Abstract:

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.

Key words: slowly digestible starch (SDS), determination condition, influencing factors