THE VOLATILE COMPOSITION OF CHARDONNAY JUICES - A STUDY BY FLAVOR PRECURSOR ANALYSIS

The free volatiles, as well as those released from their glycosidicall y bound forms by acid or enzyme hydrolysis, have been analyzed for Cha rdonnay juices from three successive vintages. One hundred eighty comp ounds were identified. Twenty-eight of these have not been previously reported as grape components. More than seventy percent of the total c oncentration of volatile secondary metabolites comprised thirteen-carb on norisoprenoids, and these were mainly observed in the acid- and the glycosidase enzyme-released fractions. Benzene derivatives accounted for a further twenty percent of the total volatile concentration, whil e monoterpenes made up only five percent of the total. Low concentrati ons of volatiles, apparently derived from primary metabolites or from chlorophyll degradation, were also observed. Volatiles with likely sen sory significance were found mainly in the acid hydrolysates. Pathways to these compounds are discussed.