Emulsion stabilizing capacity of intact starch granules modified by heat treatment or octenyl succinic anhydride
Article first published online: 7 FEB 2013
© 2013 The Authors. Food Science & Nutrition published by Wiley Periodicals, Inc.
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Food Science & Nutrition
Volume 1, Issue 2, pages 157–171, March 2013
How to Cite
Food Science & Nutrition 2013; 1(2): 117–124
- Issue published online: 14 MAR 2013
- Article first published online: 7 FEB 2013
- Manuscript Accepted: 27 NOV 2012
- Manuscript Revised: 15 NOV 2012
- Manuscript Received: 28 SEP 2012
- Lund University Antidiabetic Food Centre
- Granule size;
- heat treatment;
- OSA modification;
- Pickering emulsion;
- quinoa starch;
- starch granules
Starch granules are an interesting stabilizer candidate for food-grade Pickering emulsions. The stabilizing capacity of seven different intact starch granules for making oil-in-water emulsions has been the topic of this screening study. The starches were from quinoa; rice; maize; waxy varieties of rice, maize, and barley; and high-amylose maize. The starches were studied in their native state, heat treated, and modified by octenyl succinic anhydride (OSA). The effect of varying the continuous phase, both with and without salt in a phosphate buffer, was also studied. Quinoa, which had the smallest granule size, had the best capacity to stabilize oil drops, especially when the granules had been hydrophobically modified by heat treatment or by OSA. The average drop diameter (d32) in these emulsions varied from 270 to 50 μm, where decreasing drop size and less aggregation was promoted by high starch concentration and absence of salt in the system. Of all the starch varieties studied, quinoa had the best overall emulsifying capacity, and OSA modified quinoa starch in particular. Although the size of the drops was relatively large, the drops themselves were in many instances extremely stable. In the cases where the system could stabilize droplets, even when they were so large that they were visible to the naked eye, they remained stable and the measured droplet sizes after 2 years of storage were essentially unchanged from the initial droplet size. This somewhat surprising result has been attributed to the thickness of the adsorbed starch layer providing steric stabilization. The starch particle-stabilized Pickering emulsion systems studied in this work has potential practical application such as being suitable for encapsulation of ingredients in food and pharmaceutical products.