Published on: Mar 3, 2016
Transcripts - Nanotechreport
UNIVERSITY OF AGRICULTURE SCIENCES, GKVK,
DEPARTMENT OF FOOD SCIENCE AND NUTRITION
PG SEMINAR, FSN 651 (0+1)
II SEMINAR 2009-10
Professor and Head
Dept of Food Science and Nutrition
Nanotechnology is old science. It is responsible for determining not
only that biological and non-biological structures measuring less than 100
nm exist but also that they have unique and novel functional applications.
Nanotechnology – “Nano” Greek word, means “Dwarf”. In technical terms,
the world “nano” means 10-9 or one billionth of something. The terms
“Nanotechnology” evolved over the years via terminology drift to mean
“anything smaller than micro technology”. Nanotechnology is the emerging
scientific field of 21st century which involves working with materials and
devices that are at nanoscale level. A nanometer is one billionth of meter
that is about 1/80000 of diameter of human hair or ten times diameter of
hydrogen atom. So this technology manipulates physical, chemical and
biological properties at nanoscale, but at such scales, the ordinary rules of
physics and chemistry no longer apply for instance materials characteristics
such as their color, strength, conductivity and reactivity can differ
substantially between nanoscale and micro scale carbon ‘nanotubes’ are 100
times stronger than steel but six times lighter.
Nanotechnology is hailed as having the potential to increase the
efficiency of energy consumption, to help the clean environment and solve
major health problems. It is said to be able to massively increase
manufacturing production at significantly reduced costs, the products of
nanotechnology will be cheaper, smaller, lighter yet more functional and
require less energy and fewer raw materials to manufacture (Bhat, 2003). In
fact, the National Nanotechnology Initiative (NNI) defines nanotechnology as
“the understanding and control of matter at dimensions of roughly 1 to 100
nanometers, where unique phenomena enable novel applications.” Ideally,
systems with structural features in the nanometer length range could affect
aspects from food safety to molecular synthesis.
Food is nanofood when nanoparticles, nanotechnology techniques or
tools are used during cultivation, production, processing, or packaging of
the food. It does not mean atomically modified food or food produced by
1959: Richard Feynman: Concept of Nanotechnology; lecture “There's
plenty of room at the bottom.”
1974: Norio Tanigutchi: Coined the term “Nanotechnology”. It refers to
precision manufacturing at the scale of nanometers (nm).
1981 – IBM develops Scanning Tunneling Microscope
1985 – “Buckyball” - Scientists at Rice University and University of
Sussex discover C60
1986 – “Engines of Creation” - First book on nanotechnology by K.
Eric Drexler.Atomic Force Microscope invented by Binnig, Quate and Gerbe
1989 – IBM logo made with individual atoms
1991 – Carbon nanotube discovered by S. Iijima
1999 – “Nanomedicine” – 1st nanomedicine book by R. Freitas
2000 – “National Nanotechnology Initiative” launched
Nanotechnology, as a new enabling technique has the potential to
revolutionize agriculture and food systems. Agricultural and food systems
security, disease treatment drug delivery systems, new tools for molecular
and cellular biology, new materials for pathogen detection and protection of
the environment are examples of the important links of nanotechnology to
the science and engineering of agriculture and food systems. Some
overreaching examples of nanotechnology as an enabling technology are:
production processing and shipment of food products can be more secured
through the development and implementation of nanosensors for pathogen
and contaminant detection.
The development of nano-devices can allow historical environmental
records and location tracking of individual shipments. System that provides
the integration of “Smart systems” sensing, localization, reporting and
remote control can increase efficiency and security. Agriculture and food
systems security is of critical importance to homeland security food supply
must be carefully monitored and protected. Nanotechnology holds the
potential of such system becoming a reality, agriculture has long dealt with
improving the efficiency of crop production, food processing, food safety and
First generation-(~2004~2010)-Called as passive nanostructure
generation phase. Focus on basic R & D in nanomaterials Include
nanoparticles, nanopolymer etc.
Second generation: - (~2005 onwards) - called as Active nanostructure
generation phase. It deals with Transistors, amplifiers, sensors, fuel cells,
solar cells. This phase is going on in the laboratory.
Third generation: - (~2012 onwards), this generation will be called as 3
dimensional nanosystem with heterogeneous nanocomponents, aim to
develop robotic devices.
Fourth generation:- (~2018 onwards) In this generation develops
heterogeneous molecular systems. Here we can do nanosurgery inside cell at
Nanoscale Fullerence Co60
1.27 × 107 m 0.22 m 0.7 × 10-9 m
10 millions times smaller 10 millions times smaller
Fig 3 – nanoscale
Range of nano-size particles in foods
Structures Diameter or length (nm)
Casein micelle 60-100
PLA nanosphere 100-300
Source : Trends in Biotechnology, 2009
Stages of Nanofabrcation :
Nanofabrication refers to manufacturing or construction of
nanostructures at least with one dimension in nanometer serge, which
involves two approaches.
1. Top down approach: This means reducing the size of the smallest
structure to the nanoscale
Ex.: Photonics applications in nanoelectronics and nano-engineering.
