BRAIN: Since when has taste optimisation been a topical subject at BRAIN?

Dr Katja Riedel: BRAIN developed cell models for sensorial applications 10 years ago, with a specific focus on relieving skin pain. It’s interesting to note here that the „TRPV1” pain receptor is also found on the tongue, where it allows us to taste the “hotness” of chili peppers. Research then moved from the sensory functions of the skin to those of the tongue, i.e. taste. To examine the various taste receptors for bitter, sweet or umami in greater depth, the sensors (taste receptors) were examined using kidney cells. That was a common method used at the time to research taste.

BRAIN: Can kidney cells be compared with taste cells on the tongue?

Dr Katja Riedel: That is precisely the weak point of the kidney cell method. The manufactured kidney cell can recognise sweetness, but cannot distinguish between sugar and sweeteners, because it lacks the necessary metabolic and communication pathways.

BRAIN: Wouldn’t it be possible to directly use tongue taste cells?

Dr Christiane Gras: Unfortunately not, because they have a very short life span and are frequently renewed in the taste buds. For lab tests, they need to keep for a few months so that all experiments can be carried out with an identical cell population. Otherwise the results cannot be compared.

BRAIN: How did BRAIN nevertheless succeed in making progress with taste cells?

Dr Katja Riedel: About five years ago, BRAIN began isolating these taste cells and finally we managed to develop a cell model with a longer life span based on the cells on our tongue. This is the Human Taste Cell (HTC) technology. This cell model can now be used to search specifically for taste modulators.

BRAIN: When do sensory tests with test subjects come into play?

Dr Christiane Gras: The disadvantage of sensory tests is that time is very limited. Only a few flavour compounds can be tasted per day. If test subjects are asked to taste more than three compounds, they develop taste fatigue. HCT technology, on the other hand, makes it possible to test thousands of natural substances with no time constraints, independently of whether they have already been classified as toxicologically safe or not. The bottom line is that approx. 0.5 – 1% of candidates that are suitable for our purposes are sifted out of 20,000 examined substances. In a second step, these substances are then narrowed down again using taste tests with human testers – that’s when sensory tests can provide further findings. We can use this process to find taste modulators and then confirm their effect using sensory tests with test subjects.

BRAIN: Does that mean there are details that only human test persons can detect?

Dr Katja Riedel: Yes, for example in connection with special perceptions. Taste cells cannot detect whether a substance has an astringent effect or tingles on the tongue.

BRAIN: Is the HTC technology proprietary to BRAIN?

Dr Katja Riedel: Yes. We have applied for a so-called PCT patent for selected cell lines, which has already been granted in many countries, including the U.S. Of course, the substances discovered using such a cell line are even more interesting than new cell lines themselves. BRAIN submits patent applications for these substances and their formulations – an important milestone in the company’s development.

BRAIN: Can you name an example of such a newly discovered formulation?

Dr Christiane Gras: The bitter blocker BRA-C-000001371 was one of these milestones. For example, It can be used in drinks that incorporate sugar substitutes and have a bitter off-note. This off-note is neutralised thanks to the bitter blocker. The bitter blocker can also be used for developing or formulating medicines to offset the bitter off-note.

BRAIN: How does BRAIN measure how successful a technology or formulation really is?

Dr Katja Riedel: If potential cooperation partners from industry wish to work together with BRAIN, that is great proof of our quality and shows that we have gotten things right in many respects. Beyond this, when sensory tests with test persons offer proof of the effect of substances found in the lab, that is the best confirmation of success, and we have repeatedly been able to offer such proof.

BRAIN: Has industry become interested in the topic of taste optimisation?

Dr Christiane Gras: BRAIN has also performed a great deal of scientific research into taste cells and gained a high profile in the world of research, on the one hand through publications, and on the other through lectures and presentations at science conferences.

Dr Katja Riedel: We successfully applied for funding from the German Federal Ministry of Education and Research (BMBF) for our first basic research on generating taste cells and searching for taste cell modulators for a healthier diet. Within the NatLife 2020 innovation alliance, we were able to lay the foundation for the HTC technology that now also serves as a basis for cooperation projects with clients. One of the cooperation arrangements with several industry partners has only recently been announced. These positive developments and scientific publications have made more companies from the food and feed industry aware of BRAIN. The latter were interested in transferring the technology to animal cells.

BRAIN: What was the idea behind this?

Dr Christiane Gras: They wanted to better understand cat taste perceptions in order to modify cat food more specifically. There are still several cat taste sensors that are completely unknown, and plenty of gaps to be filled in that respect. Since cats cannot speak, which makes sensory tests more difficult, a system similar to that of human cells is required for a gradual approach to the subject.

BRAIN: Was BRAIN able to draw on existing HTC findings, or did you have to start from scratch?

Dr Christiane Gras: We were indeed able to transfer existing knowledge from the field of human taste cells to that of cat taste cells, and obtain results fairly quickly. That has a positive effect on research costs and time requirements. So it supports efficiency.

BRAIN: Does that mean there are details that only human test persons can detect?

