Changes in quality and aroma compounds of Hu sheep with different backfat thicknesses

• For the same carcass weight, differences in backfat thickness in Hu lambs can result in significant differences in body fat distribution, and differences in IMF content also result in differences in meat quality and volatile odor. • When slaughtered at equivalent weights, Hu sheep with divergent backfat thickness display distinct aroma profile differentiation. • The aroma characteristics of meat with different backfat thickness were mainly influenced by the concentration of the main volatile compounds (E)−2-decenaldehyde, 2-nonyl alcohol and 1- octanol. Backfat thickness demonstrates significant correlations with reproductive efficiency, growth performance, and meat quality parameters in lambs. In this study, we selected six Hu sheep with high backfat thickness and six with low backfat thickness. Post-slaughter meat samples were collected for comprehensive analysis. The result showed that, subcutaneous fat, visceral fat, and tail fat in the HBF group were significantly higher than those in the LBF group ( P < 0.05). Notable variations ( P < 0.05) were also observed in crucial meat quality indicators including higher water-holding capacity (WHC) and intramuscular fat (IMF), lower shear force value, moisture content and luminosity (L*) in HBF group. Among them, the IMF content in HBF group was 26.11 % higher than that in LBF group. Volatile compound profiling identified significant differences ( P < 0.05) in flavor-related metabolites between the two groups. The PUFA content of C20: 2 and C20: 3n6 in the HBF group was significantly higher than that in the LBF group ( P < 0.05), and the fatty acid-volatilome correlation analysis revealed strong associations between C20:2 and C20:3n6 fatty acids with key aroma compounds including (E)-2-decenal, 2-nonanol, and 1-octanol. These results collectively demonstrate that backfat thickness serves as a valuable indicator for predicting both qualitative characteristics and flavor compound profiles in ovine meat products.