不同柿种柿叶维生素C和酚类物质的差异

The Variations of Vitamin C and Phenolics Contents in Leaves of Diospyros L.

对15个柿栽培品种和5个柿属野生种叶中Vc和酚类物质的测定结果表明,野生种的年平均Vc、总酚、黄酮平均含量均高于栽培种,其中Vc含量排序为:野生种>涩柿品种>甜柿品种。除罗田甜柿和老鸦柿外所有材料5月份Vc含量均超过10mg·g-1(FW),大部分甜柿品种的Vc含量随季节的变化显著下降,其它(品)种则变化幅度较小。烘干(60℃)后的柿叶Vc平均保存量只有鲜叶的8 88%。总酚量最高的是野生种,年平均达44 91mg·g-1(FW),所有(品)种的季节变化规律大体上与Vc相同。柿叶中共检测到8种酚酸,其中没食子酸、肉桂酸、咖啡酸和香豆酸分别占酚酸总量的48%、21%、12%和10%。柿叶中黄酮类物质年均含量都在1 7mg·g-1(FW)以上,其中油柿超过11mg·g-1(FW),且季节变化不大。柿叶有效成分的开发可根据利用目的选用适当的(品)种或季节。

The Vitamin C and phenolics contents in 15 cultivars of persimmon and 5 wild species of Diospyros were determined.The result showed that wild species contained highest content of Vc, Phenolics and flavenes. Vc content was more than 10 mg·g in all materials except for 'luotian tian shi' and D.rhombifolia and appeared the trend of wild species>astringent type cultivars>non-astringent type cultivars. It dropped markedly in most non-astringent type cultivars along with changing of season, while others fluctuated in a narrow extent. Oven dried persimmon leaves remained as much as 8.88% of Vc in fresh leaves on oven dried basis. The annual average content of total phenolic compounds in wild species was 44.91 mg·g^(-1)(FW) which was the highest among tested materials and the tendency of seasonal fluctuation in all species and cultivars was similar to Vc. Phenolic acids in persimmon leaves consists of 8 components in which gallic acid, caffeic acid, t-cinnamic and p-coumaric acid account for 48%, 21%, 12% and 10% respectively. Total flavenes content was more than 5 mg·g^(-1) in all materials with little seasonal fluctuation, among which D.oleifera was the richest with the annual average content of 11.42 mg·g^(-1)(FW).It was proposed that extraction and exploitation of active constituents in Diospyros should choose proper species (or cultivars) and seasons according to different purposes.