Nanotechnology in the Food Industry Food Packaging Biola Ige BE 2352 October 29th, 2012
Definitions • What is Nanotechnology? • Nanotechnology in the Food Industry • Food Growth • Food Processing • Food Packaging
Outline: Nanotech in Food Packaging • Major research areas • Benefits and Risks • Projections for the future
Nanotechnology in Food Packaging Currently 4 major Areas of Research • Polymer-Clay Nanocomposites • Films with Embedded Enzymes • Silver-based Nanocomposites • Nanosensors
Polymer-Clay Nanocomposites • Definitions • Nanocomposites • Polymer Nanocomposites • Current uses in other applications Structure of a nanocomposite
Polymer-Clay Nanocomposites • Structure • Preparative Methods • Monomer Intercalation Method • Monomer Modification Method • Covulcanization Method • Common Solvent Method • Polymer Intercalation Method • Types of Polymers Used • Nylon • Polyolefin • Plant Oil • Polypropylene Different types of a nanocomposite
Films with Embedded Enzymes Plastic covers that could improve shelf life by “scavenging” oxygen from within a package, which would slow oxidation and inhibit bacteria growth. • Glucose Oxidase/Catalase Food covers that would degrade or be recyclable and therefore be better for environment than the plastic covers currently in circulation. • Embedded enzymatic degradation: Control of the lifetime of a material through embedding an enzyme in the film Layers of a film with embedded enzymes • Only petroleum based materials such as polyethylene or propylene can be used as barriers
Films with Embedded Enzymes The absorption is described as being initially diffusion controlled for a short time followed by thin-layer sorption and capillary condensation. The calculation of permeability constant for multilayered films is performed using: Where PT = Total permeability lT= Total polymer thickness ln= Thickness of the individual layer Pn= Permeability of individual layer D = Diffusion tL = time lag value in seconds D0 = Preexponential factors Ed = Diffusion activation energy R = Gas Constant T = Temperature in K PT = And diffusion is determined by: ,
Silver-Based Nanocomposites • Synthesis procedure • Consists of: • Modification of the polyol process • Two lithographic methods • A negative resist based on PVA • A positive UV resist • Chemical synthesis of colloidal NPs • Silver Nanoparticles • Biogenic Magnetite Nanoparticles isolated from magnetotactic bacteria • Polymer ex. Chitosan Example of a silver-based nanocomposite The prepared nanocomposites reveal increased bactericidal and antifungal activity and have also been proven to kill microorganisms, including several pathogens.
Nanosensors A nanosensor is a chemical or physical sensor constructed using nanoscale components, usually microscopic/submicroscopic in size. Passive nanosensors These are nanosensors that rely on observation of a change in color, opacity or fluorescence Active nanosensors These are nanosensors that have the ability to send signals which could be received remotely Different types of nanosensors It could also be a sensor that will detect the presence of nanomaterials or molecules in the nm size range or smaller.
Risks and Benefits • Nanosensors could be used as contamination sensors, detecting when food is bad and changing the color of the packaging • Silver-Based nanocompositeswould act as antimicrobial packaging • Food would last longer as the film with embedded enzymes would take away the O2 disallowing growth • Polymer-clay composites provide a barrier that would seal CO2 and N2 and keep out O2. keeping food fresh for longer. • Since the field is relatively new, there are no specific regulations controlling the research • Despite the fact that nanocomposites change fundamentally when combined, the regulations treat the components as a sum of its parts which could be harmful to the intended consumer • Nanoparticles tend to accumulate and persist in human tissues, to unknown effect
Future Projections • For films with embedded enzymes: By changing the parameters, it might be possible to further tune bioresorption rates of enzyme-embedded biomaterials making it the nanoparticles easier to digest. • Thanks to Nanosensors, we may get used to seeing entire packages change color if the product inside got too warm at some point in the supply chain, making spotting damaged food easier and less expensive. • Polymer-clay nanocomposites may lead to high-performance bio-based or even edible packaging, reducing waste and helping the environment The future
Conclusion As is evident, nanotechnology offers tremendous opportunities for innovative developments in food packaging. However, it also has applications in medicine such as stem cell and cancer cell research, applications in industry such as making stronger and lighter materials for cars and planes, and really just about everything – food processing, micro labeling, etc. Proponents say that Nanotechnology is THE technology of the future.