Comparative Emulsifying Properties of Octenyl Succinic Anhydride (OSA)-Modified Starch: Granular Form vs Dissolved State

PLoS One. 2016 Aug 1;11(8):e0160140. doi: 10.1371/journal.pone.0160140. eCollection 2016.

Abstract

The emulsifying ability of OSA-modified and native starch in the granular form, in the dissolved state and a combination of both was compared. This study aims to understand mixed systems of particles and dissolved starch with respect to what species dominates at droplet interfaces and how stability is affected by addition of one of the species to already formed emulsions. It was possible to create emulsions with OSA-modified starch isolated from Quinoa as sole emulsifier. Similar droplet sizes were obtained with emulsions prepared at 7% (w/w) oil content using OSA-modified starch in the granular form or molecularly dissolved but large differences were observed regarding stability. Pickering emulsions kept their droplet size constant after one month while emulsions formulated with OSA-modified starch dissolved exhibited coalescence. All emulsions stabilized combining OSA-modified starch in granular form and in solution showed larger mean droplet sizes with no significant differences with respect to the order of addition. These emulsions were unstable due to coalescence regarding presence of free oil. Similar results were obtained when emulsions were prepared by combining OSA-modified granules with native starch in solution. The degree of surface coverage of starch granules was much lower in presence of starch in solution which indicates that OSA-starch is more surface active in the dissolved state than in granular form, although it led to unstable systems compared to starch granule stabilized Pickering emulsions, which demonstrated to be extremely stable.

MeSH terms

  • Emulsifying Agents / chemistry*
  • Emulsions / chemistry*
  • Kinetics
  • Microscopy
  • Oils / chemistry
  • Particle Size
  • Starch / analogs & derivatives*
  • Starch / chemistry
  • Succinic Anhydrides / chemistry*

Substances

  • Emulsifying Agents
  • Emulsions
  • Oils
  • Succinic Anhydrides
  • octenyl succinic anhydride-modified starch
  • Starch

Grants and funding

The study was supported by the Crafoord Foundation through the call Research Grants 2014 (Ref. 20140816) to MM, MW, and MR; Vinnova-the Swedish Innovation Agency through the Planning Grant Fall 2014 Marie Curie Incoming (Ref. 2014-0587) to MM, MW, and MR; and Department of Food Technology, Engineering, and Nutrition of Lund University to MM and MW. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.