Role of Protein-Stabilized Interfaces on the Microstructure and Rheology of Oil-in- Water Emulsions - Food Colloids: Self-Assembly and Material Science - page 385

Chapter 26
Role of Protein-Stabilized Interfaces on the
Microstructure and Rheology of Oil-in-
Water Emulsions
Peter J. Wilde, Alan R. Mackie, Michael J. Ridout, Fiona A.
Husband, Graham K. Moates and Margaret M. Robins
INSTITUTE OF FOOD RESEARCH, NORWICH RESEARCH PARK,
COLNEY, NORWICH NR4 7UA, UK
26.1 Introduction
Emulsions have applications as wide ranging as food, pharmaceuticals, oil
production, printing, agrochemicals and photography. They are incorporated
into a broad range of food products, and it is estimated that over 40% of
processed foods contain emulsified oils or fats. The emulsified fat is included to
impart the desired texture, structure and flavour to foods. Nevertheless, dietary
fat intake is a major concern in the Western diet, and it is thought to be a major
contributory factor to increasing levels of obesity and related conditions. The
sensory perception of fat content in emulsions is poorly understood, and
although there are many successful reduced fat products on the market, fat
replacement is still seen as a major challenge in the food industry. Therefore, if
we can understand more fully the fundamental basis of sensory perception of
fat content, we can develop intelligent strategies to control the organoleptic
properties of emulsion-based foods. This study is aimed at trying to understand
the complex relationship between the physico-chemical and organoleptic prop-
erties of oil-in-water (O/W) emulsions.
Proteins are often used to stabilize food emulsions against coalescence, as
they possess unique interfacial properties that can confer high levels of long-
term stability. 1 Proteins are complex, polyionic, amphiphilic macromolecules,
and their unique interfacial properties have been studied for many years. 2,3
Following adsorption at the interface they tend to undergo rearrangement and
aggregation processes to form an immobile, elastic interfacial film. 3 Hence, the
molecular structure of the proteins can strongly influence their interfacial
rheological properties 4,5 and the stability of emulsions and foams. 1,3
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