Effect of breed on protein–lipid functional properties of raw and fermented mare milk

Background Mare milk is gaining attention as a substrate for functional fermented dairy products; however, the influence of breed on its technological behaviour remains insufficiently characterised. Aim(s) This study evaluated the effects of breed (Arabian vs. English mares) and fermentation on the compositional, biochemical and techno‐functional properties of mare milk. Methods Raw and fermented mare milk samples were analysed for gross composition, fatty acid and amino acid profiles, lactic acid bacteria (LAB) counts, organic acids, antioxidant activity, SDS‐PAGE protein patterns and rheological behaviour during refrigerated storage. Major Findings Arabian mare milk exhibited higher protein and lipid contents, along with greater proportions of unsaturated fatty acids and higher antioxidant activity compared to English mare milk. Fermentation significantly increased LAB counts and organic acid levels in both breeds, while inducing moderate changes in protein structure and redistributing fatty acid composition without marked alterations in overall fatty acid class distribution. Rheological analysis showed improved viscosity and structural stability after fermentation, particularly in Arabian mare milk. Amino acid profiles were only slightly affected, indicating limited proteolysis under the applied conditions. Scientific Implications The findings demonstrate that fermentation enhances the techno‐functional properties of mare milk primarily through structural reorganisation rather than extensive biochemical degradation, with clear breed‐dependent differences influencing product performance.