Glycogen, glucose and glucose-6-phosphate content in fresh and cooked meat and meat exudate from carriers and noncarriers of the RN- allele

The objective of this study was to investigate the content of glycogen, glucose and glucose-6-phosphate (G-6-P) infresh and cooked meat and meat exudate (purge and cooking loss) from carriers (RN-/rn(+)) and noncarriers (rn(+)/rn(+)) of the RN- allele. Loins (M. longissimus dorsi)from 13 commercial crossbred female pigs were used. The total content of glycogen, glucose and G-6-P was significantly higher in RN- carriers compared with noncarriers both in fresh and cooked muscle, as well as in fresh and cooked meat exudate. Also the sum of glucose and G-6-P was higher in all fractions for the RN(-)carriers compared with noncarriers. Loins from the RN- carriers had lower ultimate pH and higher drip, purge and cooking loss compared with loins from noncarriers. We conclude that after the postmortem process in RN- carriers there is muscle glycogen left which is subsequently released with meat exudate during storage and cooking, lowering the glycogen level in the cooked meat.