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Scopo di questo studio è la valutazione della pulizia superficiale di alcuni strumenti endodontici in Ni-Ti prima e dopo l'uso clinico. Le normali operazioni di detersione degli strumenti in Ni-Ti dopo l'uso clinico non sono da sole idonee alla rimozione dei detriti che si accumulano sulle superfici lavoranti; pertanto appare necessariol'utilizzo di ultrasuoni nella detersione di tali strumenti prima di effettuare il ciclo di sterilizzazioni. Inoltre tale metodica è fortemente consigliata anche per strumenti nuovi che non hanno mai lavorato all'interno dei canali.

Part of sulfur dioxide used to preserve wine reacts with several wine compounds and it is not anymore active and capable of performing its antioxidant and antiseptic functions. In this work, with the aim to decrease the amount of SO2-bound to acetaldehyde, the use of chitosan in pre and post fermentative phases during the production of Aglianico red wine was investigated. Two winemaking batches, one made of 100% of healthy grapes and one composed of 50% healthy grapes and 50% berries damaged by acid rot, were considered. Results highlight that the use of chitosan just after the end of the fermentation allowed a lower production of SO2-bound to acetaldehyde in finished wines. Furthermore, when chitosan was used in post-fermentative phases, a higher content of polymeric pigments and a lower content of tannins reactive towards proteins was observed. All these effects were less evident when partially acid rot contaminated grapes were used.

The oxidative behavior of five commercial enological tannins of different sources (tea, grape marc, grape seed, untoasted oak, and toasted oak) was investigated in model wine solutions in the presence or absence of SO2. Solutions of the tannins were also analyzed for total phenolics, methyl cellulose precipitable tannins, high-performance liquid chromatography, and linear sweep voltammetry. Tea and oak-derived tannin solutions were characterized by the highest oxygen consumption rates, with oak-derived tannins exhibiting the highest oxygen consumption rates per milligram of phenolic material present. Linear sweep and derivative voltammetry parameters were well-correlated with oxygen consumption rates, whereas total phenolics or total tannins were not. All tannins were associated with consumption of SO2 upon reaction with oxygen, with the lowest rate of SO2 lost per milligram of O2 reacted being observed for oak tannins.

Background During the production of red wine, moderate uptake of oxygen in the post-fermentative phase helps the stabilization of colour and the decrease of astringent tannins. However, the influence of oxygen uptake during the fermentative phase in must has not been completely investigated. In this study we evaluated the effect of controlled oxygen supply during fermentation-maceration of Corvina grapes on colour characteristics, tannins, volatile compounds, acetaldehyde production and oxidative stability of the finished wine. Results Oxygen supply during fermentation improved the formations of stable pigments of Corvina wines due to the higher production of acetaldehyde. However, in wines treated with oxygen a lower production of fruity esters by yeasts was observed. Wines obtained from higher oxygen exposure during fermentation-maceration showed reduced ability to react with oxygen during storage. Conclusions Fermentative and post-fermentative oxygenation should be considered as a technological approach for modifying colour composition and stability, as well as oxidative behaviour of wine during aging. © 2020 Society of Chemical Industry.

The oxidation of two premium wines, Chianti Classico and Brunello di Montalcino, obtained from Sangiovese grapes in 2017 and 2018 vintages, is simulated through oxygen exposure by applying three consecutive saturation/consumption cycles. After each oxidation cycle, wines are analyzed for color intensity, hue, CIElab coordinates, polymeric pigments, monomeric anthocyanins, acetaldehyde, tannins, and flavans and compared to control wines. By increasing the oxygen supply, monomeric anthocyanins decrease faster in the younger wines, acetaldehyde is highly produced in the older ones, while the formation of polymeric pigments depends on the wine type. The color intensity, the yellow and blue tint increase in all wines. The effect of oxidation on main phenolic compounds is more affected by the wine age than the type. Oxidation also significantly affects wine sensory characteristics: the astringency intensity decreases, whereas the subqualities of silk and velvet increase. The percentage increase of the silky sensation is from four to sevenfold higher in young wines. The silkiness is correlated with some anthocyanins decrease [malvidin 3-(6II-acetyl)-monoglucoside, delphinidin 3-monoglucoside, petunidin 3-monoglucoside, malvidin 3-monoglucoside]; the velvet sensation with polymeric pigments formation, acetaldehyde production, and malvidin 3-(6II-acetyl)-monoglucoside decrease. Moreover, after oxidation, aged wines are characterized by an enhanced balsamic odor and aroma.

