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Ultrasonic treatments during the alcoholic fermentation of red wines: effects on \u27Syrah\u27 wines
Get PDFGrapes grown in warm climates have shorter ripening periods. This makes the regular level of several compounds related to sensory properties in wine to remain low. Therefore, those grapes need to receive a particular treatment during winemaking processes if they have to reach the adequate content levels of colour and aroma related compounds. Applying ultrasound during some of the winemaking procedures may contribute to improving the maceration process, which would result in a higher recovery of compounds from grape skins and seeds to the must. This work studies the effect of applying ultrasound to \u27Syrah\u27 musts for two different time lengths during its alcoholic fermentation. The wines produced according to regular winemaking procedures (reference wines) were then compared to wines that had been produced under the effect of ultrasound for 30 to 60 min per day. The results showed that the wines produced using ultrasound had concentrations of volatile compounds higher than their reference wine. These data were consistent with the results from the tasting panel, where the judges highlighted the red fruit notes of the wines resulting from the application of ultrasound during the alcoholic fermentation. On the other hand, there were differences between the two wines resulting from applying ultrasound for two different lengths of time, applying ultrasound for 30 min per day proved to be more effective in terms of aroma than applying ultrasounds for 60 min per day. The conclusion of this research is that applying ultrasound during the alcoholic fermentation favours the extraction of volatile compounds. However different times can produce different results. Furthermore, an excessive application of ultrasound may lead to the degradation of some of the compounds of interest
Modification of the organic acid profile of grapes due to climate changes alters the stability of red wine phenolics during controlled oxidation
Get PDFThe effect of the main grape organic acids (tartaric, malic and citric) on the degradative oxidation of red wine was investigated by NMR, HPLC and spectrophotometry. Wines featuring the same pH value of 3.2 with different combinations of organic acids were prepared. Results showed that tartaric acid preserved native anthocyanins from oxidative degradation more than malic and citric acids, with malic acid being the one favoring oxidations the most and, consequently, acetaldehyde production. Wines richer in malic acids showed the highest reactivity towards saliva proteins and a potential higher astringency. Given the wide changes in tartaric/malic acid ratio with climate, these results can help to act in vineyard, as well as in winery, to manage the malic/tartaric acid ratio with the aim of improving red wine longevity
Using the parasitic wasp Trichopria drosophilae (Hymenoptera: Diapriidae) for augmentative biocontrol of Spotted Wing Drosophila (Drosophila suzukii; Diptera: Drosophilidae) in Germany
Get PDFSalicylic acid and proline enhance water use efficiency, antioxidant defense system and tissues\u27 anatomy of wheat plants under field deficit irrigation stress
Get PDFSalicylic acid or proline enhances plant performance and encourages resistance to abiotic stress in plants. This investigation tests the influence of soaking kernels in salicylic acid (0.1 mM) or proline (10 mM) on the growth and performance of wheat plants grown in open field under full irrigation (100% of ETc) or deficit irrigation (50% of ETc). The results revealed that plants under field deficit irrigation (FDI) stress showed a decline in growth, kernel yield, relative water content, total content of chlorophylls and carotenoids, as well as negative changes in the anatomy of leaf and stem. Addition of salicylic acid or proline notably increased water use efficiency (WUE) and mitigated the stress created by FDI. Field deficit irrigation stress greatly increased electrolyte leakage, total soluble phenols, proline, and total soluble sugar contents and activities of enzymes SOD, CAT, and POX. Salicylic acid was the more efficient in mitigating FDI stress than proline. The results conclude that salicylic acid, as a growth regulator, could be used to alleviate the negative effect of limited water-availability in soil on wheat as well as improving the growth and yield of the crop
Genetic identification, origin and sanitary status of grapevine cultivars (Vitis vinifera L.) grown in Babar, Algeria
Get PDFThis research focused on present grapevine biodiversity of neglected cultivars grown in \u27Babar\u27 region, Northeastern Algeria. The obtained results demonstrate the complex, rich, and even surprising inheritance of grapevine biodiversity in such a small region, with currently residual viticulture practiced only for direct consumption. Babar is one of the oldest inhabited areas in Algeria and part of the Atlas Mountains, considered very favorable for wild and cultivated vine growing since protohistoric times. Thirty-seven vines from the traditional growing area were analyzed using nuclear microsatellite (SSR) markers for cultivar identification and RT-qPCR analysis for virus detection and sanitary status evaluation. As a result, thirteen different genotypes were found, most of them showing a very good sanitary status, then constituting a valuable biological source for clonal selection. A close relatedness was evidenced with some Mediterranean varieties, resulting from previous exchanges of grapevine cultivars in the past. Furthermore, the present study highlighted the existence of three new genotypes, highly probably autochthonous of Babar region, with proposed names \u27Babari\u27, \u27Babar-Algeria\u27, and \u27Amesski-Babar\u27. They could represent unique Algerian varieties, probably preserved over time. The conservation of these endangered genotypes is highly recommended
