Colour Evolution of Rosé Wines after Bottling

This research reports on the colour evolution of six rosé wines during sixteen months of storage in the bottle.Colour changes were determined in terms of CIELAB colour parameters and in terms of the common colourcategories used in visual assessment. The colour measurement method reproduces the visual assessmentconditions during wine tasting with respect to wine sampler, illuminating source, observing background andsample-observer geometry. CIELAB L*, a*, b*, C* and hab colour coordinates were determined at seven differenttimes (t = 0, 20, 80, 153, 217, 300 and 473 days). The time evolution of colour coordinate values was studied usingmodels related to linear, quadratic and exponential rise to a maximum. Adjusted R2, average standard error andCIELAB ΔE* colour difference were used to compare models and evaluate their performance. For each colourcoordinate, the accuracy of model predictions was similar to the standard deviation associated with a singlemeasurement. An average ΔE* = 0.92 with a 90 percentile value ΔE*90% = 1.50 was obtained between measuredand predicted colour. These values are smaller than human colour discrimination thresholds. The classificationinto colour categories at different times depends on the wine sample. It was found that all wines take three tofour months to change from raspberry to strawberry colour and seven to eight months to reach the redcurrantcategory. Only two wines had developed salmon colour by the end of the experiment

Impact of two yeast strains on tempranillo red wine aroma profiles throughout accelerated ageing

This study aimed at determining the changes induced by two S. cerevisiae strains, (IONYS wf™ and Lalvin ICV D254™) on the sensory and chemical aroma profiles of Tempranillo wine, after fermentation and after ageing. The 64 aroma molecules determined were grouped attending to sensory and chemical similarity into 17 aroma vectors. Sensory studies included a sorting task and a descriptive analysis by flash profile with a trained panel. Results revealed that, even if ageing is the dominant factor, the strain of yeast introduces significant and consistent differences, both in sensory and aroma vector profiles (11 out 17 affected). Wines made with D254 contained higher levels of ethyl esters, acetic acid, cinnamates and ethyl acetate and lower levels of linear fatty acids, ß-damascenone, acetaldehyde, higher alcohols and lactones than those made with IONYS. The first profile was related to black and fresh fruit notes, while the second to white and compote fruits. © 2021 International Viticulture and Enology Society-IVES

Evaluation of the impact of initial red wine composition on changes in color and anthocyanin content during bottle storage

Sixteen commercial red wines, selected to cover a different range of color and total polyphenols index (TPI), were stored at 25 °C during 6 months under controlled and different oxygen additions (0, 1.1, 3.1, 10.6 and 30.4 mg L-1) during the bottling process. Changes in color and the anthocyanic composition were evaluated using transmittance spectra and UPLC-MS-UV/Vis respectively. Results reveal a general pattern in the evolution of wines. However, different patterns of evolution related to initial wine composition, especially to TPI, were observed. Wines with higher TPI had a lower evolution, whereas wines with lower TPI showed a higher evolution and greater variability in behavior. In general, oxygen seemed to accelerate all changes observed during aging although the oxygen effect was more limited than the effect of the storage time. These results are relevant for wine experts and help explain the evolution of wine at the bottling stage

A geometrically defined stiffness contact for finite element models of wood joints

Finite element models tend to overestimate the actual elastic response of structural timber connections. The paper shows how such overprediction relates to the modelling of the contact between fasteners and timber. The use of a control parameter called stiffness contact is proposed. After an experimental campaign, a method to determine it, based only on the geometry of a rectangular contact area, is proposed. The modeling adequacy is demonstrated by applying it to dowel embedment and moment resistant wood joint tests. The obtained results show good agreement with the experimental test series

Selection of Saccharomyces cerevisiae Strains Applied to the Production of Prieto Picudo Rosé Wines with a Different Aromatic Profile

The aim of this work was to select indigenous Saccharomyces cerevisiae strains based on a combination of genetic and aroma analyses to be used for inoculation in industrial fermentations and produce rosé wine with a different aromatic profile. A total of 118 indigenous strains of S. cerevisiae and one hybrid strain from five wineries and three different vintages were isolated from spontaneous microfermentations and genetically characterised according to the restriction fragment length polymorphism of their mitochondrial DNA (RFLP-mtDNA). From this group, 30 strains were subjected to phenotypic/oenological characterisation and, of these, nine were chosen as starters in wine fermentations due to their ability to ferment well and their appearance in consecutive vintages or in two or more wineries. Wines produced by these nine selected strains were aromatically and chemically characterised, revealing great differences in their sensory profiles. One of these strains (C9-I) showed the most complex aroma profile in the sensory characterisation, so it was selected to produce an industrial wine. A principal component analysis showed that the industrial wine produced was aromatically very different from several commercial wines produced by different wineries. In fact, their main aromatic attributes were not found in the commercial rosé wines selected for the sensory evaluation. The study shows that a combination of microbiological and chemical techniques can be an effective tool to improve the winemaking process to produce industrial wines with a distinctive organoleptic profile

Comparison in the aplication of the exploitation by optimal head model to hydroelectronic power station in run-of-the-river systems equipped with different types of turbines

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On the statistical significance of the conductance quantization

Recent experiments on atomic-scale metallic contacts have shown that the quantization of the conductance appears clearly only after the average of the experimental results. Motivated by these results we have analyzed a simplified model system in which a narrow neck is randomly coupled to wide ideal leads, both in absence and presence of time reversal invariance. Based on Random Matrix Theory we study analytically the probability distribution for the conductance of such system. As the width of the leads increases the distribution for the conductance becomes sharply peaked close to an integer multiple of the quantum of conductance. Our results suggest a possible statistical origin of conductance quantization in atomic-scale metallic contacts.Comment: 4 pages, Tex and 3 figures. To be published in PR

Adopting sustainability competence-based education in academic disciplines: Insights from 13 higher education institutions

Higher Education Institutions (HEIs) have been incorporating sustainability into education and curricula, where recent research has focussed on sustainability competences, pedagogical approaches, and how to connect them, generally on a single HEI. The process of integrating sustainability into education based on curricula assessment has been explained using adoption of innovations; and has the potential to explain the process of developing competences through pedagogical approaches. The aim of this paper is to investigate this process at academic discipline level. An online survey was developed to investigate teaching sustainability competences in 13 HEIs, from which 678 responses from educators were obtained. The competences and pedagogical approaches from the responses were ranked, and then the connections between the competences and pedagogical approaches per discipline were analysed using a correlations-based framework, from which three disciplines groups were created. The groups were categorised using diffusion of innovations theory, which indicated that some disciplines are more innovative than others in adopting sustainability competence-based teaching. The results are used to propose two frameworks to better understand the adoption of sustainability competence-based teaching: (a) the D-RAPID framework; and (b) the Disciplinary Multi-dimensional Sustainability Influence Change for Academia (D-MuSICA) memework. The adoption of sustainability competence-base education must expand from a single HEI perspective to a disciplinary collaborative one spanning many HEIs, where academic disciplines should learn from each other''s insights and mistakes and provide students with more transdisciplinary skillsets to make societies more sustainable. © 2021 The Authors. Sustainable Development published by ERP Environment and John Wiley & Sons Ltd

Characteristics of prosthetic joint infections due to Enterococcus sp. and predictors of failure: a multi-national study

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