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This research focuses on the aromatic composition of Muscat of Alexandria wines after the application of ultrasound for 40 or 80 min during a 4 h pre-fermentative maceration process. Two methods of ultrasound application were compared in this study: probe ultrasound and bath ultrasound, for periods of 10–20 min per hour. Increases of more than 200% were obtained for some of the compounds from the skins, such as two of its terpenes, citronellol and nerol. On the other hand, increases in alcohol and ester values were registered with the application of ultrasound for 40 min. However, a significant decrease in these compounds was recorded when the ultrasound process was extended. In fact, when ultrasound was applied for 80 min, content values were even lower than those registered for the wine produced without the application of ultrasound. At the sensory level, the effect resulting from probe and bath ultrasound application for different times were compared, where most of the judges successfully discriminated the wines resulting from the application of ultrasound bath. According to data, the wines resulting from the application of ultrasound bath for 80 min presented the most significant differences, which affected the aromas of white fruit, tropical fruit, stone fruit, flowers and citrus., This research was co-financed by the 2014-2020 ERDF Operational Programme and by the Department of Economy, Knowledge, Business and University of the Regional Government of Andalusia. Project reference: FEDER-UCA18-108366.

Vitis vinífera L. cv. Maturana Blanca is an autochthonous minor variety recently recovered in the Rioja Qualified Denomination of Origin (D.O.Ca Rioja, Spain) for the production of monovarietal white wines with singular and differentiated characteristics. In this paper, Maturana Blanca wines made with different technologies were analyzed by sensory analysis and aromatic profile by gas chromatography-mass detector. Maturana Blanca wines were characterized by low pH, high acidity, and yellowish tonalities. The compounds that most influenced the aroma of Maturana Blanca wines were those related to fruity (acetates and ethyl esters), floral aromas (2-phenylethanol), and spicy notes (γ-decalactone). These wines were mainly characterized by volatile compounds of fruity aromas of banana and apple. The use of pre-fermentative maceration increased the concentration of ethyl esters and acetates and produced wines with higher odor activity values, indicating a greater aromatic intensity. The aromatic profile of Maturana Blanca wines fermented in oak barrels showed a greater complexity as they were also characterized by the presence of important amounts of furfural, whiskey lactone, and eugenol. The sensory analysis confirmed the results obtained in the aromatic analysis, and described the wines as fresh and balanced in mouth, with notes of acidity and medium to high persistence. These results will contribute to a better knowledge of this white variety.

This study presents the effects of different working temperatures on the transfer of compounds during the pre-fermentative and fermentative stages of the wine making process with 'Cabernet Sauvignon' grapes. Two different procedures have been evaluated. Firstly, the pre-fermentative maceration of the crushed grapes at two different temperatures (20 degrees C and 10 degrees C). Then, the alcoholic fermentation under two different sets of conditions, the fermentation at a constant temperature of 20 degrees C and the fermentation under a positive temperature gradient from 10 to 20 degrees C. According to the experimental results, the phenolic contents (total phenolics, total anthocyanins, and total tannins) were mainly conditioned by the fermentation temperature, however the pre-fermentative conditions also affected the content levels of these compounds. Furthermore, the use of a fermentation temperature gradient improved the organoleptic characteristics of the wines. However, the color was not as stable as that of wines produced through fermentation at a higher constant temperature. Consequently, the implementation of a temperature gradient during the alcoholic fermentation process is recommended and a longer period at high temperature over the last phase of the process would be desirable to obtain aromatic wines with the desirable color stability., This research was co-financed by the 2014-2020 ERDF Operational Programme and by the Department of Economy, Knowledge, Business and University of the Regional Government of Andalusia. Project reference: FEDER-UCA18-108366.

The actual wine global market presents the risk of standardization of the wines and the losses of wine grape peculiarities. To combat this fact, autochthonous wine grapes are extremely interesting to use for winemaking. The use of the pre-fermentative maceration technique in autochthonous grape varieties could be an alternative of increasing their complexity. The aim of the present work was to compare the effect of five different pre-fermentative maceration treatments on the colour, phenolic and volatile composition of Prieto Picudo (PP) autochthonous red wines. The evolution during 12 months of the different wines was also studied for one vintage. Enzymatic, refrigerate and cryo-maceration treatments were applied to PP autochthonous grape varieties. The study was carried out during two consecutive vintages. Results showed that enzymatic maceration was the most effective treatment to improve levels of phenols, colour intensity and volatile compounds. Cold maceration showed also good effects. However, it was not able to improve the extractive effects of enzymatic macerations. Generally, wines obtained with pre-fermentative maceration techniques showed better colour and volatile stability than control wines.

[EN] The impact of pre-fermentative cold soak, alone or in combination with dry ice addition, on colour, phenolic and volatile composition of Tempranillo wines at 12 months after bottling was studied. A control wine without cold soak was also evaluated. A sample set consisting of 66 wines was investigated. The results from ANOVA and PCA analysis showed significant treatment-related differences for a number of chemical measurements, as well as overlapping effects. Orthogonal projections to latent structures discriminant analysis (OPLS-DA) of the data showed that the dry ice addition treatment had a major effect on the anthocyanin fraction and on the levels of ethyl decanoate, 2-phenylethyl acetate and decanoic acid. In comparison, the cold soak treatment only had a slight effect on the bisulphite bleaching anthocyanins and volatile composition., The research reported here is a project financially supported by the Spanish Government (AGL 2006-10723-C02-02) which the authors gratefully acknowledge.