Marama bean is a drought-tolerant oilseed legume. Isolated marama bean protein has high foaming capacity, strong dough extensibility and good elasticity characteristics. The dough properties of composites of defatted marama flour (DMF) and cassava starch (CS) were compared with wheat flour dough with the aim of determining the potential of DMF as a functional nutritious gluten-free ingredient in bread. DMF-CS doughs with similar strength to wheat flour dough could be produced. However, they had much shorter Mixolab development time and stability. Alveography revealed that the DMF-CS doughs could inflate into a bubble, with the 33:67 DMF-CS ratio having the most similar bubble size, extensibility and deformation energy to wheat flour dough; with a higher proportion of DMF (57:43) these parameters were lower. Rheofermentometry showed that the DMF-CS composites could also hold gas produced by yeast fermentation. Confocal laser scanning microscopy revealed that as the proportion of DMF to CS was increased, the DMF protein tended to aggregate rather distribute throughout the dough, probably because the highly hydrophilic marama protein and pectin had great affinity for each other. Nevertheless, defatted marama flour appears to have considerable potential as a functional gluten replacement for making protein-and fibre-rich gluten-free bread.

The role of phenolics and saponins in contributing to bitterness in marama beans, an underutilized legume, especially when roasted, was investigated. Marama beans were roasted at 150 °C for 20, 25 or 30 min, dehulled to separate cotyledons, and pastes were prepared from these. Water extracts were prepared from full fat and defatted flours from roasted and unroasted marama cotyledons. A sensory panel evaluated the sensory attributes of marama pastes and water extracts. Marama water extracts were analysed for total phenolic content, phenolic composition and saponin content. Roasting marama beans for more than 20 min resulted in negative properties such as bitterness. The major extractable phenolic acids present in marama water extracts were gallic and protocatechuic acids which increased as a function of roasting time. Saponin content of the water extracts was in the range of 55 to 63 mg/L. The identified phenolic acids, saponins and other as yet unidentified compounds may contribute to the perceived bitterness.