3919
( - ) - Carvone is a monoterpene ketone found in spearmint ( Mentha spicata var . crispa ) essential oil that is widely used as an odor and flavor additive .
 ( - ) - Carvone, monoterpene ketone
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 ( - ) - Carvone, monoterpene ketone