Branched chain fatty acids in the flavour of sheep and goat milk and meat: A review

•The meat and milk from sheep and goats possess unique, variable and complex flavour profiles.•The different flavour profiles result from complex interactions of genetics, age, sex, and nutrition.•Significant gaps exist in our understanding of those relationships.•Analytical techniques are being used to understand the flavour of goat and sheep meat, and milk. Globally, around 1.5 billion sheep and goats provide meat and milk on an annual basis and are important sources of nutrition as well as economic subsistence. The popularity of sheep and goat meat, along with milk, and related products occurs due to their unique nutritional properties, physicochemical composition, and sensory attributes while having species-specific flavours compared to other red meats and dairy products. The overall volatile flavour profile and sensory characteristics of the products derived from sheep and goats are key differentiators in the market. However, the flavour variation can lead to inconsistent consumer experiences. A complex relationship exists between factors such as breed, sex, and age along with nutrition which contribute to the overall flavour. Additionally, regional expectations of flavour can also influence consumers. The characteristic flavour associated with dairy products derived from sheep and goat, has a tremendous impact on the overall product quality and acceptability, distinct from that found with cow milk. This review focuses on the short branched chain fatty acids identified as relevant to the flavour associated with milk and meat from sheep and goats, the synthesis of these compounds as well as the pre- and post-gate factors which affect their accumulation in meat and milk. It will also present the pros and cons of classical and emerging analytical techniques used for their determination.