Grape Marc Distillates Research Articles

Recycling and valorization of distilled grape marc through vermicomposting: a pilot-scale study

The present study sought to evaluate the effectiveness of vermicomposting for the valorization of distilled grape marc, one of the main solid by-products of the winery sector during a 56-day pilot-scale trial. The increase in the density and biomass of earthworms (Eisenia andrei) during the earlier stages of the process reflected the suitability of the distilled marc (Vitis vinifera L. cv. Mencía) as feedstock in order to sustain large earthworm populations on a pilot-scale level. Supporting this, from 14 days onwards the pH of Mencía distilled marc fell within weak-alkaline levels and the electrical conductivity was between 0.21 and 0.11 mS cm−2 providing optimum conditions for earthworm growth. A rapid decrease in microbial activity as well as in the content of total polyphenols, both indicative of stabilized materials was also recorded after 14 days of vermicomposting. Moreover, the content of macro- and micronutrients in the end product matched with those considered to have the quality criteria of a good vermicompost with respect to plant health and safe agricultural use. Altogether, it underlines the feasibility of vermicomposting as an environment-friendly approach for the biological stabilization of distilled grape marc fulfilling both environmental protection and fertilizer production.

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.

Influence of earthworms on the microbial properties and extracellular enzyme activities during vermicomposting of raw and distilled grape marc

The treatment of winery wastes by using appropriate management technologies is of utmost need in order to reduce to a minimum their disposal and avoid negative environmental impacts. This is of particular interest for grape marc, the main solid by-product of the winery industry. However, comparative studies on a pilot-scale dealing with the impact of earthworms on marc derived from both red and white grape varieties during vermicomposting are still scarce. The present study sought to evaluate the changes in the biochemical and microbiological properties of red and white raw marc in the presence and the absence of the earthworm species Eisenia andrei. The distilled marc obtained through distillation of the red grape marc was also considered under this scenario. Samples were taken after 14, 28, 42, and 63 days of vermicomposting. On day 14 earthworms led to a pronounced increase in most of the enzymatic activities, but only in those vermireactors fed with raw marc from the red grape variety. Alfa- and beta-glucosidase as well as chitinase and leucine-aminopeptidase activities were between 3 to 5-times higher relative to the control, while alkaline phosphomonoesterase was even up to 14-fold higher with earthworm presence. From day 28 onwards the magnitude of earthworms' effect on the studied enzymes was also dependent on the type of grape marc. Reduced values of basal respiration, ranging between 200 and 350mg CO2 kg OM h-1 and indicative of stabilized materials were found in the resulting vermicomposts. Moreover, the content of macro- and micronutrients in the end products matched with those considered to have the quality criteria of a good vermicompost. Altogether, these findings reinforce the effectiveness of vermicomposting for the biological stabilization of grape marc with the dual purpose of fertilizer production and environmental protection.

Temporal Dynamics of Bacterial Communities in a Pilot-Scale Vermireactor Fed with Distilled Grape Marc.

Vermicomposting has been found as a profitable approach to dispose of and treat large quantities of raw grape marc. However, less information is available with regard to its efficiency for treating distillery winery byproducts, even though distillation has been widely used as a way to economically valorize grape marc. As such, we sought to characterize the compositional and functional changes in bacterial communities during vermicomposting of distilled grape marc by using 16S rRNA high-throughput sequencing. Samples were collected at the initiation of vermicomposting and at days 14, 21, 28, 35 and 42. There were significant changes (p < 0.0001) in the bacterial community composition of distilled grape marc after 14 days of vermicomposting that were accompanied by twofold increases in bacterial richness and diversity from a taxonomic and phylogenetic perspective. This was followed by significant increases in functional diversity of the bacterial community, including metabolic capacity, lignin and cellulose metabolism, and salicylic acid synthesis. These findings indicate that the most striking compositional and functional bacterial community changes took place during the active phase of the process. They also pinpoint functional attributes that may be related to the potential beneficial effects of distilled grape marc vermicompost when applied on soil and plants.