2. Bottom up: This involves manipulating individual atoms and
molecules into nano-structure and more closely resembles chemistry or
biology (Pabi et al, 2001).
Carbon fullerenes are large, closed caged carbon structures in a
spherical shape. Fullerenes, discovered in 1985, are stable in gas form and
exhibit many interesting properties that have not been found in other
compounds before. Figure 4 is a representation of a C60 Fullerene molecule.
A fullerene is a spherical structure composed of both pentagonal and
hexagonal carbon rings. Fullerenes are considered zero dimensional
quantum structures which exhibit interesting quantum properties. Once
fullerenes were proven to exist, research for other fullerene like structures
led to the discovery of Carbon nanotubes in 1991.
Nanotubes are the one dimensional wire form of a diameter is typically
1 to 5 nanometers, while the length can be in the range of microns. The
society stands to be significantly influenced by carbon nanotubes. The world
already dream of space elevators, hydrogen powered vehicles, artificial
muscles and so on that would be made possible by emerging carbon
nanotube science. The first carbon concentric multiwall nanotubes were
developed in 1991 as byproducts of the formation of fullerenes by the
electric arc technique. But the real breakthrough occurred two year later
when attempts were made to fill the nanotubes with various metals in situ
led to the discovery of single walled carbon nanotubes. Ideally carbon
nanotubes can be considered to be a perfect grapheme sheet to roll it into a
cylinder so that the hexagonal rings if put in contact join coherently, then to
close the tips by two caps, each cap being a hemi-fullerene with the
appropriate diameter. The sidewalls of CNT consist of only hexagonal carbon
rings, whereas the end caps are made of pentagons and hexagons in order
for curvature to exist. Due to the symmetry of the cylindrical tube, CNT have
a discreet number of directions that can form a closed cylinder.
These are used in ideal force sensors in scanning probe microscope
and USED in field emitters on flat panel display for TV or computer
Thermally stable in vacuum up to 2800 ºc Capacity to carry electric
current 1000 better than copper wire. These have twice the thermal
conductivity than diamond. Nanocomputers based on carbon nanotubes
have already been demonstrated.
Fig 4–Nano wires and nano tubes.
Nanoelectromechanical System (NEMS) Sensors
NEMS technology enables creation of ultra small and highly sensitive
sensors for various applications.
The NEMS force sensor shown in the figure is applicable in pathogenic
bacteria detection. The nanosensors to be developed will work on different
types of immunoassays depending on the application. Single modules will be
developed for the detection and quantification of specific contaminants
which can be combined according to users’ requirements. It is planned to
develop on-line systems with suitable software and automated decision
support systems for large industries as well as bench top and/or handheld
devices for small companies with flexible production units.
Fig 5 –Nanosensors for bacteria detection
Why We Use Nanotechnology….?
The texture of food can be changed as food spread ability and stability
improve with nano-sized crystals and liquids for better low fat foods. The
flavour of a food can be changed with bitter blockers or sweet and salty
enhancers. Nano-enhanced bacteria keep oxygen sensitive foods fresher.
Nanotechnology enters the food chain.
The term ‘nanofood’ describes food which has been cultivated,
produced, processed or packaged using nanotechnology techniques Tools
manufactured nanomaterials have been added Eg.nano-ingredients
nanoparticles of iron or zinc, and nanocapsules containing ingredients like
co-enzyme Q10 or Omega 3.Nanotechnology is moving out of the laboratory
and into every sector of food Production Manufactured nanomaterials are
already used in some food products.
Application of nanotechnology:-
Nanotechnology in Agriculture
There are new challenges in this sector including a growing demand for
healthy and safe food an increasing risk of disease; and threats to
agricultural and fishery production from changing weather patterns.
However, creating a bio economy is a challenging and complex process
involving the convergence of different branches of science. Nanotechnology
has the potential to revolutionize the agricultural and food industry with
new tools for the molecular treatment of diseases, rapid disease detection,
enhancing the ability of plants to absorb nutrients etc. Smart sensors and
smart delivery systems will help the agricultural industry combat viruses
and other crop pathogens. In the near future nanostructured catalysts will
be available which will increase the efficiency of pesticides and herbicides,
allowing lower doses to be used. Nanotechnology will also protect the
environment indirectly through the use of alternative (renewable) energy
supplies, and filters or catalysts to reduce pollution and clean-up existing
pollutants. An agricultural methodology widely used in the USA, Europe and
Japan, which efficiently utilizes modern technology for crop management, is
called Controlled Environment Agriculture (CEA). CEA is an advanced and
intensive form of hydroponically-based agriculture. Plants are grown within
a controlled environment so that horticultural practices can be optimized.
The computerized system monitors and regulates localized environments
such as fields of crops. CEA technology, as it exists today, provides an
excellent platform for the introduction of nanotechnology to agriculture.
With many of the monitoring and control systems already in place,
nanotechnological devices for CEA that provide “scouting” capabilities could
tremendously improve the grower’s ability to determine the best time of
harvest for the crop, the vitality of the crop, and food security issues, such
as microbial or chemical contamination.
