The current global population is nearly 6 billion with 50% living in Asia. A large proportionof those living in developing countries face daily food shortages as a result of environmental
impacts or political instability, while in the developed world there is a food surplus. For
developing countries the drive is to develop drought and pest resistant crops, which also
maximize yield. In developed countries, the food industry is driven by consumer demand
which is currently for fresher and healthier foodstuffs. This is big business, for example the
food industry in the UK is booming with an annual growth rate of 5.2%1 and the demand for
fresh food has increased by 10% in the last few years.
The potential of nanotechnology to revolutionise the health care, textile, materials.
information and communication technology, and energy sectors has been well-publicised. In
fact several products enabled by nanotechnology are already in the market, such as antibacterial
dressings, transparent sunscreen lotions, stain-resistant fabrics, scratch free paints
for cars, and self cleaning windows. The application of nanotechnology to the agricultural
and food industries was first addressed by a United States Department of Agriculture
roadmap published in September 2003.2 The prediction is that nanotechnology will
transform the entire food industry, changing the way food is produced, processed, packaged,
transported, and consumed.
Nanotechnology in Agriculture
Nanotechnology has the potential to revolutionize the agricultural and food industry withnew tools for the molecular treatment of diseases, rapid disease detection, enhancing the
ability of plants to absorb nutrients etc. Smart sensors and smart delivery systems will help
the agricultural industry combat viruses and other crop pathogens. In the near future
nanostructured catalysts will be available which will increase the efficiency of pesticides and
herbicides, allowing lower doses to be used. Nanotechnology will also protect the
environment indirectly through the use of alternative (renewable) energy supplies, and
filters or catalysts to reduce pollution and clean-up existing pollutants.
An agricultural methodology widely used in the USA, Europe and Japan, which efficiently
utilises modern technology for crop management, is called Controlled Environment
Agriculture (CEA). CEA is an advanced and intensive form of hydroponically-based
agriculture. Plants are grown within a controlled environment so that horticultural practices
can be optimized. The computerized system monitors and regulates localised environments
such as fields of crops. CEA technology, as it exists today, provides an excellent platform for
the introduction of nanotechnology to agriculture. With many of the monitoring and control
systems already in place, nanotechnological devices for CEA that provide “scouting”
capabilities could tremendously improve the grower’s ability to determine the best time of
harvest for the crop, the vitality of the crop, and food security issues, such as microbial or
chemical contamination.
Precision Farming
Precision farming has been a long-desired goal to maximise output (i.e. crop yields) whileminimising input (i.e. fertilisers, pesticides, herbicides, etc) through monitoring
environmental variables and applying targeted action. Precision farming makes use of
computers, global satellite positioning systems, and remote sensing devices to measure
highly localised environmental conditions thus determining whether crops are growing at
maximum efficiency or precisely identifying the nature and location of problems. By using
centralised data to determine soil conditions and plant development, seeding, fertilizer,
chemical and water use can be fine-tuned to lower production costs and potentially increase
production- all benefiting the farmer.8 Precision farming can also help to reduce agricultural
waste and thus keep environmental pollution to a minimum. Although not fully implemented
yet, tiny sensors and monitoring systems enabled by nanotechnology will have a large
impact on future precision farming methodologies.
One of the major roles for nanotechnology-enabled devices will be the increased use of
autonomous sensors linked into a GPS system for real-time monitoring. These nanosensors
could be distributed throughout the field where they can monitor soil conditions and crop
growth. Wireless sensors are already being used in certain parts of the USA and Australia.
The union of biotechnology and nanotechnology in sensors will create equipment of
increased sensitivity, allowing an earlier response to environmental changes. For example:
• Nanosensors utilising carbon nanotubes12 or nano-cantilevers13 are small enough to trap
and measure individual proteins or even small molecules.
• Nanoparticles or nanosurfaces can be engineered to trigger an electrical or chemical
signal in the presence of a contaminant such as bacteria.
