Abstract: Oxidized sweet potato starch was used as the raw material to prepare octenyl succinic anhydride (OSA) modified oxidized sweet potato starch. The effects of OSA amount, pH, temperature and reaction time on degree of substitution (DS) of OSA-modified oxidized sweet potato starch were studied employing response surface analysis. The optimum process conditions determined were as follows: OSA amount 7%, pH 8.40, temperature 40 ℃, and reaction time 10 h. Rapid viscosity analyzer (RVA) analysis showed that the peak viscosity of sweet potato starch decreased after oxidation, and increased after furthermodification with OSA with a positive correlation with DS.

Key words: sweet potato starch, response surface analysis (RSA), octenyl succinate anhydride (OSA)