Breakthrough technology

The evolution of the nanotech revolution

By Ahmed ElAmin

- Last updated on GMT

The emerging science of nanotechnology is the next Big Bang in food
formulation, processing and packaging.

The techniques are being developed as scientists learn how to manipulate the behaviour of foods and their components first from the molecular, then to the micro and now to the nano level. The build up to this brave new world of leveraging the science of the miniscule is already occurring, and as happens with any disruptive technology the consumer reaction against the coming revolution is starting to kick in. How to leverage nanotechnology in a positive way to produce new products and processes, while catering to the consumers' fears about the new science is the balancing trick food companies and regulators are going to have to learn how to perform. The danger is nano-tech products will face a similar reaction consumers have put up against genetically modified foods, an automatic aversion when they feel some new technology is being shoved down their throats. Public and scientific concerns have been raised that nanostructured materials could potentially lead to unforeseen health or environmental hazards. In the food area fears arise over the unknown consequences of digesting nano-scale particles designed to behave in specific way in the body. That's why many nanotech advocates have joined in the call for legislation and risk controls to be put in place before the products start appearing on the market, and not in reaction to them. Ongoing public education by the food industry is essential to the process. Nanotechnology refers to the technique of controlling and manipulating matter at near atomic scales to create new processes, materials and devices. Erich Windhab, a scientist at the Swiss Federal Institute of Technology's food processing laboratory, emphasises the need for caution in proceeding with introducing new products. He told that any developments should first take into account consumer preference, acceptance and need for nanotech products. This PAN formula, as it is known in industry, was fundamental to the acceptance of microscale encapsulated salt, used in Morocco in a study by an international nutrition research group. The group used micro capsules created by Windhab's team to carry out the efficacy study, with Morocco's health department. The capsules had a size of about 50-100 microns with Vitamin A, iodine and iron compounds encapsulated in the size range of about five microns, or about 5000 nanometers. The capsules were then timed to open up in the gut to release the nutrients. The nutrients are all missing from the soil and hence the foods grown and eaten in rural Morocco. The triple-fortified salt had no colour change and no off flavours, a major problem in previous trials at getting the community to accept salt fortified using other techniques. "It was suitable for use with their traditional foods,"​ Windhab said in describing the study. In the 2003 study 159 school children aged between 6 to 14 years-of-age were fed the salt over 10 months. "The effect was dramatic,"​ he said. "There was a significant reduction of iodine deficiency and anemia." ​ Windhab is now working on applying similar techniques to other foods and processes. "We can tailor food microstructures to meet the needs of such communities,"​ he said. It's a research area known as microfluidics processing. Micro- and nanotechnologies is being used in the research studying the structure formation in foods. The generation of microcapsules for inserting in foods such a salts marks the first success for the science. The micronutrient compounds used in the capsules are soluble in the gastric juice. That means they behave like the salt or sugar crystals you eat every day. After some time of dissolution such crystals reach the nanoscale but then disappear by further dissolution. Windhab, a food technologist, specialises in micro and nano emulsions, and filtration and separation processing flow research. He is famous in Switzerland for developing a process during the late 1990s to prevent the greying of chocolate over time due to the recrystalisation of the coco butter. By analysing the crystalline structure and the different stress factors cocobutter undergoes during processing, he was able to develop a way to get a stable, more dense crystalline structure in filled chocolate. The advance, presented in 2002, is called 'seed pre-crystallisation'. It uses micros and nano techniques to understand and control the process of crystallisation. The process takes pure cocoa butter through a process of shearing and cooling, producing smaller and more stable crystals. The crystals are then injected into chocolate mass. In layman's terms the chocolate remained shiner over a longer period of shelf life. The process time of the crystallisation procedure was also reduced to 20 seconds from 30 minutes. "There was a better colour to the filled chocolate,"​ he said. "There was less recrystallisation." ​ Buhler AG presented its machine using the process, the SeedMaster, at Interpack 2005. Now scientists are using similar techniques to study the phases meso- and nano scale structures undergo during processing. Some of the Swiss work involves studying the gelling of proteins to produce a tailored cheese with an adjusted texture and a higher protein and nutrient levels than that made in a traditional manner. Windhab is also studying droplets to generate microcapsules, similar to the work done on the salt. "It is difficult because we need a way to scale up to mass processing,"​ he said. The solution was to develop a screening membrane that allows for the microscale droplet formation. The scientists were able to get a continuous processing cycle using a rotating membrane cylinder. "This produces a flow process of drops to get multiple emulsions, thus generating multi-microcapsules,"​ he said. This process forms the basis for creating the micro and nano scale capsules. Winhab's work is being funded in part by the European Technology Platform, a means of co-ordinating scientific work throughout Western Europe. "Flow processing offers a powerful toolbox for micro structuring foods, from the molecular to the micro- scale,"​ he said. Such use of nano-science by Winhab and others holds out the promise