Friday, May 2, 2014

A Discussion on the 8 Other Taste Sensations

A Discussion on the 8 Other Taste Sensations
(Note: This was originally published in my company's Tech Weekly publication)

Many of you know that I was a professional chef in a former life. I continue to have a great interest in food (you can tell by looking at my Buddha belly) and fondness for new culinary information. Currently the sense of taste is recognized as one of the five human senses: sight, sound (hearing), smell, touch and taste. Traditionally the sensation of taste is divided into four types from which most of you are probably familiar: sweetness, sourness, saltiness and bitterness. This short article identifies 8 other “tastes”…

Recently there have been several articles discussing seven-to-eight additional taste sensations and I thought I would provide a brief description of each so all of you can be better informed (not that you need to be, but why not?): 
  1. Umami – in many lists, umami has already been added as the fifth taste sensation (but I’m leaving it on my “other” list as it wasn’t considered a taste sensation during my upbringing). Borrowed from Japanese culture, umami can be translated as “savory taste” and is a result of the receptors for glutamate and nucleotides, commonly found in the sodium additive monosodium glutamate (MSG). In general the effect is a long-lasting, pleasant brothy or meaty taste that causes your mouth to water and provides a tongue coating sensation.
  2. Calcium – turns out that some recent studies in mice have revealed that their rodent tongues have two taste receptors for calcium and that one of these has also been found on the human tongue. Since it’s described as bitter and chalky, the receptors may be there to ward humans (and mice) from eating too much rather than as a flavor enhancement.
  3. Kokumi – this is a sensation popularized by Japanese culture – the idea is that some foods have “heartiness” or “mouthfulness” as an added intensifier, similar to umami. Japanese scientist suggest that certain compounds like glutathione in yeast extract and the amino acid L-histidine, interact with our tongue’s calcium receptors, providing a richness to food you wouldn’t otherwise experience – this can be found in great concentration in slow-braised, aged or slow-cooked foods.
  4.  Piquance – this is all about spiciness – the level of capsaicin allows the TRPV1 receptors to lower the activation temperature to 95 degrees – cooler than the body temperature which otherwise would react to substances at around 107.6 degrees. This causes the receptors to shout “hot!” to the brain without actually blistering your skin. Of course it’s still possible to get burned when a pepper is especially hot (ask me how I know).
  5. Coolness – the opposite of piquance, this effect has to do with your mouth’s ability to fool the brain into thinking something is cooler than the actual temperature. An example is the herb mint or menthol, which has a cooling effect in the mouth due to the TPRM8 touch receptors.
  6. Metallicity – most of our Indian and Asian team members are already familiar with this sensation, as it’s common to apply gold or silver foil garnishes (known as “vark” in India) to sweets. Apparently the sensation has to do with electrical conductivity as a reaction between the saliva in your mouth and the metal, providing a little zap (as a kid we would put the terminals of a 9v battery on the tongue – it has a distinctive “metallic” flavor).
  7. Fat – you hear this all the time from culinary experts. Basically the human tongue is wired to taste fat – particularly long chain fatty acids (lipids) – most of us are either attracted to the flavor or repelled by it (for the latter fat tends to taste bitter).
  8. Carbon Dioxide – apparently when CO2 is dissolved in liquids, the bursting bubbles cause a particular sensation on the tongue and mouth, providing a trigeminal stimulus that’s unique and measurable. Compare the flavor of a freshly opened can of soda to one that is “flat” – same ingredients but totally different in taste – that’s the effect of the CO2.

 
Image is me as a chef in the early 90’s at a now defunct Atlanta local restaurant, Mi Spia
(the nearby McKendrick’s was opened by the same entrepreneur).


-- John