Aromatic and sensorial characterization of "Moscato pyments": an innovative beverage.

Pyment is a type of mead that is produced from the alcoholic fermentation of a honey solution with the addition of grape juice. Due to the demand for new beverages, pyment can be a profitable alternative for both grape and honey producers. Therefore, this work aimed to characterize the aromatic and physicochemical composition of pyments. The pyments were prepared with addition of 10, 20 and 30% of Moscato juice, and compared with Moscato wine and traditional mead. The results showed an increase in the fermentation rates of Moscato-pyments, indicating that the addition of Moscato juice reverses the low fermentative vigor often reported in mead fermentations. Physicochemical parameters showed an increase in total acidity and a decrease in residual sugar and alcohol, depending on Moscato juice concentration. Moscato-pyments showed an intermediate concentration of volatile compounds between the traditional mead and Moscato wine, with a better balance between fruity, floral and buttery, manifesting characteristic aromas of wines made with Moscato grapes and simultaneously, exposing characteristic aromas of honey. The sensory analysis reveals a significant difference between mead, pyments and Moscato wine. In general, pyments were considered, by the panelists, as the most equilibrated with intermediary aroma intensity, floral, fruity and honey aromas, and good persistence in the mouth.

Essential oil as sustainable alternative for diseases management of grapes in postharvest and in vineyard and its influence on wine.

This study aimed to determine the chemical composition of Eucalyptus staigeriana essential oil (EO) and its effect in vivo against Botrytis cinerea and Colletotrichum acutatum in postharvest of grapes and in a vineyard. Moreover, grapes collected from de field experiments were used to evaluate the impact of the alternative control on the alcoholic fermentation and wine composition. The major compounds of E. staigeriana EO were citral (30.91%), 1,8-cineole (24.59%), and limonene (19.47%). In the postharvest experiment, EO was efficient, reducing the incidence and severity of disease caused by B. cinerea and the incidence of disease caused by C. acutatum, both in preventive and curative treatment. Moreover, this EO reduced the incidence and severity of gray rot caused by B. cinerea and the severity of ripe rot caused by C. acutatum in the field. The alternative control did not significantly influence the alcoholic fermentation and volatile composition of wines, except for the residual presence of 1,8-cineole that can contribute to the aroma complexity of 'Isabella' wine. These results are promising and indicate that E. staigeriana EO might be further investigated as a natural alternative to control fungal rots on grapes.

Selection of low nitrogen demand yeast strains and their impact on the physicochemical and volatile composition of mead.

Mead is an ancient alcoholic beverage produced through the fermentation of a diluted solution of honey. Due to the peculiar and varied composition of honey, mead production faces several problems, such as slow or stuck fermentations mainly due to the low nitrogen concentration, lack of uniformity of the final product and the production of unpleasant aromas. In this context, this work aimed to select low nitrogen-demand yeast strains and evaluate their potential for the production of mead. Therefore, among 21 commercial wine yeast strains, 5 were selected based on their fermentative behavior at low assimilable nitrogen concentrations. The selected strains were further evaluated for their contributions in meads produced with limited nitrogen availability, and the results showed significant differences on some physicochemical parameters like biomass production, residual sugars, glycerol concentration, and fermentative rate. Moreover, meads obtained with selected strains differed in the concentration of several volatile compounds. The volatile compounds concentration and the principal component analysis based on odor activity values allowed separating strains into three groups. In general, S. cerevisiae var bayanus strains (QA23, Spark, and AWRI-R2) were the largest producers of aromatic compounds, particularly those with floral and fruity descriptors. The selection of yeast strains with low nitrogen-demand and different volatile compounds production can be explored by mead makers to limit fermentation problems and obtain characteristic products.

Physicochemical, aromatic and sensory properties of the 'Riesling Italico' wines fermented with Saccharomyces and non-Saccharomyces yeasts / Propriedades físico-químicas, aromáticas e sensoriais do vinho 'Riesling italico' fermentado com leveduras Saccharomyces e não-Saccharomyces

ABSTRACT: The sensory quality of wines is affected by the compounds produced by the action of the yeasts used in alcoholic fermentation. This work aimed at assessing the physicochemical, aromatic and sensory properties of the 'Riesling Italico' white wines produced by using the Saccharomyces and non-Saccharomyces yeasts. The yeasts S. cerevisiae, S. cerevisiae cerevisiae, S. bayanus, Torulaspora delbrueckii and Metschnikowia pulcherrima were inoculated individually into the must. For 10 days, the alcohol was left to ferment in 7 L carboys in triplicate, at 15º C temperature. The standard physicochemical analyses were done and the quality of the wines was determined. The volatile compounds were identified and quantitative descriptive sensory analyses were performed. All the yeasts produced wines with the characteristic alcohol, volatile acidity and residual sugar content as stipulated by the Brazilian legislation. The T. delbrueckii yeast produced high-content phenylethyl acetate, isoamyl acetate and ethyl decanoate wines, of superior olfactory quality and sensory rating.

