Nanotechnology in Foods - Nanotechnologies in Food and Agriculture - page 13

• “Intelligent” or “smart” food packaging incorporating nanosensors for sensing
and signaling of microbial and biochemical changes, release of antimicrobials,
antioxidants, enzymes, flavors, and nutraceuticals to extend shelf life
• Biodegradable polymer-nanomaterial composites by introduction of inorganic
particles, such as clay into the biopolymeric matrix and can also be controlled
with surfactants that are used for the modification of layered silicate (Alfadul
and Elneshwy 2010 ; Sozer and Kokini 2009 ; Chaudhry et al. 2008 ; Miller and
Senjen 2008 ; Brody 2007 ; Doyle 2006 ; Joseph and Morrison 2006 ; Lopez-Rubio
et al. 2006 ).
• Edible nano coating materials that improve the storage life and quality of food
products

1.9.1 Improved Packaging

Nanoparticle-reinforced materials termed as nanocomposites are polymers
reinforced with small quantities (up to 5 % by weight) of nanosized particles and
have been developed. These nanocomposites have high aspect ratios and are able to
improve the properties and performance of the polymer. Polymer composites with
nanoclay are among the first nanocomposites available in the market as improved
materials for food packaging. Nanoclay with natural nanoscaled layer structure
restricts the permeation of gases. Nanoclay-polymer composites have been made
from a thermoplastic polymer reinforced with nanoparticles of clay which include
polyamides (PA), nylons, polyolefins, polystyrene (PS), ethylene-vinyl acetate
(EVA) copolymer, epoxy resins, polyurethane, polyimides, and polyethylene tere-
phthalate (PET). Commercially, a number of nanoclay-polymer composites are
available. Known applications of nanoclay in multilayer film packaging include
bottles for beer, edible oils, and carbonated drinks and films (Chaudhry et al. 2008 ;
Brody 2007 ). Examples of available nanoclay composites include Imperm ® (from
Nanocor ® Inc.), Aegis ® X (Honeywell), Durethan ® KU2-2601 (Bayer AG), Plastic
beer bottles, Miller Brewing Co. (USA), and Hite Brewery Co. Nanoparticle com-
posites include DuPont Light Stabilizer 210, Durethan ® , and Bayer sshaving

(Scrinis and Lyons 2007 ;Chaudhryetal. 2008 ; Sozer and Kokini 2009 ; Miller and
Senjen 2008 ). The use of nanocomposites in food contact material has been approved
by the US Food and Drug Administration (USFDA) (Sozer and Kokini 2009 ).

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1.9.2 Active Packaging

The nanomaterials commercially important are nanosilver and nanozinc oxide for
antimicrobial action, nano-titanium dioxide for UV protection in transparent plas-
tics, nano-titanium nitride for mechanical strength and as a processing aid, and
nanosilica for surface coating in food packaging (Doyle 2006 ; Miller and Senjen