Changes to fine structure, size and mechanical modulus of phytoglycogen nanoparticles subjected to high-shear extrusion

Laura Roman; Benjamin Baylis; Karl Klinger; Jondavid de Jong; John R Dutcher; Mario M Martinez

doi:10.1016/j.carbpol.2022.120080

Changes to fine structure, size and mechanical modulus of phytoglycogen nanoparticles subjected to high-shear extrusion

Carbohydr Polym. 2022 Dec 15:298:120080. doi: 10.1016/j.carbpol.2022.120080. Epub 2022 Sep 6.

Authors

Laura Roman¹, Benjamin Baylis², Karl Klinger³, Jondavid de Jong³, John R Dutcher², Mario M Martinez⁴

Affiliations

¹ Center for Innovative Food (CiFOOD), Department of Food Science, Aarhus University, AgroFood Park 48, Aarhus N 8200, Denmark; Department of Physics, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1, Canada.
² Department of Physics, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1, Canada.
³ Mirexus Biotechnologies Inc., 574 Hanlon Creek Boulevard, Guelph, Ontario N1C 0A1, Canada.
⁴ Center for Innovative Food (CiFOOD), Department of Food Science, Aarhus University, AgroFood Park 48, Aarhus N 8200, Denmark; Department of Physics, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1, Canada. Electronic address: mm@food.au.dk.

PMID: 36241319
DOI: 10.1016/j.carbpol.2022.120080

Abstract

This study aims to enhance the understanding of the structure of maize phytoglycogen nanoparticles, and the effect of shear scission on their architecture, radius, stiffness, and deformability. Compared to amylopectin, phytoglycogen had a lower A:B chain ratio, a lower number of chains per B chain, and a much higher number of A_fingerprint chains. Phytoglycogen (M_w = 28.0 × 10⁶ g/mol) was subjected to high-shear extrusion with varying Specific Mechanical Energies (SMEs) using different screw speeds, showing a maximum stable molecular weight M_w of ∼9.31 × 10⁶ g/mol and a particle radius R reduction of 36 %, with a corresponding 20 % increase in the average mass density. Atomic force microscopy force spectroscopy revealed that nanoparticles extruded at the lowest SME (122 Wh/kg) exhibited a 20 % increase in Young's modulus. Higher SME values (up to 488 Wh/kg) resulted in an overall decrease in stiffness without further significant reductions in radius.

Keywords: Chain length distribution; Dendrimer; Molecular radius; Molecular weight; Shear-scission; Young modulus.

MeSH terms

Amylopectin* / chemistry
Elastic Modulus
Microscopy, Atomic Force / methods
Molecular Weight
Nanoparticles* / chemistry

Substances

Amylopectin