RESUMO: Durante a fermentação alcoólica as leveduras produzem compostos que influenciam a qualidade sensorial dos vinhos. O objetivo do trabalho foi avaliar as propriedades físico-químicas, aromáticas e sensoriais do vinho branco da variedade Riesling Italico elaborado a partir de leveduras Saccharomyces e "não-Saccharomyces". Foram inoculadas separadamente no mosto as leveduras S. cerevisiae, S. cerevisiae cerevisiae, S. bayanus, Torulaspora delbrueckii e Metschnikowia pulcherrima. A fermentação alcoólica ocorreu em garrafões com 7 L de mosto, em triplicata, por 10 dias a 15 ºC. Foram realizadas análises físico-químicas padrão e de identificação da qualidade dos vinhos, além das análises de compostos voláteis e sensorial descritiva quantitativa. Todas as leveduras produziram vinhos com teores de álcool, acidez volátil e açúcar residual de acordo com a legislação. A levedura T. delbrueckii produz vinhos com concentrações elevadas de acetato de feniletila, acetato de isoamila e decanoato de etila, resultando em boa qualidade olfativa e avaliação sensorial.

Alternative control of grape rots by essential oils of two Eucalyptus species.

BACKGROUND: Essential oils (EOs) are volatile natural compounds produced by plant secondary metabolism, and some of them exhibit antimicrobial activity. The objective of the present study was to determine the chemical composition the EOs of Eucalyptus staigeriana and Eucalyptus globulus, and their effect in vitro and in vivo against Botrytis cinerea and Colletotrichum acutatum, the most important fungal rot diseases of grapes. Moreover, grapes collected from field experiments were used to evaluate the impact of the alternative control on the alcoholic fermentation and wine composition. RESULTS: The major compound of E. staigeriana EO were citral 30.91% (19.74% geranial, 11.17% neral), 1.8-cineole (24.59%) and limonene (19.47%), while 1.8-cineole represented 68.26% of E. globulus EO. The two EOs showed in vitro antifungal activity against both pathogens. Eucalyptus staigeriana EO exhibited the highest activity inhibiting mycelial growth (MG) and conidial germination at 0.5 µL mL-1 . Moreover, this EO was able to reduce the incidence and severity of grey rot caused by B. cinerea and the severity of ripe rot caused by C. acutatum The alternative control did not significantly influence alcoholic fermentation, the physicochemical characteristics, and the volatile composition of wines. CONCLUSION: These results are promising and indicate that E. staigeriana EO might be further investigated as a natural alternative for the control of fungal rots on wine grapes. © 2019 Society of Chemical Industry.

Effect of glutathione addition in sparkling wine.

This study aims to evaluate the effect of the addition of glutathione (GSH) on secondary aromas and on the phenolic compounds of sparkling wine elaborated by traditional method. It was added 10 and 20 mg L(-1) of GSH to must and to base wine. The determination of aroma compounds was performed by gas chromatography. Phenolic compounds and glutathione content were analyzed by high performance liquid chromatography. Sparkling wines with addition of GSH to must showed lower levels of total phenolic compounds and hydroxycinnamic acids. Furthermore, the sparkling wine with addition of GSH to must showed higher levels of 2-phenylethanol, 3-methyl-1-butanol and diethyl succinate, and lower concentrations of ethyl decanoate, octanoic and decanoic acids. The GSH addition to the must show a greater influence on sparkling wine than to base wine, however GSH addition to base wine seems retain higher SO2 free levels. The concentration of GSH added showed no significant difference.

Geographic origin of southern Brazilian wines by carbon and oxygen isotope analyses.

We present a method that can differentiate between the varieties of grapes and the vintages of wines and show the relationship between the grapes, the wine and the geographic location. The place of origin and its geographic and climatic characteristics were determined by the isotopic ratios, (13)C/(12)C of the ethanol and (18)O/(16)O of the water content of wine (wine water), for southern Brazil wines. The producing subregions of Pinto Bandeira, Vale dos Vinhedos and Nova Pádua showed differences in the temperature, rainfall and humidity conditions used for the production under microvinification conditions of Merlot and Cabernet Sauvignon varieties, in the harvests of 2005 and 2006. An isotope ratio mass spectrometer coupled to an elemental analyzer was used to measure the (13)C/(12)C of ethanol and the (18)O/(16)O of wine water. Regardless of the grape variety used, it was possible to determine the subregion through measurement of the δ(18)O values in both harvests. The altitudes of the different subregions led to statistical differences and demonstrated an influence mainly on the δ(18)O values of wine water. The δ(18)O value of wine water was determined to be more selective for the determination of the cultivation subregions than the δ(13)C value of the ethanol. The altitude and latitude influenced mainly the δ (18)O values of wine water and the ethanol. The climatic influences are more noteworthy in distinguishing the year of the harvest than the cultivation subregion.