Ultrasound-assisted extraction of anthocyanins and total phenolic compounds in Vitis vinifera L. \u27Tempranillo\u27 winemaking lees
Get PDFWinemaking lees (WL) are the less exploited by-products from the winemaking industry. This by-product is generated after the fermentation of grape must and its composition is variable, although it is mainly made up of lysed yeasts, tartaric acid, colloids, polyphenols and ashes. Of all the compounds that can be found in lees, polyphenols exhibit particularly powerful bioactive properties and their extraction for their reuse in different matrices could be a matter of particular interest.Ultrasound-assisted extraction (UAE) has been used to extract both total anthocyanins (TA) and total phenolic compounds (TPC) from lees from Vitis vinifera L. \u27Tempranillo\u27 vinification. The optimization of six extraction variables (% methanol, pH, temperature, amplitude, cycle and ratio solvent:mass) was performed using a Box-Behnken design (BBD) where TA and TPC were considered independent variables. The UAE method that has been developed in this research could be a new rapid and efficient method to extract TPC and, coupled to chromatographic methodologies, identify up to fourteen different anthocyanins from WL. The objective of this study is to determine WL polyphenolic content and its potential for further uses in other procedures aiming to create value from vinification waste
Evaluation of the agronomic performance of \u27Syrah\u27 and \u27Tempranillo\u27 when grafted on 12 rootstocks
Get PDFBeyond pest resistance, rootstocks significantly influence the performance of grapevine varieties. However, the effect of the rootstock is strongly affected by its interaction with the environment, and it is therefore necessary to evaluate their influence in a particular terroir. With the aim of evaluating the influence of 12 rootstocks on the agronomic performance of \u27Syrah\u27 and \u27Tempranillo\u27, a trial was established in 2011 and 2012 in Miranda de Arga (Navarra, Spain), under the typical environmental conditions of the Ebro Valley. Growth and yield, as well as industrial and phenolic maturity parameters were analysed during four consecutive seasons (2015-2018). Most rootstocks showed a similar performance with both varieties, not always following the trends reported in bibliography, which highlights the relevance of studying rootstocks in different conditions. 3309 C was the rootstock conferring the highest vigour, whereas the lowest were provided by 420 A MGt and \u27Fercal\u27. The implications on grape composition were much more diverse, and were partially conditioned by yield. Results were obtained during the four first harvests of the vineyard, and could therefore change to some extent as the vineyard reaches stability
Effect of forcing vine regrowth on \u27Tempranillo\u27 (Vitis vinifera L.) berry development and quality in Extremadura
Get PDFIn warmer regions, fruit ripening in the wine grape tends to take place during the hottest part of the growing season. This can have negative consequences on the qualitative characteristics of the grape berries at harvest. Forcing vines to regrow can be an aggressive but effective technique to delay the harvest date, but needs to be evaluated carefully in each growing condition. In 2017, in an experimental vineyard in Extremadura, forcing was conducted 3 (F1 treatment) and 22 (F2 treatment) days after anthesis (May 18 and June 6) by hedging growing shoots to seven nodes and removing summer laterals, leaves and primary clusters. Vines grown using conventional practices were used for the Control treatment. Forcing delayed the harvest date from August 22 (Control) to September 14 (F1) and October 19 (F2). Shifting the berry growth period modified the duration of the different fruit development stages. Compared to the Control treatment, the F1 and F2 berries were smaller at harvest, but had similar skin weight percentages; however, the seed weight percentage of the F2 berries was higher. The differences in grape composition observed at harvest between the various treatments were further accentuated in the wines. At harvest, the F2 berries had significantly higher total polyphenol and anthocyanin content than the Control and F1 berries, which had similar values. In the wines, both F1 and F2 characteristics differed considerably from the Control, most notably in the high F2 tannin concentration. These preliminary results from the first year of study indicate the potential of this technique to obtain wine grapes with very different characteristics, offering new viticultural perspectives in warm climate areas
