Antioxidant Activities and Polyphenol Contents in Rhododendron arboreum Kombucha Flavored with Strawberry, Yellow Berry and Black Grapes

Abstract

The aim of this dissertation was to examine the potential antioxidant, polyphenolic and antimicrobial properties of Rhododendron arboreum kombucha with added flavors of strawberry, yellow berry, and black grapes. The kombucha was produced using a standard fermentation process with black tea, Rhododendron arboreum and honey as substrates in the 1st fermentation, and the fruits as flavors were added during the second fermentation. The antioxidant activity was deliberated using the DPPH assay, while the total flavonoid and phenol contents were determined using colorimetric methods. The results indicated that all three flavored kombucha samples had higher antioxidant, total phenol, and total flavonoid contents than the control sample without added flavors. Black grapes had the maximum of total phenol content and antioxidant activity, while yellow berry had the highest total flavonoid content.