Study on characteristics and acetic esterification of corn with high amylose starch

Properties and aggregate-state structure of high amylose starch corn were analyzed.The results indicated that many of the amylose starch granules assume anomaly shape,the surface is not smooth,with all kinds of tubers and many small bores with the diameter from 20 nm to 200 nm.The spectra of X-ray diffract revealed that its crystal is B type and the value is about 18%,far lower than that of ordinary maize starch.With the method of chemistry modification,we modified the amylose starch with acetates.The result showed that the best reaction condition was at the ratio of 1∶5.3(glucose∶acerbity),with MSA 1.5%(m/m) catalyzer,at 75℃ for 3 h.Under this condition,the degree of substitution was 2.84,more than that of the ordinary maize starch with 0.78.At the same time,infrared spectra determination suggests that high amylose starch corn may be used for producing biology function material.