The plant synthesizes and accumulates capsaicinoids, a group of alkaloids responsible for the hot or spicy flavor, which are located primarily in the tissue of the placenta adjacent to the seeds. Capsaicinoids are soluble in moderate polar organic solvents e.g. chloroform, acetone, ethyl acetate, methylene chloride, methanol, ethanol, acetonitrile, and among others.
Twelve compounds have been identified but capsaicin and dihydrocapsaicin are responsible for about 90% of the spiciness. Their concentration depends on genotype, fruit maturity, and conditions of cultivation.
Capsaicinoids are derivates of benzylamin. Capsaicin, a homovanillic acid derivative (8-methyl-N-vanillyl-6-nonenamide), is an active component of the red pepper.
The most abundant and potent analogues in peppers (and consequently pepper extracts) are capsaicin and dihydrocapsaicin. Capsaicin is represented with 69% in the group of capsacinoids; dihydrocapsacinoids with 22%; nordihydrocapsacinoids with 7%; homocapsaicin and homohydrocapsaicin takes only 1% in the group of capsaicinoids.
The concentration of capsaicinoids in hot pepper varieties ranges from 0.003 to 0.01%; varieties of mild chillies contain from 0.5 to 0.3%, and strong chillies are characterized by a content higher than 0.3%, reaching about 1%.
Capsaicinoids in pepper
