How Nanomaterials Are Affecting the Food Industry March 2014
Subscribe to Insights in Brief to be notified about new Featured Content as it becomes available!
The use of nanomaterials in food is a highly contentious topic, and many people are diametrically opposed to the concept of consuming foodstuffs "tainted" by nanotechnology. The heated debates surrounding this issue are not without precedent. Similar discussions about the use of genetically modified (GM) foods were extremely common in Europe in the 1990s and effectively triggered the demise of the industry before it had the opportunity to take off—despite broad scientific consensus that GM food poses no greater risk to health than does conventional food. However, in the case of GM foods, an interesting dichotomy exists between European and US attitudes: Consumption of GM products in the United States is widespread, and the US Food and Drug Administration makes no distinction between GM and non-GM products. Many opponents of the application of nanoscale materials in the food industry may not realize that many foods already contain materials at the nanoscale. Mayonnaise, for example, is essentially an emulsion of nanoscale particles of fat in water. However, rather than nanomaterials that occur through traditional fabrication methods, the real controversial issues appear to center on the addition of artificial nanomaterials and the use of nanotechnology to engineer beneficial properties in foodstuffs. Apparently the use of nanomaterials as a means of advancing food technology is currently at a crossroads similar to the one that GM food faced in the 1990s, and many factors—including potential benefits, potential risks, and public perception—stand to play an important role in determining the eventual chances of success for what could one day become a multi-billion-dollar industry.
Nanomaterials in Items of Food
Potentially, nanoscale additives to food could bring a raft of benefits. Returning to the example of mayonnaise: Scientists at Leatherhead Food Research in the United Kingdom are researching means by which to fill the nanoscale fat capsules with water—dramatically reducing the fat content of the condiment while simultaneously maintaining its consistency and texture. Other potential applications include the encapsulation of vitamins and mineral supplements that would boost the health benefits of consuming certain foods without having a detrimental effect on taste or nanoscale salt crystals that, as a result of the higher surface area, would give the same taste from significantly lower volumes of overall material—enabling people to cut down their overall salt intake. Some commentators also suggest that nanotechnology could aid in the battle against food shortages—particularly in the developing world. An additional 2 billion mouths to feed by 2050 means that novel food-production methods will be necessary to avert a potential global crisis.
Despite the potential benefits that nanotechnology could bring to the food industry, very few nanomaterials currently find use in food products. Exceptions include coffee creamer (nanoscale silica coatings on the fatty grains prevent their aggregating), titanium dioxide nanoparticles (which find use as a white pigment in a variety of products in the United States), and a methacrylate copolymer (which finds use as a glazing agent in some products). Although not strictly a foodstuff, one product that can contain a variety of nanoscale additives is toothpaste. Nanoparticles of hydroxyapatite—a naturally occurring substance in teeth and bones—coat teeth and fill in cracks. The particles break down when in contact with acidic fluids and thus sacrificially protect the enamel in teeth from attack. The additive is also a source of calcium and phosphate ions that can aid in the remineralization of the surface of teeth. Some manufacturers also add silver nanoparticles—a well-known antibacterial agent—to toothpastes, reducing gum disease and, in turn, bad breath. In sufficiently high concentrations, silver nanoparticles can, however, be highly toxic, and—as a result of tight regulations—their use in toothpaste is not common outside Asia. Nano- and microscale particles of titanium dioxide—a strong white pigment—also find use in some toothpastes. The use of titanium dioxide nanoparticles in foodstuffs is particularly controversial because the nanonparticles offer no real benefits other than color enhancement. Titanium dioxide nanoparticles can accumulate in the small intestine, and although medical practitioners are currently unaware of any adverse health ramifications, the use of nanoparticles in foodstuffs for purely cosmetic reasons is questionable and may not justify the potential risk.
Although nanotechnology is not currently widely in use in the food industry, other routes by which humans can ingest nanoscale materials remain. Nanomaterials are increasingly gaining regulatory approval for use in medical applications. Efficient cancer therapies as well as a variety of novel drug-delivery techniques are just two applications that nanomaterials are currently enabling. These measures, which by necessity must undergo rigorous regulatory procedures, could potentially open the door to more general applications that may be of interest to the food industry. The potential also exists for human ingestion of nanomaterials through the food chain by, for example, the administration of antibiotics to animals or the use of pesticides or fertilizers on crops. Strict regulations must be in place to avoid any potentially harmful or unwanted ingestion of nanomaterials through these routes.