1.1 Precision Farming:-
Precision farming has been a long-desired goal to maximize output
(i.e. crop yields) while minimizing input (i.e. fertilizers, pesticides, herbicides,
etc) through monitoring environmental variables and applying targeted
action. Precision farming makes use of computers, global satellite
positioning systems, and remote sensing devices to measure highly localized
environmental conditions thus determining whether crops are growing at
maximum efficiency or precisely identifying the nature and location of
problems. By using centralized data to determine soil conditions and plant
development, seeding, fertilizer, Chemical and water use can be fine-tuned
to lower production costs and potentially increase production- all benefiting
the farmer. Precision farming can also help to reduce agricultural waste and
thus keep environmental pollution to a minimum. Although not fully
implemented yet, tiny sensors and monitoring systems enabled by
nanotechnology will have a large impact on future precision farming
methodologies. One of the major roles for nanotechnology-enabled devices
will be the increased use of autonomous sensors linked into a GPS system
for real-time monitoring. These nanosensors could be distributed
throughout the field where they can monitor soil conditions and crop
growth. Wireless sensors are already being used in certain parts of the USA
and Australia. For example, one of the Californian vineyards, Pickberry, in
Sonoma County has installed wifi systems with the help of the IT Company,
Accenture. The initial cost of setting up such a system is justified by the fact
that it enables the best grapes to be grown which in turn produce finer
wines, which command a premium price. The use of such wireless networks
is of course not restricted to vineyards.
The union of biotechnology and nanotechnology in sensors will create
equipment of increased sensitivity, allowing an earlier response to
environmental changes. For example:
• Nanosensors utilizing carbon nanotubes12 or nano-cantilevers13 are small
enough to trap and measure individual proteins or even small molecules.
• Nanoparticles or nanosurfaces can be engineered to trigger an electrical or
chemical signal in the presence of a contaminant such as bacteria.
• Other nanosensors work by triggering an enzymatic reaction or by using
nanoengineered branching molecules called dendrimers as probes to bind to
target chemicals and proteins. Ultimately, precision farming, with the help
of smart sensors, will allow enhanced productivity in agriculture by
providing accurate information, thus helping farmers to make better
1.2 Smart Delivery Systems:-
The use of pesticides increased in the second half of the 20th century
with DDT becoming one of the most effective and widespread throughout the
world. However, many of these pesticides, including DDT were later found to
be highly toxic, affecting human and animal health and as a result whole
ecosystems. As a consequence they were banned. To maintain crop yields,
Integrated Pest Management systems, which mix traditional methods of crop
rotation with biological pest control methods, are becoming popular and
implemented in many countries, such as Tunisia and India. In the future,
nanoscale devices with novel properties could be used to make agricultural
systems “smart”. For example, devices could be used to identify plant health
issues before these become visible to the farmer.
Such devices may be capable of responding to different situations by
taking appropriate remedial action. If not, they will alert the farmer to the
problem. In this way, smart devices will act as both a preventive and an
early warning system. Such devices could be used to deliver chemicals in a
controlled and targeted manner in the same way as nano-medicine has
implications for drug delivery in humans. Nano-medicine developments are
now beginning to allow us to treat different diseases such as cancer in
animals with high precision, and targeted delivery (to specific tissues and
organs) has become highly successful. Technologies such as encapsulation
and controlled release methods have revolutionized the use of pesticides and
herbicides. Many companies make formulations which contain
nanoparticles within the 100-250 nm size range that are able to dissolve in
water more effectively than existing ones (thus increasing their activity).
Other companies employ suspensions of nanoscale particles
(nanoemulsions), which can be either water or oil-based and contain
uniform suspensions of pesticidal or herbicidal nanoparticles in the range of
200-400 nm. These can be easily incorporated in various media such as
gels, creams, liquids etc, and have multiple applications for preventative
measures, treatment or preservation of the harvested product. One of the
world’s largest agrochemical corporations, Syngenta, is using
nanoemulsions in its pesticide products. One of its successful growth
regulating products is the Primo MAXX® plant growth regulator, which if
applied prior to the onset of stress such as heat, drought.
2 Food safety and quality
Nano-biosensors can minimize the time of lengthy microbial testing in
laboratories. Applications include detection of contaminants in water
supplies, raw food materials and food products, plant pathogens in the
crops, its seed materials and animal products. Enzymes can be used as
the sensing materials in nanobiosensors to increase the accuracy and
specificity of the testing. Nanobiosensors, apart from its specificity and
accuracy will be easy to hurdle in the field and remote areas owing to its
Today sensors provide an abundance of information about such
parameters as temperature and weather data and data that provide
information on air, land and sea transportation, chemical contaminants,
deceleration for release of airbags in automobiles and countless other
variables. Biological organisms also have the ability to sense the
environment. Humans sense the environment through sight, touch,
taste, smell and sound. For example, the human ear uses nanostructures
to transduce the macro-motion of ear drum-induced fluid motion into a
chemical/electrical signal2. In living organisms, sensors operate over a
range of scales from the macro (ear drum vibrations) to the micro (nerve
cells) to the nanoscale (molecules binding to receptors in our noses).
