Michelle Dickinson: nanotechnologist explains why we find chocolate so irresistible

It’s Easter Sunday, and for many of us this means devouring one (or maybe more) chocolate Easter eggs.  As we head in for another bite, when we promised ourselves we would take it slow – the question is, why is chocolate so irresistible and moreish?  Scientists at the university of Leeds asked this question too and their results were published this week in the journal Applied Materials and Interfaces. By using high quality dark chocolate, synthetic saliva and an artificial 3D printed tongue, the researchers used a field of engineering known as tribology to study way that the surfaces in the mouth interacted with the chocolate.  They found the that the most important ingredient that gives chocolate its amazing mouth feel is fat.  When chocolate is in contact with the tongue, its warm temperature causes a phase change of the fat from a solid to liquid.  This liquid fat coats the tongue and the mouth, which them makes the chocolate feel smooth the entire time it is in the mouth.  Interestingly, they found that once the mouth is coated with fat, it doesn’t need any more fat to keep the chocolate tasting smooth and delightful. So theoretically the fat particles only need to be on the outside of the chocolate, not in the middle to maintain the chocolate sensation.  This leads the researchers to believe that a “healthier” reduced fat chocolate could easily be made by creating a low fat cocoa centre surrounded by a higher fat outer coating. They also believe that this theory could be transferred to other high fat delights including ice cream and custard.  And they think the discovery will lead to creation of chocolates that are healthier, without sacrificing either texture or taste.  LISTEN ABOVESee omnystudio.com/listener for privacy information.