• Other nanosensors work by triggering an enzymatic reaction or by using nanoengineered
branching molecules called dendrimers as probes to bind to target chemicals
and proteins.14
Ultimately, precision farming, with the help of smart sensors, will allow enhanced
productivity in agriculture by providing accurate information, thus helping farmers to make
better decisions.
Smart Delivery Systems
The use of pesticides increased in the second half of the 20th century with DDT becomingone of the most effective and widespread throughout the world. However, many of these
pesticides, including DDT were later found to be highly toxic, affecting human and animal
health and as a result whole ecosystems. As a consequence they were banned. To maintain
crop yields, Integrated Pest Management systems, which mix traditional methods of crop
rotation with biological pest control methods, are becoming popular and implemented in
many countries, such as Tunisia and India.
In the future, nanoscale devices with novel properties could be used to make agricultural
systems “smart”. For example, devices could be used to identify plant health issues before
these become visible to the farmer. Such devices may be capable of responding to different
situations by taking appropriate remedial action. If not, they will alert the farmer to the
problem. In this way, smart devices will act as both a preventive and an early warning
system. Such devices could be used to deliver chemicals in a controlled and targeted
manner in the same way as nanomedicine has implications for drug delivery in humans.
Nanomedicine developments are now beginning to allow us to treat different diseases such
as cancer in animals with high precision, and targeted delivery (to specific tissues and
organs) has become highly successful.
Technologies such as encapsulation and controlled release methods, have revolutionised the
use of pesticides and herbicides. Many companies make formulations which contain
nanoparticles within the 100-250 nm size range that are able to dissolve in water more
effectively than existing ones (thus increasing their activity). These can be easily incorporated in various media such as gels, creams, liquids etc, and have multiple applications for preventative measures, treatment or preservation of the harvested product.
One of the world’s largest agrochemical corporations, Syngenta, is using nanoemulsions in
its pesticide products. Another encapsulated product from
Syngenta delivers a broad control spectrum on primary and secondary insect pests of cotton,
rice, peanuts and soybeans. the encapsulated product “gutbuster” only breaks open to release its contents when it comes into contact with alkaline environments, such as the stomach of certain insects.
In other areas, scientists are working on various technologies to make fertiliser and pesticide
delivery systems which can respond to environmental changes. The ultimate aim is to tailor
these products in such a way that they will release their cargo in a controlled manner (slowly
or quickly) in response to different signals e.g. magnetic fields, heat, ultrasound, moisture,
etc.
New research also aims to make plants use water, pesticides and fertilizers more efficiently,
to reduce pollution and to make agriculture more environmentally friendly. Smaller
companies are forming alliances with major players such as LG, BASF, Honeywell, Bayer,
Mitsubishi, and DuPont to make complete plant health monitoring systems in the next 10
years using nanotechnologies.
Other Developments in the Agricultural Sector due to
Nanotechnology
Agriculture is the backbone of most developing countries, with more than 60% of the
population reliant on it for their livelihood. As well as developing improved systems for
monitoring environmental conditions and delivering nutrients or pesticides as appropriate,
nanotechnology can improve our understanding of the biology of different crops and thus
potentially enhance yields or nutritional values. In addition, it can offer routes to added
value crops or environmental remediation.
Particle farming is one such example, which yields nanoparticles for industrial use by
growing plants in defined soils. For example, research has shown that alfalfa plants grown
in gold rich soil, absorb gold nanoparticles through their roots and accumulate these in their
tissues. The gold nanoparticles can be mechanically separated from the plant tissue
following harvest.
Nanotechnology can also be used to clean ground water. The US company Argonide is using
2 nm diameter aluminium oxide nanofibres (NanoCeram) as a water purifier. Filters made
from these fibres can remove viruses, bacteria and protozoan cysts from water.
