Hydrolyzes the disaccharide glycosides vicianin, pNP beta-primeveroside, 2-phenylethyl beta-primeveroside and furcatin. (R)-vicianin + H2O = mandelonitrile + vicianose Expressed at high levels in seeds, at moderate levels in flowers and at low levels in roots, stems and leaves. Belongs to the glycosyl hydrolase 1 family.