Influence de la Clarification sur les caracteristiques analytiques et sensorielles du vin sec de Muscat

Abstract

[EN] The influence of the clarification on the analytical and sensorial characteristics has been studied on a dry white wine of Muscat. To carry out this work, we have used dry wine of Muscat of the Valencia denomination of origin from the 1995 vintage. The clarification has been realized with four differents c1arifying agents: gelatin, blood albumin, casein and egg albumin associated with bentonite, used in two different doses: a medium doses, calculated from the lowest and highest doses recommended by the maker, and the lowest dose. The analysis physieo-chemical have been made following the official methods of the Bulletin de l'Office Internationale de la Vigne et du Vin. The aromatic compounds (esters, high alcohols and terpenes), polyols were set by the gas chromatographie technique, with a chromatograph HEWLETT-PACKARD 5890 A, with a FID and an HP-3395, using nitrogen as carrier gas. Also the sensory characteristics have been determined. Each clarifying agent influence in different ways: gelatin and blood albumin affect fundamentaly the physico-chemieal characteristies. Whereas egg albumin decreases the contents in esters, high alcohols, acetaldehide, and methanol. To a lesser extend, blood albumine and casein affect the aromatic fraction. The use of egg albumin isn't advisable for the clarification of white wines, anyway the blood albumin because there are changes in the characteristies in a visible way. At the sight of the results, the combination of gelatin and bentonite for the clarification of a Muscat wine gives a more valuated wine by the consumers. FinaIly, the clarification has not any influence on attributes evaluated in the sensorial analysis

[Otros] L'influence de la clarification sur les caractéristiques analytiques et sensorielles est étudiée sur un vin blanc sec de Muscat. Quatre c1arifiants différents sont utilisés: gélatine, albumine de sang, albumine d' œuf et caséine, tous associés à la bentonite. Les caractéristiques physico-chimiques, les composés aromatiques (esters, alcools, terpènes) et polyols, ainsi que les caractéristiques organoleptiques des vins sont déterminés. Les résultats montrent que chaque clarifiant a une incidence différente: la gélatine et l'albumine de sang affectent fondamentalement les caractéristiques physico-chimiques des vins tandis que l'albumine d'œuf et en moindre mesure l'albumine de sang et la caséine affectent les composés aromatiques. Enfin, la clarification n'excerce aucune influence sur les critères évalués au cours de l'analyse sensorielle (couleur, odeur et goût)