Research at Lehigh University in the US shows that an ultrafine, nanoscale powder made
from iron can be used as an effective tool for cleaning up contaminated soil and
groundwater- a trillion-dollar problem that encompasses more than 1000 still-untreated
Superfund sites (uncontrolled or abandoned places where hazardous waste is located) in the
United States, some 150,000 underground storage tank releases, and a huge number of
landfills, abandoned mines, and industrial sites. The iron nanoparticles catalyse the
oxidation and breakdown of organic contaminants such as trichloroethene, carbon
tetrachloride, dioxins, and PCBs to simpler carbon compounds which are much less toxic.
This could pave the way for a nano-aquaculture, which would be beneficial for a large
number of farmers across the world.
Nanotechnology in the Food Industry
The impact of nanotechnology in the food industry has become more apparent over the last
few years with the organization of various conferences dedicated to the topic, initiation of
consortia for better and safe food, along with increased coverage in the media. Several
companies which were hesitant about revealing their research programmes in nanofood,
have now gone public announcing plans to improve existing products and develop new ones
to maintain market dominance. The types of application include: smart packaging, on
demand preservatives, and interactive foods. Building on the concept of “on-demand” food,
the idea of interactive food is to allow consumers to modify food depending on their own
nutritional needs or tastes.
The definition of nanofood is that nanotechnology techniques or tools are used during
cultivation, production, processing, or packaging of the food. It does not mean atomically
modified food or food produced by nanomachines. Although there are ambitious thoughts of
creating molecular food using nanomachines, this is unrealistic in the foreseeable future.
Instead nanotechnologists are more optimistic about the potential to change the existing
system of food processing and to ensure the safety of food products, creating a healthy food
culture. They are also hopeful of enhancing the nutritional quality of food through selected
additives and improvements to the way the body digests and absorbs food. Although some
of these goals are further away, the food packaging industry already incorporates
nanotechnology in products.
Packaging and Food Safety
Developing smart packaging to optimise product shelf-life has been the goal of many
companies. Such packaging systems would be able to repair small holes/tears, respond to
environmental conditions (e.g. temperature and moisture changes), and alert the customer
if the food is contaminated. Nanotechnology can provide solutions for these, for example
modifying the permeation behaviour of foils, increasing barrier properties (mechanical,
thermal, chemical, and microbial), improving mechanical and heat-resistance properties,developing active antimicrobic and antifungal surfaces, and sensing as well as signalling microbiological and biochemical changes.
Research by the financial firm Frost and Sullivan, found that today’s consumers demand much more from packaging in terms of protecting the quality, freshness and safety of foods, as well as convenience. They conclude that this is one of the main reasons behind the increased interest in innovative methods of packaging.
Bayer Polymers has developed the Durethan KU2-2601 packaging film, which is lighter,
stronger and more heat resistant than those currently on the market. The primary purpose
of food packaging films is to prevent contents from drying out and to protect them from
moisture and oxygen. The new film is known as a “hybrid system” that is enriched with an
enormous number of silicate nanoparticles. These massively reduce the entrance of oxygen
and other gases, and the exit of moisture, thus preventing food from spoiling.
Breweries would ideally use plastic bottles to ship beer, as these are lighter than glass and
cheaper than metal cans. However, alcohol in beer reacts with the plastic used for the
bottles, severely shortening shelf-life. Voridan, in association with Nanocor, has developed a
nanocomposite containing clay nanoparticles, called Imperm. The resultant bottle is both
lighter and stronger than glass and is less likely to shatter. The nanocomposite structure
minimises loss of carbon dioxide from the beer and the ingress of oxygen to the bottle,
keeping the beer fresher and giving it up to a six-month shelf life.
Other organizations are looking at ways in which nanotechnology can offer improvements in
sensitivity or ease by which contamination of food is detected. For example, AgroMicron has
developed the NanoBioluminescence Detection Spray which contains a luminescent protein
that has been engineered to bind to the surface of microbes such as Salmonella and E. coli.
