The food, the senses and the science
Sensory analysis, or sensory evaluation, is a method of measuring the properties of food with the aid of the human senses. Sensory science is about understanding how and why the answers we get relate in a wider perspective.
In order to understand the interaction between the food we eat and human sensory perception, knowledge of and research into many different disciplines are needed, including chemistry, food technology, psychology, physiology and statistics.
Sensory evaluation is a young science. Even so, two of those who have dedicated their working lives to this field are now coming up to retirement. The Nofima food research institute has been the workplace of both Magni Martens and Marit Rødbotten. The theme of a recent seminar that honoured them both was Sensory science – before, now and in future.
First to define sensory analysis as a science
We begin with the history, and here it is worth noting that research scientist and professor Magni Martens was the first to define sensory analysis as a science. One that lies at the intersection between natural science and behavioural science. Quality, and how to measure it, has been the constant theme of Martens’ work. Of all her publications, the book Multivariate Analysis of Quality is the best known. It considers the methods that can be used to combine what people sense with a product’s chemical properties, and in this way measure the quality. If you have studied sensory analysis, it is highly probable that this was your text book.
Honorary professor of taste, smell and feeling
Martens was not only the first to define sensory analysis as a science. She was also the first professor of sensory science at the University of Copenhagen in 1995. In 2007, she was also made an honorary professor of taste, smell and feeling.
While Magni Martens has specialised in sensory analysis methods, Marit Rødbotten has been at the forefront in developing a sensory vocabulary, practical applications and the use of sensory methods in applications such as sensory taste maps. A taste map shows the location of a selection of products within a defined category with their associated sensory properties. Rødbotten has also played a key role in the development and quality assurance of Nofima’s sensory panel. This consists of 12 judges and is the only accredited panel of sensory judges in northern Europe.
Sensory judges are the only objective assessors
The seminar attracted delegates from both Norwegian companies and foreign universities and research institutions. British professor Hal MacFie insisted that understanding "liking" is not as easy as we might think.
Untrained taste panels (consumers) are exactly that: untrained. According to MacFie, they tend to give the first samples higher scores than they would have done if they had been further down the list. He urges people who work on product development to use professional sensory panels in combination with consumer responses, to be sure that they get the right answers.
Another important theory discussed by Hal MacFie is that consumers give different answers to a question, depending on whether they are given only this question or other questions to begin with. If you serve a chocolate mousse and then ask: How sweet do you think this mousse is? you will get a different answer from the one you would have got if you had first asked, for example, how much do you think this mousse tastes of cocoa? Does it taste of milk? and then asked: How sweet do you think this mousse is?
Why does this happen? It is because the brain is divided into two systems.
Impulsive versus experienced
The impulsive system (system 1) arises automatically and does not require us to think first. We are quite uncritical. The experience-based system (system 2) comes into play when something is difficult, and we become more careful and critical. We make different decisions in system 1 and system 2, and this also applies to how we judge what we eat.
"The difference in how we think when we use system 1 or system 2 is worth considering when developing new products," says MacFie.
Maintaining and developing the sensory heritage
"Magni Martens and Marit Rødbotten have helped to build up a solid platform for present-day sensory research at institutions such as Nofima, and we will maintain this heritage and take it with us into the future," says Senior Research Scientist Margrethe Hersleth of Nofima.
She sees two important strategies for future sensory research at Nofima helping to create a healthier popular diet. One is to change the food. That is to say, using sensory analysis to encourage a change to healthier products that still taste good. The other approach is to "change the consumer". That is to say, teaching and influencing both adults and children to choose and eat healthy food.
The analytical part of the heritage left by the two retired researchers is also shown in the development of software for tests by sensory panels and software to analyse which sensory properties are important for consumer acceptance.
The software for tests by sensory panels is called PanelCheck. It has been on the market for several years and is now used by companies and institutions in more than 50 countries. The program is free of charge and can be downloaded here.
ConsumerCheck is a further development of PanelCheck that is still under development. Here, the emphasis is on methods for integrating sensory analysis and consumer research.
"This program is expected to be available in autumn 2013 and will provide completely new opportunities for rapid and effective innovation," concludes Senior Research Scientist Tormod Næs.