Effect of emulsion microgel particles on texture, rheology, structure and sensory properties of reduced-fat yogurt

Nowadays, there is an increasing consumer demand for reduced-fat foods. However, reducing fat content in yogurt often leads to a weakened texture and increased whey syneresis. Emulsion microgel particles ( EMP ) have the potential to improve the quality of reduced-fat yogurt. Nevertheless, the impact of different amounts of EMP on the quality of reduced-fat yogurt and the underlying mechanisms remain unclear. In this study, spherical, negatively charged, and micron-sized EMP were prepared and incorporated into reduced-fat milk at different amounts (0.25 %, 0.5 %, 1 %, 1.5 %, 2 %, 3 %, w/w) to produce reduced-fat yogurt. As the EMP amount increased, the rate of pH reduction during fermentation accelerated; and the proportions of α-helix and β-sheet structures, water holding capacity, hardness and viscosity value at 50 s −1 first increased and then decreased. In the samples supplemented with 1 %, 1.5 %, and 2 % EMP, EMP were uniformly dispersed within the protein network, promoting the formation of a strong and stable network structure. Additionally, the smoothness, stickiness, and thickness of the reduced-fat yogurt were improved. Principal component analysis demonstrated a close similarity between full-fat yogurt and reduced-fat yogurt supplemented with 1.5 % EMP. This study provides a scientific basis for the application of EMP in dairy products. • EMP improve texture, rheology, water retention and structure of reduced-fat yogurt. • EMP accelerate the fermentation process and enhance the storage modulus of yogurt. • A moderate amount of EMP increase α-helix and β-sheet structures in yogurt. • EMP enhance the smoothness, stickiness, thickness, and odor of reduced-fat yogurt. • PCA confirms 1.5 % EMP significantly improve the quality of reduced-fat yogurt.