When bound, it emits a visible glow, thus allowing easy detection of contaminated food or
beverages. The more intense the glow is, the higher the bacterial contamination. The
company aims to market the product under the name BioMark and is currently designing
new spray techniques to apply in ocean freight containerized shipping as well as to fight
bioterrorism. In a similar strategy to ensure food safety, EU researchers in the Good Food Project have
developed a portable nanosensor to detect chemicals, pathogens and toxins in food.
The EU-funded BioFinger project, which has the aim of developing “versatile, inexpensive,
and easy-to-use diagnostic tools for health, environmental and other applications”, has
found a different application in food analysis. The device uses cantilever technology, in
which the tip of the cantilever is coated with chemicals allowing it to bend and resonate
when it binds specific molecules (such as those on the surface of bacteria). The BioFinger
device incorporates the cantilevers on a disposable microchip making it small and portable.
Nanotechnology has also found applications in monitoring and tagging of food items. Radio
Frequency Identification (RFID) technology was developed by the military more than 50
years ago, but has now found its way to numerous applications from food monitoring in
shops to improving supply chain efficiency. The technology, which consists of
microprocessors and an antenna that can transmit data to a wireless receiver, can be used
to monitor an item from the warehouse to the consumer’s hands.34 Unlike bar codes, which
need to be scanned manually and read individually, RFID tags do not require line-of-sight for
reading and it is possible to automatically read hundreds of tags a second. Retailing chains
like Wal-Mart, Home Depot, Metro group, and Tesco, have already tested this technology.
The main drawback is the increased production costs due to silicon manufacturing. With the
fusion of nanotechnology and electronics (nanotronics), these tags should become cheaper,
easier to implement and more efficient.
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Globally, many countries have identified the potential of nanotechnology in the agrifood
sector and are investing a significant amount in it. The United States Department of
Agriculture (USDA) has set out ambitious plans to be achieved in the short, medium and
long term, and aims to discover novel phenomena, processes and tools to address
challenges faced by the agricultural sector. Equal importance has been given to the societal
issues associated with nanotechnology and to improve public awareness.
Not only developed countries, Developing countries such as Iran
have also adopted their own nanotechnology programmes with a specific focus on agricultural
applications. The Iranian Agricultural ministry is supporting a consortium of 35 laboratories
working on a project to expand the use of nanotechnology in agro sector.The ministry is
also planning to hold training programs to develop specialized human resources in the field.
They have already produced their first commercial nanotechnology product Nanocid, a
powerful antibacterial product which has potential applications in the food industry. The
product has also widespread applications in the production of various kinds of detergents,
paints, ceramics, air conditioning systems, vacuum cleaners, home appliances, shoes and
garments.
India has allocated 22.6 million USD in its 2006 budget to the Punjab Agricultural
University in Ludhiana, in acknowledgement of its pioneering contribution to the Green
Revolution. Its research on high-yielding crop varieties helped boost food production in the
1960s and new projects include the development of new tools and techniques for the
agriculture industry.
Whatever the impacts of nanotechnology on the food industry and products entering the
market, the safety of food will remain the prime concern. This need will strengthen the
adoption of nanotechnology in sensing applications, which will ensure food safety and
security, as well as technology which alerts customers and shopkeepers when a food is
nearing the end of its shelf-life. New antimicrobial coatings and dirt repellent plastic bags
are a remarkable improvement in ensuring the safety and security of packaged food.
However, there is concern over the use of nanoparticles in food and its manipulation using
nanotechnologies, which has the potential to elicit the same issues raised in the GM debate.
Finally, it may be possible one day to manufacture food from component atoms and
molecules, so-called “Molecular Food Manufacturing”. Already some research groups are
exploring this, but still from a top-down approach, using cells rather than molecules.
Although the practical application of such technology is far into the future, it is expected that
this could allow a more efficient and sustainable food production process to be developed
where less raw materials are consumed and food of a higher nutritional quality is obtained.
