Agriculture Reference
In-Depth Information
consumers; at present little is known about the extent of the use of nanomaterials in
food packaging, food processing, or food products (Galland and Passoff
2011
). A
concerning fact, given that the human exposure to nanoparticles used in food
industry is guaranteed.
Nanoparticles and other nanoscale materials have different physicochemical
properties (persistence, reactivity, and bioavailability) than their larger-scale coun-
terparts due to their much larger surface areas. Therefore, it is expected that the
toxicity profile of a nanomaterial will differ from that of the bulk counterpart, thus
making it difficult to draw any conclusions from known toxicity profiles; these
changes in toxicity are still being discovered and are poorly characterized (Chaudry
et al.
2008
). In addition, many of the nanomaterials used for improving the food
packaging properties are not considered food additives. For this reason, the toxicity
of any material used for food packaging should be tested at the actual size used for a
particular application, due to the certain human exposure and the potential envi-
ronmental release.
The use of nanotechnology in food and food packaging applications has, there-
fore, given rise to concerns about the plausible ingestion of nanosized additives and
ingredients through food and drinks and the possible hazards to consumer health.
These concerns are based on many scientific studies showing the ability of free
engineered nanoparticles (ENPs) to cross cellular barriers and the fact that exposure
to some forms of nanoparticles induces the formation of oxyradicals and, as a
consequence, produces oxidative damage to the cell (Li et al.
2003
; Donaldson
et al.
2004
). Several studies demonstrated the toxicity of different nanoparticles to
edible plants and their possible implications in the food chain. For example,
nanosilver is proved to be hazardous to different kinds of cells [liver, zebrafish
(Asharani et al.
2011
)], and edible plants (Rico et al.
2011
), producing reduced
biomass in zucchini, cell wall disintegration in onion, and reduced germination and
shoot length in flax or ryegrass. Different nanoparticles with diameters below 40 nm
have been proved to be toxic to different crops (Rico et al.
2011
), i.e., Cu
nanoparticles are toxic to mung bean, wheat, or zucchini; Zn nanoparticles to
radish, rape, ryegrass, lettuce, corn, and cucumber; ZnO nanoparticles to ryegrass,
corn, radish, rape, lettuce, cucumber, zucchini, and soybean; CeO
2
nanoparticles to
alfalfa, tomato, cucumber, maize, and soybean; Al
2
O
3
nanoparticles to maize,
cucumber, carrots, cabbage, and corn; and TiO
2
to maize. Other nanomaterials
like single-walled nanotubes are toxic to rice and tomato, functionalized carbon
nanotubes to lettuce, and multiwalled nanotubes to zucchini, lettuce, and rice (Rico
et al.
2011
).
Due to the safety concerns, governments in different countries have specific
groups regulating the use of products containing nanoparticles for food contact
applications. In the USA, the FDA (Food and Drug Administration) Nanotechnol-
ogy Task Force was formed in August 2006, and their commitment is to determine
regulatory approaches to facilitate the continued development of safe, effective,
and innovative FDA-regulated products that contain nanotechnology materials.
Their first report was published on July 25, 2007 (FDA
2007
), where they decided
not to adopt a precise definition for nanomaterials or nanotechnology, stating that
