What causes the purple pigment?
A class of compounds generally called anthocyanin. The specific anthocyanins present in the tomatoes are mainly petunidin, but malvidin and delphinidin are also present. The anthocyanins are modified by the presence of acyl (sugar) groups. Anthocyanins are a member of a larger class of compounds called flavonoids. Other members of this class include quercetin, kaempferol, naringenin, catechin, and isoflavones. Phenols or Phenolics are related compounds that differ in basic chemical structure, but have similar function. In our tomato lines many different kinds of phenolics and flavonoids are up regulated along with the anthocyanins.
