curcumin vs turmeric

curcumin

noun
  • A polyphenol (1E,6E)-1,7-bis(4-hydroxy-3-methoxyphenyl)hepta-1,6-diene-3,5-dione; a major constituent of the spice turmeric. 

turmeric

noun
  • The pulverized rhizome of the turmeric plant, used for flavoring and to add a bright yellow color to food. 

  • An Indian plant, Curcuma longa, with aromatic rhizomes, part of the ginger family (Zingiberaceae). 

  • A yellow to reddish-brown dye extracted from the turmeric plant. 

How often have the words curcumin and turmeric occurred in a corpus of books? (source: Google Ngram Viewer )