Marc Distillates Research Articles

Analysis of the Volatile Organic Compound Fingerprint of Greek Grape Marc Spirits of Various Origins and Traditional Production Styles

The most well-known traditional Greek grape marc distillate made from winemaking pomace is called “Tsipouro”. Its production involves various grape pomace cultivars, preparation protocols, and anise-flavoring or not, and it should be a colorless liquid with intense organoleptic properties due to the raw materials used in its production and have a minimum alcoholic strength of 37.5% by volume. This study aimed to characterize the volatilome of tsipouro products by covering as many geographical areas and production styles as possible, as there is a lack of characterization of the aromatic composition of this Greek traditional alcoholic beverage. A Headspace Solid Phase Microextraction Gas Chromatography–Mass Spectrometry (HS-SPME-GC-MS) method was applied in 60 samples, resulting in the identification and semi-quantification of over 90 volatile compounds. The statistical analysis pointed out the metabolites that characterized each traditional product group and underlined the influence of the geographical origin and the production protocol. Aniseed spirits from Northern Greece, Macedonia, Limnos Island, and Thessaly, produced from Muscat pomaces, were found to be richer in terpenes, terpenoids, and flavored compounds, attributing to product aroma and quality; different terpenoids were found to be dominant in Muscat distillates from different regions, showing the importance of geographical origin and production process. In conclusion, the results demonstrated the high aroma variability of the Greek Tsipouro, explained that this diversity is caused mainly by the raw material, and could be helpful in the better protection of the origin of this traditional product and the improvement of its quality.

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

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.

Characterisation of Refined Marc Distillates with Alternative Oak Products Using Different Analytical Approaches

The use of oak barrel alternatives, including oak chips, oak staves and oak powder, is quite common in the production of spirits obtained from the distillation of vegetal fermented products such as grape pomace. This work explored the use of unconventional wood formats such as peeled and sliced wood. The use of poplar wood was also evaluated to verify its technological uses to produce aged spirits. To this aim, GC-MS analyses were carried out to obtain an aromatic characterisation of experimental distillates treated with these products. Moreover, the same spirits were studied for classification purposes using NMR, NIR and e-nose. A significant change in the original composition of grape pomace distillate due to sorption phenomena was observed; the intensity of this effect was greater for poplar wood. The release of aroma compounds from wood depended both on the toasting level and wood assortment. Higher levels of xylovolatiles, namely, whisky lactone, were measured in samples aged using sliced woods. Both the NIR and NMR analyses highlighted similarities among samples refined with oak tablets, differentiating them from the other wood types. Finally, E-nose seemed to be a promising alternative to spectroscopic methods both for the simplicity of sample preparation and method portability.

Dispersive liquid–liquid microextraction and gas chromatography accurate mass spectrometry for extraction and non-targeted profiling of volatile and semi-volatile compounds in grape marc distillates

The suitability of dispersive liquid–liquid microextraction (DLLME) and gas chromatography accurate mass spectrometry (GC–MS), based on a time-of-flight (TOF) MS analyzer and using electron ionization (EI), for the characterization of volatile and semi-volatile profiles of grape marc distillates (grappa) are evaluated. DLLME conditions are optimized with a selection of compounds, from different chemical families, present in the distillate spirit. Under final working conditions, 2.5 mL of sample and 0.5 mL of organic solvents are consumed in the sample preparation process. The absolute extraction efficiencies ranged from 30 to 100%, depending on the compound. For the same sample volume, DLLME provided higher responses than solid-phase microextraction (SPME) for most of the model compounds. The GC-EI-TOF-MS records of grappa samples were processed using a data mining non-targeted search algorithm. In this way, chromatographic peaks and accurate EI-MS spectra of sample components were linked. The identities of more than 140 of these components are proposed from comparison of their accurate spectra with those in a low resolution EI-MS database, accurate masses of most intense fragment ions of known structure, and available chromatographic retention index. The use of chromatographic and spectral data, associated to the set of components mined from different grappa samples, for multivariate analysis purposes is also illustrated in the study.

