Physicochemical characteristics, antioxidant activity, and sensory quality of kombucha produced from rose, chrysanthemum, and butterfly pea flowers

This study evaluates the effects of fermentation on the physicochemical characteristics, bioactive properties, and sensory quality of kombucha produced from rose, chrysanthemum, and butterfly pea flowers. The three flower substrates were inoculated with a symbiotic culture of bacteria and yeast (SCOBY) and fermented at 30°C for 15 days. During fermentation, SCOBY biomass and titratable acidity increased, whereas pH and total soluble solids decreased. Compared with day 0, total polyphenol and total flavonoid contents on day 10 increased by 106.6–160.2% and 76.4–163.8%, respectively, while DPPH and ABTS radical-scavenging activities increased by 38.7–213.0% and 70.8–148.0%, respectively. These parameters tended to decline when fermentation was extended to 15 days. Mean sensory scores also peaked on day 10, ranging from 6.57 to 7.37. Among the fermentation times investigated, 10 days provided the most favorable balance between phenolic content, antioxidant activity, and sensory quality. The findings demonstrate that rose, chrysanthemum, and butterfly pea flowers are promising substrates for the development of herbal kombucha beverages.