Resumen de Rose Petal Tea as an Antioxidant-rich Beverage: Cultivar Effects
Yakov Vinokur, Victor Rodov, Natalie Reznick, Genady Goldman, Batia Horev, Nakdimon Umiel, Haya Friedman
Twelve rose cultivars were selected by field tasting as potential sources of edible flowers. Hot water infusions (teas) of air-dried petals of these cultivars were assayed for antioxidant activity, total phenols, and total anthocyanins contents. Their composition was analyzed by high-performance liquid chromatography (HPLC). Green tea was tested in parallel as a reference antioxidant-rich beverage. Rose petal teas from different cultivars exhibited scavenging capacity toward 2,2′-azino-bis-(3-ethylbenzothiazoline)-6-sulfonate cation radical (ABTS+) ranging between 712.7 and 1770.7 μM Trolox equivalents (TE) per gram of dry petals, as compared with 1227.6 μM TE/g dry weight in the green tea. The range of total phenols content in rose teas was 50.7 to 119.5 mg gallic acid equivalents (GAE) per gram of dry matter, as compared with 62.1 mg GAE/g dry weight in the green tea. The rose teas were rich in free gallic acid. The highest values of antioxidant activity, total phenols, and gallic acid contents were found in the cultivars San Francisco, Katharina Zeimet, and Mercedes and in the essential-oil-bearing rose Rosa damascena. The correlation coefficients between antioxidant activity, on the 1 hand, and the contents of total phenols and of gallic acid in various rose cultivars, on the other hand, were 0.79 and 0.81, respectively. No clear relationship between anthocyanin level and radical-scavenging activity was revealed. Teas from different rose cultivars significantly differed in their sensory properties. It was concluded that dried rose petals may be used for preparing antioxidant-rich caffeine-free beverages, either separately or in combination with other herbal materials.
