Properties of biomacromolecules in African-grown rice species

Oryza glaberrima, commonly known as African rice, is a native African domesticated rice and has interesting properties from both a sustainability and a nutritional standpoint. The aim of this study was to compare the properties of starch and proteins of Oryza glaberrima with those of Africa-grown Oryza sativa cultivars, in order to identify the molecular basis of their use in specific food products. Information on the protein pattern was gathered by protein aggregation studies, by electrophoresis, and by assessing the accessibility of specific residues and of specific regions involved in determining the properties of final products. The overall protein structural organization in O. glaberrima is quite different from the one in O. sativa, as proteins in O. glaberrima are organized in highly polymeric forms, mainly stabilized by disulphide bonds. Starch properties were addressed by viscoamilography that highlighted a peculiar pasting behavior, thus suggesting that O. glaberrima cultivars may be suited for the production, among others, of rice-based pasta. The approaches presented here seem able to provide useful insights as for the intrinsic structural characteristics of starch and proteins in this two African rice species.