Establishing the influence of oak extract and sugar caramel on the composition of phenolic and furanic compounds in cognac distillates

The aim of the study is to establish the effect of oak extract and caramel color on the quantitative and qualitative content of phenolic and furan compounds by adding these auxiliary agents in different concentrations to cognac distillate. The basis of the experiment was the creation of solutions of young or aged cognac distillates with the addition of caramel color, oak extract and bringing the resulting solutions to a volume fraction of ethyl alcohol of 40 %. The color was added according to visual control until the usual color of the cognac was created. The resulting solutions were aged for at least 10 days, without access to oxygen. Then, studies were conducted to identify mass concentrations of phenolic and furan compounds. In the experiment with young cognac distillate, a tendency was monitored for the introduction of certain amounts of syringaldehyde (0.1–0.4 mg/dm3) and gallic acid (0.8–5.9 mg/dm3) by oak extract, depending on the dosage. The control sample of aged cognac distillate contained sinapic, coniferyl and syringaldehydes, vanillin, syringic and gallic acids (0.2–5.3 mg/dm3). When oak extract was added with increasing dosage to the aged distillate, the mass concentration of gallic acid increased significantly – from 1.9 to 5.3 mg/dm3. When adding sugar color, the appearance of 5methylfurfural in the composition of cognac distillates was noted at a concentration of 1.7–2.8 mg/dm3 for young, 1.0–2.5 mg/dm3 for aged. With an increase in the dose of caramel color added to both young and aged cognac distillate, a decrease in the 5methylfurfural/2furfural ratio was observed from 3.8 to 2.3 and from 6.0 to 2.6, respectively.