Industry Insights: Nano Bioplastics
The Nano Approach to Flexible Packaging
While the focus for flexible packaging suppliers has been firmly on sustainability issues as much as performance in recent years, a new generation of packaging technologists is looking at new, and potentially ground breaking, nanomaterials and coatings to create new products.
Nano is showing great promise across a number of areas and is gaining increasing acceptance with regulatory authorities. For example, the European Food Safety Authority (EFSA) approved three nano coatings for use with material in contact with food earlier this year.
Silicon dioxide, titanium nitride and carbon black are all authorized for use in plastic food contact material. Major energy savings can be achieved when making plastics film containing these nano chemicals, up to 38 percent has been claimed.
A spokesman for the Nano Industries association (NIA) says, “These materials can be used by manufacturers of food packaging to improve the properties and characteristics of their products. The benefits these nano materials brings to packaging is to be explored and commercialized by food packaging manufacturers.”
More exotic ideas are also beginning to surface. For example, Nofima is participating in a major EU-financed project in which “active” packaging based on raw materials from shrimp shells improves and conserves food products, and after use, the packaging biodegrades. Called the Chitopack project, the goal is to expand on the positive properties of chitin nano-fiber to development new food packaging.
Project researchers are looking at biodegradable packaging made of chitin and chitosan from shrimp shells that will improve and conserve food products. These are biocompatible, naturally biodegradable polymers, non-toxic and show antimicrobial and UV adsorption characteristics. Used as an integrated part of the packaging, chitosan can have an antibacterial affect on the food. Materials range from hard bioplastic to thin film that can come in direct contact with food products.
Elsewhere, at Michigan Technological University, scientist Jaroslaw Drelich has found a new way to destroy bacterial infections on flexible materials.
His innovation relies on copper, long recognized for its antibiotic properties. Drelich has discovered how to embed nanoparticles of this metal into vermiculite, an inexpensive, inert compound sometimes used in potting soil. If it were incorporated into food packaging materials, it could help prevent a variety of food borne diseases, including listeria and salmonella, according to initial tests.
The copper-vermiculite material mixes well with many other materials, such as plastic, so it could be used in a variety of packaging materials. And because the cost is low – 25 cents per pound at most – it would be an inexpensive, effective way to improve the safety of the food supply, especially fruits and vegetables.
Scientists from ETH Zurich have developed a nanomaterial that protects other molecules from oxidation. Unlike many existing active substances, this antioxidant has a long shelf life, which makes it ideal for industrial applications.
Antioxidants are found in many fruit and vegetable varieties, coffee, tea and red wine and are generally regarded as healthful; they are also used as food additives to preserve items for longer.
The problem in using these antioxidants is that many of these molecules are not actually very stable. Researchers have now developed a special nano antioxidant that is considerably more stable than its conventional counterparts, so it can be stored more easily and is effective in smaller amounts. ETH Zurich's researchers coupled gallic acid with silicon dioxide nanoparticles to stabilize the antioxidant.
In addition, the nano antioxidant is temperature-resistant and could protect food that is pasteurized or polymers that are produced at high temperatures. Conventional antioxidants become inactive at these temperatures.
Refreshingly, not all these developments rely on nanoscience. Symphony Environmental Technologies has developed a range of anti-bacterial and antifungal formulations called ‘d2p’, which can be put into plastic products during manufacturing and will help prevent the spread of infection, it claims. Michael Laurier, Symphony’s CEO says, “d2p is definitely needed in food packaging, as well as other plastic products likely to transfer microbes, such as credit cards.”
Research has shown that reusable grocery bags can become an active microbial habitat and a breeding-ground for bacteria, yeast, mould and coliforms. Similar conclusions reached by the University of Arizona found that consumers almost never wash reusable bags.
d2p (AB) has been successfully tested against more than 50 common organisms, including dangerous bacteria, such as MRSA, e.coli, salmonella and listeria.
While the other formulation, d2p (AF) inhibits the growth of fungi, bacteria, mildew and algae that can cause discoloration, staining and odors. It can also increase the shelf-life of bread and other foods, and reduce the need for preservatives, whilst maintaining the aesthetic and functional properties of plastic products, says the company.
With the reduction in food waste becoming a priority in both developed and emerging economies, it is essential that packaging plays its part in delivering longer shelf-life and anti-bacterial solutions. The advent of nano ingredients and other formulations are making it possible to achieve major improvements that can benefit every part of the supply chain and offer the consumer a better product that lasts longer.
These are just a few examples of how active and intelligent packaging are making a major impact on the way we use our packaging and, hopefully, will improve the public’s perception of its value.
Active & Intelligent Packaging Industry Association (AIPIA)