4D DIA proteomic analysis of gender and age influences on meat quality and flavor in Hetian white sheep.

To investigate the impact of age and gender on mutton flavor and quality, we analyzed mutton from 12-month-old and 6-month-old rams and ewes. The results indicated that 12 months Hetian white sheep exhibited higher levels of amino acids, protein, free fatty acids, and reducing sugars compared to 6-months. Additionally, amino acid, protein, and reducing sugar levels were higher in ewes than 12 months rams. Proteomic analysis revealed that proteins related to fatty acid metabolism, intramuscular fat (IMF), and mitochondrial function were more abundant in ram. The upregulation proteins involved in amino acid metabolism in ewes highlights its richer flavor profile compared to ram. Proteins associated with muscle development and mitochondrial activity were more highly expressed in the 12-month-old samples compared to those from 6-month-old sheep. ECI1, highly expressed in rams, is linked to IMF content. We hypothesize that ECI1 may serve as a potential protein marker for mutton quality.