Piceid, the major resveratrol derivative in grape juices

The levels of trans-piceid, cis-piceid, trans-resveratrol, and cis-resverat rol have been measured in 36 grape juices using an HPLC system with spectra l analysis of eluting peaks. The piceid (glucosides) were the major compone nt in the grape juices. In red grape juices the average concentrations were 3.38 mg/L for trans-piceid, 0.79 mg/L for cis-piceid, 0.50 mg/L for trans- resveratrol, and 0.06 mg/L for cis-resveratrol. In white grape juices the l evels were, on average, 0.18 mg/L for trans-piceid, 0.26 mg/L for cis-picei d, and 0.05 mg/L for trans-resveratrol, and cis-resveratrol was not detecte d in any sample. Levels of total resveratrol (trans- and cis-resveratrol an d -piceid) found in red and in white grape juices are similar to those desc ribed in Spanish red and white wines. Due to their resveratrol content, as well as other phenolics, grape juices may have a beneficial health effect o f interest to those who cannot drink wine.