Melatonin contents in mulberry (Morus spp.) leaves: Effects of sample preparation, cultivar, leaf age and tea processing
Melatonin contents in mulberry (Morus spp.) leaves: Effects of sample preparation, cultivar, leaf age and tea processing
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DOI：
10.1016/j.foodchem.2011.03.045
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发表时间：
2011-09-15
期刊：
影响因子：
8.8
通讯作者：
Tongchitpakdee, S.
中科院分区：
文献类型：
--
作者：
Pothinuch, P.;Tongchitpakdee, S.
研究了制样方法、品种、叶龄和茶叶加工对桑葚褪黑激素含量的影响。叶进行了调查。样品制备使用超声波技术结合固相萃取导致高回收率（76%），相比，均质化结合液-液萃取程序（12%的回收率）。采用高效液相色谱-荧光检测法对泰国3个主要桑树品种（布里拉姆60、Sakonnakhon和Khunphai）的桑葚中褪黑素含量进行了测定。桑葚中褪黑激素的平均含量。布里拉姆60（279.6纳克/克干重）高于cv. Sakonnakhon（100.5纳克/克DW）和cv. Khunphai（40.7纳克/克干重）。所有品种的褪黑激素含量均以叶尖最高，幼叶次之，老叶最低。两种桑葚茶的褪黑激素含量比较。还测定了布里拉姆60。茶叶加工过程中的热处理降低了桑葚中褪黑激素的含量。布里拉姆60的约87%，当与鲜叶相比时。但经烫漂处理的桑葚茶（桑葚绿色茶）与未经烫漂处理的桑叶茶（桑葚红茶）的褪黑素含量差异不显著。(C)2011爱思唯尔有限公司保留所有权利。
The effects of sample preparation, cultivar, leaf age and tea processing on melatonin content of mulberry (Morus spp.) leaves were investigated. Sample preparation using ultrasonic technique in combination with solid phase extraction resulted in high recovery rate (76%), when compared to homogenisation in combination with liquid-liquid extraction procedure (12% recovery rate). The melatonin contents in mulberry leaves harvested from three major cultivars (Buriram 60, Sakonnakhon and Khunphai) grown in Thailand were identified and quantified using high-performance liquid chromatography combined with fluorescence detector. The average melatonin content of the mulberry leaves cv. Buriram 60 (279.6 ng/g dry weight (DW)) was higher than those of cv. Sakonnakhon (100.5 ng/g DW) and cv. Khunphai (40.7 ng/g DW). The melatonin contents of all cultivars tested were highest in the tip of the leaves, followed by that in the young leaves, whereas the lowest was found in the old leaves. The melatonin contents of the two types of tea produced from mulberry leaves cv. Buriram 60 were also determined. Heat treatment during tea processing decreased the melatonin content in mulberry leaves cv. Buriram 60 by approximately 87%, when compared to that of the fresh leaves. However, there were no significant differences between the melatonin contents of the mulberry leaf tea produced with blanching (mulberry green tea) and those produced without blanching (mulberry black tea). (C) 2011 Elsevier Ltd. All rights reserved.