The Volatile Composition of Chardonnay Juices: A Study by Flavor Precursor Analysis

Abstract

The free volatiles, as well as those released from their glycosidically bound forms by acid or enzyme hydrolysis, have been analyzed for Chardonnay juices from three successive vintages. One hundred eighty compounds were identified. Twenty-eight of these have not been previously reported as grape components. More than seventy percent of the total concentration of volatile secondary metabolites comprised thirteen-carbon 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, while monoterpenes made up only five percent of the total. Low concentrations of volatiles, apparently derived from primary metabolites or from chlorophyll degradation, were also observed. Volatiles with likely sensory significance were found mainly in the acid hydrolysates. Pathways to these compounds are discussed.