Abstract: Three sweet potato starches and three sweet potato flours were assayed to a number of different RVA profiles.Significant difference in viscosities was observed with different RVA operating conditions. The most important factors causingthese variations were the heating rate, the holding time at 95℃, the final holding time and the shear thinning. In addition, the peakviscosities were kept at high level when initial holding time was zero or one minute. Otherwise the maximum peak viscosity wasshown with heating for 4min or 6min. The cooling time and the final temperature were important factors affecting the finalviscosity, but the desired conditions for them were dependent on attributes of instrument. A proposal for RVA procedure ofsweet potato samples is: to hold at least 1min at 50℃, to heat to 95℃ for 4min, to hold at 95℃ for 5.5min, to cool to 50℃ for4min, and to hold at 50℃ for 4min.

Key words: sweet potato, starch, flour, rapid visco-analyser, pasting properties