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4. Vincenzi S., Polesani M., Curioni A. 2005: Removal of specific protein components by chitinenhances protein stability in a white wine. American Journal of Enology and Viticulture56 , 246 -254.The effect of chitin [poly(N-acetyl-1,4-ß-D-glucopyranosamine)], an abundant, low-cost natural polymer, onwhite wine stabilization on a laboratory scale was studied in comparison with bentonite fining. Treatments ofan unfined wine with increasing doses of chitin allowed a reduction of up to 80% of the haze induced by theheat test, which corresponded to a reduction in wine protein content of less than 29%. In contrast, bentonitefining, although allowing a complete stabilization, resulted in the removal of almost all the proteins from wine.These results suggest that chitin can remove from wine protein components involved in haze formation morespecifically than bentonite. SDS-PAGE analysis of both the proteins remaining in wine and those adsorbed bychitin confirmed this specificity. Chitinolytic activity detection after SDS-PAGE separation demonstrated thata main protein component removed by chitin corresponded to the class IV chitinase of grape origin involved inwhite wine instability. Because class IV chitinases are characterized by bearing a chitin-binding domain, aspecific interaction of these wine proteins with chitin can be suggested. Preliminary trials with chitin immobilizedin a column system indicated the possibility to regenerate this matrix and to use it continuously for whitewine stabilization. However, the effects on both the organoleptic quality and the long-term stability of whitewines treated with chitin need to be determined in the actual winemaking conditions5. Vincenzi S., Mosconi S., Zoccatelli G., Dalla Pellegrina C., Veneri G., Chignola R., PeruffoA., Curioni A., RizzI C. 2005. Development of a new procedure for protein recovery andquantification in wine. American Journal of Enology and Viticulture 56 ,182-187.In order to develop a procedure for protein recovery and quantification in wines, known amounts of bovine serumalbumin (BSA) were added to samples of protein-free wine. Dialysis followed by lyophilization, precipitationswith ethanol, acetone, trichloroacetic acid, and by a new method that precipitates proteins as protein- potassiumdodecyl sulfate complexes (KDS method) were used to recover BSA from protein-free wine. RecoveredBSA was then quantified by three colorimetric assays: Bradford, Lowry, and Smith. The KDS method followedby the Smith assay obtained the best match between actual and measured BSA quantities. When this procedurewas used for quantification of wine proteins, the results were in accordance to those determined by densitometricquantification of the protein bands separated by sodium dodecyl sulfate–polyacrylamide gel electrophoresis(SDS-PAGE), indicating that the proposed method allows a reliable determination of the protein content of wine.SISTAL - SOCIETA’ ITALIANA DI SCIENZE E TECNOLOGIE ALIMENTARIDipartimento di Scienze e Tecnologie Agroalimentari, Università degli Studi della TusciaVia San Camillo de Lellis, 01100 ViterboTel.: 0761- 35 74 94/7 , Fax: 0761- 35 74 98, e-mail: mmoresi@unitus.it307