Effect of Substitution of White Sorghum Flour with Unripe Plantain and Sweet Potato (Ipomoea batatas) on the Nutritional, Functional and Sensory Properties of Composite Flour for Cooked Dough
Mary Isi Agbi *
Department of Chemistry, Centre for Food Technology and Research, Rev. Fr. Moses Orshio Adasu University, Makurdi, Benue State, Nigeria.
Joseph Ikwebe
Department of Biochemistry, Federal University, Wukari, Taraba State, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Aims: To evaluate the effect of progressively substituting white sorghum flour with unripe plantain and sweet potato flours on the proximate, functional, mineral and sensory properties of composite flour intended for cooked dough (swallow), compared with a commercial wheat semolina control.
Study Design: Experimental study involving the formulation of five composite flour blends and a wheat-semolina control, evaluated by proximate, functional and mineral analysis and by a structured sensory panel.
Place and Duration of Study: Department of Chemistry laboratories, Rev. Fr. Moses Orshio Adasu University, Makurdi, Nigeria, between September 2025 and September 2026.
Methodology: Unripe plantain, sweet potato and white sorghum were processed into flour and blended at five ratios (Samples A–E), with sorghum decreasing from 85% to 45% and plantain and sweet potato increasing correspondingly, alongside a 100% wheat-semolina control (Sample F). Proximate composition (ash, moisture, fat, fibre, protein, carbohydrate, and energy), functional properties (water absorption capacity, swelling capacity, least gelation concentration, bulk density) and mineral content (calcium, iron, and zinc) were determined in duplicate. Cooked dough prepared from each blend was evaluated by a 20-member panel on a 9-point hedonic scale for color, aroma, taste, texture, appearance and overall acceptability. Data were subjected to one-way ANOVA, with meanss separated by Duncan's Multiple Range Test (p<.05).
Results: Ash, moisture, fat, protein and fibre content increased significantly (p<.05) from Sample A to Sample E (e.g., protein rose from 12.64% to 19.66%, against 9.08% in the control), while carbohydrate and energy values decreased. Water absorption capacity declined from 3.24 to 1.14 g/g, while least gelation concentration and bulk density increased with substitution. Calcium, iron and zinc rose four- to eight-fold from the control to Sample E (p<.05). Sensory evaluation showed that formulation significantly affected aroma, texture and overall acceptability (p<.05) but not color, taste or appearance; Samples C (65:20:15) and E (45:30:25) were rated comparably to the control.
Conclusion: Composite flour from white sorghum, unripe plantain and sweet potato can substitute wheat semolina in cooked dough with sensory quality comparable to the control and superior protein, ash, fibre and mineral density, at a modest reduction in energy value; Sample C offered the most balanced overall performance among the blends examined.
Keywords: Composite flour, white sorghum, unripe plantain, white sweet potato, cooked dough, wheat substitution