R S Rajkumar, Suresh R, Susitha K, Prejit and S Wilfred Ruben
The word ‘nano’ comes from the Latin word. “Dwarf”. The concept of nano-technology was first given by Noble Laureate Physicist Richard P. Fennan in Southern California in 1952 (Kakade, 2003). Eric Drexler popularized the term ‘nanotech’ in 1980’s. Nanotechnology involves experimenting and manipulating with particles, called nano-particles that are demonstrated in the scale of nanometres (a billionth of a metre). Nano-technology is thus the manufacture of structures, materials, decades and machines using nano-particles with programmed precision (Chaudary et al., 2006).
Nanotechnology has the potential to revolutionize the global food system. Novel agricultural and food security systems, disease treatment delivery methods, tools for molecular and cellular biology sensors for pathogen detection, environmental protection, and education of the public and future workforce are the examples of the important impact that nanotechnology could have on the science and engineering of agriculture and food systems (Carmen et al., 2003). This article discusses application of nanotechnology in meat packaging industry.
Use of Nanotechnology in Meat Packaging
The flexible packaging industry is growing rapidly. It is a $38 billion global market. With the demand for flexible packaging growing at an average rate of 3.5 percent per year, flexible materials need to meet and exceed the high expectations of consumers and the stressors of the supply chain. Increasing competition between suppliers, along with government regulations, have resulted in innovations in films that enhance product and package perfor
mance, as well as address worldwide concerns with packaging waste.
The consumer demands meat, to remain fresh for long time, ease in handling, safe and healthy with environmental friendly packaging.
Properties such as mechanical and heat resistance can be increased (www.azonano.com). Packaging materials that have improved temperature performance can be used for hot fill operations. Very thin films that can offer the advantages of flexibility and functionalities like being anti-counterfeit, anti-tamper and anti-microbial should be made. Self-heating feature can also be incorporated in the packaging material. Environment friendly, lightweight-packaging materials can be made for use in army rations. In future, with the aid of nanocomposites we may be able to modify plastic into a super barrier just as glass or metal (Brody, 2003).
Nanocomposites, defined as polymers bonded with “nano” particles to produce materials with enhanced properties are recently gaining momentum in mainstream commercial packaging use. One such innovation is polymer nanocomposite technology, which holds the key to future advances in flexible packaging. “Nanocomposites appear capable of approaching the elusive goal of converting plastic into a super barrier – the equivalent of glass or metal-without upsetting regulators.” (Brody, 2003).
Polymer nanocomposites are constructed by dispersing a filler material into nanoparticles that form flat platelets. These platelets are then distributed into a polymer matrix, creating multiple, parallel layers that force gases to flow through the polymer in a “tortuous path,” forming complex barriers to gases and water vapour. The more is tortuosity present in a polymer structure, the higher is the barrier properties. The permeability coefficient of polymer films is determined using two factors: diffusion and solubility coefficients, i.e., P = DxS.
Different types of fillers are utilized; the most common is a nanoclay material called montmorillonite – layered smectite clay. Clays in a natural state are hydrophilic, while polymers are hydrophobic. To make the two compatible, the clays’ polarity must be modified to be more “organic.” One way to modify clay is by exchanging organic ammonium cations [positively charged ions] for inorganic cations from the clays’ surface. Many different types of commercial plastics, flexible and rigid, are utilized for nanocomposite structures, including polypropylene, nylon, polyethylene terephthalate (PET) and polyethylene.
Chemical giant Bayer produces a transparent plastic film (called Durethan) containing nanoparticles of clay. The nanoparticles are dispersed throughout the plastic and are able to block oxygen, carbon dioxide and moisture from reaching fresh meats or other foods. The nanoclay also makes the plastic lighter, stronger and more heat-resistant.
Nylon nanocomposites, used as barrier layers for multilayer PET containers, prove to perform as much as two to three times better than the traditional ethylene vinyl alcohol barrier layers, since nylon has a 50°F higher melt temperature.