Herbal distillates: A new era of grape marc distillates with enriched antioxidant profile

Grape marc distillates are traditional alcoholic beverages, produced mostly in the Mediterranean countries. The present study proposes the enrichment of a Greek traditional grape marc distillate (tsikoudia) with selected herbs to enhance its natural antioxidants and functional properties. Total phenolic content, the antiradical and antioxidant activities, as well as the phenolic and sugar profiles using NMR and FT-IR spectroscopy were evaluated. The enrichment of distillates with Syzygium aromaticum L., Jasminum officinale L. and Eucalyptus globulus Labill. exhibited the highest total phenolic content as well as the highest antioxidant and antiradical activities, whereas the lowest values were observed with Hippophae rhamnoides L. and Lycium Barbarum Mill. The implementation of NMR and FT-IR spectroscopies attested to the presence of phenolic compounds and of specific carbohydrates in herbal distillates, postulating their migration from selected herbal species to tsikoudia and probably contributing to their organoleptic characteristics. The target of this approach leads to new added-value distillates with enhanced characteristics.

Optimisation of accelerated ageing of grape marc distillate on a micro-scale process using a Box-Benhken design: influence of oak origin, fragment size and toast level on the composition of the final product

Background and Aims The ageing process, in wooden barrels, is used to improve the sensory quality of wines and distillates. This process, however, is costly, often leading to an alternative strategy of using wood fragments. The main aim of this work was to evaluate the influence of size, toast level and origin of the oak fragments on the composition of grape marc distillates. Methods and Results The accelerated ageing process of grape marc distillate was optimised with a Box–Benhken experimental design. Five dependent variables were evaluated: the concentration of vanillin, whiskey lactone and phenolic substances, the antioxidant activity and the colour parameters to determine the influence of the independent variables: concentration of oak fragments, proportion of ethanol in Galician grape marc distillate (Orujo) and the time of maceration. The concentration of oak fragments was the variable with the greatest effect on the dependent variables evaluated, except for whiskey lactone. The optimal conditions obtained were applied in 11 experimental accelerated ageing processes to study the influence of size, toast level and origin of the oak fragments on the parameters previously mentioned. Conclusions The best results were obtained with the smaller fragment size (granular) from Quercus petraea with medium toast level. The contact time did not significantly influence the parameters evaluated. Significance of the Study This study, performed at a micro-scale, determined the optimum conditions for greater extraction of compounds from oak with beneficial characteristics: volatile compounds with positive notes, vanillin and whiskey lactone, and the phenolic substances with antioxidant properties. This option allows producers to reduce considerably the cost of the process.

Phenolic compounds and aroma‐impact odorants in herb liqueurs elaborated by maceration of aromatic and medicinal plants in grape marc distillates

We are grateful to the Spanish Ministry of Economy and Competitiveness for the financial support of this work (project CTQ201571436-C2-1-R), which has partial financial support from the FEDER funds of the European Union. Jose Manuel Salgado was supported by the grant SFRH/BPD/84440/2012 from Fundacao para a Ciencia e Tecnologia - FCT, Portugal.

Optimization of the process of aromatic and medicinal plant maceration in grape marc distillates to obtain herbal liqueurs and spirits

Herbal liqueurs are alcoholic beverages produced by the maceration or distillation of aromatic and medicinal plants in alcohol, and are also highly valued for their medicinal properties. The process conditions, as well as the number and quantity of the plants employed, will have a great influence on the quality of the liqueur obtained. The aim of this research was to optimize these important variables. A Box-Benhken experimental design was used to evaluate the independent variables: alcohol content, amount of plant and time during the experimental maceration of plants in grape marc distillate. Four plants were assessed, with the main compound of each plant representing the dependent variable evaluated with respect to following the evolution of the maceration process. Bisabolol oxide A in Matricaria recutita L., linalool in Coriander sativum L. and eucalyptol in Eucalyptus globulus Labill. were quantified using a gas chromatography-flame ionization detector. Glycyrrhizic acid in Glycyrrhiza glabra L was determined using a high-performance liquid chromatography-diode array detector. Other dependent variables were also evaluated: total phenolic content, color parameters and consumer preference (i.e. appearance). The experimental designs allowed the selection of the optimal maceration conditions for each parameter, including the preference score of consumers: 70% (v/v) of ethanol, 40 g L-1 plant concentration and a maceration process of 3 weeks. © 2016 Society of Chemical Industry.

