In this work, studies were performed in Brazilian asphaltic cements by separating fractions of maltenes and asphaltenes using nonaqueous ion exchange liquid chromatography (NIELC). Initially, three different aging processes (RTFOT, PAV, and SUNTEST) were applied to 23 different asphaltic cements for evaluating the changing of asphaltenic (12.7 ± 2.5%) and maltenic (90.6 ± 5.0%) compounds. The RTFOT+SUNTEST process was studied in a comparative way for 5 asphalt cements samples, since it caused the more pronounced changes in maltenes and asphaltenes among the asphaltic cements supplied by different Brazilian refineries. Asphaltenes presented the highest amount of polar compounds in all the studied samples, herein attributed to compounds of acidic and basic character that contain sulfur. It was also found that the aging of asphalt cement leads to an increase of the more reactive acidic (9.5–18.9%) and basic (14.6–30.9%) fraction in both asphaltenes and maltenes. As a result, a reactivity index (I r) for asphaltic cements was calculated and proposed for classifying the studied samples regarding their aging susceptibility. It was also observed that the less reactive asphaltic cement presented the highest amount (>80%) of neutral sulfur compounds in maltenic fraction. Lastly, it was concluded that a higher content of total sulfur in asphalts does not imply necessarily in a higher chemical reactivity (susceptibility to aging) of the cement, as observed for 5 studied samples having total sulfur ranging from 1.8 to 3.4% (w/w). The presence of functional groups related to their specific heteroatoms, such as sulfur, suggest a possible way to explain a greater or lesser susceptibility of asphalts to aging.

The redox behavior of ethanethiol in wines was studied considering its action in presence of resveratrol and gallic acid, as well as its influence on both antioxidant activity and the values of phenol total in wines (red, white and rose). Ethanethiol acted as antioxidant in presence of resveratrol and gallic acid. Conversely, ethanethiol acted as oxidant in wine samples. This antagonism was explained by the ability of ethanethiol being stable in reduced and oxidized forms and also due the presence of several redox couples in wines. The action of ethanethiol was evaluated by following during 60 days the variations on the antioxidant activity (diphenyl-1-picrylhydrazyl method) as well as the total phenol (spectrophotometric method) in fortified wine samples. Control samples were also included in the study. Significant influence of ethanethiol on the total phenol was observed in all samples, while the antioxidant activity was affected only in white and rose wines. PRACTICAL APPLICATIONSWine consumption has been growing in recent years and nowadays this drink is appreciated almost all over the word. The main reason for that are the beneficial effects for human health. A large set of species take part in wine composition including also sulfur compounds. Among these compounds ethanethiol play an important role, since it can generate unpleasant smell with changes in the organoleptic proprieties affecting the final quality of wines. In the present work, we investigate the influence of ethanethiol on both the antioxidant activity and the phenol total concentration of wines.

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