Professor Peter Barham, University of Bristol
Part of the show Science of Seduction, Pheromones and the Food of Love
Kat - So Pete, what's the best thing to serve on Valentine's Day?
Pete - Goodness me that's a difficult question! The best thing to serve on Valentine's Day is whatever your partner likes the most.
Kat - But what makes things taste good to people?
Pete - That's largely a matter of individual experiences. We all have these senses in our noses and in our mouths that tell us what we like, and as you've already noted, flavour and taste are very strongly related to memory. So things we like tend to be things associated with really good memories. So something that we really liked or enjoyed in our childhood tend to give us something that we like more. It's not quite as simple as that, but that's the basic idea.
Chris - Let's just get into the nuts and bolts of how taste works. First of all, when I put something in my mouth, what's actually happening at a neurological level for me to be able to taste it?
Pete - That's a question no-one knows the answer to. Where do you think we taste something?
Chris - Most people believe that taste is all down to the tongue, but that's not true is it?
Pete - Not at all. Our tongue can detect five different sensations: salt, sour, sweet, bitter and umami. Those are the five basic senses we've got in our mouth and they really are pretty crude. They can't distinguish much at all. Then they give signals to our brain. When you're eating and chewing, some of the molecules from your mouth go up the back of your nose and you breathe them out. It's mostly on the breathing out that you detect them. You nose has hundreds of different sensors in it, and it can recognise millions of different molecules. The nose is where most of the taste information going to your brain comes from.
Chris - So there is truth in the claim that if you hold your nose when you're eating something you don't like, such as brussel sprouts, you should be able to abolish the unpleasant taste.
Pete - You will change it. Of course, with brussel sprouts you've got that sour taste if they're over cooked. That acidic taste will still be in the mouth because it's coming from the tongue, but it's not just your tongue and your nose. You also taste with your eyes and hands and ears. If you think about it, when you're eating something you see it first. The very first thing you do is look at and say 'What am I expecting?' Expectation is set up. If you don't see it or if you see something unexpected, your brain won't work right. A good example of that is if you give professional wine tasters a red wine to taste and a white wine to taste, they will tell you that they're different. But if the red wine is just the same white wine with food colouring added, they still won't recognise them as the same wine because they expect something different.
Kat - A lot of people for Valentine's Day will be giving each other chocolates. Why does chocolate taste so good?
Pete - Of course chocolate has a combination of two of the things that we really like: that's sugar and fat. That's probably built into us from evolutionary times before supermarkets, when if you could get sugar you were able to run around and catch food, or if you ate fat you could lay it down and store it for the future. Those were really important things of which people wanted to get as much as they could. Put them together in something and that makes it really good. Sugar and fat alone is one reason for liking it.
Chris - Have people built systems so that people can work out what the taste profile of a substance is and then predict what it will go well with?
Pete - There are lots of people out there in various research institutions and food companies who are very concerned with knowing what the main flavour molecules are in any specific product. So far in coffee, over a thousand different molecules have been identified. Even if you know what they all are, knowing which the important ones are is quite difficult because you can feed different people different combinations of them and ask them what they taste, but different people will give you different answers. But yes, people have done research on it, and once you've identified the key molecules then you can look at profiles and starts to work out whether one food will go well with something else.
Kat - So what are particularly romantic tastes? Are there certain tastes that are more sensual?
Pete - I think the sensual tastes are those which coat the mouth and give a nice warm feeling. Chocolate is great for that as it cools the mouth when you put it in because it melts the chocolate. Other ones are things that are very crisp, clean and clean the palate, such as caviar and champagne. These are all things that people tend to like as very special foods. Rare and expensive foods also tend to be sensual because you fell as though you're being treated to something important.
Chris - Do you think there'll be a day when we might be able to go to the supermarket and buy foods depending on their profile? Someone will say that you can mix two items because the taste profile of one thing will map onto the taste profile of another and you can get a really bizarre combination that tastes great. This is the basis of molecular gastronomy isn't it?
Pete - It's something that some people call molecular gastronomy, yes. Some chefs are doing exactly that. I think to do it in a supermarket would be very boring!
Chris - I think it'd be really interesting!!