Bartlett pear unsaturated ethyl deconoates and C 9 compounds among components characterizing cv. Catalan roxo grape marc distillates

Catalan roxo marc distillates contain compounds at an unusual level in a grape derivate. The most peculiar are several unsaturated ethyl decanoates typical of Bartlett pear distillates and derived from ethyl esters found in the grape skins, some of which partially modified in the stereoisomery probably by the fermentation process. Remarkable compounds are unbranched aliphatic C-9 compounds at different oxidation state as well as ethyl nonanoate. At sensorially interesting levels methyl and ethyl salicylate and ethyl cinnamate, monoterpenols typical of floral-like varieties, vitispiranes and 4-ethylguaiacol are detected. Methyl salicylate is found in the berry as free and bound compound as several monoterpenols.

First Approach to the Analytical Characterization of Barrel-Aged Grape Marc Distillates Using Phenolic Compounds and Colour Parameters.

Phenolic compounds (benzoic and cinnamic acid derivatives) were determined by high-performance liquid chromatography with multiple wavelength detector (HPLC- -MWD) in grape marc distillates aged in Quercus petraea, Quercus robur and Quercus alba wooden barrels. In addition to colour indices and evaluable polyphenols, all samples were described by sensorial analysis. There were significant differences in the mean concentrations of the majority of phenolic compounds among the samples. Gallic and benzoic acids were the most abundant and samples aged in Q. robur from Galicia (NW of Spain) had the highest concentration of most of the determined phenols. Grape marc distillates aged in Q. robur obtained the highest values of all sensorial attributes, whereas samples aged in Q. petraea and Q. alba obtained similar scores. Principal component analysis accounted for 88.32% of total variance, showing a good separation of aged distillates in terms of phenolic compounds and colour characteristics, according to the species and origin of the oak wood used in the ageing process.

Assessment of minerals in aged grape marc distillates by FAAS/FAES and ICP-MS. Characterization and safety evaluation

Orujo is the name of the Galician (NW of Spain) grape marc distillate. The usual way of Orujo consumption is as young brandy due to the lack of knowledge about the most appropriate type of barrel for aging and the high cost of the final product. However in the past years, demand for this aged distillate has increased. This manuscript has a double aim: contribute to the analytical characterization of this traditional beverage in terms of mineral constituents and evaluate the influence of the species of wooden barrel in the mineral content. Analyses were performed by flame atomic absorption spectrophotometry (Cu, Mn, Zn, Fe, Ca and Mg), flame atomic emission spectrophotometry (Na and K) and inductively coupled plasma mass spectrometry (Al, Cd and Pb). Orujos aged in Quercus alba showed significant higher value for the majority of metals whereas those aged in Quercus petraea showed the lowest contents. K, Na and Ca were the more abundant minerals in the analyzed distillates. The PCA analysis clearly showed a good separation of samples in terms of mineral constituents. The very low concentrations of all minerals evaluated indicated the good manufactured process and the consumer safety of aged Orujos.

NMR metabolite profiling of Greek grape marc spirits

This 1H NMR based study profiles metabolites in Greek grape marc distillates, tsipouro and tsikoudia.Eightysix samples of indigenous and international varieties, stemming from major vine growing regions of Greece were investigated. The monitoring protocol addressed the global metabolic profile of untreated samples and accomplished the unambiguous assignment of 35 metabolites.NMR spectra were acquired by applying the robust, sensitive and rapid WET1D NMR pulse sequence, which succeeded to unveil the presence of minor compounds in a high ethanol matrix.PCA classified the samples according to their provenance, incorporating also information related to the variety, vintage year and production process within each formed regional assembly. Metabolites such as fusel alcohols, polyols, ethyl esters, mono- and di-saccharides were associated with the classification of samples. OPLS-DA ascribed to samples of common regional entity characteristic genotypic metabolites and probed to the potential influence of the vintage effect. Finally, metabolite profiling underlined the influence of the fermentation and distillation procedures.

