Lecture Dr. Frans W. H. Kampers of Wageningen University at the AAAS-meeting in Chicago, 14th Februari 2009
Nanotechnology is a rapidly developing innovative technology with applications in very many area’s, including food, nutrition and food industry. Many people associate nanotechnology with nanoparticles and link the hazards of nanoparticles to all applications of nanotechnology. However, most nanotechnology does not result in nanoparticles and most nanoparticles are from natural origin and therefore should not be considered nanotechnology. The opportunities of doing business at the nanolevel in food applications arises from the realization that foodstuff usually has a structural hierarchy that starts at the molecular and supramolecular level. Creating new functionality in a food product therefore often means starting the modifications at the nanolevel.
There are four global challenges regarding food where state-of-the-art technologies like micro- and nanotechnologies can contribute: feeding the increasing world population in a sustainable way; improving the quality and safety of foods; delivering those nutrients to individual consumers that are required for good health; and helping in the prevention of welfare diseases like obesity. These will be discussed next.
The increasing levels of welfare in large populations will result in shifts in diets towards more protein rich components (meat and fish). Our planet is not big enough to produce the corresponding amounts of meat and/or fish in the traditional way. New technologies will have to be developed to utilize the plant protein sources more efficiently than via animal production. The realization that meat is a material with structural elements also at the nanolevel implies that developing a good meat replacement from plant or dairy protein sources requires structuring the product at the nanolevel and constructing the structural hierarchy all the way up to the macrolevel. Ongoing research at Wageningen UR (Atze Jan van der Goot, Food and Bioprocess Engineering) has delivered first results of such a development.
Although food never was as safe as it is now in industrialized countries, a report from the WHO from 2002 shows that there is still much room for improvement. Food industry is always looking for opportunities to monitor food quality in various stages of the chain more accurately. However, they are handicapped in the sense that measuring microbial activity on a food material requires a well utilized lab, qualified personnel and time. And time is something that is valuable in chains where quality deterioration occurs rapidly. Food industry would like to have fast, cheap, easy to use, sensitive and accurate devices that can be used close to the production line of foods for the detection of pathogens or the quantification of spoilage organisms. Nanotechnology can contribute to the fulfillment of this demand. The method could be based on the detection of specific DNA fragments of which an example is shown, developed by Wageningen UR (Aart van Amerongen, AFSG).
Nanotechnologies are also used to improve packaging materials in such a way that the quality of the packaged products is maintained for longer periods in time. Barrier properties, to reduce oxygen leakage in modified atmosphere packaging systems is a low tech application of nanostructured clay materials. Adding nanoparticles with antimicrobial properties to the packaging material helps to reduce the bacterial pressure inside the package and therefore slows down spoilage. RFID technology in combination with head space sensors can directly communicate information about the real quality status of the product to the logistical systems, the cash desk or even the refrigerator. This will become economically viable in combination with printable electronics, another result of nanotechnologies.
If everybody eats a varied diet with 200 g of vegetables and two pieces of fruit a day we all would get all the nutrients we need to stay health. Unfortunately there are very few people who eat this sensible. Large groups in society have one sided diets and run the risk of missing out on certain nutrients. Especially since our food is extremely rich in calories while our digestive system—evolved in times when periods of food scarcity where abundant—is optimized to store as much of the calories as possible. This effect in aggravated because of our life styles that require virtually no exercise to get the food and in which much less energy is required to maintain our body temperature. The result is that we eat much less high calorie food that does not contain very many other components. Our gastro-intestinal tract, designed to process large quantities of low calorie foods, has very little possibility to extract all the necessary nutrients. The food industry therefore develops novel food products that are fortified with specific ingredients. Nanotechnology can provide microsized containers that can contain various nutrients. The supramolecular structures used for this purpose can mask undesired flavors that would spoil the flavor of the product, can protect the substances from inactivation, can improve the bio-availability of the nutrients and can deliver them to specific parts of the Gastro-Intestinal tract where they are most effective. Creating these structures in a cost effective way is not trivial and requires intricate knowledge of self-assembly mechanisms. At Wageningen UR (Physical and Colloid Chemistry) fundamental research is being done to understand these mechanisms and to find new ways to create these innovative encapsulation systems.
It is well known that welfare diseases like obesity rapidly develop in an epidemic that could threaten the healthcare system in the industrialized world. Apart from the lack of exercise, the main problem is the fact that our food contains too many calories. The intricate understanding of processes at the micro- and nanolevel allow us the re-engineer processes in food industry and to create new products that taste and feel the same, but contain less calories. As an example Wageningen UR research on double emulsions (Food and bioprocess Engineering) was presented where the core of oil droplets of an oil-in-water emulsion is replaced by water. This could result in a mayonnaise that tastes and feels like the full fat kind, but contains much less calories.
At Wageningen UR we are very well aware of the discussions within society about applications of nanotechnologies in food. Societal acceptance is a condition sine qua non to be able to make use of the opportunities discussed before. On of the key aspects of that is the risk/benefit evaluation of these applications. Unfortunately the general public lacks the ability and the information to make a good risk assessment and predominantly is focused on the hazards in stead of hazard times exposure. Moreover, since the general perception is that nanotechnology equals nanoparticles, the hazards of nanoparticles are equated with risks of nanotechnology. But the hazards of nanoparticles concentrate on the non-dissolvable, persistent particles often made of metals or metal oxides. These particles can sometimes traverse barriers, get in the blood stream and enter certain tissue. Persistent nanoparticles are rarely used in food products for the very simple reason that the body can not benefit from them. The nanotechnology in products largely is used to create encapsulation systems that are designed to fall apart in the Gastro-Intestinal tract and release their contents. Afterwards only molecules of food-grade materials remain and no particles are found in the feces of the consumer. Moreover, these encapsulates are usually larger than 100 nm and therefore do not constitute nanoparticles. The nanotechnology is in the wall of these particles to create the specific functionality that offers the new properties to the product.