Enzymatic digestible starch from pyrodextrinization to control the release of tocopheryl acetate microencapsulation in simulated gut model

High amylose rice starch was modified using a pyrodextrinization process under conditions designed to avoid gelatinization of starch. Rice starch was hydrolyzed with 0.5% HCl and 0.5% citric acid solution at 130 degrees C for 1 h (H1), 2 h (H2), and 3 h (H3) respectively. Hydrolyzed starches (25% moisture content) were then Heat moisture treatment (HMT) at 115 degrees C for 1 h. Pasting properties, swelling power, solubility, crystallinity and in vitro and in vivo starch digestibility were investigated. Pyrodextrinized-HMT rice starch was then used as wall material for tocopheryl acetate encapsulation by spray drying. The encapsulation capacity, microstructure, in vitro releasing property under simulated gastric (SGF) and intestinal fluid (SIF) were measured. Results show an insignificant increased in rapid digestible starch (RDS) after pyrodextrinization. SDS drastically decreased in proportion to the increase in RS content. Blood glucose responses in Wistar rats fed with pyrodextrinized-HMT starch were slower than those fed with native starch. The pyrodextrinized-HMT starch microcapsule showed higher encapsulation capacity, better resistance to in vitro digestibility, prolonged release in SGF but higher release in SIF without changing its crystalline patterns. (C) 2014 Elsevier Ltd. All rights reserved.