Dr Katja Riedel: Yes, for example in connection with special perceptions. Taste cells cannot detect whether a substance has an astringent effect or tingles on the tongue.

BRAIN: Is the HTC technology proprietary to BRAIN?

Dr Katja Riedel: Yes. We have applied for a so-called PCT patent for selected cell lines, which has already been granted in many countries, including the U.S. Of course, the substances discovered using such a cell line are even more interesting than new cell lines themselves. BRAIN submits patent applications for these substances and their formulations – an important milestone in the company’s development.

BRAIN: Can you name an example of such a newly discovered formulation?

Dr Christiane Gras: The bitter blocker BRA-C-000001371 was one of these milestones. For example, It can be used in drinks that incorporate sugar substitutes and have a bitter off-note. This off-note is neutralised thanks to the bitter blocker. The bitter blocker can also be used for developing or formulating medicines to offset the bitter off-note.

BRAIN: How does BRAIN measure how successful a technology or formulation really is?

Dr Katja Riedel: If potential cooperation partners from industry wish to work together with BRAIN, that is great proof of our quality and shows that we have gotten things right in many respects. Beyond this, when sensory tests with test persons offer proof of the effect of substances found in the lab, that is the best confirmation of success, and we have repeatedly been able to offer such proof.

BRAIN: Has industry become interested in the topic of taste optimisation?

Dr Christiane Gras: BRAIN has also performed a great deal of scientific research into taste cells and gained a high profile in the world of research, on the one hand through publications, and on the other through lectures and presentations at science conferences.

Dr Katja Riedel: We successfully applied for funding from the German Federal Ministry of Education and Research (BMBF) for our first basic research on generating taste cells and searching for taste cell modulators for a healthier diet. Within the NatLife 2020 innovation alliance, we were able to lay the foundation for the HTC technology that now also serves as a basis for cooperation projects with clients. One of the cooperation arrangements with several industry partners has only recently been announced. These positive developments and scientific publications have made more companies from the food and feed industry aware of BRAIN. The latter were interested in transferring the technology to animal cells.

BRAIN: What was the idea behind this?

Dr Christiane Gras: They wanted to better understand cat taste perceptions in order to modify cat food more specifically. There are still several cat taste sensors that are completely unknown, and plenty of gaps to be filled in that respect. Since cats cannot speak, which makes sensory tests more difficult, a system similar to that of human cells is required for a gradual approach to the subject.

BRAIN: Was BRAIN able to draw on existing HTC findings, or did you have to start from scratch?

Dr Christiane Gras: We were indeed able to transfer existing knowledge from the field of human taste cells to that of cat taste cells, and obtain results fairly quickly. That has a positive effect on research costs and time requirements. So it supports efficiency.

BRAIN: Does that mean humans and cats are very similar?

Dr Katja Riedel: We mainly work with primary cells taken from tissues. The functionalities of these are very similar in humans and cats. But that doesn’t mean they perceive taste in the same way.

BRAIN: How does taste in cats differ from that of humans?

Dr Christiane Gras: Cats cannot perceive sweetness, because their gene for the sweetness receptor does not work. Whereas the reward system in humans and many other animals perceives sweetness as a positive factor, this mechanism can’t be used for cats. That makes it difficult to optimise cat food, and means we need to look for other solutions.

BRAIN: How can cat tastes be tested at all, given that we can’t ask the animals for their opinion?

Dr Christiane Gras: Sensory tests can still be carried out with cats. They are given aqueous solutions, and then we measure how much of these they have drunk. Since cats generally drink very little, the intake of solutions is measured by their regular intake of water.

BRAIN: How do cats react to bitter tastes?

Dr Katja Riedel: Cats find bitter tastes unpleasant. That’s where we can compare them again with humans and most animals. So if the cats drink hardly anything of a test solution, that may be because it contains bitter substances.

BRAIN: Why is there a need to optimise cat food, in particular?

Dr Christiane Gras: Unlike other pets, cats are very choosy about their food. In nature, they mainly eat mice and small birds. They are pure carnivores. If cats are kept inside the house, their food must be chosen so that the cat accepts it without problems, and it must contain all the nutrients the cat needs.

BRAIN: What is the market potential that can be expected in this segment?

Dr Christiane Gras: Based on 618 million cats and dogs in 2014, the number of pets is growing constantly by an average of 2.1% per year. The market for cat food alone is growing by 1.7% per year, as published by Euromonitor. In 2014 alone, 22 mega- tonnes of animal food were produced with a value of EUR 53 billion.

BRAIN: Who is BRAIN cooperating with? Can you give us any names?

Dr Christiane Gras: We are cooperating very successfully with DIANA Pet Food, a manufacturer of cat food. The aim in the coming years is to develop taste modulators that make cat food even tastier.

BRAIN: Does BRAIN have its sights on other animal feed segments?

Dr Christiane Gras: Our findings in the field of cat taste cells open up enormous potential for optimising other kinds of animal feed. We will naturally work on these so that the taste of other types of animal feed can be optimised as well.