Formulation and characterization of basil-flavoured oat-based milk substitute ice cream as a sustainable alternative to dairy ice cream

Abstract

The growing demand for sustainable dairy alternatives has driven innovation in plant-based frozen desserts like oat-based milk substitutes (OMS). In this study, whole oat groats were processed into a plant-based milk substitute using the combined acid–enzyme hydrolysis technique, leveraging their low environmental impact and desirable techno-functional properties, including effective emulsifying and stabilizing capacities to develop basil-flavored oat-based milk substitute ice cream. Among the various formulations explored, OMS replacing dairy milk at 50% and 100% levels, in combination with 10% basil leaf extract, demonstrated superior acceptability and was used for the development of ice cream. The physicochemical, rheological, textural, nutritive, storage, organoleptic, and microbial parameters of the Basil-Flavoured Oat-based Milk Substitute (BF-OMS) ice creams were assessed and compared with full-cream dairy milk (FCDM) ice cream as the control. The experimental samples showed optimum pH and titrable acidity values, i.e., 6.91–6.94 and 0.25–0.27%, respectively. The resultant higher total carbohydrate (40.7–51.76%), total solids (48.70–55.95%), and total ash content (1.05–1.15%) in OMS ice creams led to an increased viscosity of the OMS ice-cream mix, ranging from 35.13 to 146 cP, improving their melting properties and structural integrity. BF-OMS ice creams exhibited pseudoplastic, non-Newtonian behaviour with higher viscosities than the control and a strong power law model fit (R² = 0.998). The presence of β-glucans in the OMS might have contributed to enhanced gelling and water-binding capacities, resulting in desirable firmness and a smooth texture. The nutritional analysis showed that the partially substituted BF-OMS ice cream maintained the protein content (4.69%), comparable to the control (5.39%). Both 50% and 100% BF-OMS ice-creams had lower fat content (1.1–2.25%) compared to the control (4.1%). Additionally, OMS ice creams exhibited significantly higher total polyphenol content (45.44–46.68 mg GAE/100 g) and DPPH inhibition activity (89.85–92.81%) than the control. More importantly, an increment was observed in total polyphenols (26.34–58.05%) and DPPH inhibition activity (1.70%) in experimental samples at the end of 15 days of storage, indicating enhanced antioxidant potential during storage studies. Overall, the findings suggest that BF-OMS ice creams with dairy milk substitution can support a more sustainable industry transition with high consumer acceptance.