The effect of rapid prerigor freezing and postrigor freezing and postrigor @entity12374 injection on the tenderness of callipyge longissimus was studied. Ewe and wether @entity742 (n = 49; 1/2 Dorset x 1/2 Romanov) were grain-fed and slaughtered at approximately 250 d of age. Based on leg conformation scores, 23 of the carcasses had the callipyge phenotype. Within each phenotype, approximately one-half of the carcasses were chilled conventionally (24 h at -2 degrees C). At approximately 17 min postmortem, the remaining carcasses were submersed in liquid @entity1568 for 15 min and then held at -2 degrees C for 4 d. At 1 d postmortem for carcasses chilled conventionally and at 4 d postmortem for carcasses frozen in liquid @entity1568 , the longissimus muscles from both sides were removed. The longissimus from one side of each carcass was vacuum-packaged and aged (1 degrees C) conventionally for 7 or 14 d. The remaining muscles were injected with a 2.22% solution of food-grade @entity12374 at 5% by weight, vacuum-packaged, and aged as above. Liquid @entity1568 freezing was effective in limiting sarcomere shortening (1.99 vs 1.63 microm; P < .05). Warner-Bratzler shear force values of callipyge longissimus were 222 and 232% of that of normal longissimus after 7 and 14 d postmortem, respectively (P < .001). Also, trained panel tenderness rating was decreased by 49.4% in untreated callipyge longissimus after 14 d postmortem. Liquid @entity1568 , @entity12374 injection and their combination did not affect d-14 longissimus shear force and sensory tenderness for normal @entity742 because untreated muscles were already tender. Liquid @entity1568 freezing improved the shear force and sensory tenderness rating of callipyge longissimus by 30 and 86.2% after 14 d postmortem, respectively. @entity12374 injection improved the shear force and sensory tenderness of callipyge longissimus by 36.7 and 86.2% after 14 d postmortem, respectively (P < .001). The most effective treatment for mitigating the callipyge effect on tenderness was the combination (freezing and @entity12374 injection) treatment, which improved the shear force and sensory tenderness by 51.2 and 124.2% after 14 d postmortem, respectively (P < .001). We conclude that either treatment can effectively mitigate the negative effect of callipyge phenotype on longissimus tenderness. Callipyge lamb carcasses subjected to the combination of prerigor liquid @entity1568 freezing, postrigor @entity12374 injection, and 14 d postmortem storage had tenderness similar (P > .05) to that of normal, untreated carcasses after 14 d of postmortem storage.

Effect of prerigor freezing and postrigor XXXX injection on the tenderness of callipyge longissimus.

@entity12374 :: ('MESH:D002122', 'Chemical') :: ['calcium chloride', 'Calcium chloride'] @entity1568 :: ('MESH:D009584', 'Chemical') :: ['nitrogen'] @entity742 :: ('9940', 'Species') :: ['lambs']
@entity12374 :: (MESH:D002122,Chemical) :: ['calcium chloride']