Kinetic models for conventional and ultrasound assistant extraction of polyphenols from defatted fresh and distilled grape marc and its main components skins and seeds

Kinetic modeling is essential for industrial applications. The applicability of six mathematical models (parabolic diffusion, power law, Weibull’s equation, Elovich’s equation, second order rate, two- site kinetic models) to describe the kinetics of the conventional (CSLE) and ultrasound assistant extraction (UAE) of polyphenols (TPC) from fresh and distilled grape marc and its components, seeds and skins, after removal of non-polar compounds was studied. The best extraction yield of TPC for all the samples was obtained using UAE with ethanol-water mixture (57:43 v/v) as solvent, 200 W and 26 kHz after 30 min. The two-site kinetic model showed (R2 0.9965–1.000, NRMSD (%) 0.21–2.29) the best agreement with the experimental results.Important proanthocyanidins concentrations and significant antioxidant activity were observed both for fresh and distilled grape marc and its components. Fresh grape skins resulted particularly rich of oligomeric proanthocyanidins and the distilled ones of polymeric proanthocyanidins. These extracts could be used for different healthy purposes.

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

Study of the volatile compounds produced by Debaryomyces hansenii NRRL Y-7426 during the fermentation of detoxified concentrated distilled grape marc hemicellulosic hydrolysates

The volatile compounds produced by Debaryomyces hansenii NRRL Y-7426 during the fermentation of detoxified concentrated distilled grape marc hemicellulosic hydrolysates was analysed by GC-MS. Thirty-five compounds corresponding to ten groups of volatile compounds: terpenes, higher alcohols, C₆ alcohols, aldehydes, volatile acids, acetates, ethyl esters, volatile phenols, sulphur compounds and hydrocarbons were identified. The supplementation with commercial nutrients increased the concentration of 2-phenylethanol, a commercial flavour and fragrance compound, with a rose-like odour, employed in cosmetics and food industries; and other positive compounds to the aroma such as terpenes and ethyl esters. Non-supplemented media produced the highest content in higher alcohols, volatile acids, sulphur compounds and in the majority of hydrocarbons detected, meanwhile supplementation with vinasses hardly produced volatile compounds. Only four volatile compounds contributed directly to the aroma according to the OAVs values higher than 1. Finally, a PCA analysis allowed accounting for 100 % of the variance.

EFFECT OF NUTRIENT SUPPLEMENTATION OF CRUDE OR DETOXIFIED CONCENTRATED DISTILLED GRAPE MARC HEMICELLULOSIC HYDROLYSATES ON THE XYLITOL PRODUCTION BY Debaryomyces hansenii

Biosynthesis of xylitol using the yeast Debaryomyces hansenii NRRL Y-7426 was carried out using distilled grape marc (DGM) hemicellulosic hydrolysates directly concentrated by vacuum evaporation or after detoxification with activated charcoal. The effect of nutrient supplementation with vinasses, corn steep liquor (CSL) or commercial nutrients was explored. Using crude concentrated hemicellulosic hydrolysates, the maximum xylitol concentration, 11.3 g/L, was achieved after 172 hr (Q xylitol = 0.066 g/L-hr; Y xylitol /SC = 0.21 g/g); meanwhile, using detoxified concentrated hydrolysates, the concentration increased up to 19.7 g/L after 72 hr (Q xylitol = 0.274 g/L-hr; Y xylitol /SC = 0.38 g/g). On the other hand, using crude or detoxified hydrolysates, the xylose-to-xylitol bioconversion was strongly affected by the addition of nutrients, suggesting that these hydrolysates present essential nutrients favouring the growth of D. hansenii.

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.

Stability and Emulsifying Capacity of Biosurfactants Obtained from Lignocellulosic Sources Using Lactobacillus pentosus

Lactobacillus pentosus grown on sugars from agricultural residues produces biosurfactants with emulsifying properties that could facilitate the bioremediation of hydrocarbon contaminated sites. The biosurfactans obtained after growing L. pentosus cells on distilled grape marc hydrolyzates gave values of relative emulsion volume (EV) close to 50%, being stable after 72 h when gasoline or kerosene were employed. These EV values were higher than those achieved using commercial surfactin (14.1% for gasoline and 27.2% for kerosene). Moreover, assays carried out with kerosene showed that L. pentosus produced biosurfactants from distilled grape marc hydrolyzates with the highest stabilizing capacity value (ES) to maintain the emulsion (99%) followed by biosurfactants produced from hazelnut shell hydrolyzates (97%). These data are comparable with those obtained using sodium dodecyl sulfate, SDS (87.7%), whereas surfactin only gave an ES value of 65.4%. Consequently, this work shows that utilization of low-cost feedstock agricultural residues as substrates for producing biosurfactants/bioemulsifiers is possible thus removing obstacles for the wide-scale industrial application of biosurfactants/bioemulsifiers.