Ramashia, S. E.Jideani, A. I. O.Mokhele, Tabea Mokgalakane2026-06-302026-06-302026-05-19Mokhele, T.M. 2026. Nutritional, functional, and sensory properties and rapid market appraisal of sorghum-cowpea gluten-free bread. . .https://univendspace.univen.ac.za/handle/11602/3313Ph.D. in Agriculture (Food Science and Technology)Department of Food Science and TechnologyIn recent years, there has been growing interest in compositing cereal flour with high-lysine legume flour, such as cowpea flour, to enhance the protein quality of baked products. Nonetheless, the usage of cowpea flour in gluten-free baked products has not been fully explored. This study aimed to evaluate the effect of cowpea (white and red) flour on the nutritional, functional, and sensory properties of gluten-free sorghum bread. Superfine sorghum flour was blended with white and red cowpea flour in ratios of 90:10, 80:20, and 70:30. The control sample was the 100% sorghum flour. Wheat brown bread served as the reference sample for evaluating bread properties. Proximate composition, functional, pasting, thermal, and colour properties of sorghum-cowpea composite flours were determined. Moreover, physicochemical properties, nutritional quality (e.g., amino acid composition), antioxidant properties, sensory characteristics, microstructural properties, consumer surveys, and rapid market appraisal (RMA) were evaluated. The packed bulk density of composite flour significantly increased (p < 0.05) with values ranging from 0.92 - 1.18 g/mL (sorghum flour enriched with white cowpea flour) and 0.83 - 2.39 g/mL (sorghum flour enriched with red cowpea flour). Furthermore, the addition of white and red cowpea flour significantly enhanced (p < 0.05) the water absorption capacity of sorghum flour. On the other hand, the incorporation of white and red cowpea flour significantly decreased (p < 0.05) the loose bulk density of the sorghum flour, with values ranging from 0.53 - 0.51 g/mL (white cowpea enriched flour) and 0.54 - 0.52 g/mL (red cowpea enriched flour). There was no significant difference (p > 0.05) between the oil absorption capacity of the control and sorghum-enriched flours. Adding white and red cowpea flour increased the onset and peak temperatures, while decreasing the enthalpy of sorghum flour. All pasting attributes, such as peak, trough, breakdown, final, setback, and setback viscosities, as well as peak time, significantly decreased with the inclusion of cowpea flour. However, the pasting temperature of sorghum flour significantly increased (p < 0.05), with values ranging from 86.15 to 86.63 °C (white cowpea-enriched flour) from 86.87 to 87.63 °C (red cowpea-enriched flour). The ash, protein, carbohydrates, energy content, and amino acids of gluten-free sorghum bread significantly increased with the increase in the substitution levels of white and red cowpea flour. The colour of the crust and crumb of the sorghum-cowpea gluten-free bread was significantly increased (p < 0.05) compared to the control. In terms of textural properties, 100% sorghum bread was found to be harder than the other composite breads. Sorghum 80% - white cowpea 20% composite bread was chewier than the control and other composite breads. The addition of white and red cowpeas significantly increased (p < 0.05) the polyphenols and antioxidant activity of gluten-free sorghum bread. The consumer acceptability results showed that there was no significant difference (p > 0.05) in the colour of the crust, crumb, aroma, taste, and mouthfeel between the control and the sorghum-enriched bread, except for the texture of the bread added with 20% and 30% red cowpea flour. The consumer survey results showed that most consumers were unaware of gluten-free products; however, they could identify sorghum bread as a gluten-free option. Nevertheless, most consumers were unaware of the health benefits of gluten-free products and the diseases associated with consuming gluten-containing products. The majority of consumers were unwilling to buy sorghum-cowpea bread. The results of the RMA show that bakeries A and B face power disruptions, rising costs, and labour shortages, yet brown bread is the best seller due to its flavour and price. They both employ local inputs and handmade (artisanal) processes, differing mainly in scale and consistency. Wheat bread dominates in Thohoyandou, while gluten-free options from sorghum and cowpea show promise but are limited. Despite competition and price pressures in the health-focused products sector, with local production and improved infrastructure, there is still room for growth. Despite its cost-effectiveness, acceptability, and long-term health implications, the study recognises sorghum-cowpea gluten-free bread's health and functional potential as a healthy baked food.1 online resource (xxi, 168 leaves): color illustrationsenUniversity of VendaSorghum - CowpeaFlourUCTDGluten-free breadNutritional qualityConsumer acceptabilityRapid market appraisalThesisMokhele TM. Nutritional, functional, and sensory properties and rapid market appraisal of sorghum-cowpea gluten-free bread. []. , 2026 [cited yyyy month dd]. Available from:Mokhele, T. M. (2026). <i>Nutritional, functional, and sensory properties and rapid market appraisal of sorghum-cowpea gluten-free bread</i>. (). . Retrieved fromMokhele, Tabea Mokgalakane. <i>"Nutritional, functional, and sensory properties and rapid market appraisal of sorghum-cowpea gluten-free bread."