Relationship between volatile aroma compounds and sensory quality of fresh grape marc distillates

To investigate possible relationships, the volatile aroma compound composition of 30 grape marc distillates obtained from six varieties was correlated with the sensory scores for basic properties (clearness, odour and taste) obtained by sensory testing using the hedonic German DLG model. High negative Pearson's correlation coefficients were determined between total concentrations of long-chain ethyl esters and the scores for the property clearness. Strong positive correlation of middle-chain fatty acids and their ethyl esters, and strong negative correlation of sesquiterpenes, diterpenes, methanol, C6-alcohols, acetic and short-chain fatty acids, long-chain ethyl esters, ethyl acetate, other acetate esters, acetaldehyde and furanic compounds with the properties odour and taste were found. Principal component analysis corroborated these results. Monoterpenes were confirmed to be responsible for a typical Muscat aroma, as well as for descriptors such as flowery, rose, citrus and spicy/menthol in distillates made from Muscat varieties. A significant degree of correlation was found between the concentration of C6-alcohols and the frequency of quotation of the descriptor vegetative/grass. Indications were found that vegetative odours of C6-alcohols may act as suppressants of Muscat aroma. A certain degree of congruence was noted between higher concentrations of medium-chain ethyl esters and acetaldehyde, and the occurrence of fruity and nutty odours, respectively. Copyright © 2012 The Institute of Brewing & Distilling

Characterization by chemical and sensory analysis of commercial grape marc distillate (Orujo) aged in oak wood

The main physicochemical parameters and sensory profile of commercial aged distillates from grape marc, Orujo, have been determined in this study. Significant differences were obtained for the mean concentration of the chemical parameters determined among the samples analysed. All samples fulfilled the values fixed for each parameter by the corresponding Regulation Council and the values obtained showed differences with respect those obtained for other similar beverages (whisky, rum, cognac) owing to the characteristics of the raw material employed. The results from sensory analysis showed that Orujo aged over 60 months in wooden barrels from Quercus robur reached the highest overall quality, next to the distillate aged over 144 months in Quercus petraea oak wood. The tasters evaluated more positively the species of oak used in the aging process than the time that the distillate remained in contact with the barrel. Samples aged in oak wood from Quercus robur during 60 months and from Quercus petraea during 144 months had a similar sensory profile and obtained a greater intensity in all qualifying parameters. The principal components analysis clearly showed a good separation of the aged Orujo samples in terms of sensory descriptors according to the species and origin of the oak wood employed in the aging process. Copyright © 2012 The Institute of Brewing & Distilling

Comparative study between Italian and Spanish grape marc spirits in terms of major volatile compounds

Twenty nine samples of grape marc spirits, nineteen from Spain (Orujo) and ten from Italy (Grappas) were analyzed by GC–MS in order to determine their major volatile composition. The results obtained showed that Orujo samples contained significantly higher concentration of methanol, 2-butanol, ethyl acetate and ethyl lactate. Grappas were defined as distillate with low contribution of the majority volatile compounds, both from qualitatively and quantitatively point of view. This aspect has a notable interest because, in the case of single-varietal aromatic distillates, the contribution of the primary aroma will be more intense. 2-phenyl ethanol, hexenols, aldehydes and the majority of ethyl esters and acetates showed large variations of concentrations between the samples; consequently they could be the responsible of the particular characteristics in these grape marc distillates.

Characterization and Differentiation of Monovarietal Grape Marc Distillates on the Basis of Varietal Aroma Compound Composition

To investigate the varietal aroma compound composition of monovarietal grape marc distillates made from six different varieties (Vitis vinifera L.) in the region of Istria (Croatia), 30 samples were subjected to GC/MS and GC/FID analysis. A total of 73 compounds were identified: 45 monoterpenes, 20 sesquiterpenes, 3 diterpenes, and 5 C(13)-norisoprenoids. The largest number and the highest concentration of monoterpenes were found in Muscat Blanc, followed by Rose Muscat of Porec (Muskat ruza porecki) distillates, which were both characterized as highly aromatic. Lower, but still significant monoterpenol content was determined in distillates made from Istrian Malvasia (Malvazija istarska) grape marc. Chardonnay, Cabernet Sauvignon, and Teran distillates exhibited poorer monoterpene profiles, while Teran distillates contained elevated sesquiterpene concentrations. It was concluded that investigated monovarietal grape marc distillates significantly differ in varietal aroma compound composition. Stepwise linear discriminant analysis provided efficient discrimination models, and extracted various monoterpenes, sesquiterpenes and C(13)-norisoprenoids as important differentiators of distillates according to varietal origin.

