red, orange and yellow terpenoids, based on tetraterpenes (C40), including the carotenes (simple hydrocarbons) and the xanthophylls (oxygenated hydrocarbons) occuring in chloroplasts and chromoplasts in all the plant and algal groups as accessory pigments or as pigments protecting the major photosynthetic pigments against photo-oxidation. As food colourings they are moderately heat resistant; easily oxidized unless stabilized by ascorbic acid., terpeenide (isoprenoidide) hulka kuuluvad tetraterpeensed ühendid, looduses tavalised taimepigmendid (annavad õie kroonlehtedele jm taimeosadele kollase, oranži, punase või violetse värvuse). K-d lähevad toiduga taim- ja segatoidulistesse loomadesse (ka inimese organismi); osa neist seal ei lagune, vaid lahustuvad lipiidides ja kogunevad rasvkoesse (sellest nt veiste rasviku kollakas värvus). Olulisimad k-d on karotiinid (alfa-, beeta- ja gammakarotiin, A-vitamiini provitamiinid) ja ksantofüllid.