The cis-resveratrol Concentration is Proposed as a New Indicator of the Hop Freshness
trans-Piceid, cis-piceid and trans-resveratrol contents of hop cones and hop pellets from six American varieties (harvest 2004) were monitored by RP-HPLC-APCI(+)-MS/MS over 12 months of storage. trans-Resveratrol, cis-piceid and trans-piceid were found in all samples. After 8 months of storage, the overall stilbene content was decreased in the same range whatever the conditioning. Absent in fresh hop cones or pellets, cis-resveratrol was released from cis-piceid in all stored samples. cis-Resveratrol concentration revealed very interesting for assessing hop freshness.
BrewingScience - Monatsschrift für Brauwissenschaft, 62 (July/August 2009), pp. 141-146