Effect of ethanol-water solution on the crystallization of short chain amylose from potato starch

摘要

In this study, B-type microcrystalline (BM) starch was prepared by acid hydrolysis and crystallization of native potato starch. Then, BM was used as the raw material to prepare A+V type starch in ethanol-water solution. The effects of the amount of ethanol, the treatment temperature, and the time on the structure of the precipitates were investigated. The optimal conditions to form A+V type starch are 22mL ethanol at 50 degrees C, for 120min. The onset temperature (T-o), the peak temperature (T-p), the conclusion temperature (T-c), and the gelatinization enthalpy (oH) of native potato starch, acid hydrolyzed potato starch (AH), BM type starch, and A+V type starch were estimated by differential scanning calorimetry (DSC). It indicates that the AH starch has a more ordered and stable structure, while the A+V type starch is more difficult to gelatinize. Fourier transform infrared spectroscopy (FT-IR) indicated that the intensities of the main infrared absorption peaks of the A+V type starch were significantly higher than those of the native, AH and BM type starches, although the peak shapes were similar. SEM photos showed that the A+V type starch consisted of a flat structure with irregular edges and small, well-dispersed spherical particles. This study clearly showed that the A+V type starch exhibited weak thermal stability owing to the characteristics of the granules.