Nanomaterials in Food Packaging
Food packaging is one area in which nanotechnology is already making a significant impact in the food industry. Potential applications of advanced or "smart" packaging range from the advanced—for example, the introduction of packaging that keeps food fresh for longer than does standard packaging or that incorporates sensors that inform users whether the items inside are still fresh—to the less radical—for instance, the use of stronger, lightweight composites that enable an overall reduction of material necessary to package items of food.
SABMiller, the US brewer, incorporates clay nanoparticles into its plastic beer bottles in order to prevent the outgassing of carbon dioxide molecules. In addition to preventing the beer from going flat, the composite material—which is significantly less permeable than standard plastic—also inhibits the ingress of oxygen, which can spoil the beer's flavor. In general, nanoclay-plastic composites are up to 100 times stronger than regular plastics, which means that less material is necessary in the packaging of food. In addition, nanoclay, when embedded into polylactic acid—a biodegradable plastic that finds use in food packaging—causes the material to degrade at a faster rate than do standard biodegradable plastics, helping to regulate a substantial environmental problem.
In July 2013, scientists from Michigan Technological University published their research into a new composite material that could find use in antibacterial food-packaging applications. The team combines copper nanoparticles and vermiculite—an inexpensive, moldable ceramic that already finds use in a wide range of commercial applications—and can incorporate the resulting composite into a variety of standard packaging materials such as cardboard and plastics. The copper nanoparticles supply the antibacterial properties that could, in principle, aid in the prevention of several food-borne diseases and keep food fresh. The lead researcher in the project, Professor Jaroslaw Drelich, aims to commercialize these materials for food-packaging applications through his spin-off company Micro Techno Solutions, although the inexpensive nature of the materials currently in use means that breaking into a well-established market could prove relatively difficult.
Materials such as copper and silver nanoparticles can function as antibacterial agents in food packaging and help inhibit the spread of harmful microbes. However, metallic nanoparticles can also aid in keeping food—specifically fruit—fresh by acting as a catalyst that breaks down ethene gas that ripening fruit produces and that also accelerates the ripening process. In June 2013, Professor Atsushi Fukuoka and coworkers from Hokkaido University published their research into mesoporous silica substrates decorated with platinum nanoparticles, showing that the material can achieve conversion rates of over 99.8% at temperatures as low as 0°C—a previously unheard of result. The efficacy of this material could result in more far-reaching applications than simple food packaging. The removal of ethene from warehouses that store perishable items is an extremely important commercial process, with previous attempts at using biotechnological methods proving prohibitively expensive or ineffective. Professor Fukuoka admits that "the costs in producing the catalysts is a critical issue," but he is currently collaborating with industrial partners to commercialize these catalysts.
Safety concerns, although less pronounced than in the case of nanoscale food additives, persist with food packaging. Most scientific studies conclude that the risk of human exposure through the migration of nanoparticles from packaging to food is minimal. However, public-health bodies tend to promote a cautionary approach. Human exposure is not the only concern. The risks of environmental contamination remain high, and legislators must take into account these risks alongside any perceived benefits when considering approval for the widespread use of these materials. Nanotechnology-enabled food packaging currently finds use in the United States and in other parts of the world. However, it is not available in the European Union—where nanomaterials regulations tend to be significantly stricter.
Conclusions and Implications
Despite massive potential benefits, use of nanomaterials in the traditionally conservative food industry remains limited to a handful of applications. A key factor that will determine the extent to which—if at all—nanotechnology will affect the food industry is public perception of safety and risk. The example of GM food highlights the importance of public perception—an issue that a previous Explorer article explored in depth. The general public will likely have difficulty in accepting "unnatural" nanoscale food additives unless compelling—and risk-free—health benefits exist. Regulatory challenges also pose a large barrier to rapid development within the sector and, indeed, from 2015 onward, all nanomaterial-containing food products for sale in the European Union will have to have clear labels as such. Open dialogue between scientists, key industrial players, and consumers must exist in order to overcome any negative perceptions and enable nanotechnology to fulfill its potential in the food industry.