Dr Katja Riedel talks about BRAIN’s research into the perception of different tastes for healthier foods.
BRAIN: What does your research into taste perception involve?
Katja Riedel: We examine and use the taste sensors of the human tongue that are responsible for perceiving bitter, sweet, salty, savoury (umami) or sour tastes. Added to these are complex perceptions such as the taste of fat. Our research aims among other things to find natural substances that can replace sugar or enhance its taste. That also applies to the perception of saltiness or bitter off-tastes as well as the texture of fat and the sensation it provides. This type of natural substance should be used to make a food or drink healthier, while retaining its customary taste. Basically, we intend to use natural alternatives to improve food formulations.
BRAIN: To what extent do you use cell-based assays to identify such ingredients?
Katja Riedel: At BRAIN, we initially started out by researching the sensory functions of the skin [see interview with Dr Alice Kleber and Dr Dirk Sombroek in this issue of Blickwinkel, editor’s note]. Very soon, though we transferred this knowledge to the sensory functions of the human tongue. The TRPV1 ion channel, for instance, can be found both in the skin and on the tongue. In the skin it transmits a burning and prickling sensation, on the tongue the hot sensation of chilli peppers. In evolutionary terms, the channel in both systems has the task of warning us again potentially dangerous exposure. We have succeeded in developing cell-based assays for examining our perception of taste; these facilitate the previously very time-consuming search for flavourings. These models are based on tongue cells, among others, and enable us to search for alternatives to sugar, salt and fat on a large scale. They are part of our patented Human Taste Cell (HTC) technology. Using these cell-based assays, we can examine the effect of thousands of natural substances from edible plants or microorganisms rapidly and with a high level of efficiency.
BRAIN: Are there other fields of application for your HCT technology?
Katja Riedel: We have been able to successfully transfer our knowledge about human tongue cells to assays based on animal cells, such as those of cats. The aim here is to improve food for pets. Cats are very choosy, and used to feed predominantly on small prey in their natural habitat. So it is not easy to provide house cats with adequate food that they find appetising. In this field we are cooperating very successfully with DIANA Pet Food.
BRAIN: How do you apply your technologies in food products?
Katja Riedel: One early result of our work was to identify a natural substance that can mask bitter off-tastes as part of our ANTI-BITTER development programme. This substance can be used in drinks with sugar substitutes or when formulating medicines to neutralise off-tastes. The bitter taste is a key research area because it is more complex than other tastes and is perceived very differently by different people. In an effort to reduce excessive levels of sugar and calories in as many foodstuffs as possible, we launched the DOLCE programme for natural sweeteners and sweetness enhancers together with AnalytiCon Discovery and the French Roquette company. The first suitable natural products for specific applications are now being selected with companies of the food and beverages industries. Salt is the focus of our ongoing SALT-E development programme. Another development programme is being prepared to look into the taste of fat. Excessive consumption of these two substances can impair health, just like sugar. Here too, the aim is to find natural alternatives that help make our foods more healthy.
Dr Katja Riedel
Dr Katja Riedel studied applied natural sciences at TU Bergakademie Freiberg (University of Resources) and obtained her doctorate at the German Institute of Human Nutrition in Potsdam-Rehbruecke. She joined BRAIN in 2011, where she now works as a programme manager in System Products Nutrition.