Scoville scale Scoville Heat Units can be made by multiplying ppm H by a factor of 15" (modified to a factor of 16 by others). Another source using subjective assessment stated: "Conventional methods used in determining the level of pungency or capsaicin concentration are using a panel of tasters (Scoville Organoleptic test method). ... Pepper pungency is measured in Scoville Heat Units (SHU). This measurement is the highest dilution of a chile pepper extract at which heat can be detected by a taste panel (Bosland et al., 2007)." Since Scoville ratings are defined per unit of dry mass, comparison of ratings between
Scoville scale the parts-per-million by 16." HPLC results permit the measurement of a substance’s capsaicin capacity to produce perceived heat ("pungency"). This method yields results in American Spice Trade Association (ASTA) "pungency units", which are defined as one part capsaicin per million parts dried pepper mass. For parts per million (ppm) measurements: "Scoville Heat Units are calculated in parts per million of heat (ppm H) based on sample dry weight according to the following equation from ASTA (1985): ppm H = [Peak area of capsaicin + (0.82)(peak area of dihydrocapsaicin)](ppm standard)(ml acetonitrile) ÷ (Total capsaicin peak area of standard)(g sample). Conversion to