The Collaborative International Dictionary of English v.0.48:

Raffinose \Raf"fi*nose`\ (r[a^]f"f[i^]*n[=o]s`), n. [F. raffiner
   to refine.] (Chem.)
   A colorless crystalline slightly sweet substance obtained
   from the molasses of the sugar beet.
   [1913 Webster]

WordNet (r) 3.0 (2006):

raffinose
    n 1: a trisaccharide that occurs in sugar beets and cotton seeds
         and certain cereals