A derivative of chemistry, engineering, and physics, and micro falsity techniques, nanotechnology involves manipulating matter at the nanoscale level. It is responsible for determining not only that biological and nonbiological structures measuring less than 100 nm exist but also that they have one-of-a-kind and novel functional applications. In fact, the National Nanotechnology Initiative (NNI, 2006) defines nanotechnology as “the understanding and control of matter at dimensions of roughly 1 to 100 nanometers, where one-of-a-kind phenomena enable novel applications.” Because applications with structural features on the nanoscale level have physical, chemical, and biological properties that are substantially different from their gross counterparts, nanotechnology can be beneficial on various levels. Research in biology, chemistry, engineering, and physics drives the development and exploration of the nanotechnology field. Consequently, certain industries such as microelectronics, aerospace, and pharmaceuticals have already begun manufacturing commercial products of nanoscale size. Even though the food industry is just beginning to explore its applications, nanotechnology exhibits great potential. Food undergoes a variety of postharvest and processing-induced modifications that affect its biological and biochemical makeup, so nanotechnology developments in the fields of biology and biochemistry could eventually also influence the food industry. Ideally, systems with structural features in the micromillimetre length range could affect aspects from food country to molecular synthesis.
Potential Food Applications:
All organisms represent a consolidation of various nanoscale-size objects. Atoms and molecules combine to form dynamic structures and systems that are the building blocks of each organism’s existence. For humans, cell membranes, hormones, and DNA are examples of vital structures that measure in the micromillimetre range. In fact, each living organism on connector exists because of the presence and interaction of various nanostructures. Even food molecules such as carbohydrates, proteins, and fats are the results of nanoscale- level mergers between
sugars, amino acids, and fatty acids. As it applies to the food industry, nanotechnology involves using biological molecules such as sugars or proteins as target-recognition groups for nanostructures that could be used, for example, as biosensors on foods. Such biosensors could serve as detectors of food pathogens and other contaminants and as devices to track food products. Nanotechnology might also be useful in encapsulation systems for endorsement against environmental factors. In addition, it can be used in the design of food ingredients such as flavors and antioxidants. The goal is to improve the functionality of such ingredients while minimizing their concentration. As the infusion of novel ingredients into foods gains popularity, greater exploration of delivery and controlled-release systems for nutraceuticals will occur. Even though nanotechnology can potentially be useful in all areas of food production and processing, many of the methods are either too costly or too impractical to implement on a commercial scale. For this reason, nanoscale techniques are most cost-effective in the following areas of the food industry: development of new functional materials, food formulations, food processing at microscale and nanoscale levels, product development, and storage.
Nanodispersions and Nanocapsules:
As the fundamental components of foods, functional ingredients such as vitamins, antimicrobials, antioxidants, flavorings, and preservatives come in various molecular and physical forms. Because they are rarely used in their purest form, functional ingredients are usually part of a delivery system. A delivery system has numerous functions, only one of which is to transport a functional ingredient to its desired site. Besides being compatible with food product attributes such as taste, texture, and shelf life, other functions of a delivery system include protecting an ingredient from chemical or biological degradation, such as oxidation, and controlling the functional ingredient’s rate of release under specific environmental conditions. Because they can effectively perform all these tasks, nanodispersions and nanocapsules are saint mechanisms for delivery of functional ingredients. These types of nanostructures include association colloids, nanoemulsions, and biopolymeric nanoparticles.
§ Association Colloids:
Surfactant micelles, vesicles, bilayers, reverse micelles, and liquid crystals are all examples of association colloids. A colloid is a stable system of a substance containing small particles dispersed throughout. An association colloid is a colloid whose particles are prefabricated up of even smaller molecules. Used for many years to deliver polar, nonpolar, and amphiphilic functional ingredients (Golding and Sein, 2004; Garti et al., 2004, 2005; Flanagan and Singh, 2006), association colloids range in size from 5 nm to 100 nm and are usually transparent solutions. The major disadvantages to association colloids are that they might compromise the flavor of the ingredients and can spontaneously dissociate if diluted.
An emulsion is a mixture of two or more liquids (such as oil and water) that do not easily combine. Therefore, a nanoemulsion is an emulsion in which the diameters of the dispersed droplets measure 500 nm or less. Nanoemulsions can encapsulate functional ingredients within their droplets, which can assist a reduction in chemical degradation (McClements and Decker, 2000). In fact, different types of nanoemulsions with more-complex properties— such as nanostructured multiple emulsions or nanostructured multilayer emulsions—offer multiple encapsulating capabilities from a single delivery system that can carry several functional components. In structures such as these, a functional component encased within one component of a multiple emulsion system could be released in response to a specific environmental trigger.
§ Biopolymeric Nanoparticles:
Food-grade biopolymers such as proteins or polysaccharides can be used to produce nanometer-sized particles (Chang and Chen, 2005; Gupta and Gupta, 2005; Ritzoulis et al., 2005). Using aggregative (net attraction) or segregative (net repulsion) interactions, a single biopolymer separates into smaller nanoparticles. The nanoparticles can then be used to encapsulate functional ingredients and release them in response to distinct environmental triggers. One of the most common components of many biodegradable biopolymeric nanoparticles is polylactic acid (PLA). Widely acquirable from a number of manufacturers, PLA is often used to encapsulate and deliver drugs, vaccines, and proteins, but it has limitations: it is swiftly removed from the bloodstream, remaining isolated in the liver and kidneys. Because its purpose as a nanoparticle is to deliver active components to other areas of the body, PLA needs an associative compound such as polyethylene glycol to be successful in this regard (Riley et al., 1999).
