Volatilization kinetics of secondary compounds from sugarcane spirits during double distillation in rectifying still

Abstract

The qualitative variation of secondary components plays a key role in the aroma and taste of the sugarcane spirit. The objective of this work was to study the volatilization kinetics of secondary components of sugarcane spirits during double distillation process in a rectifying still to verify the cutoff point in ethanol between "head" and "tail" fractions. Fermented sugarcane juice was distilled in rectifying still according to the methodology used for whisky production. Both distillates from first and second distillations were collected in fractions of 500 mL and analyzed for the concentrations of ethanol, copper, volatile acidity, furfural and hydroxymethylfurfural, aldehydes, esters, methanol and higher alcohols. In the first distillation, aldehydes and esters were distilled at the beginning of the distillation, while acetic acid was distilled at the end of the distillation. Methanol was found in the fractions up to almost half of the first distillation. Higher alcohols were distilled during the whole first distillation, but with greater intensity up to the alcoholic degree of 40% v v-1 of the distillate. During the second distillation, aldehydes, esters and methanol were distilled in the first distillate fractions, being collected mainly at alcohol concentrations above 80% v v-1. Acetic acid was distilled in the final distillate fractions, with concentrations in alcohol content below 20% v v-1. Higher alcohols followed a distillation kinetics pattern similar to ethanol, being collected mainly at alcoholic concentrations above 60% v v-1 of the distillate. The presence of copper, furfural and hydroxymethylfurfural was not detected in any fraction of the distillates of the first and second distillation.