Effect of the Heat-Moisture Treatment on the Enzymatic Susceptibility of Corn Starch Granules

The influence of hydrothermal treatments on the structural properties and digestibility of water caltrop starch was investigated. Scanning electron microscopy (SEM) showed some small dents on the surface of starch granules for samples treated with heat moisture treatment (HMT), but not for samples treated with annealing (ANN) which generally showed smoother surfaces. The gelatinization temperature of starch was generally increased by hydrothermal treatments, accompanied by a trend of decreasing breakdown viscosity. These results implied the improvement of thermal and shearing stability, particularly for HMT in comparison to ANN. After being cooked, the native and ANN-modified water caltrop starch granules were essentially burst or destroyed. On the other hand, the margin of starch granules modified by HMT and dual hydrothermal treatments remained clear with some channels inside the starch granules. X-ray diffraction revealed that the crystalline pattern of water caltrop starch changed from the CA-type to the A-type and the relative crystallinity reduced with increasing moisture levels of HMT. Results of ANN-modified water caltrop starch were mostly similar to those of the native one. Moreover, water caltrop starch modified with HMT20 and dual modification contained a pronouncedly higher resistant starch content. These results suggested that HMT, ANN, and dual modification effectively modified the functional properties of water caltrop starch.

Download Full-text

Development of resistant corn starch for use as an oral colon-specific nanoparticulate drug carrier

Pure and Applied Chemistry ◽

10.1515/pac-2017-0806 ◽

2018 ◽

Vol 90 (6) ◽

pp. 1073-1084 ◽

Cited By ~ 3

Author(s):

Norul Nazilah Ab’lah ◽

Nagarjun Konduru Venkata ◽

Tin Wui Wong

Keyword(s):

Molecular Weight ◽

Drug Release ◽

Resistant Starch ◽

Corn Starch ◽

Drug Carrier ◽

Scanning Calorimetry ◽

Native Starch ◽

Heat Moisture Treatment ◽

Moisture Treatment

Abstract Starch is constituted of amylose and amylopectin. Debranching of amylopectin converts it into amylose thereby producing resistant starch which is known to be less digestible by the amylase. This study designed resistant starch using acid hydrolysis and heat-moisture treatment methods with native corn starch as the starting material. Both native and processed starches were subjected to Fourier transform infrared spectroscopy, X-ray diffractometry, differential scanning calorimetry and molecular weight analysis. They were nanospray-dried into nanoparticles with 5-fluorouracil as the drug of interest for colon cancer treatment. These nanoparticles were subjected to size, zeta potential, morphology, drug content and in vitro drug release analysis. Heat-moisture treatment of native corn starch enabled the formation of resistant starch through amylopectin debranching and molecular weight reduction thereby enhancing hydrogen bonding between the starch molecules at the amorphous phase and gelatinization capacity. The nanoparticles prepared from resistant starch demonstrated similar drug release as those of native starch in spite of the resistant starch had a lower molecular weight. The resistant starch is envisaged to be resistant to the digestive action of amylase in intestinal tract without the formed nanoparticles exhibiting excessively fast drug release in comparison to native starch. With reduced branching, it represents an ideal precursor for targeting ligand conjugation in design of oral colon-specific nanoparticulate drug carrier.

Download Full-text