缓慢消化淀粉测定过程中的影响因素分析

Factors Affecting the Determination of Slowly Digestible Starch by the Guraya Method

研究缓慢消化淀粉测定过程中的影响因素,探讨前处理、底物浓度、热处理时间、酶用量以及消化时间对SDS的影响。结果表明,最适的测定条件为:200mg淀粉于50ml试管中,加入15ml磷酸缓冲液(0.5mol/L,pH6.9)和4000U胰淀粉酶,在37℃条件下水浴振荡,水解1h和10h时各取0.5ml水解液,采用DNS法在波长540nm处测定水解液中麦芽糖含量。

The Englyst and Guraya methods developed for the determination of slowly digestible starch （SDS） have been reported frequently. However, compared to the former, the latter can be performed more simply and conveniently in that only pancreatic amylase is adopted in determination. The factors [including pretreatment （defatting or defatting plus protein removal）, substrate concentration, heating duration, enzyme dose and hydrolysis duration] influencing the determination of SDS by the Guraya method were explored by one-factor-at-a-time design in this study. An actual SDS content could be obtained by the following determination procedure： incubating the mixture of 200 mg of starch that could be directly taken to determine without any pretreatment, 15 ml of 0.5 mol/L phosphate buffer at pH 6.9 and 4000 U of pancreatic amylase in 37 ℃ water bath, and then determining the maltose contents in 0.5 ml of 1-h and 10-h hydrolysates at 540 nm by DNS method respectively.