|December 2005||National Research Flagship||www.csiro.au|
The art of microencapsulation
To deliver health-giving substances in food it is important that they reach the right part of the body. One way of doing this is through microencapsulation - the packaging of small particles of solid, liquid or gas within a secondary material and delivering them in small particles. Microencapsulation is part of the suite of research initiatives in Food Futures Flagship’s Innovative Processing portfolio.
Consumers may choose to eat food products containing microencapsulated ingredients, which once ingested, move through the body until they reach a targeted area of the gut. At this point the capsules release their contents of healthy ingredients, providing specific health benefits to the target area.
Microencapsulation is now used by formulation scientists to protect sensitive or unpalatable bioactives from harsh external environments. Forms of encapsulation can vary from simple membrane coatings to multiwalled structures or numerous cores within a single walled structure.
Food ingredients have been microencapsulated since the 1930’s when flavours were spray dried using acacia gum as the coating material. Nowadays food ingredients/bioactives are encapsulated to make their handling easier and to improve their stability to food processing conditions, including controlling or sustaining their release when food is processed or eaten. The variety of encapsulated ingredients now includes acids, bases, artificial sweeteners, colourants, preservatives, leavening agents, antioxidants and agents with undesirable odours and tastes. Encapsulated ingredients have been incorporated into cheese processing, spreads, breads, fruit juices, energy bars, baby foods and yoghurt.
Targeted delivery of bioactives
The encapsulated bioactive can be released by external triggers such as pH, temperature, pressure, solvent-activation or by degradation by bacteria in the human gastrointestinal tract. The encapsulant materials that are being used for food applications are limited to natural sources derived from lipids, proteins and carbohydrates. Controlled release of the encapsulated bioactive can be achieved by designing tailor-made materials that can deliver the encapsulated bioactive at a specific site in the gastrointestinal tract.
Recently, research into encapsulation has been examining the potential of controlled release of bioactives which could be used to mitigate the onset of diseases. The successful incorporation of these targeted bioactives will potentially lead to the future development of novel functional foods.
The Food Futures’ research team in Innovative Processing, in conjunction with Food Science Australia, a joint venture of CSIRO and the Victorian Government, is continuing to develop an understanding of the effects of the molecular environment in emulsions on the physical stability and rate of oxidation of emulsified long chain omega-3 polyunsaturated oils. Through the improved understanding about interfaces at the molecular level using techniques, such as Nuclear Magnetic Resonance, the project team will explore and develop application strategies into a range of food systems using microencapsulated omega-3 oils. Development of new food grade encapsulant materials for protection and delivery of water soluble bioactives into foods are also being investigated to widen the range of options available.
|IN THIS EDITION:|
The Food Futures Flagship is a CSIRO initiative and part of the National Research Flagships program that aims to deliver scientific solutions to advance Australia's most important national objectives. One of the largest scientific initiatives ever mounted in Australia, it aligns closely with the Federal Government's National Research Priorities. The initiative brings together our national research resources to deliver breakthroughs in fields ranging from healthcare to light metals and the environment.
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