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01/11/2010
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Ruud van der Sman
Food science and the food industry face the enormous challenge of making food both healthy and tasty. I would like to suggest that food science desperately needs the help of physicists on this issue.
Because of the pressures of life in modern society, many consumers tend to choose food rich in fats and carbohydrates – which is logical, given our genetic background. However, the society of today is far removed from the living situation in which we evolved, and these biologically dictated choices can result in obesity and diabetes. The challenge for the food industry is to make healthy food a logical choice for the consumer.
This logical choice can be realised by manipulating the structure of food, as shown in figure 1. Figure 1 also clearly shows what food actually is from the standpoint of physics: a complex liquid with structural elements such as gas bubbles or oil droplets.
Figure 1. Examples of healthy and tasty food structures: a & b) air bubbles covered with a layer of protein, which feels greasy, and c) double emulsions, in which fat droplets are filled with water. Both structures result in a taste experience which is very fatty or creamy, but their fat content is reduced as a result of the enclosed air or water.
Physicists call this type of complex liquid “soft matter,” and the field which studies it is called “soft matter physics”. Physicists are looking for the universal laws which apply in this sort of physics. For example, they consider food to be in the first place a liquid with hard balls, while food scientists exclaim that every food ingredient has its own functionality and it is impossible to generalise about food in that way. Actually, the truth can be seen in both sides. However, soft matter physics shows that the functionality of food structure at a micrometre scale is determined purely by the form and functionality of the structural elements and much less by the chemical details at the molecular level. These chemical details do, of course, determine the taste and the nutritional value.
Knowledge about the manipulation of food structure is only now beginning to be well developed. A few scientists from Wageningen UR are active in this field and are making important advances. For instance, how meat is cooked, the thermodynamics of carbohydrates, and filtering milk and beer have all been examined from the point of view of soft matter. Our discoveries within this field are gaining appreciation from physicists, judging from the large number of scientific publications in the leading journal Soft Matter.
However, the questions regarding food structuring are too large for the few food scientists concerned with soft matter physics. It is essential to involve top physicists in this issue.
Wageningen UR is developing activities which will make it clear to leading figures in physics that food is more than just “daily bread,” it is also one of the most complex forms of soft matter, and therefore the ultimate challenge for physicists. For instance, in 2012 we will be organising a Faraday Discussion about “Soft Matter Approaches to Food Structuring”.
An intense collaboration between food scientists and physicists will result in major progress in the creation of food structures which are both healthy and tasty. In addition, we will gain insight into the preparation of food structures using the elementary building blocks of proteins, carbohydrates and fats. This will also enable us to connect our work to research into the sustainable production of food ingredients from various agricultural raw materials, which is another major challenge for the food industry.
We also hope to encourage the physicists of the future, who are currently in school or at university, to use their talents for the sake of these challenges.
Ruud van der Sman
- Senior researcher at Wageningen UR Food & Biobased Research
- Assistant Professor at Wageningen University, Food Process Engineering