Understanding complex emulsions
2nd July 2010
New work from the Institute of Food Research has shown how sugar beet pectin acts as an efficient emulsifier, using a technique that could be used to unravel in the finest detail how such important food ingredients work.
Emulsions are stabilised dispersions of oil droplets in water and are found everywhere, in pharmaceuticals, cosmetics and in a wide range of foods. Emulsions can be stabilised and prevented from separating by emulsifiers: molecules that accumulate at and stabilise the surface of the droplets.
Pectin is a familiar but complex polysaccharide that forms an integral part of plant cell walls. For commercial use pectin is usually derived from waste material in citrus processing and cider making, but pectin extracted from sugar beet pulp is attracting more and more interest because it has unusual emulsifying properties.
Supported by the Biotechnology and Biological Sciences Research Council (BBSRC), Dr Axel Gromer working with Dr Rob Penfold, and Professor Vic Morris and his group at the Institute of Food Research, an Institute of the BBSRC, have probed the molecular basis of sugar beet pectin’s emulsifying properties. At the same time they have been uncovering new ways to learn more about how emulsions themselves work. They have used atomic force microscopy (AFM) to image the structures formed by sugar beet pectin at oil droplet surfaces and, for the first time, to measure directly the effects of these surface structures on the forces between two oil drops in water.
The studies, published in the journal Soft Matter, have revealed new insights into the way droplets in emulsions interact with each other. These techniques allow us to understand how droplets behave when they collide: do they fuse, aggregate or bounce apart, and why? Such understanding underpins the ability to design emulsions with improved quality and to engineer such structures to produce new functional foods with improved nutritional and health benefits.
Notes to Editors:
Reference: Molecular basis of the emulsifying properties of sugar beet pectin studied by atomic force microscopy and force spectroscopy. Axel Gromer, Robert Penfold, A. Patrick Gunning, Andrew R. Kirby and Victor J. Morris DOI: 10.1039/c0sm00089b was published online by Soft Matter on 29th June 2010
More information on AFM and imaging at IFR is available at http://www.ifr.ac.uk/info/science/resources/imaging.htm
The mission of the Institute of Food Research (www.ifr.ac.uk ) is to undertake international quality scientific research relevant to food and human health and to work in partnership with others to provide underpinning science for consumers, policy makers, the food industry and academia. It is a company limited by guarantee, with charitable status, grant aided by the Biotechnology and Biological Sciences Research Council (www.bbsrc.ac.uk ).
BBSRC is the UK funding agency for research in the life sciences. Sponsored by Government, BBSRC annually invests around £450 million in a wide range of research that makes a significant contribution to the quality of life in the UK and beyond and supports a number of important industrial stakeholders, including the agriculture, food, chemical, healthcare and pharmaceutical sectors.
For more information see: http://www.bbsrc.ac.uk