The food industry has already incorporated nanomaterials into its products and production processes. Products utilizing nanomaterials and nanotechnology include agricultural seed varieties with in-built pesticides that will release under certain environmental conditions; nanocapsules for altering the nutritional composition, flavor and other attributes of food; and anti-microbial food and beverage packaging for longer-shelf life and food safety. Surfaces with the capability to prevent microbiological contamination (salmonella, listeria, legionnella) are of great interest to the food industry and nanocoatings can enhance sanitary security in food preparation and processing. Applications at different stages of commercial development include:
• Edible inorganic nanocoatings
• Nanosensors for monitoring crop growth
• Nanocoatings for food packaging
• Anti-microbial food packaging
• Nanosilver coated anti-bacterial surfaces
• Nanocomposite barrier polymers
• POSS barrier packaging
• Nanosensors for food and drink packaging to monitor contamination
• Nanoscale freshness indicators
• Nanosensors for pathogen and bacteria detection
• Electronic tongues.
Food packaging
Packaging has an important role to play in food safety with potential applications of nano enabled packaging allow for detection of pathogens and microbial contamination, as well as optimal product quality (ripeness). For many food and beverage products, packaging plays an important role not only in advertising the product, but also in maintaining flavour, texture, shelf life and appearance. We are already witnessing the replacement of traditional packaging with multi-functional intelligent packaging methods to improve the quality of the packaging contents and provide both supplier and consumer information. Nanocomposites have already been commercialized in plastic beer bottles. In food and beverage packaging, organically modified clays dispersed in a nylon-6–polymer matrix greatly improve the dimensional stability and the barrier properties. In beverage packaging, when the layers are delaminated, it increases the effective path length for molecular diffusion and the path becomes highly tortuous to reduce the effect of gas and moisture transmission through the film. Based on the barrier properties, nanocomposite packaging films made in polyethylene terephthalate (PET) have been studied as replacements for conventional polymer films. Honeywell has developed commercial clay–nylon-6 nanocomposite products for drink packaging applications. Mitsubishi Gas Chemical and Nanocor have co-developed nylon-MXD6 nanocomposites with multilayered PET for bottle applications. Toyota Technological Institute is commercializing PLA/layered silicate nanocomposites for packaging materials and also for short-term disposable applications. This is commercially available through Unitika Ltd., Kyoto, Japan. POSS-plastic composites regulate gas permeability and other properties in packaging. POSS packaging exhibits good permeation to CO2 and smoke while providing some barrier to water; Increased shelf life of product, up to 20 days without refrigeration; Increased hydrophobicity eliminates need for drying PA before processing; Reduced viscosity allowing higher throughput of material lowers production costs; Better clarity and surface of film; Better printability; Increased temperature resistance allows for pasteurization and sterilization; Higher yield of film per kilogram of resin relative to cellulose.
Coatings
Nanocoatings have been applied mainly on a trial basis to the food processing industry on food contact surfaces. Companies such as Nanopool have sold their coatings to both food retailers and manufacturers. Nanoscale silver coatings preserve food shelf-life by delaying the development of salmonella, listeria and E-coli. Food safety concerns are a main driver for adoption of anti-microbial and self-cleaning coatings in this area. Regulatory issues and consumer acceptance are likely to be a hindrance at present to adoption. Easy clean nanocoatings have been applied in agribusiness for sanitization processes for facilities and the protection of equipment. Unlike traditional cleaning methods, where chemicals are applied that can be toxic or contaminating, the coating has no or few residual effects in the control of microorganisms, bringing self-cleaning to the substrates and permanent biological control. This allows for significant savings in time, energy, labour and water in the washing and cleaning processes of agriculture, facilitating water flow and preventing the formation of salt and carcareous crust. The process also prevents corrosion and the accumulation of dirt.
