Cereal Chem 53:282 - 290.  |  VIEW ARTICLE
In Vitro Digestibility of Hydroxypropyl Distarch Phosphate and Unmodified Tapioca Starch.

L. F. Hood and V. G. Arneson. Copyright 1976 by the American Association of Cereal Chemists, Inc. 

Unmodified and modified (hydroxypropyl distarch phosphate) tapioca starches were treated with fungal or pancreatic amylase under experimental conditions designed to simulate in vivo digestion conditions. The effects of gelatinization and retrogradation on enzyme susceptibility were investigated. Hydrolysis and alterations in granule structure were evaluated by quantitative reduction of ferricyanide and scanning electron microscopy, respectively. Ungelatinized starches were hydrolyzed to a greater extent by pancreatic amylase than by fungal amylase. The reverse was true for gelatinized starches. Modification of the starch increased the enzyme susceptibility of the ungelatinized, but decreased the susceptibility of the gelatinized starch. Acid pretreatment and retrogradation had little effect on enzyme susceptibility. The relative degree of hydrolysis of the gelatinized modified to the unmodified starch was similar for the two enzymes preparations, suggesting that either enzyme preparation would be suitable for the estimation of the digestibility of modified starches in vitro. Most of the gelatinized granules were destroyed by pancreatic amylase. Pores were evident in the few granules that remained.