chocolate

   Chocolate  is a  food  made from roasted and ground  cacao seed  kernels that is available as a liquid, solid,        or paste, either on its own or as a  flavoring agent  in other foods. Cacao has been consumed in some form        since at least the  Olmec  civilization (19th–11th century) and the majority of  Mesoamerican  people,                    the  Maya  and  Aztecs , made chocolate beverages. In a study, which has been published in the journal ACS Applied Materials and Interfaces, the Leeds researchers explained that when those bites of chocolate hit our tongue, a “fatty film” — their words — is released into our mouths, providing an irresistibly smooth sensation as we chew.