Development of a new procedure for the determination of the reactivity of brandies used in wine fortification

The main purpose of this work was to describe and validate a new methodology for the determination brandy reactivity index (BRI) towards flavan-3-ol compounds in wines (catechins condensed tannins) correlate with amount type aldehydes present those brandies. This method consists two reactions: a) ability react C8 and/or C6 positions phloroglucinol ring catechin excess (A ring); b) further reaction remaining free p-dimethylaminocinamaldehyde (DMACA) yielding formation blue compound that can be quantified by Visible spectroscopy at 640 nm. impact different experimental conditions such as reagent concentrations time on BRI were also evaluated. validated through repeatability (intra-day variability) reproducibility. considered acceptable CV 11.87 %. analysis reproducibility variance, S2R (11.59), limit R (9.5) coefficient variation, CVR (15.25 %) postulates reliable robust.Using developed methodology, fourteen commercial brandies some pure standards determined. brandies, content total determined GC-MS then correlated BRI. In general, it observed direct correlation between concentration aldehydes, particular acetaldehyde.