Identification and comparison of mutton flavor related branched-chain fatty acids among 4 Chinese indigenous sheep

The characteristic ‘mutton flavor’ primarily emanated from subcutaneous adipose tissue and was associated with the levels of three branched-chain fatty acids (BCFAs). This study focused on assessing the quantitative distribution of BCFAs in four sheep breeds from northern China and initially explored the influence of genetic and feeding factors through systematic GC-MS analyses and multidimensional statistics. A total of 164 samples were procured from four breeds of Chinese indigenous sheep, including small-tailed Han sheep (SHS, n = 30; rams 12, ewes 18), Altay sheep (AS, n = 30; rams 15, ewes 15), Short-tailed Steppe sheep (STSS, n = 44; rams 14, ewes 30), and HulunBuir sheep (HBS, n = 60; rams 30, ewes 30), all 8 months old. The results indicated that SHS exhibited the highest levels of BCFAs, followed by AS. No significant difference between STSS and HBS, both with notably lower levels of mutton flavor-related BCFAs. Additionally, rams generally harbored higher levels of BCFAs in comparison to ewes. Collectively, this study provides valuable insights for improving the mutton flavor.