Effects of Starter Concentration and Fermentation Time on Microbiological, Physicochemical, Nutritional, and Sensory Properties of Young Coconut Drink–Based Yogurt

Abstract

The development of plant‐based yogurt alternatives continues to expand in response to lactose intolerance, sustainability concerns, and demand for nondairy fermented products. Young coconut drink, derived from a mixture of coconut water and young coconut flesh, has been reported to contain fermentable sugars, minerals, and bioactive compounds that support microbial growth, suggesting its potential as a fermentation substrate. However, its fermentation characteristics remain underexplored. This study evaluated the effects of starter culture concentration (0.8% and 1%) and fermentation time (8 and 10 h) on the microbiological, physicochemical, nutritional, mineral, and sensory properties of young coconut drink–based yogurt. Yogurt was produced using Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus at 45°C. All formulations achieved lactic acid bacteria viability above 107 CFU/g, indicating adequate LAB viability after fermentation. Starter concentration significantly influenced acidification, viscosity, proximate composition, carbohydrate utilization, and sensory acceptability, whereas fermentation time exerted a secondary effect. The formulation containing 1% starter fermented for 10 h exhibited the most balanced profile, combining desirable texture, acidity, and overall acceptability. This selected formulation showed a fatty acid profile dominated by medium‐chain fatty acids, particularly lauric acid, a diverse amino acid profile characteristics of the plant‐based matrix, and high mineral bioaccessibility (> 90%) for potassium, magnesium, and iron as determined by an in vitro gastrointestinal digestion model. Overall, young coconut drink–based yogurt demonstrates potential as a plant‐based fermented beverage derived from locally available resources. However, further studies are required to enhance its nutritional profile and sensory characteristics.