We learn at school that there are four primary tastes ( Sweet, Sour, Bitter & Salty) The rest of your ‘organoleptical’ experience is provided by the olfactory region of the nose which we perceive with our nose via an open connection or passage from the back of the mouth to the nose.
Amazingly, the 4 primary taste concept goes back to 5th Century BC Greece when a guy called Democritus identified the primary tastes and declared them to be due to food breaking down into minute components with four different shapes that interacted on the tongue. Not a half bad conclusion considering he only had metaphysics, his favorite tree to contemplate under and maybe his mom’s Moussaka to guide him.
So, for 2300 years everything was right in the tasting world until the first murmurings of dissent were heard around the turn of the century (19C>20C) when a mover and shaker, French chef called Auguste Escoffier developed a veal, demi-glace stock. He had reached new culinary heights and demonstrated a new taste category; his customers agreed and thought it was best food they ever tasted but no-one knew why.
On the other side of the planet the same light bulb went on for a Kikunae Ikeda-san, his specialty was a seaweed soup called dashi which was also used as a base stock. Ikeda decided that his soup also contained a fifth primary flavor component and by chemically analyzing foods he considered to be high in the new flavor, he successfully isolated the compound responsible – Glutamate. A huge industry was founded based on glutamate, and eventually in 2002 it was made official, there was indeed a 5th primary taste and it was dubbed umami (delicious).
Scientists confirmed that the human tongue has receptors for L-glutamate; the L- indicates that it is the laevo or left handed version of the molecule that triggers the sensation. Democritus had it so right. The shape of the glutamate molecule -made out of 5 Carbon, 9 Hydrogen, 4 Oxygen and 1 Nitrogen atom - has to be so exact, like a glove; the right handed version of glutamate doesn’t fit and wont do .
Question: Why did we humans bother to evolve a taste for glutamate?
A possible clue might lie in modern versions of Escoffier’s recipe which utilize a lot of bone marrow. If marrow is an important source of glutamates, could that be how or why our 2 million year ancestor, Homo habilis is thought to have carved a carnivorous or at least omnivorous niche for him or herself ? The theory goes that Homo habilis extracted nutritious bone marrow from the bones of animal carcasses that other predators found hard to reach, by using some of the first stone implements – but then I digress 
References:
Escoffiers recipe
http://www.npr.org/templates/story/story.php?storyId=15819485
http://www.bbc.co.uk/science/cavemen/factfiles/homo_habilis.shtml
http://www.flavor-online.com/2004s/pdf/Degen_cont.pdf
And why I order Eel (Unagi) or Mackerel (Saba).
In the recent study, FDA’s Patricia Nyman and colleagues point out that benzene, a long established, 6 cylinder carcinogen, can form in some beverages that contain food preservative, benzoate, in addition to ascorbic acid or vitamin C.
Want to party like it’s 1899? Well, now you can–sort of. After nearly a century-long ban on absinthe in the U.S., a federal agency has begrudgingly allowed two European distillers to sell the mysterious liquor Stateside. Renowned for its supposedly hallucinogenic effects, the anise-flavored alcohol was rumored to have caused an epidemic of psychosis in France in the late 1800s–most infamously, leading Vincent van Gogh to cut off his ear.
A sumptuous recipe for this cold weather classic.