Discrimination and risk assessment due to the volatile compounds and the inorganic elements present in the Greek marc distillates Tsipouro and Tsikoudia

&lt;p style="text-align: justify;"&gt;Tsipouro and Tsikoudia are two denominations with geographic indications of the traditional Greek marc distillate, which is produced in continental Greece and in the island of Crete respectively. It is produced by the Greek winegrowers as well as by the professional distillers. To provide data on the safety of domestic Tsipouro and Tsikoudia distillates for human consumption and to draw conclusions from any essential results, which might have an impact on the quality of this product, 23 samples were analysed for: (a) Volatile compounds by the use of gas chromatography, (b) Inorganic elements, using atomic absorption spectrometry and (c) the pH values through-out using standard methods. Data revealed differences between these two denominations, which have been confirmed by the application of a statistic analysis and a PCA. Thus, Tsikoudia was found to contain statistically higher amounts of acetalde-hyde. However, the levels that have been observed did not exceed the official limits. Most of the Tsipouro and Tsikoudia samples also contained low concentrations of estragol, an anise compound, lead and copper, which do not represent a risk to consumer health due to their toxicity. On the other hand, the total concentration of higher alcohols was higher than the official minimum limit (140 g.hl&lt;sup&gt;-1&lt;/sup&gt; Absolute Alcohol-AA), while the amylic alcohols rarely exceeded 300 g.hl&lt;sup&gt;-1&lt;/sup&gt; AA. The high concentrations of ethyl acetate (&amp;gt;300 g.hl&lt;sup&gt;-1&lt;/sup&gt; AA) and ethyl lactate in a few samples showed the necessity of limiting unwanted fermentations in the grape pomace. The analytical study showed that the quality of the marc distillate is, generally, satisfactory. However, it revealed great differences between Tsipouro and Tsikoudia even among the samples of each denomination and, con-sequently, these domestic distillates need standardization and a more systematic production.&lt;/p&gt;

Variation of Volatile Organic Acids in Spirits during Storage at Low and Room Temperatures

The volatile organic acids are formed during storage of the spirit under inadequate conditions and their presence in the marc distillate has a negative influence on its sensorial characteristics. The object of refining marc distillates is to improve their sensorial characteristics. In this study, this process was carried out on a distillate of grape pomace that was maintained for 7 mo at two temperatures (cold at 5 °C and at room temperature, 25 °C) in order to understand the influence of both the parameters (time and temperature) on the volatile acids content. For the concentration of the volatile acids, solid-phase-extraction (SPE) was employed as the stage previous to determination by gas chromatography. The results of the analysis indicate that, in general, the concentration of the organic acids tends to decline during the refining period, this decline being more important after the fourth month. This decrease is especially important with regard to the acetic acid, due to which the refining process is beneficial, because this is the major distillated acid. With regard to temperature, no significant differences have been found in the comportment of the acids.

Relationships Between Storage Conditions of Grape Pomace and Volatile Composition of Spirits Obtained Therefrom

This study reports on the effects of addition of tartaric acid, addition of pectinase, time of anaerobic storage, and the storage container material on the concentrations of volatiles in marc distillates of <i>Alvarinho</i> and <i>Loureiro</i> varieties. The aim of this work is to predict how the concentration of every major volatile responds to each manipulated processing factor in each of three distillate cuts, a condition necessary to rationalize the process of the manufacture of <i>bagaceiras</i>. Fusel alcohols were, quantitatively, the largest group of flavor compounds in all cases, ranging from 395 to 2029 mg/L. Ethyl acetate and ethyl lactate were the most concentrated esters, ranging from 176 to 9614 and from 0 to 310 mg/L, respectively. Fermentation time is the manipulated variable that most strongly affected composition of marcs in terms of higher alcohols, while addition of pectinases and material of container are the manipulated variables that most strongly affected composition in terms of methanol (with a concentration range of 2694 - 6960 mg/L) and 2-butanol (with a concentration range of 0 - 279 mg/L). The effect of pectinase addition is statistically the most significant for the methanol content, whereas the effect of fermentation time is statistically the most significant for the 2-butanol content.