The advantages of nanocomposite films are numerous, and the possibilities for application in the packaging industry are virtually endless. Because of the nanocomposite process’s dispersion patterns, the platelets result in largely improved performance in the following properties:
- Gas, oxygen, water, etc. barriers
- High mechanical strength
- Thermal stability
- Chemical stability
- Dimensional stability
Good optical clarity (since particles are nano-size). By 2009, it is estimated that the flexible and rigid packaging industry will use 5 million lb of nanocomposite materials in the food and beverage industry. By 2011, consumption is estimated to be 100 million lb. Polymer nanocomposites are the future for the global packaging industry. Once production and materials costs decrease, companies will be using this technology to increase their product’s stability and survivability through the supply chain to deliver higher quality to their customers while saving money. The advantages that nanocomposites offer far outweigh the costs and concerns, and with time, the technology will be further refined and processes more developed. Other types of nanofillers, allowing new nanocomposite structures with different, improved properties that will further advance nanocomposite are being developed for uses in many diverse packaging applications.
Antimicrobial and Active Packaging using Nanotechnology
Nano materials helps to keep products fresh for a longer period of time by using nano-sensors placed in meat production and distribution facilities, meat packaging or the meat itself which can detect all kinds of meat borne pathogens like E. coli, Campylobacter, Salmonella and Listeria spp by attaching themselves to the pathogens. Nanostructured film can prevent the invasion of bacteria and microorganisms and ensure the meat safety, a consultancy said. With embedded nanosensors in the packaging, consumers will be able to determine whether meat has gone bad or find out its nutrition content (www.azonano.com).
Anti-microbial packaging materials are very useful. It is hoped that with the advancement and growth in nano-science we can expect almost all packaging materials with anti-microbial agents incorporated in them. By placing Nano-sensors in packages, problems such as contamination, toxins or lapses in expiry dates can be detected (www.azonano.com).
Another window of opportunity for nano-particles is represented by meat safety applications. Latour et al. (2003) are investigating the ability of synthesized adhesin-specific nano-particles to irreversibly bind to targeted types of bacteria, inhibiting them from binding to and infecting their host. This research is aimed at reducing the infective capability of human meat borne entero-pathogens in poultry products, using two types of nano-particles. One type is based on the self-assembly of organic polymer (e.g., polystyrene), and the other on inorganic nano-particles functionalized with polysaccharides and polypeptides that promote the adhesion of the targeted bacterial cells.
Understanding the interaction between contaminated surfaces and microorganisms allowed the design of materials that are resistant to bacterial adhesion. Researchers are already making efforts to develop a new generation of “self-cleaning” materials loaded with anti-microbial compounds that can be released under certain environmental conditions and kill the contaminant micro flora (Shefer and Shefer, 2003).
Baker and coworkers have used high-shear mixing of a lipid oil discontinuous phase with an aqueous continuous phase to develop nano-emulsions, which is an effective solution for disinfecting sensitive equipment safely (Lerner, 2000). Nano-emulsions consist of oil droplets of 400-800 µm in diameter that are able to fuse with and subsequently disrupt the membrane of a variety of different pathogens, such as bacteria, spores, enveloped viruses, and fungal spores.
Kodak, best known for producing camera film, is using nanotech to develop antimicrobial packaging for meat products are commercially available since 2005. Kodak is also developing other ‘active packaging,’ which absorbs oxygen, thereby keeping meat fresh.
Electronic Tongue Technology and Smart packaging
Today, meat packaging and monitoring are a major focus of meat industry-related nanotech R&D. Packaging that incorporates nano materials can be “smart,” which means that it can respond to environmental conditions or repair itself or alert a consumer to contamination and/or the presence of pathogens. According to industry analysts, the current US market for “active, controlled and smart” packaging for foods and beverages is an estimated $38 billion – and will surpass $54 billion by 2008.
