«Алкогольная» ферментация табака в дубовых бочках. Часть 2. Количественное изменение хлорогеновой кислоты и ее определение методом ВЭЖХ

Abstract

We studied a quantitative change in chlorogenic acid (CGA) content in raw tobacco during its fermentation in oak barrels in a gas-liquid medium of cognac distillate for six months. Cuban cigar tobacco of the HP variety was used as the object of research. Quantitative determination of CGA was carried out on a liquid chromatograph with a spectrophotometric detector using the external standard method in gradient elution mode. An external standard of CGA was obtained from green coffee beans by extraction with a 40% aqueous solution of methanol, followed by further treatment of the extract with Carrese solutions and evaporation of the treated extract on a rotary evaporator under vacuum. As a result of chromatography of the external standard, a chromatogram in the form of a double peak was obtained. To analyze the tobacco samples under study, their water-methanol extracts were first obtained using the Soxhlet method. HPLC results showed that the mass fraction of CGA in unfermented tobacco raw materials was 0,29%. In fermented tobacco, the content of CGA was 0,19%, which corresponds to a loss of CGA during fermentation by 42,9%. To identify the possible diffusion of CGA from tobacco raw materials into oak staves, a similar analysis was carried out on 1 mm thick oak chips cut from the inner surface of the barrel before and after the fermentation process. Chromatography results showed the absence of CGA in oak chips cut before tobacco fermentation. The chromatogram of the extract of oak chips cut after fermentation showed a peak corresponding to CGA in an amount of 0,047%. However, the peak shape does not allow to unequivocally state that this peak directly relates to CGA.