A Research For Influence Of Reaction Condition On Acetylation Of Potato Starch And Its Storage Stability

Experiments are conducted to prepare acetylated starch and determine the influence of pH, reaction temperature, adding speed of acetic anhydride and type of native potato starch on acetyl group. The maximum acetyl group can be gotten if pH is kept between 8.0-8.5, reaction temperature is between 20 to 25℃; and adding speed of acetic anhydride is 40g/hr. Then use different native potato starch can get different quality acetylated starch. Reaction temperature is too low or too high is not well for acetylation. At the same time, quality changes of acetylated starch during storage is also discussed, that is high temperature is not fit for long time storage of acetylated starch. The quality of acetylated starch is not stable during high temperature storage. The peak viscosity decreased and conductivity increased.By HLPC and starch washing experiment, We found degrading of high starch chain and high conductivity during storage is the main reason that cause decreasing of peak viscosity and increasing of gelatinization temperature of acetylated starch.For the stability of acetylated starch decreased during high temperature storage, We improved processing technology by adding some sodium tripolyphosphate after acetylation.Furthermore we introduced manufacture of acetylated starch in industry in this paper.