Scientists at Kraft, as well as at Rutgers University and the University of Connecticut, are working on nano-particle films and other packaging with embedded sensors that will detect meat pathogens. Called “electronic tongue” technology, the sensors can detect substances in parts per trillion and would trigger a colour change in the packaging to alert the consumer if a meat has become contaminated or if it has begun to spoil.
While devices capable of detecting meat-borne pathogens could be useful in monitoring the meat supply, sensors and ‘smart packaging’ will not address the root problems inherent in industrial meat production that result in contaminated meats: these problems are faster meat (dis)assembly lines, increased mechanisation, a shrinking labour force of low-wage workers, fewer inspectors, the lack of corporate and government accountability and the great distances between meat producers, processors and consumers. Just as it has become the consumer’s responsibility to make sure that the meat one is consuming has been cooked long enough to ensure that pathogens have been killed. Consumers will soon be expected to act as their own meat inspectors so that industry can continue to trim safety overhead costs and increase profits.
Nanotechnology and transportation of gases
Through nano-technology we can increase or decrease gas transmission rate to suit the packaging requirements of the product. Nanotechnology enables designers to alter the structure of the packaging materials on the molecular scale. With different nanostructure, plastics can gain various gas and water vapour permeability to fit the requirements of preserving fruit, vegetable, beverage, wine and other foods. By adding nano particles, people can also produce bottles and packages with more light- and fire-resistance,
stronger mechanical and thermal performance and less gas absorption.
Such nano tweaking can increase the shelf life of meats and preserve flavour and colour. SINTEF-Nanotech to create small particles in the film and improve transportation of some gases through the plastic film to pump out dirty air such as carbondioxide has been developed.
Dispersing a filler material into nano particles, creates multiple, parallel layer that force gases to flow through the polymer in a “tortous path”, forming complex barriers to gases and water vapour
Nanotech Bio-switch in ‘Release on Command’ Meat Packaging
Researchers in the Netherlands are going one step further. They want to develop intelligent packaging that will release a preservative if the meat within begins to spoil. This “release on command” preservative packaging is operated by means of a bio-switch developed through nanotechnology to extend the shelf life of meat / food (Gogotsi, 2006). Research project in Finland is working on printable indicator, which contains reactive substance that signals if oxygen is present in package.
Meat Packaging Sensors in Defence and Security Applications
Developing small sensors to detect meat-borne pathogens will not just extend the reach of industrial agriculture and large-scale meat processing. The US military however views it a, it’s a national security priority. With present technologies, testing for microbial meat-contamination takes two to seven days and the sensors that have been developed to date are too big to be transported easily. Several groups of researchers in the US are developing biosensors that can detect pathogens quickly and easily, reasoning that “super sensors” would play a crucial role in the event of a terrorist attack on the food supply. Researchers at Purdue University are working to produce a hand-held sensor capable of detecting a specific bacterium instantaneously from any sample. They’ve created a start-up company called BioVitesse. Environmental friendly, lightweight-packaging materials can be made for use in army rations (Brody, 2003).
Overall advantages of nanotechnology on meat packaging
- Thermal Stability and Chemical Stability
- Heat resistance
- Gas, Oxygen, water etc., barrier.
- Dimensional stability and Flexibility
- Functionality – Anti-counterfeit, Anti-tamper, Anti-microbial, Sensors (temperature, moisture, light, decay)
- High mechanical Strength
- Good optical density
Companies working on Nano meat packaging
- CONSTAR® International: “Diamond Clear” – nanomaterial blended with polyethylene terephthalate – oxygen scavenger
- Air product polymer: “AIR FLEX EF 9100 EMULSION” – prevent penetration of liquid or gases and environment friendly.
