Freeze-Drying Encapsulation of Red Wine Polyphenols in an Amorphous Matrix of Maltodextrin

Abstract

Maltodextrin DE 10 was added to Argentine red wine (Cabernet Sauvignon) in a 20% concentration (total weight basis), and the resulting solution was freeze-dried. Water and almost all ethanol were eliminated during freeze-drying leaving an amorphous glassy maltodextrin microstructure (i. e., "wine powder"), containing the red wine's polyphenols (as well as other non-volatile constituents of the dry extract). Almost no loss of total polyphenols was found in the freeze-drying process. Upon milling, the maltodextrin microstructure yielded a free-flowing powder, and its glassy nature was confirmed by measuring its glass transition temperature (Tg). After 15 days, storage at 38 °C total polyphenols content in the "wine powder" remained practically unchanged. This free-flowing powder contained 3. 7 times the concentration of polyphenols in red wine, while only containing less than 1% ethanol. This might be added to other powdered foods as a source of wine polyphenols.