Research Progress on Muttony Flavor Regulation and the Establishment of Its Digital Intelligent Evaluation System From a Global Perspective

Muttony flavor is a species-specific characteristic of ovine meat and a critical determinant of consumer acceptance and market demand worldwide. The characteristic flavor primarily originates from two key classes of compounds: Branched-chain fatty acids (BCFAs), particularly 4-methyloctanoic acid (4-MOA), 4-ethyloctanoic acid (4-EOA), and 4-methylnonanoic acid (4-MNA); and skatole (3-methylindole), a ruminal microbial metabolite of tryptophan. Genetic analysis based on candidate genes is considered an effective approach to elucidate the physiological mechanisms regulating the expression of complex traits. This review systematically examines the biosynthetic pathways of these compounds, clarifying the roles of ruminal microorganisms, host genetic factors, and key regulatory genes including FASN, CYP2E1, CYP2A6, and MMUT, thereby providing genetic strategies and methods for the regulation of muttony flavor, while also supplementing nongenetic approaches for flavor control. The integration of these strategies indicates that the identification of candidate genes and the elucidation of their expression regulatory networks provide a theoretical basis for future marker-assisted selection programs, thereby potentially enhancing the precision and sustainability of ovine industry breeding strategies, while nongenetic regulation can further assist in fine-tuning flavor control. As a validation, this review also provides a systematic overview of analytical methods for muttony flavor evaluation, tracing the evolutionary trajectory from traditional sensory evaluation through instrumental analysis to intelligent sensory technologies, and clarifying the applicable scenarios and complementary relationships among various techniques. By integrating the current understanding of formation mechanisms, regulatory networks, and evaluation technologies, this review establishes a theoretical framework for developing market-oriented flavor control strategies.