Valorization of winery effluent using kombucha culture

Abstract

Effluent from clarifying the must from wine production was used as a sole medium for kombucha fermentation. Usually, this effluent is disposed in the communal sewage system. This way of use and treating wastewater is certainly ecologically beneficial. The initial substrate for cultivation was prepared by diluting sterilized winery effluent to 70 g/L of total sugars, using boiled tap water. Kombucha starter was prepared using black tea and sucrose and added 10% (vol/vol) to the initial substrate. Fermentation was performed at 25°C. The obtained beverage was appropriate for consummation after 6 days. Obtained kombucha product had an enjoyable taste with wine alike note. The produced beverage had supreme DPPH radical scavenging ability and reducing power compared to traditional black- and green- tea based kombucha. Hydroxyl radical scavenging ability was also significant. A variety of organic acids was detected. Ascorbic acid content was 3.6 mg/L on the consumption day. Practical applications Using winery wastewater this way provides benefits for both winemakers and kombucha producers. Winemakers eliminate effluent with a lot of organic compounds for free and kombucha producers ensure raw material for the fermentation. An additional benefit is the eco-friendly disposal of wastewater that generally goes to communal sewerage.