ENZYMIC DIGESTIBILITY OF MODIFIED STARCHES

Gelatinized unmodified and modified wheat starches were hydrolysed with porcine pancreatic α‐amylase. The digestibility was estimated by increase in reducing power and by decrease in blue value. The digestibility of the starch was considerably reduced by substitution with hydroxypropyl and acetate groups, while crosslinking with phosphate had a lower effect on its digestibility. Etherification with hydroxypropyl groups lowers the digestibility of the starch to a larger extent than esterification with acetate. Substitution with hydroxypropyl and acetate groups increases the degree of random attack by porcine pancreatic α‐amylase on the wheat starch to a larger extent than cross‐linking with phosphate. Copyright © 1979 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim