seen in SM, where a gradual increase in blooming took place throughout the aging period. The colour stability was found to be superior in aged pork from experimentally fed pigs. The discoloration rate was faster in SM compared to LT. In conclusion, the present study shows that the diet composition can be used as a tool to control meat colour and colour stability in pork.