Development and Evaluation of Nutritional Value of Plant-based Yogurt Using Egusi Kernels and Bambara Groundnut Milk

Abstract

Aims: This study aimed to produce and evaluate the nutritional value of a plant-based yogurt made from egusi kernel milk and Bambara groundnut seed milk. Twelve yogurt samples were prepared using milks from two egusi species (Cucurbita maxima and Cucumeropsis mannii) and Bambara groundnut (Vigna subterranea) seeds in different proportions. Place and Duration of Study: V. subterranea seeds and egusi kernels (C. maxima and C. mannii) were purchased from Bambui market in the North-West Region of Cameroon. The lyophilised microbial starter culture was purchased from Bamenda market. Production and characterisation of the samples were carried out at the Food Science and Technology Laboratory of the College of Technology, The University of Bamenda, Cameroon. The study was conducted between February and July 2025. Methodology: Milk from each egusi species was mixed with Bambara groundnut milk (BM) at 100:0, 90:10, 80:20, 70:30, 60:40, and 50:50 (egusi milk: BM; v:v). The resulting milks were pasteurised, cooled, and fermented with a 1:1 mixture of Streptococcus thermophilus and Lactobacillus bulgaricus at 5 log CFU/mL for 6 h at 42 °C. The proximate composition, sensory attributes, and nutritional value of the fermented yogurt samples were evaluated. Results: Increasing the proportion of BM in the mixture was associated with lower protein content and generally lower lipid content, while yogurt acceptability improved (P<0.05). In-vivo evaluation showed that the yogurt containing 60% C. mannii milk and 40% BM had the highest protein efficiency ratio among the yogurt diets, whereas all yogurt samples showed true digestibility above 90%. The measured biochemical and haematological parameters did not indicate adverse effects compared with the protein-containing control groups under the study conditions. Conclusion: Yogurt produced using a 60:40 mixture of C. mannii milk and BM combined favourable sensory properties with the highest protein efficiency ratio among the yogurt diets and high protein digestibility.