No abstract

Phenolic compounds are of crucial importance for red wine color and mouthfeel attributes. A large number of enzymatic and chemical reactions involving phenolic compounds take place during winemaking and aging. Despite the large number of published analytical methods for phenolic analyses, the values obtained may vary considerably. In addition, the existing scientific knowledge needs to be updated, but also critically evaluated and simplified for newcomers and wine industry partners. The most used and widely cited spectrophotometric methods for grape and wine phenolic analysis were identified through a bibliometric search using the Science Citation Index-Expanded (SCIE) database accessed through the Web of Science (WOS) platform from Thompson Reuters. The selection of spectrophotometry was based on its ease of use as a routine analytical technique. On the basis of the number of citations, as well as the advantages and disadvantages reported, the modified Somers assay appears as a multistep, simple, and robust procedure that provides a good estimation of the state of the anthocyanins equilibria. Precipitation methods for total tannin levels have also been identified as preferred protocols for these types of compounds. Good reported correlations between methods (methylcellulose precipitable vs bovine serum albumin) and between these and perceived red wine astringency, in combination with the adaptation to high-throughput format, make them suitable for routine analysis. The bovine serum albumin tannin assay also allows for the estimation of the anthocyanins content with the measurement of small and large polymeric pigments. Finally, the measurement of wine color using the CIELab space approach is also suggested as the protocol of choice as it provides good insight into the wine's color properties.

Climate change refers to an alteration in the state of the climate that can be identified by changes in the mean and the variability of its properties. Climate change reflects abnormal variations in the Earth's atmosphere and subsequent effects on other parts of the planet, such as on crop lands, reducing the annual yield. The objective of this paper was to contribute to a better understanding of the scientific knowledge in climate change and his effect concerning agriculture, as well as to investigate its evolution through the published papers. Items under study were obtained from Web of Science (WOS) platform from Thomson Reuters. A bibliometric and social network analyses was performed to determine indicators of scientific productivity, impact and collaboration between authors, institutions and countries. A subject analysis taking into account the key words assigned to papers and subject areas of journals was also carried out. A total of 1,471 articles were included in the selected subject categories in WOS since 2005 until 2014. The most productive journals were Agricultural and forest Meteorology, Forest Ecology and Management, and Agriculture Ecosystems & Environment. Excluding climate or climatic change, the most frequent keywords have been CO2, Adaptation, Model, Temperature and Impact. The network of collaboration between countries shows the central position of the United States, together with other leading countries such as China, Canada, Australia, Germany, and United Kingdom. This work has provided helpful insights into the climate change research in Agricultural subject areas, wich had grown steadily during the last decade. The network of collaboration between institutions and countries involve both centres from developed and developing countries, and it is noteworthy the cooperation between US and China. Highly cited papers reveal the concern on emerging climate change risks for forest, the impact on forest ecosystems, the effect on plant diseases and adaptation options.

There have been a substantial number of studies suggesting possible health benefits from polyphenols in wine, especially red wine. These hypothetical effects, in addition to those of alcohol, are attributed by many to antioxidant and anti-inflammatory effects of the polyphenols. The aim of this paper was to map the scientific research on wine and health by using bibliographic analyses of papers published during the period 2002-2011. Papers were published in 535 different journals and in 106 different subject categories, the most productive journals being the Journal of Agricultural and Food Chemistry, Food Chemistry and Molecular Nutrition, and Food Research, and the most productive subject category being food science and technology. Institutions in the main network of collaboration between centers were primarily located in France, Italy, and the United State. The number of papers on the medicinal use of wine has been dramatically rising in recent years because of the increased awareness of its importance in modern society. We emphasize the large distribution of information among numerous journals and the multidisciplinary nature of the topic. In the network of co-words, we observe the central role played by the terms "resveratrol", "wine", and "polyphenols".

The influence of the prefermentative addition of copigments and different winemaking technologies on the polyphenolic composition of Tempranillo red wines after malolactic fermentation, was studied. Six experiments dealing with the prefermentative addition of caffeic acid, rutin, (+) catechin, white grape skin tannin, white grape seed tannin and control wines were realised. Three different winemaking technologies (traditional vinification, prefermentative cold maceration at 6-8 ºC and cold soak at 0-2 ºC with dry ice) were studied. Prefermentative addition of copigments increases anthocyanin copigmentation reactions and produces wines with a greater colour, a higher anthocyanin concentration, a superior contribution of anthocyanins to the colour of the wine, a superior percentage of tannins polymerized with polysaccharides and less astringency.Cold prefermentative maceration increases the extraction of polyphenols, the anthocyanin copigmentation reactions and the polymerization reactions between tannins and polysaccharides.The effectiveness of the combination of copigments and prefermentative maceration treatments was demonstrated by the increase of the concentration of the polyphenolic compounds.

Ninety-one young varietal wines from the Valencian community (Spain), made from Cabernet Sauvignon, Tempranillo, Monastrell, and Bobal grapes, were tested on the basis of 33 variables: 9 conventional parameters, 10 alcohols and polyols, and 14 esters. Discriminant analysis was used to identify and explain the differences among samples, as well as to determine whether it is possible or not to differentiate among varieties. This differentiation (100% of the samples) has been possible due to the new discriminant analysis based on only 11 main variables: total acidity, cis-3-hexenol, methanol, glycerol, 2,3-butanediol, isobutyric alcohol, 1-pentanol, acetaldehyde, ethyl propionate, ethyl decanoato, and gamma-butyrolactone, which allow differentiating 100% of the 1994 vintage and 97% of the 1995 vintage.

No abstract

No abstract