Cereal Chem. 70:345-350   |  VIEW ARTICLE

Enzyme-Resistant Starch. II. Influence of Amylose Chain Length on Resistant Starch Formation. R. C. Eerlingen, M. Deceuninck, and J. A. Delcour.

Cereal Chem. 70:345-350. Potato starch amylose was hydrolyzed to varying degrees by incubation with barley beta-amylase for different periods. Determination of reducing sugars and gel-permeation chromatography showed that amylose fractions with different number average chain lengths (DP[n] 40-610) were obtained. Enzyme- resistant starch (RS) was formed from the fractions in aqueous solutions (0.83%, w/v) at 4 C. Under the experimental conditions, the yield of RS increased with DP[n] to plateau values of 23-28% within a region of DP[n] of 100-610. X-ray diffraction showed a B-pattern for all RS samples obtained. The DP[n] of the RS varied only between 1 and 26 and, thus, it is independent of the chain length of the amylose from which it was formed (DP[n] 40-610). The results suggest that RS may be formed by aggregation of amylose helices in a crystalline B-type structure over a particular region of the chain (about 24 glucose units).