Base wines films

Table 2 Global foam parameters and film equilibrium thickness of base wines and of model solvent and model solutions. The analogy between the 1993 and 1994 base wines on one side, and, except for the existence of a residual foam, between the 1990 base wine and the YGP 1 model solution is remarkable. The reported experiments were done early 1996. Nitrogen was used as sparging gas. (.n.m.) = non-measurable with the available test tube...

Microinterferometry images of the films formed from the different base wines and solutions are shown in Figures 4-6. 

Figure 4 Interference pictures of draining films formed from base wines...

It is remarkable that the 1993 and 1994 base wines compare so well within the experimental errors, at the local scale with same kinetics of film drainage and same aggregates, and at the global scale with same order of magnitude of the three foam parameters. It is amazing that the foam expansion E, the foam lifetimes Ln and L(2, and the foamability X all have smaller values with the 1990 wine than with the two others. Not less remarkable is the comparison between the 1990 and the dilute YGP model solution, the main difference between the wine and the model solution being the existence of residual foams with wines which do not exist in the case of the model solution. And finally the behaviours of the films and foams of the MBSA solutions are completely different from the wine and YGP solutions ones. 

Figure 7 Drainage kinetics of films formed from base wines and YGP model solutions 1990 wine one,...

Rodriguez Mendez and coworkers did a series of researches in the development of new sensors able to detect the odors and aromas [32,58,75-78], They first used lutetium bisphthalocyanine (LuPc ) LB and evaporated films for the detection of the aroma of olive oil or wine (hexanol, hexanal, -buthyl acetate, and acetic acid) based on the changes in their conductivity [76], The kinetics and the intensity of the response of the films depend not only on the morphology and the thickness of the films but also on the nature of the reactant gas. They detected acetic acid down to 88 mmol/L, based on the refractive index changes in combination with an optical fiber... 

That work was extended to the zincfll) and free-base porphyrin derivatives, and the electrocatalytic activity of polymeric films demonstrated for reduction of nitrite [30] and sulfite in water/ethanol solution [31]. The modified electrodes prepared by successively cycling the potential in the -1.20 to 1.50 V range (50 times), exhibited high electrocatalytic activity for reduction of SO2 at pH 1.0, which was significantly decreased at pH 3.5. The modified electrodes were explored as sulfite sensors in wine samples where the detection and quantification limits, respectively, of 1.40 and 4.68 mg/L were achieved for the polymeric Ni-(5-N02)TRP derivative. High selectivity and electrocatalytic activity for oxidation of gallic acid was also reported. 

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