Development of coconut-based non-dairy ice cream using underutilized Sri Lankan fruits and evaluation of its sensory and physicochemical properties

Abstract

The growing demand for dairy-free frozen desserts has encouraged the development of plant-based ice creams with improved nutritional and functional qualities. This study developed a coconut milk–based vegan ice cream incorporating soursop (Annona muricata) and Ceylon olive (Elaeocarpus serratus) and evaluated its sensory, proximate, physicochemical, functional, and storage properties comparison with a control. Four formulations with different soursops to Ceylon olive puree ratios were prepared: T1 (1:1), T2 (1:2), T3 (2:1), and T4 (0:0 control). Sensory evaluation with 50 untrained panelists on a 5-point hedonic scale identified T1 (1:1) as the most preferred formulation. Proximate analysis of T1 revealed 55.67 ± 0.84 g/100 g moisture, 1.29 ± 0.01 g/100 g protein, 0.55 ± 0.00 g/100 g fiber, 23.00 ± 1.78 g/100 g carbohydrate, 19.09 ± 0.34 g/100 g fat, and 0.73 ± 0.07 g/100 g ash. Functional analysis showed significantly higher antioxidant activity (542.14 ± 11.00 mg TE/100 g), flavonoid content (725.00 ± 22.05 mg QE/100 g), and total phenolic content (334.33 ± 9.38 mg GAE/100 g) than the control (p < 0.05). During one month of storage at −18 °C, T1 showed a pH reduction from 4.42 ± 0.01 to 3.86 ± 0.02, total soluble solids increased from 23.27 ± 0.75 to 26.87 ± 0.61 Brix, and titratable acidity rose from 0.72 ± 0.06% to 1.22 ± 0.06%, compared with the control. Microbiological analyses was assessed biweekly for two months under the same conditions confirming the product safety, with total plate count decreasing from 5 × 10³ CFU/g initially to less than 1 × 10³ CFU/g, while presumptive coliforms, Salmonella spp. and Escherichia coli were absent. It can be concluded that the developed product represents a safe and promising plant-based frozen dessert alternative with enhanced fiber, fat, and functional properties.