of better quality and safer foods, with specific health benefits. According to various studies the four major areas in food production that may benefit from nanotechnology development are microscale and nanoscale processing, product development, and methods and instrumentation design for improved safety and biosecurity. A survey of current research by scientists Jochen Weiss, Paul Takhistov, and Julian McClements found other ongoing work in the area includes the molecular design of protective surface systems, surface engineering, and various methods of manufacturing, such as electrospinning and nanofiltration. The influence of the material properties of foods at the nanoscale level on their bioavailability and nutritional value has been highlighted by at least two scientific studies. In addition, other scientists have investigated the relationship between the morphology of food materials and their bulk physicochemical properties. Such studies include ones on biopolymers in solutions, gels, and films. One study found functional nanostructures can incorporate individual biological molecules, which is useful in the development of biosensors that can use natural sugars or proteins as target-recognition groups. Such areas include the development of functional ingredients such as drugs, vitamins, antimicrobials, antioxidants, flavorings, colourants, and preservatives. Association colloids could be another fertile area for commercialisation, they suggest. Nano-emulsions such as the use of high-pressure valve homogenizers or microfluidizers could be used to incorporate functional food components within the droplets, the interfacial region, or the continuous phase. Nanostructured multiple emulsions can be another area of work, used to create delivery systems with novel encapsulation and delivery properties. The most common examples of this are oil-in-water-in-oil and water-in-oil-in-water emulsions. With such work under way research institutes and regulators on both sides of the Atlantic are beginning to move toward regulation the technology. Last year the UK Royal Society and the Royal Academy of Engineering produced a report considering the possible health, social, ethical, safety and environmental questions that could be raised by nanotechnologies. The scientific bodies stated that while nanotechnologies offer many benefits, more public debate is needed about their development. It called for research to address uncertainties about the health and environmental effects of nanoparticles - one area of nanotechnologies. Other countries are also determining how to approach the technology. According to a consumer survey last year by Germany's Federal Institute for Risk Assessment (BfR) clear definitions, terms and standards as well as far more research into the potential problems of nanotechnology is needed before the science is used to a greater degree in products. Consumers were especially critical of the use of nanomaterials in foods, the BfR stated. The agency has commissioned a study on the potential risks of nanotechnological applications in food, cosmetics and other everyday items. In Denmark, scientists at the National Food Institute are currently working on a project to assess the risks nanomaterials pose to health. The project is testing methods to extract or liberate nanosized matter from food contact materials or from cells. "The hypothesis is that the mere nanometre size of matter, and its associated large surface area, may lead to adverse effects in living organisms including humans,"​ they stated in a description of their project. The project started last year and is due to be completed by 2010. Meanwhile a report last year by UK research firm Cientifica singled out active packaging as the most promising area for nanotechnology development. These are packaging materials that interact with the products they contain to preserve or enhance quality The firm singled out three additional areas it believes will result in commercial implementation in the next six years. This includes food safety nano-devices that will detect harmful contaminates, methods to change raw food ingredients into consumable products and additives that will be added to a final product to enhance its quality. Such applications will create a $5.8bn (€4.5bn) market by 2012, with active packaging and food safety showing the highest growth potential. Nano-additives will be the smallest contributor to the overall market largely due to the safety concerns regarding these materials, states Cientifica The development of these materials are being spearheaded by the big players in the food industry who are looking to use nanotechnology to engineer, process and package food. Among the biggest companies with research and development agendas are Altria, Nestle, Kraft, Heinz and Unilever, as well as smaller nanotech start-ups. Cientifica found over 150 applications in the food industry at present and states that the amount of companies applying nanotechnology to food to be in the area of 400. It is impossible to gauge the full-scale integration into the market as many companies regard their nanotech projects as sensitive, the firm noted. In the UK food manufacturers and others are been asked to provide any information on nanotechnologies they are working on, under a voluntary programme launched last year by the government. The government review follows a report in May by the country's Food Standards Agency (FSA), which said gaps existed in EU legislation in regulating the future uses of nanotechnology. Worldwide sales of nanotechnology products to the food and beverage packaging sector jumped to US$860m (€687.5m) in 2004 from US$150m (€120m) in 2002, according to a study by consultant Helmut Kaiser. The German firm predicts that nanotechnology will change 25 per cent of the food packaging business in the next decade leading to a yearly market of about $30bn (€24bn). Nanotechnology is the ability to measure, see, manipulate and manufacture materials at usually between 1 and 100 nanometers. A nanometer is one billionth of a meter. A human hair is roughly 100,000 nanometers wide. The science exploits the fact that some materials have different properties at this ultra small scale from those at a larger scale.

Related topics: Processing & Packaging

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