关键词: 柿叶茶, 加工过程, 抗氧化活性, 黄酮, 总酚

Abstract: Antioxidant activity of processed persimmon (Diospyros) leaves was determined by DPPH,ABTS free radical scavenging,reducing power (Fe³⁺ and Cu²⁺), and metal-chelating assays (Fe²⁺ and Cu²⁺).Total flavonoids and polyphenols contents were also determined spectrophotometrically.Persimmon leaf tea showed excellent  in vitro antioxidant activity as determined by both chelating metal ions and scavenging free radicals.Processing steps (fixation,infusion,shaping,drying and frying) improved the antioxidant activity of persimmon (Diospyros) tea leaves to different extent depending on the assay.Thus,the ABTS+· scavenging ability and the Cu²⁺ reducing power were significantly improved by processing;whereas,the Fe²⁺ chelating ability was significantly decreased.On the other hand,the DPPH· scavenging ability,the Fe³⁺ reducing power,and the Cu²⁺ chelating ability of persimmon leaves were not affected by tea processing.There were no significant differences in total flavonoids and polyphenols contents between fresh and processed persimmon tea leaves,and values were significantly correlated with antioxidant activity.

Key words: persimmon (Diospyros) leaf tea, manufacturing processes, antioxidant activity, flavonoids, polyphenols