The exciting possibility of combining biology and nanoscale technology
into sensors holds the potential of increased sensitivity and therefore a
significantly reduced espouse-time to sense potential problems. Imagine,
for example, a bioanalytical nanosensor that could detect a single virus
particle long before the virus multiplies and long before symptoms were
evident in the plants or animals. Some examples of the potential
applications for bioanalytical nanosensors are detection of pathogens,
contaminants, environmental characteristics (light/dark, hot/cold,
wet/dry), heavy metals, and particulates or allergens. Many significant
challenges remain. For example, while it is likely that we will be able to
detect a single virus or other foreign particle, getting the foreign particle
to the detection point at an opportune time will be a significant challenge.
The panel identified desirable characteristics of biosensors as: small,
portable, rapid response and processing (i.e., real-time), specific,
quantitative, reliable, accurate, reproducible, robust and stable.
3 Food additives:-
Currently, some food additives with nanoingredients (according to
claims by the producers) are being sold in the USA and Germany. These
additives may imply that nanoparticles are present in the food. The
additives are mainly aimed at the diet, sports and health food markets
and contain minerals with a nano-formulation, such as silicon dioxide,
magnesium, calcium, etc. The particle size of these minerals is claimed to
be smaller than 100 nanometre so they can pass through the stomach
wall and into body cells more quickly than ordinary minerals with larger
particle size. Nano-additives can also be incorporated in micelles or
capsules of protein or another natural food ingredient. Micelles are tiny
spheres of oil or fat coated with a thin layer of bipolar molecules of which
one end is soluble in fat and the other in water. The micelles are
suspended in water, or conversely, water is encapsulated in micelles and
suspended in oil. Such nanocapsules can for example contain healthy
Omega3 fish oil which has a strong and unpleasant taste and only
release it in the stomach such as in “Tip Top Up”® bread sold in
3.1 Nano in your sausage :-
NovaSol the solution for meat curing and colour stability”
Industrial sausage and cured meat production requires the addition of
numerous additives to speed up the production process, to stabilize colour
and ‘improve’ taste. German company Aquanova has developed a
nanotechnology-based carrier system using 30nm micelles to encapsulate
active ingredients such as Vitamins C and E and fatty acids which can be
used as preservatives and aids (Aquanova undated). Aquanova markets its
micelles as “NovaSol” and claims that the nanoscale carrier system
increases the potency and bioavailability of active ingredients. The German
industry magazine “Fleischwirtschaft” claims that NovaSol offers
considerable advantages for meat processors: faster processing, cheaper
ingredients, higher colour stability, and ready to use liquid form. These
nanoformulations of these additives have been available to German
manufacturers since 2006. They may be used in an assortment of cured
meats and sausages currently available to European consumers. The failure
to identify nano-ingredients on product labels prevents their tracking.
However it is conceivable that consumers worldwide have been exposed to
these nano-materials through exports. Nanoparticles and particles up to
300nm in size are added to many foods as processing aids.
Nano-encapsulated active ingredients including vitamins and fatty
acids are now sold commercially for use in processing and preservation of
beverages, meats, cheese and other foods (Aquanova undated).
Nanoparticles and particles a few hundred nanometres in size added
intentionally to many foods to improve flow properties (e.g. how well it
pours), colour and stability during processing, or to increase shelf life. For
instance, aluminum-silicates are commonly used as anti-caking agents in
granular or powdered processed foods, while anatase titanium dioxide is a
common food whitener and brightener additive, used in confectionery, some
cheeses and sauces. In bulk form (conventional, larger particle size), these
food additives are usually biologically inert and are considered by regulators
in the European Union and elsewhere to be safe for human consumption.
Dairy products, cereals, breads and beverages are now fortified with
vitamins, minerals such as iron, magnesium or zinc, probiotics, bioactive
peptides, antioxidants, plant sterols and soy. Some of these active
ingredients are now being added to foods as nanoparticles or particles a few
hundred nanometres in size. Colour and stability during processing, To
increase shelf life Aluminum-silicates are commonly used as anti- caking
agents in granular or powdered processed Foods Anatase titanium dioxide is
a common food whitener and brightener additive, used in confectionery,
some cheeses and sauces
4 Food processing:-
Knives and chopping boards can be coated with antibacterial silver
nanoparticles. When products treated with nanosilver are washed,
nanoparticles are released into waste water treatment facilities and can
never destroy beneficial bacteria
4.1 Electronic tongue:-Electronic tongue detecting chemicals
released during food spoilage. It detects chemicals, pathogens, & toxins in
food. Can detect allergen proteins to prevent adverse reaction to foods.
Colour change in the packaging to alert the consumer.
