Callipyge genotypic effects on meat quality attributes and oxidation stability of ovine M. longissimus

The objective of this study was to evaluate the effects of callipyge (C) genotypes on quality attributes and oxidation stability of aged lamb loins. Only lambs possessing a wildtype maternal allele and a paternal callipyge allele (+/C) express a muscle hypertrophy phenotype. Seventeen lambs (7 months), consisting of all four possible callipyge genotypes (C/+, C/C, +/C and +/+), were harvested. Loins (M. longissimus thoracis) were separated from each carcass at 3 days postmortem, cut into 3 sections, and randomly assigned into three aging periods (3, 6 and 9 days). Genotype had no impact on proximate composition, mineral content, and pH of lamb loins (P > 0.05). In terms of water-holding capacity, slightly increased purge/thaw loss of +/C lamb loins was observed (P < 0.05), but cooking, drip and display weight losses were unaffected by callipyge genotype (P > 0.05). The highest shear force was found at +/C lamb loins (P < 0.05). +/C lamb loins showed initially less redness, but greater color stability during 7 days of display compared to loins from the other genotypes. Heme iron content of +/C lamb loins was a significantly lower than the other genotypes. Genotype had no impact on lipid oxidation stability (P > 0.05). Our results indicate similar quality attributes of lamb loins between non-callipyge phenotypes (C/C, C/+ and +/+) and suggest that callipyge lamb loins have superior color stability, while exhibiting lower tenderness compared to loins from non-callipyge phenotype lambs.