Volatile aroma compounds of distilled “tsipouro” spirits: effect of distillation technique

Abstract

The main objective of the present study was to determine the effect of the distillation technique: (i) fractional column distillation (FCD), (ii) copper alembic distillation (CAD), and (iii) home distillation (HD) on the aroma profile of the distilled spirit “tsipouro”. Volatile compounds were identified and semi-quantified in all above fractions for comparison purposes using Solid Phase Micro-extraction–Gas chromatography/Mass Spectrometry (SPME–GC/MS). Τhe richest (p < 0.05) distillate in volatile compounds was that of the FCD, with a total concentration of 768.38 mg/L followed by the HD (577.79 mg/L) and CAD (315.30 mg/L). The concentrations of the volatiles determined (alcohols, aldehydes, ketones, acetals, esters, organic acids, terpenes, hydrocarbons, and heterocyclic compounds) were found to be similar to those of other Greek and European distilled marc spirits. Ethanol and total volatile compound content were within limits set by Greek and EU legislation. Methanol, a toxic compound of grape marc distillates, was determined only in the entire product of CAD 1st distillation (19.35 mg/L) and the “head + tail” fraction of the CAD 2nd distillation (12.82 mg/L) in amounts well below the EU legal limit of 1000 g/hL of absolute alcohol. A general reducing trend was noted in most volatile compound concentration proceeding from the 1st to the 2nd CAD distillation refining the flavor of tsipouro.

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

“…in the study of Fluoros et al they were found in an average of 1027.5–1076.9 mg/L. Soufleros et al reported values for isoamyl alcohol at 86.51–264.44 mg/L in Tsipouro and 81.94–387.54 mg/L in Tsikoudia samples and in the latest study of Kokoti et al they were found in a range of 91.85–143.55 mg/L. Cortes et al .…”

“…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. ,,, …”

“…The main source of nitrogen in fermentation is amino acids; therefore, volatiles that are immediately related to amino acids could also be an index of terroir and not only fermentation conditions. There are some factors, such as geographical location and grape variety, that affect the amino acid composition of grapes, wines, and, subsequently, grape marc spirits. , In previous studies on the volatile profile of Greek grape marc spirits with gas chromatography, Apostolopoulou et al studied spirits from Epirus using direct injection in a GC-FID and an LLE technique with a GC–MS, Fluoros et al studied the effect of different storage conditions on resulting volatiles and Kokoti et al studied again products from the Epirus region, but this time focusing on the distillation techniques applied. Amyl alcohols in the first study were one of the ten (10) major volatiles, in a concentration of 133.1–325.0 mg/mL p.a.…”

“…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 7 and several studies related to grape marc distillate drinks. 10,11,25,30 Distillate drinks compose a complex matrix due to their high ethanol content and the presence of several hundreds of volatile and semivolatile compounds, posing challenges from a chromatographic point of view.…”

“…6 More recently, a study also focusing on the administrative and geographical area of Epirus and the grape variety "Debina" investigated the effect of different distillation techniques on the aroma profile of the final product, measured through gas chromatography−mass spectrometry (GC−MS). 7 In general, there are few studies on targeted compounds of those products, such as the one of Geroyiannaki et al, 3 in which 28 samples and a gas chromatographic technique were used for the determination of acetaldehyde and methanol, and the one of Diamantidou et al, 31 where they developed a new, fast, high-throughput, accurate, and sensitive ultrahigh performance liquid chromatography-tandem mass spectrometry method for the separation and quantification of 12 phthalate esters in 45 grape marc spirit samples, from Greece and Cyprus. NMR spectroscopy has also been employed, along with multivariate statistical analysis procedures, to classify that product category, using 57 Greek grape marc spirits from different regions (North Greece and Crete Island) and five grape varieties (Romeiko, Malvasia, Xinomavro, Sangiovese, and Nebbiolo).…”