</i> ., , 2026.TY - Thesis AU - Mokhele, Tabea Mokgalakane AB - In recent years, there has been growing interest in compositing cereal flour with high-lysine legume flour, such as cowpea flour, to enhance the protein quality of baked products. Nonetheless, the usage of cowpea flour in gluten-free baked products has not been fully explored. This study aimed to evaluate the effect of cowpea (white and red) flour on the nutritional, functional, and sensory properties of gluten-free sorghum bread. Superfine sorghum flour was blended with white and red cowpea flour in ratios of 90:10, 80:20, and 70:30. The control sample was the 100% sorghum flour. Wheat brown bread served as the reference sample for evaluating bread properties. Proximate composition, functional, pasting, thermal, and colour properties of sorghum-cowpea composite flours were determined. Moreover, physicochemical properties, nutritional quality (e.g., amino acid composition), antioxidant properties, sensory characteristics, microstructural properties, consumer surveys, and rapid market appraisal (RMA) were evaluated. The packed bulk density of composite flour significantly increased (p < 0.05) with values ranging from 0.92 - 1.18 g/mL (sorghum flour enriched with white cowpea flour) and 0.83 - 2.39 g/mL (sorghum flour enriched with red cowpea flour). Furthermore, the addition of white and red cowpea flour significantly enhanced (p < 0.05) the water absorption capacity of sorghum flour. On the other hand, the incorporation of white and red cowpea flour significantly decreased (p < 0.05) the loose bulk density of the sorghum flour, with values ranging from 0.53 - 0.51 g/mL (white cowpea enriched flour) and 0.54 - 0.52 g/mL (red cowpea enriched flour). There was no significant difference (p > 0.05) between the oil absorption capacity of the control and sorghum-enriched flours. Adding white and red cowpea flour increased the onset and peak temperatures, while decreasing the enthalpy of sorghum flour. All pasting attributes, such as peak, trough, breakdown, final, setback, and setback viscosities, as well as peak time, significantly decreased with the inclusion of cowpea flour. However, the pasting temperature of sorghum flour significantly increased (p < 0.05), with values ranging from 86.15 to 86.63 °C (white cowpea-enriched flour) from 86.87 to 87.63 °C (red cowpea-enriched flour). The ash, protein, carbohydrates, energy content, and amino acids of gluten-free sorghum bread significantly increased with the increase in the substitution levels of white and red cowpea flour. The colour of the crust and crumb of the sorghum-cowpea gluten-free bread was significantly increased (p < 0.05) compared to the control. In terms of textural properties, 100% sorghum bread was found to be harder than the other composite breads. Sorghum 80% - white cowpea 20% composite bread was chewier than the control and other composite breads. The addition of white and red cowpeas significantly increased (p < 0.05) the polyphenols and antioxidant activity of gluten-free sorghum bread. The consumer acceptability results showed that there was no significant difference (p > 0.05) in the colour of the crust, crumb, aroma, taste, and mouthfeel between the control and the sorghum-enriched bread, except for the texture of the bread added with 20% and 30% red cowpea flour. The consumer survey results showed that most consumers were unaware of gluten-free products; however, they could identify sorghum bread as a gluten-free option. Nevertheless, most consumers were unaware of the health benefits of gluten-free products and the diseases associated with consuming gluten-containing products. The majority of consumers were unwilling to buy sorghum-cowpea bread. The results of the RMA show that bakeries A and B face power disruptions, rising costs, and labour shortages, yet brown bread is the best seller due to its flavour and price. They both employ local inputs and handmade (artisanal) processes, differing mainly in scale and consistency. Wheat bread dominates in Thohoyandou, while gluten-free options from sorghum and cowpea show promise but are limited. Despite competition and price pressures in the health-focused products sector, with local production and improved infrastructure, there is still room for growth. Despite its cost-effectiveness, acceptability, and long-term health implications, the study recognises sorghum-cowpea gluten-free bread's health and functional potential as a healthy baked food. DA - 2026-05-19 DB - ResearchSpace DP - Univen KW - Sorghum - Cowpea KW - Flour KW - Gluten-free bread KW - Nutritional quality KW - Consumer acceptability KW - Rapid market appraisal LK - https://univendspace.univen.ac.za PY - 2026 T1 - Nutritional, functional, and sensory properties and rapid market appraisal of sorghum-cowpea gluten-free bread TI - Nutritional, functional, and sensory properties and rapid market appraisal of sorghum-cowpea gluten-free bread UR - ER -