Fig 6- Electronic tongue
5 Food packaging:-
Applications of nanotechnology within the food sector is in packaging
Between 400 and 500 nanopackaging products are estimated to be in
commercial use now, while nanotechnology is predicted to be used in the
manufacture of 25% of all food packaging within the next decade. A key
purpose of nano packaging is to deliver longer shelf life by improving the
barrier functions of food packaging to reduce gas and moisture exchange
and UV light exposure For example, DuPont has announced the release of a
nano titanium dioxide plastic additive ‘DuPont Light Stabilizer 210’ which
could reduce UV damage of foods in transparent packaging . In 2003, over
90% of nano packaging (by revenue) was based on nano-composites, in
which nanomaterials are used to improve the barrier functions of plastic
wrapping for foods, and plastic bottles for beer, soft drinks and juice (PIRA
International cited in Louvier 2006; see Appendix A for products). Nano
packaging can also be designed to release antimicrobials, antioxidants,
enzymes, flavours and nutraceuticals to extend shelf-life
5.1 Edible nano coatings:-
Most of us are familiar with the waxy coatings often used on
apples.Now nanotechnology is enabling the development of nanoscale edible
coatings as thin as 5nm wide, which are invisible to the human eye. Edible
nano coatings could be used on meats, cheese, fruit and vegetables,
confectionery, bakery goods and fast food. They could provide a barrier to
moisture and gas exchange, act as a vehicle to deliver colours, flavours,
mantioxidants, enzymes and anti-browning agents, and could also increase
the shelf life of manufactured foods, even after the packaging is opened.
United States Company Sono-Tek Corp. announced in early 2007 that it has
developed an edible antibacterial nano coating which can be applied directly
to bakery goods; it is currently testing theprocess with its clients
5.2 Chemical release nano packaging:-
Chemical release nano packaging enables food packaging to interact
with the food it contains. The exchange can proceed in both directions.
Packaging can release nanoscale antimicrobials, antioxidants, flavours,
fragrances or nutraceuticals into the food or beverage to extend its shelf life
or to improve its taste or smell. In many instances chemical release
packaging also incorporates surveillance elements, that is, the release of
nano-chemicals will occur in response to a particular trigger event.
Conversely, nano packaging using carbon nanotubes is being developed with
the ability to ‘pump’ out oxygen or carbon dioxide that would otherwise
result in food or beverage deterioration. Nano packaging that can absorb
undesirable flavours is also in development.
Table 2 - Example of chemical release nano packaging under
5.3 Nano-based antimicrobial packaging and food contact material:-
Distinct from trigger-dependent chemical release packaging, designed
to release biocides in response to the growth of a microbial population,
humidity or other changing conditions, other packaging and food contact
materials incorporate antimicrobial nanomaterials, that are designed not to
be released, so that the packaging itself acts as an antimicrobial. These
products commonly use nanoparticles of silver although some use nano zinc
oxide or nano chlorine dioxide. Nano magnesium oxide, nano copper oxide,
nano titanium dioxide and carbon nanotubes are also predicted for future
use in antimicrobial food packaging.
Table 3: Nano-based antibacterial food packaging and food contact
5.4 Nano-sensor and track and trace packaging:-
Packaging equipped with nano sensors is designed to track either the
internal or the external conditions of food products, pellets and containers
throughout the supply chain. For example, such packaging can monitor
temperature or humidity over time and then provide relevant information on
these conditions, for example by changing colour. Companies as diverse as
Nestlé, British Airways, MonoPrix Supermarkets, 3M and many others are
already using packaging equipped with chemical sensors, and
nanotechnology is offering new and more sophisticated tools to extend these
capabilities and to reduce costs (Nanotechnology is also enabling sensor
packaging to incorporate cheap radio frequency identification (RFID) tags
Unlike earlier RFID tags, nano-enabled RFID tags are much smaller, can be
flexible and are printed on thin labels. This increases the tags’ versatility (for
example by enabling the use of labels which are effectively invisible) and
thus enables much cheaper production. Other varieties of nano-based track
and trace packaging technologies are also in development. For instance,
United States company Oxonica Inc has developed nano barcodes to be used
for individual items or pellets, which must be read with a modified
microscope. These have been developed primarily for anti-counterfeiting
purpose). An ingestible nano-based track and trace technology is promised
by pSiNutria, a spin out of nanobiotechnology company pSivida. Potential
pSiNutria products include: “products to detect pathogens in food, for food
tracing, for food preservation, and temperature measurements in food
5.5 Nano biodegradable packaging:-
The use of nanomaterials to strengthen bioplastics (plant-based
plastics) may enable bioplastics to be used instead of fossil-fuel based
plastics for food packaging and carry bags Potential environmental benefits.
Table 4 -Development of nano-composite bioplastics
5.6 Non-stick nano lining for mayonnaise and tomato sauce bottles:-
Promising an end to the need to tap or shake mayonnaise or ketchup
bottles to remove the last of their contents, several German research
institutes, industry partners and the Munich University of Technology have
joined forces to develop non-stick nanofood packaging. The researchers have
applied thin films which measure less than 20nm to the inside surface of
food packaging. They have already developed their first samples, and hope to
release the new packaging commercially in the next 2 – 3 years. The
researchers promote their product as an environmentally friendly solution to
reduce leftover traces of condiments in bottles. However there are concerns
that manufactured nanomaterials are released into the environment from
waste streams or during recycling. This may present a new range of serious
ecological risks. It is therefore possible that such packaging may introduce
more pollution problems than it solves
6. Other applications:-
6.1 Medicine: The biological and medical research exploited the properties
of nano-materials for various applications.
