The effect of dephlegmation on the relative volatility of fruit spirit components

Tuesday, November 29, 2016

Author: László Nagygyörgy


Keywords: brewing palinka, dephlegmation, main aroma of palinka, gamma-decalactone, allyl alcohol, distillation curve, heads, tails, fusel alcohols, vapor pipe

1. Summary

With the support of the National Research, Development and Innovation Fund, within the framework of the KMR-2 project, a research was carried out by WESSLING Hungary Kft. between 2013 and 2015, in connection with changing the distillation parameters of fruit spirits, among other things. Within the framework of the research, characteristic volatile components of different fruits (apples, pears, sour cherries, apricots and plums) were investigated. It was determined that, during distillation, the different components are transferred into the distillate according to typical distillation curves, so they can be grouped easily according to their propensity to be enriched in the vapor phase at the end of the vapor pipe in the heads, hearts or the tails phase. When analyzing sample fractions taken systematically during the distillation, a clear correlation could be demonstrated between the change in the partial condensation used in the distillation, the so-called dephlegmation degree, and the change in the relative volatility of the volatile components entering the distillate from the vapor phase during distillation. When the dephlegmation degree decreased, of the components analyzed, the relative volatility of methanol compared to ethanol decreased, while it increased for all other components analyzed, i.e., the concentration of the volatile components entering the distillate during the preparation of fruit spirits will be higher or, in other words, the fruity character will be more intense if the dephlegmation degree is lower. Given the results of the project, it becomes possible to influence the distillate composition consciously by changing the distillation parameters.


2. Selection of the components to be analyzed and the measurement method

When determining the range of volatile components to be analyzed, several factors were taken into con­sideration. On the one hand, components that are relevant from the point of view of meeting legal re­quirements of fruit spirits, such as methanol [1] and 9 other legally prescribed components [2] were ana­lyzed. On the other hand, those components were selected which can be considered main aromas of the fruits investigated, i.e., which have a major effect on the development of the characteristic smell and taste specific of the fruit for the consumer, such as gamma-decalactone in the case of apricots [3], [4], [5], [6], [7], [8], [9], [10], [11], [12], [13], [14], [15]. Furthermore, among the components to be analyzed were also included several compounds that can indi­cate distillation errors, such as 2-phenylethanol and allyl alcohol.

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