ACTION PATTERN OF PORCINE PANCREATIC ALPHA-AMYLASE ON HYDROXYPROPYL DERIVATIVES OF MAIZE, WAXY MAIZE AND HIGH AMYLOSE MAIZE STARCHES

Differences in the action pattern of porcine pancreatic .alpha.-amylase during hydrolysis of maize, waxy maize and high amylose maize starches and their hydroxypropyl derivatives were examined by measuring changes in blue value and reducing value during digestion. Among the unmodified starches, the degree of random attack increased in the order waxy maize < high amylose maize < maize. Increasing substitution with hydroxypropyl groups led to increased random attack for both maize and high amylose maize starches. For waxy maize starches random attack increased up to a molar substitution of 0.07 and subsequently declined.