Development of Macadamia-milk Dual-Protein Yogurt: Formulation Optimization, Physicochemical Properties, and Sensory Characteristics

Driven by increasing consumer interest in diversified dairy products containing both animal- and plant-based proteins, dual-protein yogurt has emerged as a promising product category. This study developed a novel dual-protein yogurt by utilizing macadamia protein and milk protein. The effects of different formulation conditions and process parameters on yogurt fermentation activity, physical properties, rheological behavior, and sensory qualities were systematically optimized, followed by an evaluation of storage stability. The results indicated that the optimal processing conditions were as follows: 70 g/L macadamia protein concentration (replacing 500 mL/L of milk protein), an inoculation rate of 5.10 × 10 6 CFU/mL, and fermentation at 40 °C for 7 h. Under the optimal conditions, the dual-protein yogurt exhibited superior fermentation characteristics, desirable texture profiles, and enhanced rheological properties, achieving a highest water-holding capacity of 50.68% and a sensory score of 84.31. Additionally, the dual-protein yogurt maintained excellent flavor, texture, and stability during 21 days of storage at 4 °C. These results demonstrate the feasibility of integrating macadamia protein into dairy systems, providing practical support for developing dual-protein dairy products.