Mechanical properties of starch-filled alginate gel particles

Ioanna Zafeiri; Akash Beri; Bruce Linter; Ian Norton

doi:10.1016/j.carbpol.2020.117373

Mechanical properties of starch-filled alginate gel particles

Carbohydr Polym. 2021 Mar 1:255:117373. doi: 10.1016/j.carbpol.2020.117373. Epub 2020 Nov 8.

Authors

Ioanna Zafeiri¹, Akash Beri², Bruce Linter², Ian Norton³

Affiliations

¹ School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK. Electronic address: I.Zafeiri@bham.ac.uk.
² PepsiCo International Ltd, 4 Leycroft Rd, Leicester, LE4 1ET, UK.
³ School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.

PMID: 33436205
DOI: 10.1016/j.carbpol.2020.117373

Abstract

The aim of this work was to investigate the mechanical behaviour of alginate-based composite particles. Alginate gel beads with entrapped starch were used as the replicates of storage cells of plant tissue. Beads were formulated using different ratios of both ingredients and were produced using two methods, resulting in particles in the macro- and micro-scale size range. Compression tests revealed an effect of bead size on mechanical properties and a dominant role of the alginate on the material properties. Starch was successfully encapsulated as native granules in the beads and once encompassed, it suffered restricted swelling, up to 45 % of its original size, after undergoing heating. Force versus displacement data were fitted to both an empirical and the Hertz model and Young's modulus was found to increase only with heated starch inclusions. Microscopy was deemed crucial for the interpretation of mechanical measurements.

Keywords: Alginate; Deformation; Encapsulation; Gel beads; Hertz theory; Micromanipulation; Starch; Young's modulus.