Dietary phenolic compounds possess potent bioactivity against inflammatory pathways of chronic inflammatory conditions, such as type 2 diabetes. Here, the phenolic profile and bioactivity of Italian red wines Gaglioppo, Magliocco, and Nerello Mascalese were characterized. NMR, HPLC/UV-Vis and spectrophotometric characterization showed that Magliocco was the richest wine in monomeric anthocyanins (two-fold), catechins, and low molecular weight phenolics (LMWP). A positive correlation was observed between the polyphenolic content and antioxidant capacity (p &lt, 0.05), with Magliocco displaying the highest antioxidant capacity (p &lt, 0.01). In vitro evidence on the endothelial cell models of insulin resistance and hyperglycemia showed the ability of Magliocco to reduce reactive oxygen species (ROS) (p &lt, 0.01) and cytokine release (p &lt, 0.01) and to upregulate SIRT1 and SIRT6 (p &lt, 0.01). On the whole, the results indicated that the quantitative and qualitative phenolic profiles of red wines influence their in vitro beneficial effects on oxidative and proinflammatory milieu in endothelial cells, showing a positive modulation of SIRT1 and SIRT6, both implied in vascular aging.

(1) Background: most premium red wines are rich in tannins but the effect of chitosan on these macromolecules is unknown. In this work, the effect of a treatment with 0.5 g/L of chitosan on red wines, W, enriched with condensed tannins, CT, ellagitannins, ET, and gallotannins, GT, was evaluated. In addition, to understand if the effect of C was stable during wine evolution, treated wines underwent an oxidative stress simulating an exposure to 18 mg/L of oxygen. (2) Methods: parameters describing the reactivity of phenolic compounds were determined: iron reactive phenolics, BSA reactive tannins, vanillin reactive tannins, and the saliva precipitation index. Individual anthocyanins, total and polymeric pigments and chromatic characteristics were evaluated to determine the influence of each treatment on colour parameters. (3) Results: a decrease in BSA reactive tannins after the addition of C was detected for all wines and the effect persisted after oxidation. W and CT wines previously treated with C and oxidized showed a significant decrease in the reactivity towards salivary proteins. C caused a lower formation of polymeric pigments in all wines. (4) Conclusion: these results suggest a possible use of C to treat wines very rich in condensed tannins and excessively astringent.

Background: Three accelerated oxidation tests were proposed to simulate red wine oxidation thus providing information useful to correctly manage moderate oxygen exposure of wine during aging in regard to phenolic composition and wine color. Since the results of the tests have never been compared on wines with different initial composition, the aim of this study was to find a suitable method to simulate oxidation of any still red wine. Methods: Aglianico, Barbera, Gaglioppo, Magliocco, and Nerello wines were treated with (1) three cycles of air saturation, (2) the addition of hydrogen peroxide, and (3) the addition of acetaldehyde. Changes in chromatic characteristics and phenolic composition were determined by spectrophotometric and HPLC methods. Results: Important differences in the behavior of the different wines were detected: the highest formation of polymeric pigments was observed in Barbera and Aglianico wines. In contrast, Gaglioppo and Magliocco wines showed a lower variability before and after the oxidation probably due to the lower anthocyanin/tannin ratio. Among the accelerated oxidation tests applied, no significant differences in color parameters and phenolic composition were detected in samples treated with the addition of H2O2 and the air saturation method. Conclusion: The study demonstrated that H2O2 addition is a successful tool to predict the evolution of different phenolic compounds during the air saturation treatment of wines.