Characterization of Flavor Compounds in Distilled Spirits: Developing a Versatile Analytical Method Suitable for Micro-Distilleries

Abstract

Over the last few years, the development of micro-distilleries producing diverse spirits with various flavors has been observed. Versatile analytical techniques for the characterization of aroma compounds in such alcoholic beverages are therefore required. A model mixture embodying a theoretical distilled spirit was made according to the data found in literature to compare usual extraction techniques. When it was applied to the model liquor, the headspace solid phase microextraction (HS-SPME) extraction method was preferred to the liquid-liquid extraction (LLE), solid phase extraction (SPE) and stir bar/headspace sorptive extraction (SBSE/HSSE) methods according to efficiency, cost, and environmental criteria. An optimization study using the model mixture showed that the extraction was optimal with a divinylbenzene/carboxen/poly(dimethylsiloxane) DVB/CAR/PDMS fiber, during 60 min, at 35 °C and with the addition of 10% NaCl. This method was successfully applied to three different commercial liquors and led to the identification of 188 flavor compounds, including alcohols, esters, lactones, carbonyls, acetals, fatty acids, phenols, furans, aromatics, terpenoids, alkenes, and alkanes.

Volatile Profile in Greek Grape Marc Spirits with HS-SPME-GC-MS and Chemometrics: Evaluation of Terroir Impact

“…Taking all parameters into account, SPME was the method of choice for further optimization of the sample preparation suited to the particular type of spirits. Similarly, this has been the preferred method of sample preparation in the study of Kokoti et al and several studies related to grape marc distillate drinks. ,,, …”

“…During the extraction, competition is created between ethanol and other volatile compounds, while the large peak area of ethanol alters the signal of the other compounds in chromatographs. There are studies showing that higher ethanol content decreases the extraction efficiency, , while dilution to less than 10% ethanol decreases the sensitivity of the extraction. , …”

“…The same procedure was carried out, with the only difference being the addition of NaCl. The salting out effect by adding NaCl to samples is used to promote the extraction efficiency of volatile compounds …”

“…The salting out effect by adding NaCl to samples is used to promote the extraction efficiency of volatile compounds. 25 2.2.2. Dispersive Liquid−Liquid Microextraction.…”

“…Enables sampling and sampling preparation into one step, a factor that is very attractive for analysts as a simplified methodology. It is the most applied method for the analysis of volatile and semivolatile compounds in distillate products. , The extraction efficiency of the method is affected by several parameters, such as the fiber coating, time and mode of extraction, temperature, and agitation speed. ,, In addition, the optimal ethanol–water ratio for SPME might affect it . LLE, on the other side, is also an efficient extraction method that has been widely used in distillate spirits due to the ability to separate the substances through different solubility, despite the matrix phenomenon …”