At present there is no internationally agreed definition for nanotechnology but nanoparticles are often defined as having at least one dimension less than 100 nanometers (nm). A nanometer is one thousand millionths of a meter (1x10-9). It is generally accepted that nanotechnology involves the use of nanomaterials (incredibly small particles) that measure between about 1 and 100 nm. For comparison, a water molecule measures 0.3nm which illustrates the fact that particles of this small size are abundant in nature.
Nanotechnology is a science that manipulates materials by controlling their shape and size at the nanoscale. At this scale particles can exhibit new and unusual properties, such as altered chemical reactivity or changed electronic, optical or magnetic behaviour. These nanomaterials have many applications across a range of sectors, from healthcare to construction and electronics. Because nanotechnology covers such a wide range of activities, it is probably more correct to refer to it as ‘nanotechnologies’1,2. Nanotechnologies have the potential to offer promising applications for health, food, consumer products, information technology, energy supply and distribution, water and the environment. However, they may also pose unknown and unpredictable risks3.
So far, they have been used for the design, characterisation, production and applications of structures, devices and systems. For example, carbon nanotubes are molecular-scale tubes of graphitic carbon with exceptional properties. They are among the stiffest and strongest known fibres and have distinctive electrical properties. There are numerous areas of technology where carbon nanotubes are already being used. These include flat-panel displays, scanning probe microscopes and sensing devices4.
Nanotechnology and Food
Nano-sized particles occur naturally in soil, dust, aerosols or volcanic dust, and they are also a by-product of combustion (including burning candles), car tyre erosion and waste processing. They also occur naturally in food, and some traditional food manufacturing processes involve the formation of nano-sized particles. For example, the normal production of ricotta cheese involves allowing whey proteins to accumulate as nano-sized protein molecules. However, it is the potential use of ‘engineered’ nanomaterials that has been identified by scientists as a potential cause for concern due to the current lack of scientific evidence and knowledge about their impact on human health and in the environment.
In 1999, the first commercial nanotechnology laboratory was established and since then scientists have been researching different applications for nanotechnologies. This research has also included applications that might be relevant for use in the food industry. There has been particular interest in finding applications that have the potential to offer benefits to consumers as well as to industry. Ideas being researched include ways of producing foods with the same taste properties but that are lower in fat, salt or sugar; encapsulation of flavours, vitamins and minerals; developing packaging that keeps food fresh for longer, or even packaging that ‘tells’ the customer when the food is no longer safe to eat (by a change in colour), with the aim of reducing food waste. At present, no food products are available in Europe that contain ‘engineered’ nanomaterials and only a few are produced worldwide. For example, in Australia a brand of bread contains nano-capsules of fish oil to provide omega 3 fatty acids. However, it is predicted that over the next five years more food products containing functional nanomaterials will be developed.
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