The eating quality of lamb in pre-rigor, rigor mortis and post-rigor phases was investigated by using consumers’ sensory evaluation to understand the differences of eating quality characteristics of lamb in different postmortem phases under instant boiling, roasting, boiling and stir-frying conditions, which was expected to provide the reference for lamb quality evaluation and high-quality meat production.

The oyster cut, short loin, knuckle and silverside in per-rigor, rigor mortis and post-rigor phases were obtained from small-tail Han sheep (male, 8 months old). The sensory attributes (including tenderness, juiciness, flavor and overall liking) of lamb after instant boiling, roasting, boiling and stir-frying were evaluated by consumers. The MQ4 (Meat Quality, 4 variables) equation and the grades boundaries were determined by linear discriminant analysis, which were used to analyze the preference score and eating quality grade of lamb.

After instant boiling, the short loin and silverside in pre-rigor had higher tenderness, flavor and MQ4 scores than those in rigor mortis and post-rigor phases (P<0.05), while there was no significant difference in consumers’ scores of oyster cut and knuckle in different postmortem phases (P>0.05). After roasting, the oyster cut in per-rigor and the silverside in post-rigor phase had higher tenderness, juiciness, overall liking and MQ4 scores than those in rigor mortis (P<0.05), but there was no significant difference in consumers’ scores of short loin and knuckle in different postmortem phases (P>0.05). After boiling, the juiciness and overall liking scores of knuckle in post-rigor were higher than those in per-rigor and rigor mortis phases (P<0.05), and there was no significant difference in consumers’ scores of oyster cut, short loin and silverside in different postmortem phases (P>0.05). After stir-frying, the tenderness, overall liking and MQ4 scores of oyster cut in pre-rigor and post-rigor were higher than those in rigor mortis, while the tenderness, flavor, overall liking and MQ4 scores of short loin in pre-rigor were higher than those in rigor mortis and post-rigor (P<0.05). There was no significant difference in consumers’ scores of knuckle and silverside in different postmortem phases (P>0.05). The premium quality (4star) and good quality (5star) samples were higher in pre-rigor (5star: 0%-8.33%; 4star: 47.83%-72.22%) and post-rigor (5star: 0%-8.70%: 4star: 52.78%-58.33%). There were no unsatisfactory quality (2star) samples in pre-rigor and post-rigor phases, while 4.17% and 4.35% of the samples in rigor mortis were 2star after roasting and boiling, respectively.

In general, the pre-rigor and post-rigor lamb had a superior eating quality to rigor mortis lamb based on consumers’ sensory evaluation, and the pre-rigor and post-rigor lamb were preferred by Chinese consumers.