Sensors
Nanoscale sensors are increasingly applied for food safety and quality management applications. When incorporated into food packaging, nanosensors can detect chemicals, pathogens and toxins in food; detect allergen proteins to prevent adverse reactions to foods such as peanuts, tree nuts and gluten; and can be printed onto the packaging, where they act as ‘electronic tongues’ or ‘noses’ by detecting chemicals released during food spoilage. Sensors can detect substances in parts per trillion and would trigger a colour change in the packaging to alert the consumer if the food has become contaminated or if it has begun to spoil.
Companies and products
• Amcol International Co-op
NANOCOR® Polymer blended with nanocrystal. www.amcol.com
• Bioni
Bioni CS GmbH has developed an antibacterial coating, Bioni Hygienic that contains silver nanoparticles that destroy mold and mildew, fungi spores, and bacteria on contact for application in food industry facilities and food packages. www.bioni.de
• BioNano International Singapore Pte. Ltd.
BioNano LK6200 is a computerized electrochemical instrument. The company utilizes multi-wall carbon nanotubes as nanosensors/nanobiosensors for detection of trace biological samples in therapeutic drugs and patient samples in the healthcare and bioprocessing industry; presence of genetically-modified foods in the food processing and manufacturing industry; and monitoring of contaminants in the water treatment and environmental monitoring sectors. www.bionano.com.sg
• CONSTAR® International
“Diamond Clear” – nanomaterial blended with polyethylene terephthalate – oxygen scavenger. www.constar.net
• Freshpoint
OnVu relies on the properties of nanoscale pigments that change colour over time and if the temperatures fluctuate. www.freshpoint-tti.com
• Eminate
SODA-LO® is a clean label salt product that enables salt content to be reduced in food without loss of flavour or structure. www.eminate.co.uk
• Green Earth Nano Science, Inc.
The company’s titanium dioxide (TiO2) photocatalyst coating for surface purification in combination with HVAC air purification systems utilizing UV-C ultraviolet light is used for surface and air bio-contamination risks faced by food processing facilities, food transportation and poultry farming. www.greenearthnanoscience.com
• InMat
Produce NanoLok high barrier nanocomposite coatings for food packaging. www.inmat.com
• IOTA NanoSolutions Ltd
IOTA’s proprietary platform technologies allow the transformation of insoluble materials into dry solid formats that form nanodispersions on contact with a range of liquids. The nanodispersions enable the enhanced formulation and performance of insoluble materials in various environments and in so doing address many of the issues that restrict the exploitation of insoluble/poorly soluble active ingredients. www.iotanano.com
• Nano Hygiene Coatings Ltd
The company develops easy-clean and antimicrobial coatings for food and drink, and dairy. www.nanohygienecoatings.co.uk
• NAnutrients
NAnutrients uses wet nanotechnology to encase nano vitamins in molecular water clusters to ensure high effectiveness and quality in their products. This is better than emulsification because changes in the molecular structure of the nano vitamins can occur when they migrate through the liquid. http://nanutrients.com
• Nanopool GmbH
Nanopool GmbH develops SiO2 nanolayering technology (SiO2 = pure glass) coatings for food hygiene applications. Milk-tankers, pigsty units, poultry transporters, wash basins, mirrors, toilets, door handles, taps, shower curtains, baths, work surfaces, cookers, hobs etc. can be treated with a simple wipe or spray in a matter of seconds creating washroom areas which will be bacteria free for at least 6 months. Once treated with this food safe coating, surfaces can be cleaned very easily as the soiling agents will not have adhered to the surface. www.nanopool.eu
• NutraLease, Ltd.
Nano-sized Self-assembled Structured Liquids (NSSL) micelle that encapsulates the target molecule. The Fortified Nano-Vehicles (FNV’s) delivery platform improves bioavailability by releasing the active compound into the membrane between the digestive system and the blood and subsequent absorption into the blood. The NSSL vehicles are viable at a wide range of pH and are thermodynamically stable. NSSL allows alcohol-free formulation of oil-soluble aroma chemicals, oils and nutrition ingredients. www.nutralease.com
• Ripesense
Nanoscale based intelligent sensor label to indicate the ripeness of fruit. www.ripesense.com
• Shiratori NanoTechnology Co.
The company develops nanoscale film and coatings for application in food and hygiene. www.snt.jp
