Optimization of Englyst Method for Determination of Starch Digestibility of Japonica Rice Based on AOAC Method

It is of great significance to study a rapid and accurate method for determining the digestion characteristics of japonica rice starch. Taking japonica rice starch as the research object and the determination results of AOAC method (AOAC Official Method 2002.02) as the standard, the test conditions of Englyst method were optimized to obtain a determination method, which was suitable for the digestion characteristics of japonica rice starch. The accuracy and precision of the determination results were analyzed. When the hydrolysis time was 270 min, the proportion of mixed enzymes was 10:1, the amount of mixed enzyme was AMY (3600 U)+AMG (360 U), the pH of mixed enzyme was 6.0, and the sample was not gelatinized, there was no significant difference between the RS content 2.13%±0.05% measured by the improved Englyst method and that 2.02%±0.06% measured by AOAC method. Compared with the AOAC method, the determination time was adjusted from 16 h of AOAC method to 270 min, the test time was greatly shortened. Compared with Englyst method, the improved method 2.13%±0.05% had good repeatability. Therefore, the improved Englyst method can quickly and accurately determine the digestion characteristics of japonica rice starch.