Ex.: Contrast agents for cell imaging and therapeutics for treating cancer.
The field described as
¨ Biomedical nanotechnology
¨ Molecularly engineered biodegradable chemicals for nourishing plant and
protecting against insect.
¨ Genetic improvement for animals and plants.
¨ Delivery of genes and drugs to animals.
¨ Nano-array based technologies for DNA testing
The integration of nano-material with biology has led to the development of
diagnostic devices, contrast agents, analytical tools, and therapy and drug-delivery
6.2 Cancer treatment:-
Golden “nanobullets” are developed that can destroy inoperable
human cancers. The nanobullet consist of Silica shells plated with gold and
when these are heated with infrared light the cancer are destroyed for which
carbon nanotubes have been transported in to cell nucleus and continuous
infrared radiation is made available (Ferrari, 2005).
6.3 Water purification:-
The physical filters with nanometer – scale pores can remove 100% of
bacteria, viruses and even prions. Well structured filter materials and
smaller actuators will allow even the smallest filter elements to be self
monitoring and self cleaning. For the treatment of wastewater, PiO2, ZnO
and SnO2 are used. Nanoparticles are used i.e., these decomposes waste and
toxic pesticides which take a long time to degrade under normal condition.
The identification tags are ultra miniatures used multiplexed
bioassays and general encoding. It contains different fluorescent materials,
that are identified by using UV light and optical microscope are used for
application in DNA hybridization assays. These nanobarcodes are
encodeable, machine readable and durable.
6.4 Toxic gas detection:-
Electronic Nose (E-Nose) is a device mimicking the operation of the
human nose, which uses a pattern of response across on array of gas
sensors to identify different types of odors, estimates the concentration and
its properties. These gas sensors are composed to ZnO2, narowires.
6.5 Solar energy:-
The nanoparticles help in storage, conversion etc. by reducing
materials and process rates, which ultimately helps in energy saving.
Ex. : Thermal insulation and by enhanced renewable energy source.
6.6 Animal husbandry:-
These nano sensors help in alternate uses and better residual
management. It also helps in reduced discharges of pathogens, veterinary
pharmaceuticals, ebtogen and androgens, stored hormones, reduced air
emissions of ammonia methane, hydrogen sulfide and pathogen, water and
I) Animal tracking devices:
Tracking devices used in valuable farm animals or wild life
conversation. The microchips are injected for improving animal welfare and
safety to study the behaviors in the wild life. These microchips act as
nanosensors which are fitted with animals to locate about their health and
geographical location to a central computer.
ii) Microfluidics for breeding animals:
Nano-Eugenics are used to accelerate genetic uniform within livestock
1) DNA nano-vaccines using nano-capsules and ultrasound:-
The mass vaccination of fishes is done by using ultrasound. These
nano capsules containing a short stand of DNA which are added to on fish
pond, where they are adsorbed into the cells of the fish, sound is used to
rupture the capsule and release, the DNA and eliciting immature response
from the fish.
Ex. : Tested on rainbow trout by clear springs foods.
2) Clearing of fish pond:-
Navada based Altair® - Nano-technologies make water clearing products for
swimming pool and fish ponds called nano-checks. There are 40 nm
particles. These absorb phosphates from water and prevent algal growth.
6.7 Food processing and storage:-
The improved plastic film coating for food packaging and storage that
enable a wider and more efficient distribution of food products to remote
areas in less industrialized countries, antimocribial emulsions made with
nano-materials for the decontamination of food equipment, packaging of
food and the nanotech based sensors to detect and identify contamination.
¨ Addition of specific nano-particles to remove the infecting bacteria.
¨ Nano-particles block the bacterial colonization.
Nano-technological antimicrobial and polymer films are used in food safety
Need of agri food inventory:-
A large focus on food packaging and sensing for food borne pathogens
and also focus on retail and consumer application. Generally, more focus on
health, benefits than on environment.
6.7 Drug delivery systems:-
Nanocapsules, dendrimers and bucky balls are made up of carbon atoms
at nanoscale for slow and sustained drug release within the system. This
reduces transportation cost and dosage by improving shelf life,
thermostability and resistance to change in climatic condition.
• Drugs are packed into nanoparticles deliver drugs at targeted parts,
which avoids side affects e.g. fumagillin
• Targeted drug delivery is facilitated by conjugating nanoparticles with
certain binding groups such as monoclonal antibodies or ligands
• Small enough to pass through cell barriers & circulate inside body or
taken up by cells by endocytosis.
6.8 Chemistry and environment:
Chemical catalysts and filtration techniques are two prominent
examples where nanotechnology already plays a vital role. The synthesis
provides a more material with fixed/specific features and chemical
Ex: Nano-particles with a distinct chemical surrounding ligands or specific
6.9 Energy : The most advanced nanotechnology projects related to energy
as storage, conversion, manufacture, improvement by reducing materials
and process rates and energy saving.
