Abstract:

This study investigated the effects of postmortem aging time on meat quality of yaks at different ages as indicated
by the changes in pH, meat color, total myoglobin (TMb) content share force, water loss rate and cooking loss and analyzed
the correlations between meat quality and postmortem aging time or slaughter age. The results showed that the L* and b*
values of yak meat at different slaughter ages initially rose and then decreased with postmortem aging, while a* values
showed the contrary trend. The content of TMb decreased with postmortem aging, and the pH was significantly changed
(P < 0.05) in the first three days during the period of aging although not significantly affected by different slaughter (P > 0.05).
The water loss rate and cooking loss reached the maximum on the third day of aging. Share force significantly declined
(P < 0.05) after three days of aging. There was a positive correlation between slaughter age and the quality indexes of yak
meat as well as highly positive correlations of postmortem aging time with L* values , b* values, water loss rate and cooking
loss, whereas the correlations with share force and TMb contents were significantly negative (P < 0.05). After seven days of
postmortem aging, the differences in yak meat at different slaughter ages were less apparent and the tenderness of meat was
improved at the same time.

Key words: yak meat, aging, age at slaughter, meat quality