Journal des bioprocédés et des biotechniques

Effects of Different Drying Methods on the Antioxidant Properties of White Wine Lees

Abstract

Benjamin Poulain, Hassana Hsein, Pierre Tchreloff and Claudia Nioi

This study investigated the influence of different drying processes and their operating conditions on the preservation of the antioxidant properties of white wine lees. Four white wine lees were dried using different methods: Spray Drying (SD), Freeze Drying (FD) and Vacuum Oven (VO). Physicochemical characteristics of the dried lees powders were analysed in terms of residual moisture content, particle morphology, particle size and antioxidant properties which were assessed via DPPH, FRAP assays and Total Polyphenol Content (TPC). The powders obtained via the different drying processes had different physical characteristics, with particle sizes ranging from 5 to 100 μm depending on the drying technic. FD and VO resulted in larger particle sizes than the powders obtained from SD. This result was confirmed by SEM observation and laser diffraction particle sizing technique. After FD, VO and SD<200°C the antioxidant capacities of the all studied lees was maintained. The DPPH values ranged from to 9.5 to 10.8 mg TE/g DM and the FRAP values ranged from 31.2 to 37.3 mg TE/g DM. Even after 12 months of storage at room temperature, the antioxidant properties of the wine lees remained unchanged. It can be concluded that these drying techniques make it possible to preserve the antioxidant properties of white wine lees and thus that wine lees are a potential natural source of antioxidants for food, nutraceutical, pharmaceutical and cosmetic fields.