An incredible article that is less about McDonald's fries and more about the history and inner workings of the flavor industry, and the relationship between sight, smell and taste.
A nose can detect aromas present in quantities of a few parts per trillion — an amount equivalent to about 0.000000000003 percent. […]
The chemical that provides the dominant flavor of bell pepper can be tasted in amounts as low as 0.02 parts per billion; one drop is sufficient to add flavor to five average-size swimming pools.
These observations remind me of something similar I read recently in Neil Shubin's Your Inner Fish: A Journey into the 3.5-Billion-Year History of the Human Body (which is wonderful by the way), namely that 3% of our genome is devoted to genes for detecting different odors (i.e., each gene makes a receptor for an odor molecule). Wow!