Ex: Thermal insulation and by enhanced renewable energy sources.
Main thrust of research in nanotechnology
4. Life science
Risks may pose by nanotechnology:
Nanoparticles are more chemically reactive than larger particles
Nanoparticles have greater access to our bodies than larger particles
Greater bioavailability and greater bioactivity may introduce new
Nanoparticles may have longer term pathological effects
Our bodies’ defensive mechanisms are not as effective at removing
nanoparticles from our lungs, gastro-intestinal tract and organ
Nanoparticles will be more toxic per unit of mass than larger particles
of the same chemical composition.
Nano particles have larger surfaces this makes them susceptible to to
get absorbed in the macromolecules in an animal body. They can
hinder biological processes, thus intervening the functionality of
Since these particles are very small, problem can actually arise from
inhalation of these minute particles.
Fabrication of nanomaterials is very costly method and also very
Atomic weapons are made to be more powerful and more destructive
these can become more accessible with nanotechnology.
Nanocomposite edible films from mango puree reinforced with cellulose
To evaluate the effect of different concentrations of cellulose
nanofibres added as nanoreinforcing component on tensile properties, water
vapor permeability and glass transition temperature of mango puree edible
Materials and Methods:
The mango puree (29% total solids, 27% total soluble solids) and
cellulose nanofibers(CNF) were procured.
An aliquot of the CNF suspension was mixed with an equal volume of
2% urinyl acetate(UA)
A 10 μl drop of the UA fibril mixture was dispensed on to a 400 mess
copper grid allowed to stand for 30 to 60s.
The grid was air dried.
Fiber lengths and widths were directly measured from transmission
Different concentration of CNF were added to the mango puree and
dispersions were homogenized.
A control film was elaborated only with mango puree.
The physical properties Tensile strength, water vapor permeability and
glass transition temperature and elongation at break of the films were
Table 1: Physical properties of mango puree edible films with different
concentration of CNF nano
TS (MPa) EB (%) WVP
0 4.09 44.07 2.66 -10.60
1 4.24 42.42 2.40 -8.51
2 4.42 43.40 2.17 -8.57
5 4.58 41.79 2.16 -7.72
10 4.91 43.19 2.03 -6.81
18 5.54 39.8 1.90 -5.88
36 8.76 31.54 1.67 -6.04
· Cellulose nanofibers were effective in increasing tensile strength
· Elongation at break was not significantly impaired at CNF
concentrations; it decreased when compared to the control.
· CNF was more effective to decrease water vapor permeability (WVP) of
mango puree films
· Although Transition temperature increases have been small with CNF
incorporation, it was significant.
The cellulose reinforcement was well dispersed into the mango puree
The performance of mango puree edible films was noticeably improved
by CNF reinforcement.
Mechanical properties except elongation, were improved by the by the
addition of cellulose nanofibres.
Physical, chemical and microbiological changes in stored
green asparagus spears as affected by coating of silver
To evaluate the effect of a silver nanoparticles-PVP coating
on the weight loss, ascorbic acid, total chlorophyll, crude fibre,
color, firmness and microbial quality of green asparagus stored at
2 and 10º c
Materials and methods:
Preparation of silver nanoparticles
Plant material and handling:
Fresh green asparagus was harvested
Straight, undamaged spears, 8-20mm in diameter and
22cm in length
Submerged in 100mg/L NaOH solution for 15 min at room
Immersed in the coating solution for 3 min at room
Treated asparagus was dried in cold air dried for 10 min
All the asparagus samples were stored for up to 20 days at
2 ant 10º c with RH 90-95%.
Both control and treated were analyzed for the following at a 5
Weight loss and ascorbic acid
Total chlorophyll and crude fibre
The silver nanoparticles were almost spherical with mean
diameter around 15-25 nm
Transmission electron microscopy (TEM) of silver nanoparticles
Changes of weight loss (A), ascorbic acid (B), total chlorophyll (C) and crude
fiber (D) in green asparagus stored at 2 and 10 °C. Control, stored at 2 °C □.
Coated, stored at 2 °C( ) Control stored at 10 °C( ) Coated, stored at
10 °C ( )
Different letters within the same storage day indicate that means are
different at the 0.05 level of significance.
Total aerobic psychrotrophic count (A), yeasts and moulds (B) on asparagus
stored at 2 and 10 °C. Control, stored at 2 °C ( ) Coated, stored at 2 °C
( ). Control, stored at 10 °C ( ) Coated, stored at 10 °C (
· The diameter of the silver nanoparticles prepared in this research was
about 20 nm, spherical with diameter 15-25nm
· The weight losses were reduced from 9.2%to 13.8%. the coating
significantly reduced weight loss over the storage period at both
· The largest weight loss reduction was obtained from coated application of
nanosilver particles PVP at the end of the storage.
