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Depuis les années 70, les préparations enzymatiques sont des auxiliaires technologiques d'origine biologique de plus en plus appréciées pour l'aide qu'elles apportent dans les différentes étapes de la vinification (Débourbage, pressurage, macération, filtration et stabilisation microbiologique). Les activités utilisables en œnologie sont décrites par le règlement européen 1493/1999 et les résolutions œnologiques 11–18/2004 de l'OIV. A ce jour, les protéases ne font pas partie des activités enzymatiques autorisées car jugées inefficaces dans le milieu hostile qu'est le vin. Plus récemment, il a été démontré que l'utilisation d'une aspergillopepsines couplée de la flash pasteurisation permettait l'hydrolyse complète des protéines thermo-instables des vins blancs à l'échelle pilote et industrielle. L'objectif de ce travail est d'explorer de nouvelles applications œnologiques à l'utilisation de protéases. Pour cela, 4 protéases industrielles ont été testées sur l'amélioration de la filtrabilité des vins et l'élevage sur lies d'un vin rouge et un vin blanc. Ce travail a permis de mettre en évidence que l'utilisation de protéase pouvait améliorer sensiblement la filtrabilité des vins. L'amélioration observée est plus importante avec un test de filtrabilité (Vmax sur membrane 0.45 μm) qu'en filtration tangentielle (membrane céramique 0.2 μm). Enfin, en l'absence de flash pasteurisation les protéases ne semblent pas avoir d'effet sur la filtrabilité ou l'élevage sur lies des vins. Mots clés : Enzyme, Protéase, filtrabilité, filtration tangentielle, vin.

Over the last decade, several distinct research groups tested possible uses of membrane contactors for the wine industry, notably for the management of dissolved gases in wines, adjustment of the CO2 concentration while reducing the O2 concentration at the same time. Other experiments were done with partial alcohol reduction and addition of N2 to wines. The contactor's heart is its Liqui-Cel™ membrane where the two separate circuits meet. The membrane's hydrophobic characteristics allows a liquid to get in contact with a gas, without dispersing into it. The directions that these gases take through the membrane depend on their partial pressure differences within the two circuits. However, other factors need to be considered to determine exact exchange rates for each target gas. The present article describes the new membrane contactor prototype that was co-developed by the University of applied Sciences and Arts, Viticulture and Enology at Changins, Switzerland, and the School of Engineering and Architecture at Fribourg, Switzerland. The prototype was designed for small scale operations. Flow rates, temperatures and internal pressures can be instantly measured and graphically visualized. Also, O2 concentrations are measured inside the liquid. CO2 concentrations in the liquid can be measured with a device that is connected to the liquid circuit through a bypass after the membranes.

The aim of this study is to present an evaluation of HbA(1c) Assay on Architect CI8200 (Abbott Diagnostic). The measurement includes Hb assay by colorimetry and HbA(1c) by immunoturbidimetry. The percentage of HbA(1c) is the report HbA(1c)/complete Hb with a conversion coefficient. Repetability (n = 30; CV: 1.15-1.91%) and reproductibility (n = 30; CV: 2.09-2.64%) are good. Abbott results cannot be returned above 12%. Comparison between HbA(1c) Abbott and HbA(1c) Bio-Rad is performed on 161 patients samples ranging from 4.7 and 12%. Results show a correlation coefficient of 0.9847 (N = 161) with a regression equation: [Abbott] = 1.02x [Bio-Rad]-0,636]. Differences between two methods are normally distributed. 95% of differences lie between limits (-0.61%; +0.61%). Such differences are clinically important and interchangability of two measurements can't be possible now because lack of agreement. We hope that IFCC standardization will reduce these differences. Presence of a jaundice and carbamylation of haemoglobin do not interfer with Abbott assay. Hemoglobin variants are not detected. Therefore, monitoring of diabetic patients with HbA(1c) is possible only if hemoglobinopathy has been identified before.

The aim of this study is to present an evaluation of HbA(1c) Assay on Architect CI8200 (Abbott Diagnostic). The measurement includes Hb assay by colorimetry and HbA(1c) by immunoturbidimetry. The percentage of HbA(1c) is the report HbA(1c)/complete Hb with a conversion coefficient. Repetability (n = 30; CV: 1.15-1.91%) and reproductibility (n = 30; CV: 2.09-2.64%) are good. Abbott results cannot be returned above 12%. Comparison between HbA(1c) Abbott and HbA(1c) Bio-Rad is performed on 161 patients samples ranging from 4.7 and 12%. Results show a correlation coefficient of 0.9847 (N = 161) with a regression equation: [Abbott] = 1.02x [Bio-Rad]-0,636]. Differences between two methods are normally distributed. 95% of differences lie between limits (-0.61%; +0.61%). Such differences are clinically important and interchangability of two measurements can't be possible now because lack of agreement. We hope that IFCC standardization will reduce these differences. Presence of a jaundice and carbamylation of haemoglobin do not interfer with Abbott assay. Hemoglobin variants are not detected. Therefore, monitoring of diabetic patients with HbA(1c) is possible only if hemoglobinopathy has been identified before.