Debittered pomelo (Citrus maxima) seed powder as a functional ingredient in low-fat ice cream

Abstract

By-product valorisation is a hallmark of sustainable processing and resource efficiency. Repurposing wastes into functional entities fosters environmentally responsible and viable industrial practices. In this study, pomelo (Citrus maxima) seed powder was explored as a functional ingredient in low-fat ice cream. Both raw (OSP) and de-oiled seed powders (DSPs) were first debittered using appropriate methods, achieving over 90% reduction in limonin and naringin. The processes also remarkably eliminated tannins, phytic acid and trypsin inhibitors. DSP exhibited >200% enhancement in functional properties over OSP. Improved melting resistance (0.32 g min⁻¹ to 0.64 g min⁻¹) and reduced overrun (51.49% to 29.74%), indicating enhanced ice cream matrix stability, were attained. Hardness, adhesiveness, and gumminess increased with rising concentrations (1–5%) of the powder, indicating the roles of seed polysaccharides and proteins in inducing structural integrity in the pseudoplastic emulsions. This was supported by steady and dynamic rheometry, revealing significant enhancements in apparent viscosity (1.52 Pa s to 9.33 Pa s), consistency index (7.36 Pa s to 47.92 Pa s), yield stress (23.83 Pa to 398.74 Pa) and viscoelastic moduli (G′ and G′′), with decreases in the flow behaviour index (0.66 to 0.17) and loss tangent (0.251 to 0.137). However, prominent color differences, as affirmed by spectrophotometric analysis of lightness (L*), whiteness (WI) and yellowness (b*) occurred. Fuzzy logic-based sensory evaluation identified the formulation with 4% DSP as the most acceptable in terms of taste, creaminess, mouthfeel and appearance. Nutritional analysis re-confirmed the low-caloric nature of the final product. Hence, the processed seed powder served a dual-function as a fat mimetic and stabilizer in the low-fat dairy system.