You searched for: “torrefied rhubarb
torrefied rhubarb (s)  (noun), torrefied rhubarb; torrefied rhubarbs (pl)
Rhubarb that has had its purgative powers diminished by roasting: Torrefied rhubarbcan have the effect cleansing of the bowels, but its astringency is not affected.

"Astringency" is the taste experience that takes place when a substance causes the mouth to pucker.