· Significant increase in the ascorbic acid loss after treatments took place
at 2ºC during the storage time from 5 to 10 days but at 10ºC only for the
storage of 20 and 25days
· Significant differences are found between the coated asparagus and the
control sample in total chlorophyll content of the green spears were
observed after stored at 2ºC from 5 to 10 days but at 10ºC only for 25
· The presence of silver nanoparticles-PVP coating had a positive effect on
chlorophyll content at only 2ºC.
· Asparagus with silver nanopartcle - PVP coating had lower the crude fiber
content compared to the control samples.
· A decrease in the hue angle was observed with storage time. The
reduction of the hue angles of the samples correlated well with reduction
of the total chlorophyll concentration over the storage.
· Changes in the total aerobic psychotropic count were found at both
temperatures. The silver nanoparticles-PVP coating significantly hindered
the increase in total aerobic psychotropic count compared to control.
· Similar effect of coating was observed in reducing the growth of yeasts
and moulds during the storage.
Applications of silver nanoparticles-PVP coating to green asparagus
were shown to be beneficial in keeping the quality of the storage. Coating of
silver nanoparticles-PVP slowed down the weight loss, ascorbic acid and
total chlorophyll, reduced the color changes in the skin of asparagus, the
growth of microorganism and increased the shelf-life of asparagus by about
10 days at 2 °C.
Effect of nano-packing on preservation quality of Chinese
jujube (Ziziphus jujuba Mill. var. inermis (Bunge) Rehd)
To prepare a novel nano-packing material and investigate
its effect on preservation of Chinese jujube during room
Materials and methods:
500g matured green Chinese jujube were selected.
Packed in nano packing (15 bags) and polythene bag (15
Stored at 16-26ºc for 12 days
They were subjected to
Physical property analysis and microstructure
Firmness and weight loss rate
Fruit decay rate and browning rate
Evaluation of total soluble sugars and reducing sugars
Measurement of total soluble solids, titrable acid and
· Physical properties of normal packing and nano-packing
(g/m2 24 h)
O2 Transmission rate
(cm3/m2 24 h·0.1 MP
2.85 12.83 32.35
2.05 12.56 40.16
Fig. 1. SEM micrographs of nano-packing materials (a) and
normal packing materials (b).
Fig. 2. Effects of nano-packing and normal packing on sensorial qualities of
jujube during room temperature storage. (a) firmness; (b) weight loss rate;
(c) fruit decay rate and (d) browning rate.
Fig. 3. Effects of nano-packing and normal packing on physicochemical
indices of jujube during room temperature storage. (a) total soluble sugars
content; (b) reducing sugars content; (c) total soluble solids content; (d)
titratable acid content and (e) ascorbic acid content.
· The transmission rate of humidity (RH) and oxgen of nanopackaging
materials were decreased when compared to control.
· The longitudinal strength of nanopackaging was 1.24 fold higher than
that of the control.
· From the microstructure observation it appeared that the
nanoparticles were uniformly distributed in the nano-packing film
with irregular shape.
· The dimensions of nano particles 300-500nm
· Fruit firmness rapidly decreased in control group compare to
· The nano packing delayed the decline of firmness and had a beneficial
effect on firmness retention.
· Compared to the control, jujube stored with nano-packing exhibited a
significantly lower weight loss.
· Fruit decay rate: The jujube stored with control packing started
decaying from on day 1 and reached 66% decay rate on day 12 during
room temperature storage.
· During storage, the browning rate of all groups increased with time.
Moreover the browning rate of nanopacked jujube was always lower
than that of the control.
· Total soluble sugars: nano packing could significantly inhibit the
increase of total soluble sugar content compound with the control.
· The reducing sugars content of the nano-packing group was lower
than that of the control.
· The results indicated that the application of nanopacking might be
able to slow down the metabolism to give prolonged life to the fruit.
· The total soluble solids of jujube increased with the time during room
· The Titrable acid and ascorbic acid content was decreased
continuously for all the packing which was consistent with the decline
in edible quality.
· The nano-packing was better for maintaining the content of Titrable
acidity and ascorbic acid compared to control.
The nano-packing material had quite beneficial effects on
physicochemical and physiological quality compared with normal packing
material. Further research will be needed to explore the exact nano-packing
mechanism during storage to facilitate the application of nano-technology
over a broader range in the future.
The performance of mango puree edible films was noticeably
improved by CNF reinforcement.
Coating of silver nanoparticles-PVP slowed down the weight
loss, ascorbic acid and total chlorophyll, reduced the color
changes in the skin of asparagus, inhibited the increasing of
the tissue firmness, the growth of microorganism and
increased the shelf-life of asparagus by about 10 days at
The nano-packing material had quite beneficial effects on
physicochemical and physiological quality compared with
normal packing material.
Nanotechnology is becoming increasingly important for food
As with any new technology there is a significant challenge
to create awareness and gain acceptance of the use of
nanotechnology in the food industry.
In its widest sense nanotechnology is a part of food
processing and conventional foods because the
characteristic properties of many foods rely on nanometre
Most aspects of incremental nanotechnology are likely to
enhance the product quality and food safety.
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