The influence of Bambara groundnut (<i>Vigna subterranean</i>) flour on the nutritional, physical and antioxidant properties of steamed bread
Mpho Edward Mashau, Thompho Admire Mukwevho, Shonisani Eugenia Ramashia, Muthulisi Siwela
Abstract
This study aimed to evaluate the influence of fortifying steamed breads with Bambara groundnut (BGN) flour (5%, 10%, 15% and 20%) on their physicochemical and antioxidant characteristics. The water absorption capacity of the flour increased with increasing BGN flour fortification levels, while oil absorption capacity decreased. The pH and leavening capacity of the BGN flour fortified dough decreased during incubation, whilst the titratable acidity for dough fortified with 15% and 20% BGN flour increased. The inclusion of BGN flour improved the protein, ash, and crude fibre contents of flour and steamed breads. The HunterLab colour values show that BGN flour increased the yellowness (b* value) of flour and steamed bread samples, while the lightness, redness and Chroma decreased. The antioxidant properties of flours and steamed breads increased significantly (p < 0.05) with the BGN flour fortification levels. Moreover, the weight and spread ratio of the breads increased, whilst the texture became soft. The BGN flour can be utilised as a functional ingredient to enhance the nutritional and antioxidant properties of cereal-based foods such as steamed bread.