Production and Characterization of Plant-based Yoghurt from Blends of Tigernuts (Cyperusesculentus) and Pumpkin Seeds (Cucurbita pepo)

Abstract

Background: Plant-based yoghurt was produced from tigernut (Cyperus esculentus) and pumpkin seed (Cucurbita pepo) blends and evaluated for quality. Results showed improved nutrition and acceptable sensory properties, indicating potential as a dairy-free alternative. Aim: This study assessed the nutritional, physicochemical, microbiological, and sensory characteristics of plant-based yoghurt derived from mixtures of tigernut (Cyperusesculentus) and pumpkin seed (Cucurbita pepo) milk substitutes. Location and Duration of Study: Department of Food Science and Technology, Yaba College of Technology, Yaba, Lagos, Nigeria, from July 2025 to January 2026. Methodology: Milk analogues were combined in ratios of 100:0, 95:5, 90:10, 85:15, and 80:20 (tigernut: pumpkin seed) and subsequently fermented into yoghurt. The proximate composition, physicochemical qualities, anti-nutritional factors, microbiological quality, and sensory attributes were assessed using standardised methodologies. Data were evaluated via ANOVA accompanied by Duncan’s multiple range test at p < 0.05. Results: Significant differences (p < 0.05) were noted among formulations for the majority of samples. Protein (4.98–6.88%), fat (2.44–3.97%), ash (1.25–1.84%), fibre (0.43–0.70%), total solids (21.92–26.21%), and energy (93.42–114.96 kcal/100 g) exhibited a significant increase with the incorporation of pumpkin seeds, although moisture content reduced (73.80–78.02%). The physicochemical properties were significantly altered (p < 0.05), with viscosity (19.13–23.07 cp) and titratable acidity (0.583–0.863%) rising, whereas °Brix dropped (26.64–40.23) as the quantity of pumpkin seed increased. The pH varied between 4.84 and 5.24, indicating mild fermentation. Anti-nutritional factors were low and considerably reduced (p < 0.05) in enriched samples, with tannins (0.024–0.122%), phytates (0.082–0.113%), and oxalates (0.106–0.127%) remaining within acceptable limits. Microbial counts (TPC: 3.5×10⁵–8.35×10⁵ cfu/mL) were typical of fermented products; nevertheless, the presence of detectable coliforms (1.05×10⁵–4.55×10⁵ cfu/ml) suggests potential post-processing contamination. Sensory evaluation revealed no significant differences (p > 0.05) among the samples; however, the control (100% tigernut) had the highest overall acceptability score (7.05/9). Conclusion: The addition of pumpkin seed milk significantly improved the nutritional and functional attributes of tigernut yoghurt while maintaining sensory acceptance. A suggested addition of up to 20% enhances protein, energy, and textural attributes, rendering the product a feasible lactose-free functional dairy substitute.