The effect of milk-based protein concentrates addition on the characteristics of Saanen goat milk yoghurt

This study was conducted to investigate the effect of three types of proteins (WPC- Whey protein concentrate, MPC- Milk protein concentrate, SMP- Skim milk powder) on quality traits of Saanen goat milk yoghurts. Manufactured yoghurt samples were analyzed for compositional, physicochemical properties, free fatty acid (FFA) profiles, volatile components and sensory attributes during 21-day storage period. There were significant differences in physicochemical properties (protein, dry matter contents, whey separation and hardness) of milk-based yoghurts throughout the storage (p<0.05). Yoghurts containing WPC showed a slow decrease in pH during the first 7 days of storage, which may increase product shelf life by reducing high acidity. Yoghurt with SMP showed higher FFA profiles as compared to yoghurt made with MPC and WPC, indicating different lipid degradation and flavor characteristics. MPC significantly reduced whey separation in goat yoghurts, leading to better structural stability. Yoghurts with MPC had the highest scores in terms of taste-flavor, consistency and overall acceptability. They also had higher octanoic acid content, contributing to good flavor notes and higher acidity, which helped reduce the 'goaty' taste. MPC-supplemented yoghurts showed the hardest structure, most noteworthy protein content and the most favorable FFA and volatile compounds, including significant volatiles like octanoic acid, arsenous acid tri ester and D-limonene. It was concluded that milk-based proteins, especially MPC with the best structural stability for the shelf life, the hardest structure, higher protein and lower lactose content, the most abundant favorable free fatty acid contents and volatile components, could be used to improve physicochemical and compositional quality properties of goat milk yoghurts.