【摘要】 为实现快捷、经济的稻米升糖指数(GI)估测，首先以不同直链淀粉含量的水稻品种紫金糯2号、南粳04062、宁西优Y16稻米为研究材料，分析了样品前处理方式、α-淀粉酶和淀粉糖苷酶的添加量及方式等对稻米淀粉水解的影响，明确了稻米淀粉体外消化的适宜前处理方式、α-淀粉酶和淀粉糖苷酶的适宜添加量和方式，进而根据淀粉水解指数和水解率进行了稻米升糖指数的估算。结果表明，稻米升糖指数估算适宜的淀粉体外消化试验方法是0.75 g精米加水煮熟后，人工研棒挤压30下，加pH6.8的磷酸盐缓冲液定容至15 ml,同时加入300 U/ml的α-淀粉酶和50 U/ml的淀粉糖苷酶各1 ml联合水解60 min,通过监测水解液葡萄糖含量动态变化，计算1 h内的淀粉水解指数及1 h的水解率，即可实现稻米升糖指数的估算；9个稻米样本的GI估算结果表明本研究建立的试验方法能实现低GI稻米资源和遗传材料的初步筛选。更多还原

【Abstract】 In order to estimate the glycemic index(GI) of rice quickly and economically, the rice varieties Zijinnuo 2, Nanjing 04062 and Ningxiyou Y16 with different amylose contents were used as the research materials. The effects of sample pretreatment methods, the addition amount and method of α-amylase and amyloglucosidase on the hydrolysis characteristics of rice starch were analyzed. The suitable pretreatment method of rice starch in vitro digestion, the suitable addition amount and method of α-amylase and amyloglucosidase were determined. The GI value of rice was estimated according to the starch hydrolysis index and hydrolysis rate. The results showed that the suitable starch in vitro digestion test scheme for estimating the glycemic index of rice was as follows: 0.75 g of polished rice was boiled with water, then extruded 30 times by artificial stick, and the volume was adjusted to 15 ml with pH 6.8 phosphate buffer. Then, 1 ml 300 U/ml α-amylase and 1 ml 50 U/ml amyloglucosidase were added synchronously to hydrolyze for 60 min. By monitoring the dynamic change of glucose content in the hydrolysate, the GI value of rice could be estimated by the starch hydrolysis index within 1 h and the hydrolysis rate at 1 h. The GI estimation values of nine rice samples indicated that the experimental method established in this study could realize the preliminary screening of low GI rice resources and genetic materials.更多还原