Restoring taste to chewed chewing gum

Chris -   Now we're returning to our theme this week, which is Tricks of the Mind and how the brain works. In a minute we'll find out why names are so easy to forget. And we'll also find out how the placebo effect comes about. But before that we'll return to Barry Smith, who's with us for this week's program. And, you've got another trick for us.

Barry -   Yes. So Martha's been chewing some minty chewing gum and I hope by now the mintiness has disappeared.

Martha -   Yes and it's going a bit cardboardy and generally not very nice.

Barry -   OK. So now what I'm going to do is I'm going to ask you to take it out of your mouth and roll it in this little mound of icing sugar that I've got in front of you and if you just pop that back and have a chew on it.

Martha -   Urgh, choking on some icing sugar.

Barry -   Tell me how it tastes now. Just keep chewing away for a moment or two. So what we're really investigating is the way that one sense has an impact on another. So, here we're talking about how taste might affect smell.

Martha -    Mmm...Yeah, so it's definitely tasting newer again and yeah, the mintiness is coming back.

Barry -   So the mintiness has come back and that's amazing because there is no mint in icing suger. So that's a strange effect. What you're getting is the fact that when you combine the sugar with the odour in your mouth, you get something super-additive that's more than the sum of the parts. You're not getting them both together, you're getting the sugar boosting your ability to detect mint and the mint seems to resume its presence.

Chris -    Does this manifest anywhere else in the food industry? Do other manufacturers use this effect to enhance other flavours?

Barry -   Yes, and they do it often with smell to taste going in the other direction. So when you smell vanilla, people often say it smells sweet. And we know that if you're tasting a liquid, say, and get a vanilla aroma with it, it will taste sweeter. And that's, in fact why vanilla ice cream is much better to make than anything else, because you can use less sugar to produce it because you've got the vanilla smell to give us this sweet experience.

Chris -   You can legitimately argue it's a diet ice cream.

Barry -   It's a diet ice cream!