Nutritional and Quality Characterization of Noodles from Wheat-Water Yam (Dioscorea alata) Flour Blend

Abstract

The nutritional inadequacy of conventional wheat-based noodles, characterized by low dietary fibre, limited micronutrient density, and a high glycaemic profile, poses a growing public health challenge across sub-Saharan Africa. Water yam (Dioscorea alata) is a nutritionally rich indigenous tuber crop with documented therapeutic properties, yet it remains substantially underutilized in noodle product development. This study assessed the proximate composition, mineral and vitamin contents, cooking properties, and colour characteristics of noodles formulated from wheat-water yam composite flour at three substitution levels. Noodles were prepared at wheat-to-water yam flour ratios of 70:30 (D), 80:20 (E), and 90:10 (F), with 100% wheat flour as the control. Standard AOAC methods were used for proximate and mineral analyses; HPLC was used to quantify vitamins; cooking yield and loss were assessed gravimetrically; and colour parameters were measured colorimetrically. Composite noodles exhibited significantly (p < 0.05) higher protein (up to 14.50 g/100g), crude fibre (up to 5.48 g/100g), ash, and total fat compared with the control. All mineral parameters, such as calcium, potassium, iron, magnesium, selenium, zinc, and sodium, were markedly elevated across composite blends. B-complex vitamins (B2, B3, B6, B9) and vitamin A were substantially enriched relative to the control. Cooking yield declined with increasing yam flour substitution, while cooking loss increased. Colour analysis indicated progressive darkening and reduced lightness with higher water yam flour incorporation. Wheat-water yam composite noodles at 70:30 (Sample D) demonstrated the most favourable nutritional profile, while Sample F (90:10) showed the most acceptable cooking loss profile. These findings support the use of water yam flour as a functional ingredient for producing nutritionally enhanced noodles