Development and Comprehensive Quality Characterization of Soybean-Coconut Composite Milk Yoghurt as a Functional Dairy Alternative

This study investigated the proximate composition, mineral content, physicochemical characteristics, bacterial viability, and sensory attributes of soybean–coconut composite milk yoghurts formulated in different ratios (100:0, 75:25, 50:50, 25:75, and 0:100) of soybean to coconut milk, codename SCMY01 to SCMY05. The moisture content of approximately 86% with no significant difference among the samples, dominates the proximate results. A gradual reduction in protein (3.79–1.21%) was observed with higher coconut substitution. Sample SCMY05 had the highest fat content (6.48%). Ash, crude fibre, and carbohydrate were highest in sample SCMY01 (0.71, 0.41, and 7.11%). Mineral analysis revealed that soybean-dominant samples were richer in calcium, sodium, magnesium, iron, and zinc, whereas potassium levels were significantly higher in coconut-rich formulations (202.25 to 220.10mg/100g). Physicochemical assessment revealed a decline in pH (4.35–3.90) and an increase in titratable acidity (0.70–1.05%) as the coconut content increased, accompanied by a substantial improvement in total solids (12.00–21.25%). No significant difference was observed in total soluble solid results. Microbial counts ranged from (7.2–8.5 log₁₀ cfu/ml), with soybean-based samples supporting relatively higher microbial growth. Sensory analysis revealed that 100% coconut milk yoghurt was most favoured in terms of colour, taste, flavour, and overall acceptability, whereas soybean-based yoghurt, despite being nutritionally superior, was less accepted due to its pronounced beany flavour. This study highlight soybean–coconut composite yoghurt as a sustainable and health-promoting alternative to dairy yoghurt, with prospects for broader consumer acceptance and commercialization.