Nanotechnology as applied to Food and Human Nutrition – An Overview By Stelios Anestis2,Athan Labropoulos1, Milena Kostova3 and Eleni Stamatopoulou4 (1E. Prof. Texas A&M Univ.& Ε. Prof.TEI-A;2Prof TEI-A;3Agric Un.of Blovdic, Bulgaria;4H.C.D.C.P. , Minister of Health) Abstract Food nanotechnology is an emerging area which opens new possibilities for the food and nutrition industry. Nanotechnology applications in the food industry are many such as to detect bacteria, produce stronger flavors, better appearance, quality, nutrition and safety. In general, legislation for the regulation of nanotechnology in food is varied among continents. The nanotechnology promises to provide many benefits to consumers introducing innovations in the food industry at an immense speed, but health uncertainty concerns must be taken into consideration. Nanotechnology can extend the self-life of foods, improve the nutrition aspects, alert the consumers for contaminated or spoiled foods, improve food packaging, and replace chemical for natural preservatives. In this study we will discuss some of the potentially beneficial effects nanotechnology-enabled innovations could have on foods and, subsequently, on human health. Food applications of nanotechnology opportunities and challenges are: Processed nanostructure - textured foods (e.g. less use of fat and emulsifiers); nanocarrier systems for delivery of nutrients and supplements (forms of liposomes or biopolymer-based nanoencapsulated substances); organic nanosized additives (for food supplements and animal feed); inorganic nanosized additives (for food, health food, and animal feed); food packaging applications (e.g. plastic polymers containing or coated with nanomaterials for improved mechanical or functional properties); nanocoatings on food contact surfaces (for barrier or antimicrobial properties); surface-functionalized nanomaterials; nanosized agrochemicals; nanosensors (for food labeling); and water decontamination Key words: Food nanotechnology, food nanostructure, nanosized nutrition, Introduction The organisation of materials at the nanoscale level was first visioned more than 50 years ago and the term ‘nanotechnology’ was introduced more than two decades later to evoke scientists to develop methods and potential tools to detect structural information and manipulate matter on a miniaturised scale (1,2). This inspirational thought aided by sophisticated instrumentation and methodologies to visualise and control nanomaterials promises so that to redefine the potential of “exploitable materials” on a global scale (3). The ability to tailor such materials for specific functions has opened a door of opportunities for future development of diverse products. Characteristics of nanomaterials include size, shape, surface properties, aggregation state, solubility, structure and chemical composition. Miniaturisation results in significant changes in the surface to volume ratio of nanoparticles affecting their overall property. The interest in functional materials of the order 1-100 nm is associated with their novel physical and chemical properties and their potential for introducing highly innovative technologies with major applications in foods, nutrition, health, diagnostics and therapies, engineering, safety, energy, electronics, chemical and physical properties of foods among others (4). The food industry has also embraced the ‘nano’ technology in response to a growing need by consumers for healthier products. The possibility of using ‘nanotechnology’ has pus food scientists to think innovatively. However, the nanofood market despite the initial excitement has been slowed by the potential risks of implementing nanoparticles in food stuffs as consumers, the World Health Organisation, governmental regulatory bodies, academia and industry currently debate and assess new standards for food safety and the likely impact of nanofood products on the human population (5,6). Although nanomaterials are universally accepted to be between 1-100 nm, their dimensional size varies significantly beyond the standard definition particularly for applications in food technology which is a complicating factor in regulating nano-based food products (7). Nanotech foods The application of nanotechnology in food offers a number of opportunities to provide better and safer consumer products. Food nanotechnology is foreseen to have an impact on four major areas in food development, food processing, food packaging and the supply of nutritional. A growing knowledge in the food industry driven by food engineers, microbiologists, chemists and material scientists is pushing innovation to new heights with possibilities on an interdisciplinary scale. The areas of key focus for the future development of food governed by the size and functional nature of nanoparticles broadly center on (a) nanosizing micronutrients and incorporating novel functional properties to form novel nanomaterials (b) using nanomaterials to encapsulate and deliver bioactive food components to enhance their nutrition. (c) functionalising nanoparticles for biosensing of food borne microbials (d) innovative packaging to enhance food safety the shelflife of products. These developments will have a huge impact on food product and processing from agricultural growth to catering of food products. Nanofoods are being designed to react to consumer’s choice of colouring and flavouring by activating their release from ‘programmable’ nanocapsules’ via ‘smart functional’ materials. Nanoparticles also have the potential to deliver a multitude of textures in food by using nanoemulsions that affect their structure and chewiness . The increasing demand to deliver more green based technologies to grow food by reducing environmental pollution may be facilitated by using nanocapsules designed to dispense pesticides more controllably to target the nutritional and water requirements of crops. Another area which is actively in development in addition to products that are already on the market relates to packaging of food materials. Using nanotechnology to enhance the availability of food by reducing spoilage and wastage and increasing the safety and quality of products will have obvious implications on the health and agricultural industry and the environment. Despite the uncertainty surrounding the use of nanoparticles in edibles, their use will result in smarter products and will change greatly our current perception towards food. Nanomaterials in foods The availability of different types of nanostructures with varying properties and compositions have enabled food engineers to design and incorporate nanomaterials inventively to produce novel food products (8). As scientists increase their understanding of the structure-functional relationships of different nanomaterials, the impact of this ‘newly acquired knowledge’ on the future development of food will greatly accelerate in years to come. At the present time, realisation of the functional significance of the different types of nanomaterials is predicted to have the greatest impact in the design of greener processes to produce healthier and more nutriently enriched foods of the highest quality and safetyThe development of nanomaterials has involved using both inorganic and organic materials engineered to perform task specific functionalities. Examples of soluble organic nanoparticles include liposomes, vesicles, micelles and polymers. Nanocomposite materials have also attracted much interest in food technology because of a number of