Steve Konings skonings at
Tue Nov 8 12:17:49 EST 1994

Dennis J. Reeder (djreeder at wrote:

: My colleague, R.G. Christensen, of the Organic Analytical Research Division at NIST writes:

: The pungency or "hotness" of chili peppers is quantified in terms of Scoville Heat Units (SU). 
: It is defined as the dilution at which the sensation of hotness can barely be detected by a trained
: tester.  The dimensions of the SU pungency are therefore mL/g.  Ordinary
: dried chilies have an SU rating of perhaps 20,000.  Habanero peppers have
: an SU rating of around 100,000.  The hotness of the pure hot compound
: (capsaicin) found in peppers is about 16 million.  This means that pungency can
: be detected by tast of 1 gram of the stuff dissolved in 16,000 liters of water.

: The SU of a preparation is determined, as implied above, by a trained tester making dilutions
: and tasting them.  I don't know of any international standards, either as methods of measurement
: or of reference materials with standardized properties.

: djreeder at				Dennis J. Reeder	
: 						Biochemical Measurements
: 						Chem. Sci. & Technology Laboratory

I'm no taste physiologist, but I suspect that the receptors for this
chemical has a lot to do with the perceived hotness of the same pepper by
different people.  It is my hypothesis (often see people incorrectly say
theory here) that the people who like really hot stuff either have few
receptors or their receptors have a low affinity for the chemical.  The
people who don't like the hot stuff, have a lot of receptors or high
affinity receptors, or both.  Thus they get intense stimulation quicker
than someone with fewer/low affinity receptors.  There really is no way to
compare the intensity of a pepper by 2 different people unless they have the
same receptors.  Its just like vision and color.  How do we know that the
color you call blue is the same hue as the color I call blue?

Steve Konings, MS
Blood Research Lab
Milw WI - A Great Place On A Great Lake

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