Story by Ottilia Saxl (Nano Magazine) and Douglas K Robinson (teQnode).
Nanotechnology is a technology based on the understanding of what happens at the scale of 10-9 meters, the scale of atoms and molecules, and also the scale at which food, like everything else we see about us, acquires its recognisable properties of flavour, aroma, texture and so on.
There are several key areas where the food industry is particularly working on the development of new techniques, including the following:
Nanotechnology is the basis of many novel and functional foods. For example, food colours, flavours and textures can all be manipulated and altered at the nanoscale.
An important nano technique is encapsulation, which has been derived from the pharmaceutical industry. Encapsulation is critical to the delivery of flavours or nutrients in products tailored to suit consumer preferences or health requirements.
Encapsulation is also used to improve the stability of a mix of ingredients, and to create novel textures and tastes, as well as disguising unpleasant flavours, such as fish oil.
Nanotechnology also has a role to play in altering the colour and flavour of foods. For example, differently ‘twisted’ molecules (the direction of chirality) can determine whether the flavour imparted is ‘lemon’ or ‘orange’.
Another example is the use of mineral nano particles. For those of us that love the taste of salt but are worried about its health implications, nanoparticulate salt gives a salty taste to foodstuffs, but much less is required than if conventionally sized salt grains are used. This has been the subject of much research by Leatherhead Food Research, which is supporting the use of nanoscale salt by food companies in their bid to bring their products in line with daily intake guidelines.
Many foods and beverages contain naturally occurring nanoscale colloidal components (dairy for example), and these components can also be manipulated by food companies to add novelty and/or improve the longevity, taste, flavour and calorific content of their products.
Nano also has a role to play in providing a burst of a specific flavour. At the University of Nottingham, scientists investigating nanoscale aroma release have shown that this ‘flavour burst’ is related to the physical and chemical characteristics of the flavants at the nano and micro scale.
Food processing nanotechnologies also offer many improvements for the food processing industry. One example is in relation to the customisation of emulsions, important in many areas such as sauces, ready-made meals and puddings.
Nanoparticles can also be used as thickeners. Some processing utilises nano-structured, porous membranes to create specific-shape holes that allow the size of, say, oil droplets to be controlled to a very high degree, for example, in emulsification. This enables manufacturers to develop double, triple or even multiple emulsions as the basis for many new products, allowing multiple components to be enclosed in a single oil droplet.
Nanoscale membranes can also provide filtration and purification for air and water, and nano-modified surfaces, coatings and finishes provide antibacterial properties and dirt repellency, all very useful in food preparation.
With regard to safety, nanofilters can also be used to remove toxins such as pesticides. The Dutch company Aquamarijn produces microsieves with fine-tuned nanopores that act as filters for a variety of applications.
The critical need for food safety provides an opening for many new techniques based on nanotechnology. For example, in food preparation areas, nano filters are used to clean the environment, and there are nano-enhanced antibacterial surfaces, while nano coatings on tools and equipment make them sharper, longer lasting and easier to clean.
Novel nanobiosensors, developed by other industries including medicine and defence, can rapidly detect the presence of pathogens, pollutants and toxins in the processing of foods. These tiny sensors are cheap to produce, have high sensitivity, specificity, robustness, reliability and are more easily integrated into food production systems.
They are replacing bit-by-bit, the more expensive and time-consuming analytical methods that involve sending samples to a laboratory.
Nanosens in the Netherlands is already making portable sensing systems for the rapid detection of biological and chemical contaminants in food and other application areas.
There is a large and increasing market for foodstuffs with enhanced vitamin and other supplements, where nano encapsulation can again have a major impact.
Through using encapsulation techniques, nanotechnology enables the production of ‘healthy’ foods such as low-fat dairy and non-dairy oils, low salt and sugar products, and foods that can counteract certain diseases by the incorporation of specific vitamins and minerals, and by making them more easily absorbable in nanoparticulate form.
Other nanoscale phenomena, such as those included within the term ‘colloid science’, are also exploited in nutraceutical and functional food formulations, manufacturing and processing.
A number of companies are active here, for example Nutralease, based in Israel, has created nano-sized concentrates of vitamins E, D, A, K and isoflavones.
The active ingredients in sports drinks need to be absorbed quickly to assist performance and maintain the health of the athlete. These benefits can be achieved by including these ingredients in nanoparticulate form (this is also the way that less soluble medicines are administered).
The kinds of nano techniques used in sports foods and drinks, such as improved bioavailability of vitamins and minerals and encapsulation and release of energy-generating foodstuffs, are also widely used in those drinks that offer a quick ‘kick’, and in certain foods where the release of fats, sugars, proteins, vitamins and minerals can be programmed to suit the activity levels of the consumer.
Advanced Sports Nutrition (ASN) is one company that offers a sports drink with nanoscale ingredients. Its product, HPC – High Performance Creatine ‘uses nanotechnology, and … ingredients that have been scientifically proven to maximise uptake of creatine into muscle cells and also provide optimal hydration and support for maximum performance during exercise and nutrient uptake after exercise’.
Food packaging is an area of the industry where nanotechnology has been most rapidly embraced, as it offers many benefits ranging from improving barrier properties, thus preventing contamination of foodstuffs by specific gases (eg oxygen) or unwelcome scents, to using in-built nano sensors that can detect when perishable contents are spoiling and change colour to warn consumers.
Similarly, ‘smart’ packaging can maintain an internal ambient temperature for longer, increasing the lifespan of the contents.
Some packaging also has antibacterial and sun-blocking properties based on the application of nanotechnology, and nano devices placed in packaging would enable easy tracking of large quantities of product and act as a deterrent to counterfeiters.
Who is monitoring nano in foods? The European Commission (EC) considers that current regulations suffice for nanotechnologies. A review of the Novel Foods Regulation that was designed to ‘allow for safe and innovative foods to reach the European market faster’ and to ‘encourage the development of new types of foods and food production techniques (such as nanotechnologies)’, collapsed in 2011 (29 March).
While the collapse of this amendment wasn’t related specifically to the provisions for nanotechnologies (it was related to genetically modified livestock), the impact of this collapse is that nano-foods remain unregulated and are not subject to European labelling.
In early 2010, the mandatory labelling of nanomaterials in cosmetics came into force. Although in a different sector, it set a precedent that could spread to other sectors.
In April 2012, the US Food and Drug Administration issued guidance documents that address the use of nanotechnology in the food and cosmetics sectors.
Companies are ‘encouraged’ to contact the FDA about nano-enabled food items as they no longer fall under the automatic heading of ‘generally recognised as safe’, as was previously the case.
Without a clear regulatory landscape calibrated to standards, there is limited incentive for industry to invest in developing nano-food innovations. This is in part because of liability issues, but is also due to the risk of being seen as less than cautious by watchdogs and consumer groups, which are already anxious about new food technologies and their safety.
There are significant challenges for the food industry in its adoption of the technology in terms of potential legislative and consumer acceptance hurdles. However, nanotechnology may hold the key to solving many critical issues facing the world’s food supply today. Only time will tell how this technology will continue to develop in the future.
FoodBev Media Ltd 2015