- KODAK®: Antimicrobial food packaging
- Amcol International Co-op – NANOCOR®: Polymer blended with nanocrystal
- Honey well®: Polymer nanoclay – gas barrier
- OX – Oxygen scavenger
- HFX – Hot Filled Application
- CSD – Carbonated soft drink
- SOLPHAS®: Environment friendly nano-particle for coating plastic film, Antimicrobial packaging
- BAYON®: Supply nano-composite nylon film to juice carton
- KRAFT®: Working on nano-particle films that willl detect meat pathogens
Global overview of Nanotechnology food
A handful of food and nutrition products containing invisible nano-scale additives are already commercially available. Hundreds of companies are conducting research and development (R&D) on the use of nanotech to engineer, process, package and deliver meat and nutrients to our shopping baskets and our plates. Among them are giant food and beverage corporations, as well as tiny nanotech start-ups.
The U.S. is leading in nanotechnology research, with more than 400 research centers and companies involved and more than $3.4 billion in funding. Europe has more than 175 companies and organizations involved in nanoscience research, with $1.7 billion in funding, and Japan has more than 100 companies working with nanotechnologies. Globally, the market for nanocomposites is expected to grow to $250 million by 2008, with annual growth rates projected to be 18 percent to 25 percent per year. A 2004 report produced by Helmut Kaiser Consultancy, “Nanotechnology in Food and Food Processing Industry Worldwide,” predicts that the nanofood market will surge from $2.6 billion today to $7 billion in 2006 and to $20.4 billion in 2010.
Status in India
To promote research and development in nano-science the Government of India has launched a programme “Nano-Material Science And Technology Initiative” (NSTI) in tenth five-year plan One hundred crore rupees have been allocated. Yet, this technology is in budding stage and not entered the field of meat science and technology. Mumbai based “Yash Nanotech” is a business information provider and consultant to entrepreneurs and is aiming to become leading suppliers of nanotech tools, products and services in India. (Mettoth, 2004)
Hazards and risks
Although the hazards and risks of nano-technology are not known but can be assumed that like any other technology this may also have associated hazards and risks. Environmentalists are afraid that nano-technology may produce contaminants, which because of their nano-size, may pose to be ultra-hazardous. Even if these particles are not harmful, their interaction with products may be harmful (www.enn.com). However, judicious use of nano-technology will find tremendous applications in various fields. Research has shown that nano-sized particles accumulate in the nasal cavities, lungs and brains of rats, and that carbon nano-materials known as ‘buckyballs’ induce brain damage in fish. Vyvyan Howard, a toxicologist at the University of Liverpool in the United Kingdom, has warned that the small size of nanoparticles could render them toxic, and is of the opinion that full hazard assessments are needed before manufacturing is licensed.
Many interested parties, including the Canadian ETC Group and the insurance company Swiss Re, have expressed their concern over releasing tiny particles, which, because of their small size, are able to travel very far into the environment. They warn that we do not yet know how these particles will act in the environment or what chemical reactions they will trigger on meeting other particles. However, these same groups also concur with nanotechnology advocates who feel the field may offer ‘cleaner’ technologies, and, ultimately, a cleaner environment. But mostly, the concern is for the lack of research into nanotechnology’s potential threats to human health, society and the environment. After witnessing widespread rejection of genetically modified meats, the meat industry may be especially skittish about owning up to R&D on “atomically modified” meat products (www.enn.com).
There are lots of challenges in the upcoming nano-technology. Based on its applications in almost all the fields, it is gaining popularity and needs to be harnessed through a holistic approach. Scientists from different streams viz., microbiology, material sciences, chemistry, chemical engineering, bio-engineering, bio-chemistry, food science, meat science, public health have to join hands together for the cost effective and safe meat. Nanotechnology can meet consumer demand for cost effective and safe meat. Nano-packed meats have better shelf life, lighter weight and better recyclability. In long run nanotechnology will change the fabrication of whole packaging. Nano-technology can make products cost-effective. Production will be carried out by self-replicating nano-devices using small assent of material, energy, low capacity, less labour and land. Thus production is more efficient. The potential of nano-technology in meat industry cannot be fully appreciated yet because of lack of sufficient knowledge. If nano-technology continues to advance at its current pace, we could expect that soon we will be able to create unlimited amount of meat by synthesis at the atomic level, which would eradicate hunger (Carmen et al., 2003).
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