Chocolate Aromas

http://www.sciencedaily.com/releases/2011/08/110829142510.htm

Chocolate is a favorite food among many. Would it still be if one knew that it is composed of substances that, when separated out, smell like raw beef fat and human odor?  This article discusses the perception of taste and how individually different substances can combine to form a taste.

When chocolate is processed the beans are fermented in a basket for days and then left out to dry. This process creates a reaction that then reacts, when roasted, to release aroma compounds. The reaction that occurs is known as the Maillard reaction, a reaction that happens between an amino acid and a reducing sugar, and normally requires heat.  The carbon molecules in the sugars combine with the amino acids in proteins in this reaction. While many parts of this reaction are unknown, pH, types of amino acids present, the temperature, and the amount of water present are known to influence the aroma and color of the food. It is this reaction that produces the mixture of flavor compounds in each food, in this case the multitude of flavor compounds in chocolate.

The Maillard reaction describes the many flavors within chocolate but doesn't completely describe why it tastes the way it does. Scientists noted that the taste buds weren't the only receptors that defined the taste of something. Odor receptors in the nose also contribute to the perception of taste. These scientists identified some substances in chocolate aromas that bind to the odor receptors in the nose and then created "recombinants" containing those ingredients. Taste testers couldn't tell the difference
in the new substances they created though, individually, some of the substances used smelled like cooked meat and beef fat. Using chemistry by separating different aromas and ingredients in a food, scientists were able to relate odor and the perception of taste. In fact, as stated in the article, " Only 25 of the nearly 600 volatile compounds in a cocoa bean are needed to create a good cocoa aroma".  In addition, scientists were able to discover a chemical reaction, the Maillard reaction, that releases flavor components in foods through a series of chemical reactions. Scientists conclude that taste is a combination of both human odor and taste receptors working together to generate a perception or taste to the brain.

Maillard Reactions. (n.d.). Retrieved September 6, 2011, from Food-Info.net website:
     http://www.food-info.net/uk/colour/maillard.htm

Pollick, M. (n.d.). What is the Maillard Reaction. Retrieved September 6, 2011, from Conjecture
     Corporation website:  http://www.wisegeek.com/what-is-the-maillard-r


Posted by Gen Eng-Surowiec