Modulating protein-polysaccharide gel networks via almond protein to improve physicochemical stability of...

Low soluble protein content and poor gelation in millet milk compromise the formation of firm set yogurts. This study developed a millet-based set yogurt with improved physicochemical stability by incorporating almond protein isolate (API; 0-2%, w/v), which contributes a mild flavor, acid stability, and gel-forming capacity. API supplementation promoted acid-induced gelation via ionic interactions within the protein-polysaccharide matrix. Formulations with 0.5-1% API formed self-supporting gels with higher firmness (1.46-7.31 N), higher water-holding capacity (97.92-99.00%), greater post-shear recovery, and lower deformation (p < 0.05). API supplementation elevated lactic acid bacteria counts in a concentration-dependent manner (5.29-7.00 log CFU/g; p < 0.05), with increased acid production and taste acceptability. However, 2% API caused excessive aggregation, pore collapse, syneresis, and structural heterogeneity. Accordingly, 1% API provided the best balance of stability, texture, and sensory acceptability, demonstrating the potential of this plant-derived protein for developing cereal-based yogurt alternatives.