Acid hydrolysis of amylose granules and effect of molecular weight on properties of ethanol precipitated amylose nanoparticles

• Published in: Carbohydrate polymers Vol. 252; p. 117243
• Main Authors: Yan, Xiaoxia, Wei, Hongyuan, Kou, Lvheng, Ren, Lili, Zhou, Jiang
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 15-01-2021
• Subjects: Acid hydrolysis; Amylose; Amylose - chemistry; Chemical Precipitation; Ethanol - chemistry; Hydrochloric Acid - chemistry; Hydrolysis; Molecular Weight; Nanoparticles; Nanoparticles - chemistry; Nanoprecipitation; Viscosity; Nanoparticles; Acid hydrolysis; Amylose; Nanoprecipitation; Molecular weight
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2020.117243

•Amylose granules were hydrolyzed with HCl for various periods of time.•Molecular weight of the acid hydrolyzed amylose was characterized.•Amylose nanoparticles (ANPs) were prepared by precipitation using hydrolyzed granules.•Short chain sugars derived from the acid hydrolysis were not incorporated into the ANPs.•Size and crystallinity of the ANPs depended on the longer residual amylose chains.
Amylose granules hydrolyzed with 2 M hydrochloric acid for various periods of time were used to prepare amylose nanoparticles through ethanol precipitation. Value of dextrose equivalent, viscosity average molecular weight and molecular chain length distribution of the acid hydrolyzed amylose granules were determined. The precipitated amylose nanoparticles were characterized by using dynamic light scattering and X-ray diffraction. Results showed that, after 48 h acid hydrolysis, viscosity average molecular weight of amylose decreased from 3.35 × 105 to 0.336 × 105 and the amylose macromolecular chains with DP > 1000 were cut into short ones. The short chain sugar molecules derived from the acid hydrolysis were not involved in the ethanol precipitation or incorporated into the precipitated amylose nanoparticles. The length and quantity of the residual amylose macromolecular chains after the acid hydrolysis were the main factors to influence size and crystallinity of the precipitated amylose nanoparticles.