Effect of Wet and Dry Processing on the Proximate and Mineral Composition of Traditional Nigerian Steamed Legume Pudding (Moi-Moi) Prepared from Cowpea (Vigna unguiculata) and Bambara Groundnut (Vigna subterranea)

Abstract

Moi moi is a widely consumed steamed legume pudding in Nigeria, traditionally prepared from cowpea (Vigna unguiculata) but increasingly formulated with other legumes such as Bambara groundnut (Vigna subterranea). This study evaluated the effects of wet and dry processing on the proximate and mineral compositions of moi-moi, a traditional Nigerian steamed legume pudding prepared from cowpea (Vigna unguiculata) and Bambara groundnut (Vigna subterranea). Four samples of moi-moi formulation were prepared from wet-processed beans, dry-processed beans, wet-processed Bambara groundnuts, and dry-processed Bambara groundnuts. Proximate analysis of composition (protein, fat, fibre, ash, moisture, and carbohydrates) and mineral analysis (magnesium, potassium, calcium, iron, zinc, and phosphorus) were conducted using the standardized procedures of AOAC with data analysis through ANOVA with Bonferroni multiple paired comparisons at p < 0.05. Dry processing significantly increased the concentrations of protein, fibre, and ash compared to wet processing in the two legumes. The highest protein concentration was observed in the dry bean moi-moi sample (24.23%), while the lowest was recorded in the wet Bambara groundnut moi-moi sample (16.67%). Magnesium and calcium concentrations were highest in the dry Bambara groundnut moi-moi sample (68.56 mg/100g and 88.97 mg/100g, respectively). Potassium, iron, zinc, and phosphorus concentrations were highest in the dry bean moi-moi sample (231.09 mg/100g, 12.43 mg/100g, 8.24 mg/100g, and 119.22 mg/100g, respectively). Dry processing retained higher mineral content than wet processing, while Bambara groundnut enhanced nutritional value. Dry-processed Bambara groundnut moi-moi offers a nutrient-dense alternative for improving dietary quality.