Sweet potato (kumara) tubers of differing colours (orange, red and white) were used to produce tuber flour, a purified starch fraction and an isolated fibre extract. The fractions from each tuber colour were added into a biscuit mixture, and the effects of tuber source and fraction composition were observed in relation to the physico-chemical characteristics of biscuits. Addition of sweet potato flour and fibre fractions to white wheat flour significantly reduced the pasting properties (peak and final viscosity) of the resulting gels by up to seven-fold compared with the control wheat flour gel (as determined by the Rapid Visco Analyser). The addition of sweet potato starch affected the pasting properties of wheat flour-sweet potato starch mixes to a lesser extent. Biscuit texture (force required to cause a biscuit to fracture) was significantly reduced with the incorporation of sweet potato fibre into the biscuit dough preparation, this was linked to a reduction in biscuit thickness and spread ratio. However, the addition of sweet potato flour and starch resulted in biscuits of similar firmness as the control biscuits.

This research drew from social learning and international development literature. The purpose of this community research was to trace the spread and impact of sweetpotato flour in two rural communities in Papua New Guinea. Research strategy was participatory learning and action utilizing participatory mapping. The paper mapping process was documented using a video recorder and field notes. Geographic Information Systems technology was then used to incorporate local spatial knowledge on scale maps to show spread of knowledge. The main finding was the identification of social networks through tracking of sweetpotato knowledge: identifying who used the knowledge and whether there were any modifications, the location of those who used the knowledge and whether this was shared and with whom. Most significant was the enabling factors that strengthened existing and potential future networks. Community leadership styles determine success of development projects. Rural communities are diverse needing participatory multi-layered methodologies that are people oriented for agricultural technologies to be learnt and utilized for improved livelihood.