CapsaicinoidsCapsaicinoids are what make hot peppers and chilies hot. Capsaicin is the main component and most pungent, comprising about 69% of capsaicinoids in an average pepper (different species will have different ratios). Dihydrocapsaicin is the second most abundant and is almost as pungent as capsaicin, comprising about 22% of the pungent compounds in an average pepper. These two both have a chain of 7 hydrocarbons after the amide group. Nordihydrocapsaicin (7%) has a chain of 6, while homodihydrocapsaicin and homocapsaicin (1% each) each have a chain of 8. The latter three are less pungent than the two most common ones, suggesting that the human TRPV1 channel binds a 7 hydrocarbon chain capsaicinoid better than any other number. There is one common synthetic one called nonivamide that has a chain of 8 after the amide, and is also more pungent than the ones without 8. Whether peppers have this naturally or not is disputed, but if they do it is certainly in very small concentrations. The ratio between the 5 natural capsaicinoid content is what determines the hotness of a pepper. Habaneros and chilies have lots of capsaicin and dihydrocapsaicin, while capsicum annuum green bell peppers have virtually none, but have some of the other three. The best way to determine the relative amounts is a chemistry technique called High Performance Liquid Chromatography. In this technique, extracts of the pepper in an organic solution are pumped through a column (usually a type of silica) and seperated based on their affinity for the column. They are therefore seperated by hydrophobicity (ability to dissolve in water), and then a technique such as mass spectroscopy is used to determine their relative amounts. Research has shown that these five compounds are all physiologically (virtually) identical, with very few differences other than binding efficacy to TRPV1. Given the natural function of capsaicinoids in peppers (to deter mammals and some insects from eating them while letting birds eat them), it is possible that some other species have receptors which bind better to the less pungent compounds (to humans that is). |
Capsaicinoids are what make hot peppers and chilies hot. Capsaicin is the main component and most pungent, comprising about 69% of capsaicinoids in an average pepper (different species will have different ratios). Dihydrocapsaicin is the second most abundant and is almost as pungent as capsaicin, comprising about 22% of the pungent compounds in an average pepper. These two both have a chain of 7 hydrocarbons after the amide group. Nordihydrocapsaicin (7%) has a chain of 6, while homodihydrocapsaicin and homocapsaicin (1% each) each have a chain of 8. The latter three are less pungent than the two most common ones, suggesting that the human TRPV1 channel binds a 7 hydrocarbon chain capsaicinoid better than any other number. There is one common synthetic one called nonivamide that has a chain of 8 after the amide, and is also more pungent than the ones without 8. Whether peppers have this naturally or not is disputed, but if they do it is certainly in very small concentrations.