Bakers Journal

It’s a Nano World

November 5, 2007
By Rob McMahon

A look at nanotechnology’s impact on everything from food packaging to food itself

One of four key areas that nano-technology is predicted to affect within the food industry is develop-ments in food production equipment.

Even at this early stage in the developments of nanotechnology, it appears the field can assist in creating food products, and in developing new forms of food packaging. Major food companies such as Kraft are investing in expensive nanotechnology research (through their research consort-ium Nanotek, formed in 2000), in part for its cost-saving potential. Some findings point to the field’s potential to save money through more effective packaging, and improved manufacturing methods.

Dr. Paul Takhistov, with the department of food science at Rutgers University, said that while the science is not yet at the phase where it can significantly change existing equipment, it can significantly impact product formulation. See the November issue of Bakers Journal for ingredient innovations that have come about through nanotechnology.

One major promise of food nanotechnology, in terms of its usefulness for bakers, is packaging. An article that appeared in Packing Digest found that 44 per cent of nanotechnology is centred on coatings and film layers, and encompasses a variety of features – from self-cleaning coatings to those with thermal protection or that repel micro-organisms, such as bacteria.

In an interview, Dexter Johnson, conference director at Cientifica, outlined five areas where packaging benefits from nano-technology. Nanosensors embedded in packaging can detect pathogens and contaminants, while microbial coating can protect contents from bacteria. Packages can be created with tracking functions that can help producers monitor products as they move through the supply chain, and nano-sized polymer composites – such as the nanoclays Johnson outlined in last month’s article (“The Future Is Now”) – will improve the strength and flexibility of packing materials. Finally, smart and active packaging systems can allow producers to trigger flavour releases at certain times, or under certain conditions.

For example, by manipulating the relationship between packaging and the products it houses, nanotechnology-derived materials can work as catalysts for specific functions, such as formulating new, more effective methods of food preservation. This is done by using nanotechnology as a tool, to generate materials that help catalyze certain reactions. These reactions can be guided to only occur during specific conditions. Instead of aiming to preserve a fully formed product over its entire shelf life, certain compounds would be introduced by triggers, such as opening a package, or when an environment reaches certain levels of temp-erature or humidity.

“You don’t need to have certain compounds [introduced] over the whole shelf-life of a product,” said Dr. Takhistov. “Instead, they could be released when a product is opened – for example, [a bag of] coffee or [package of] fresh-baked bread.”

Along with novel development in the controlled release of beneficial compounds, such as nutraceuticals and anti-microbials in food products, nanotechnology has resulted in the develop-ment of so-called “smart” packaging. This includes everything from smart tagging and labelling to self-venting films, self-opening packages, and freshness indicators. Dr. Takhistov noted that packaging that allows product tracking (RFID) is not nano-
technology. However, nano-sized particles do allow labelling at the atomic level. Sensors can be embedded in the structure of product packaging, rather than simply attached to it.

“Nano-sized labelling particles can be individually used in packing materials,” said Dr. Takhistov.  Packaging could also become more biodegradable through nanotechnology. Making something biodegradable isn’t the direct result of nanotechnology. Instead, nanotechnology can be used to control the compositions of packing materials, such as some made from soy, corn or oil, and be used to direct how molecules from these natural materials are ‘”coerced” into connecting into a specific pattern that leads to a biodegradable material. For example, many producers now use aluminum for products that require a long shelf life. Nanotechnology could apply a thin layer of a clay-based substance onto biodegradable containers that contain almost the same properties of aluminum, but are more environmentally friendly, since they are composed entirely of organic materials.

In the U.K., since June 2004, the Sainsbury’s chain of supermarkets has joined 34 other partners in a four-year, 30 million £, EU-funded project, aimed at developing biodegradable packaging. The SustainPack project – which the group states, is the “biggest research project ever undertaken for paper and board-based (i.e., fibre-based) packaging” – aims to create strong, flexible, sustainable fibre-based packaging that is also cost-effective. In an  interview, project researcher Chris Breen, who is based out of Sheffield Hallam University in the U.K., explained that the project is strongly influenced by the Swedish wood and paper industry, and it is attempting to improve the strength and long-term viability of paperboard, as well as reduce its weight.
“The advantage of fibre-based and renewable packaging is in the ecological aspect,” he wrote. “A polyethylene bottle takes a long, long time to degrade in a landfill, whereas fibres and renewable [materials] can be reprocessed, and when eventually landfilled, will be more readily biodegradable.”
As well as focusing on product strength, flexibility and sustainability, the project has experimented with the use of clay nanoparticles as coatings that improve the barrier properties of non-petroleum based containers made from more renewable polymers, such as polyactic acid. The team has also experimented with coating paper or board materials with barrier layers made from material like starch, chitosan, and gelatin. Sub-projects are also exploring three-dimensional applications (think egg cartons for muffins), and communicative packaging that informs suppliers and consumers about the freshness or authenticity of a product.

Breen explained how the nanotechnology aspects of renewable, biodegradable packaging are important in making the materials more competitive with standard packaging – at present, renewable packaging can’t compete with petroleum-based materials. The project’s newsletter states that its findings aim to reduce supply-chain costs, and add value by enhancing the functionality of fibre-based packaging. However, when asked if fibre-based packaging is more cost-effective than standard packaging, Breen said it depends on where you begins your calculation.

“Petroleum-derived packaging has a heavy carbon footprint, whereas renewables can be reprocessed,” he wrote. “Clearly [when] the petroleum products contain a hefty portion of recycled material, then the gap closes.”

At present, products created from SustainPack are not commercially available, but there will be demonstrator products designed to convey the properties and advantages of renewable packaging, wrote Breen. These include a flexible packaging film for snack products that incorporates a barrier coating, and a relative humidity indicator – perfect for wrapping fresh muffins.

“In the strictest sense, SustainPack isn’t about food, it’s about packaging,” he wrote. “We are not putting nanoparticles into food. We are trying to develop packaging that is [ideally suited] to a selected purpose, and has an ecological advantage, compared to petroleum-derived products.”
Anti-microbial coating is not a major feature of SustainPack’s project, but Breen said that some of the project’s partners are involved in developing that aspect of packaging. The food safety benefits – and concerns – of nanotechnology will be explored in an upcoming issue of Bakers Journal. Stay tuned for more information!

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