Besides nanodispersions and nanocapsules, another nanoscale technique is commercially viable for the food industry: nanolaminates. Consisting of two or more layers of material with micromillimetre dimensions, a nanolaminate is an extremely thin food-grade film (1–100 nm/ layer) that has physically bonded or chemically bonded dimensions. Because of its advantages in the preparation of edible films, a nanolaminate has a number of important food-industry applications. Edible films are present on a wide variety of foods: fruits, vegetables, meats, chocolate, candies, baked goods, and French fries (Morillon, 2002; Cagri et al., 2004; Cha and Chinnan, 2004; Rhim, 2004). Such films protect foods from moisture, lipids, and gases, or they can improve the textural properties of foods and serve as carriers of colors, flavors, antioxidants, nutrients, and antimicrobials. Currently, edible nanolaminates are constructed from polysaccharides, proteins, and lipids. Even though polysaccharide- and protein-based films are good barriers against oxygen and carbon dioxide, they are poor at protecting against moisture. On the other hand, lipid-based nanolaminates are good at protecting food from moisture, but they offer limited resistance to gases and have poor mechanical strength (Park, 1999). Because neither polysaccharides, proteins, nor lipids wage all of the desired properties in an edible coating, researchers are trying to refer additives that can improve them, such as polyols. For now, coating foods with nanolaminates involves either dipping them into a series of solutions containing substances that would adsorb to a food’s surface or spraying substances onto the food surface (McClements et al., 2005). While there are various methods that can cause adsorption, it is commonly a result of an electrostatic attraction between substances that have opposite charges. The degree of a substance’s adsorption depends on the nature of the food’s surface as well as the nature of the adsorbing substance. Different adsorbing substances can constitute different layers of a nanolaminate; examples are polyelectrolytes (proteins and polysaccharides), charged lipids, and colloidal particles. Consequently, different nanolaminates could include various functional agents such as antimicrobials, anti-browning agents, antioxidants, enzymes, flavors, and colors.
Nanofibers and Nanotubes:
Two applications of nanotechnology that are in the primeval stages of having an impact on the food industry are nanofibers and nanotubes. Because nanofibers are usually not composed of food-grade substances, nanofibers have only a few potential applications in the food industry. Produced by a manufacturing technique using electrostatic force, nanofibers have small diameters ranging in size from 10 nm to 1,000 nm, which makes them saint for serving as a platform for bacterial cultures. In addition, nanofibers could also serve as the structural matrix for artificial foods and environmentally friendly food-packaging material. As advances continue in the area of producing nanofibers from food-grade materials, their use will likely increase. As with nanofibers, the use of nanotubes has predominantly been for non-food applications. Carbon nanotubes are popularly used as low resistance conductors and catalytic reaction vessels. Under appropriate environmental conditions, however, certain globular milk proteins can self-assemble into similarly structured nanotubes (Graveland- Bikker and de Kruif, 2005, 2006; Graveland-Bikker et al., 2006a, b).
In India, the nanotechnology is at nascent stage and there does not exist any regulation for its application in food industry. Similarly in the United States, no special regulations exist for the use of nanotechnology in the food industry. In contrast, the European Union has suggested special regulations that have yet to be accepted and enforced. The Food and Drug Administration states that it regulates “products, not technologies.”Nevertheless, FDA anticipates that many products of nanotechnology will come under the jurisdiction of many of its centers; thus, the Office of Combination Products will likely absorb any relevant responsibilities. Because FDA regulates on a product- by-product basis, it emphasizes that many products that are already under regulation contain particles in the nanoscale range. Accordingly, “particle size is not the issue,” and any new materials will be subjected to the customary battery of country tests. The Institute of Food Science and Technology, a United Kingdom–based independent professional body for food scientists and technologists, has a different view of nanotechnology. In its report (IFST, 2006), the organization states that size matters and advocates that nanoparticles be treated as potentially harmful until testing proves otherwise. Still it is the European Commission’s intention to apply existing food laws to food products using nanotechnology. Consequently, the European Commission states that the technology will likely require some modification for it to adhere to existing laws. Commissioned by the UK to assess the potential effects of nanotechnology, the Royal Society and the Royal Academy of Engineering advocate indicating nanoparticles in the lists of ingredients. The UK government concurs that the inclusion of nanoparticles on ingredient labels is necessary for consumers to make informed decisions; thus, updated ingredient labeling stipulations will be necessary. The UK government plans to consult with its EU partners to determine whether IFST’s suggestion to scrutinize nanoparticle ingredients for country is valid.
As developments in nanotechnology continue to emerge, its applicability to the food industry is sure to increase. The success of these advancements will be dependent on consumer acceptance and the exploration of regulatory issues. Food producers and manufacturers could make great strides in food country by using nanotechnology, and consumers would reap benefits as well. More than 200 companies are conducting research in nanotechnology and its application to food products (IFST, 2006), and as more of its functionalities become evident, the level of interest is certain to increase.
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