Effects of added resulting flours from heat-treated Bambara groundnut seeds on properties of composite Bambara groundnuts–wheat dough and bread

Background

This work determined the effect of compositing wheat flour with the resulting flour (15% and 30%) from heat-treated Bambara seeds on dough rheology and breadmaking properties. Bambara seeds (conditioned 53% moisture) were infrared or microwave heat (1200 W at 130°C) treated alone and in combination. Mixolab, Alveograph, and the creep and recovery test were used to determine the rheological properties of composite dough. A rheofementometer was used to elucidate composite dough behavior during proofing. Bread texture was determined using a texture analyzer and bread characteristics such as loaf volume and size were also determined.

Results

The results showed that the principal component analysis (PCA) explained 67.4% of variations, with Component 1 explaining 34.4% and Component 2 explaining 33%. From the PCA, mixolab parameters, such as WA, protein weakening, and starch behavior parameters (C3–C5), were a better predictor of composite dough behavior than the alveograph and the creep and recovery test. According to the PCA plot, samples composited with 15% Bambara groundnut flour from 53% moisture conditioning and heat treated with a combination of microwave and infrared closely resemble the wheat dough and bread.

Conclusion

PCA showed that composites made with flours from the 53% moisture-conditioned Bambara groundnut seeds and heat-treated using a combination of microwave and infrared were closer to wheat, particularly those composited with 15% Bambara groundnut flour.

Significance

This study provides the nutrient-dense Bambara groundnut flours from heat-treated seeds as a suitable alternative to improve the nutritional quality of composite wheat bread. The study also provides insight into the composite dough's rheological and bread physical properties.