key characteristics largely owing to their mechanical strength (9). BIOAVAILABILITY and NUTRITION Nanotechnology is being used to deliver nutritional supplements in the form of nutraceuticals such as vitamins, antioxidants, fats, proteins, natural product extracts and minerals of low bioavailability affected by factors such as solubility and stability leading to limited absorption of body nutrients. Nutraceuticals have the potential to offer huge health benefits by effectively delivering nutrients and help prevent bone disease (arthritis), regulate blood glucose and cholesterol levels, reduce the risk of cancers and boost immune responses. In reality, the benefits of food are lost because many bioactive components are not water soluble. For example, fat soluble substances like vitamins are not readily processed and taken-up by the small intestine as water soluble components but are required to undergo a pre-treatment phase involving micelle encapsulation to penetrate cells to release their contents. Food processing treatments involving heating, drying, freezing and addition of preservatives markedly affect the stability and viability of products. Incorporation of functional ingredients in functionally coated nanomaterials to drive the development of functional nanofoods is another area of major active interest in the food industry. In pursuit of this technology, a number of coating methods like physical and chemical vapour deposition, pyrolysis, sol-gel processes and supercritical carbon dioxide have been used. Nanotechnology is also playing a role in enhancing the delivery of probiotics. Delivery of beneficial microorganisms that increase nourishment through natural biological processes has also benefited from nanoencapsulation technology. Examples of favourable bacteria used in probiotics are Lactobacillus salivarius, Lactobacillus acidophilus, Saccharomyces boulardii, Saccharomyces thermophilus and Bifidobacterium species that aid the digestion of food, increase energy storage and fermentation of sugars, help prevent tumour formation, stimulate the production and release of vitamins and antibiotics and inhibit the development of pathogenic conditions such as those associated with infections, inflammation and heart Safety and Reduced Wastage Food preservation has always been a major concern. Methods to guard food from contamination and spoilage by microorganisms date back to the eighteenth and nineteenth century such as appertisation (e.g. air tight containers) and pasteurisation (destruction of microbes by heat treatment) over long periods. Such approaches have limited use in protecting food against opportunistic, rapidly evolving and highly resistant airborne microbes. Another major global concern is the wastage and spoilage of food which occurs when food particles are exposed to atmospheric gases, moisture and light for prolonged periods. The barrier properties of food packaging can play a critically important role in food preservation and reduce wastage output of contaminated food products as a result of degradation by the elements. The food industry has responded by enhancing the barrier properties of packaging by incorporating nanomaterials that materially reduce the entry of degrading agents from the atmosphere. Manufacturing of antimicrobial food packaging has been a developing interest in the food industry particularly for the increased quality and shelf-life of food products. In the interests of enhancing food safety, nanosilver composites offer added value in food packaging because of their antibacterial properties. Nanomaterial-based biosensors for the detection of foodborne pathogens will also have great utility in monitoring food safety. For example, a US government driven initiative resulted in a patented nanoparticle tracer-based electrochemical DNA sensor for detecting pathogens in food products (10). Safety and rgulation of nanofoods The introduction of nanofoods into the consumer market has largely focused on providing healthier, safer and quality products for better eating and living. The benefits of nanofoods have been widely reported but the health-risks associated with nanoparticles have not been fully evaluated to date. The size dependent properties of nanomaterials and their miniaturisation together offer valuable scope for nanotechnological innovation. However, the same characteristics in these materials may result in toxicological outcomes during their interaction with biological cells, tissues and organs via nanofoods and food contact materials. The risks associated with the inhalation, ingestion and skin absorption of engineered nanoparticles of unknown toxicity urgently demands the development of reliable analytical tools to conduct a safety risk evaluation of nanofood products (11). With the introduction of nanoparticles in foods, methods for the identification and quantification of nanosized particles in food matrices are being developed for future regulatory testing in terms of the distribution and migration of engineered particles in food stuffs. These devices will be necessary to instil public confidence in nanoparticle based products to ensure that shelf products are quality assured and safe. A lack of analytical assessment tools in this area has been met by efforts to establish methodologies and instrumentation for food analysis. However, this area will require further attention as regulatory authorities may implement restrictions on the use of nanoparticles as food components in the future. Conclusion Through improved knowledge of nanomaterials and the realisation of their potential in the food industry, the introduction of nanotech foods will provide solutions for persisting problems associated with foods and will offer long-term economic benefits. Globally, nations will profit from increased food productivity with cost effective returns, innovative products with tuneable properties to deliver smarter and healthier foods and equally intelligent packaging systems with enhanced storage properties for better food protection. Nanomaterials in foods will have a huge impact on sustainability and will be accompanied by health and environmental benefits if regulated properly. However, as the challenge in assessing the safety of nanofoods and nanopackaging becomes more complex with the arrival of novel nanomaterials for use in the food industry, greater cooperation is required to ensure that human and environmental concerns are not compromised as new products are released. Therefore, the pace of introducing food technology must be sufficiently slowed to allow potential risks to be identified and assessed for a safer future. This essentially means that innovation must be balanced by regulatory guidelines through the availability of reliable and robust risk-assessment tools which currently do not exist for nanofoods. Also, if nanofoods are to be implemented successively in our food cycle, the benefits of nanotech foods must be accompanied by greater transparency of the risks of such foods publicly to build consumer confidence. Public engagement acting in concert with public opinion is likely to play a critical role in the acceptance of nano processed foods. References  [1] Taniguchi N. On the basic concept of 'nano-technology’. Proceedings of the International Conference of Production Engineering. Tokyo, Japan, 1974.  [2] Yang H, Wang Y, Lai S, An LH, Li Y, Chen F. Application of atomic force microscopy as a nanotechnology tool in food science. 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