Formulation and Optimization of Low-sugar Carrot Milk Drink Using Response Surface Methodology

Abstract

Growing demand for functional dairy beverages has encouraged the development of nutrient-enriched, reduced-sugar formulations. Carrot juice is a rich source of β-carotene, phenolics, minerals, and antioxidants, but its incorporation into milk requires technological optimization for balanced sensory and physicochemical attributes. Milk fat also influences carotenoid solubility, mouthfeel, and overall acceptability. This study aimed to optimize milk fat content and processed carrot juice level for developing a reduced-sugar carrot milk drink with desirable equalities. Three carrot varieties (Madhuvan, Durga-4, Nantes) were screened for sensory and chemical attributes. The potassium content of carrots ranging from 0.64% to 1.57%, with notably higher levels in Nantes correlating with its sweet taste and higher mineral content, and calcium content reaching up to 3618.75 ppm. Processed carrot juice was prepared through washing, blanching, juice extraction, filtration, and pasteurization. A Central Composite Rotatable Design (CCRD) with two independent variables, milk fat (0.38–4.62%) and carrot juice level (7.9–22.07%), was used to generate 13 formulations. Nantes carrots showed the highest β-carotene (176.19 mg/100 g), TSS (13.3 °Brix), potassium, and juice yield, and were therefore selected for optimization. Sensory evaluation indicated significant effects of carrot juice on color (p < 0.001), flavor (p < 0.001), and overall acceptability (p < 0.001). Milk fat significantly influenced consistency (p < 0.05), sweetness (p < 0.05), and overall acceptability (p < 0.05). The CCRD formulations demonstrated that higher carrot juice (20–22%) improved color and flavor, whereas milk fat around 4% enhanced texture, sweetness perception, and mouthfeel. The best-performing formulation (4% fat, 20% juice) achieved the highest overall acceptability (7.75). RSM identified an optimized formulation consisting of 4% milk fat and 20% processed carrot juice, yielding superior sensory quality and desirable functional properties. Carrot juice significantly enhanced color and flavor due to high carotene content, while milk fat improved texture and sweetness perception. The optimized reduced-sugar carrot milk drink offers a nutritionally enriched, consumer-acceptable functional dairy drink.