Production and Characterization of Plant-based Yoghurt from Blends of Tigernuts (Cyperusesculentus) and Pumpkin Seeds (Cucurbita pepo)
H. T. Olaleye
*
Department of Food Science and Technology, Yaba College of Technology, Yaba, Lagos, Nigeria.
T. O. Oresanya
Department of Food Science and Technology, Yaba College of Technology, Yaba, Lagos, Nigeria.
O. O. Ogundipe
Department of Food Science and Technology, Yaba College of Technology, Yaba, Lagos, Nigeria.
*Author to whom correspondence should be addressed.
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.
Keywords: Plant-based yoghurt, tigernut, pumpkin seed, functional food, dairy alternative