Related Experiment Video
Updated: Sep 2, 2025

Methane Hydrate Crystallization on Sessile Water Droplets
Published on: May 26, 2021
Degradation of corn starch with different moisture content by gaseous hydrogen chloride
Chia-Long Lin1, Jheng-Hua Lin2, Ciao-Ling Pan1
1Department of Food and Nutrition, Providence University, Taichung 43301, Taiwan.
Abstract:
Corn starch, subjected to solid-state degradation using gaseous hydrogen chloride, was characterized to investigate the parameter effects on starch properties and further explore the thermal behavior of inter-crystalline amorphous lamellae of starch. The obtained starch granules exhibited A-type polymorph with 75-98 % recovery (w/w). Degreasing moisture content (6-12 %) with increasing duration (1-8 h) and temperature (25-45 °C) progressively decreased the weight-average degree of polymerization to 55-75 anhydroglucose unit and increased the gelatinization temperature range. However, starch degraded at 6 % moisture and 25 °C exhibited much higher polydispersity index than those degraded at 9-12 % moisture, accompanied by the decreased start but comparable onset gelatinization temperatures. This thermodynamic difference was inherent but diminished gradually with increasing degradation temperature. These findings suggest that the degradation at 9-12 % moisture starts from the bulk amorphous region of starch then sequentially reaches its inter-crystalline amorphous lamellae, while the simultaneous degradation of both regions is for starch with 6 % moisture.
Related Concept Videos
Acid Halides to Carboxylic Acids: Hydrolysis
As shown below, the mechanism involves a nucleophilic attack by water at the carbonyl carbon to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen π bond along with the departure of a halide ion. A final proton transfer step yields carboxylic...
Hydrolysis
Hydrolysis is a chemical reaction in which the addition of water breaks down a polymer into its simpler monomer units. For example, peptides break into amino acids, carbohydrates into simple sugars, and DNA into nucleotides. Enzymes often facilitate these processes.
Hydrolysis Reverses Dehydration Synthesis
Complex carbohydrates can be broken down by breaking the bonds between individual sugar units. The reaction breaks a glycosidic bond as water is added to the compound. The...
Hydration of Cement
Aldehydes and Ketones with Water: Hydrate Formation
The formation of hydrates is a reversible reaction. Hydrate formation is influenced by steric and electronic factors accompanying the alkyl substituents on the carbonyl group: The rate of hydrate formation increases with a decrease in the number of alkyl groups attached to the carbonyl carbon. Hence,...
Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration
Hydrolysis of Chlorobenzene to Phenol: Dow Process

