Song Lixia, Wang Xiangshe, Zheng Xueqin, Huang Dejian
Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, No. 4 Xueyuan Road, Longhua District, Haikou, Hainan 571101, China.
Food Science and Technology Programme, Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore.
Food Chem. 2011 Nov 15;129(2):351-357. doi: 10.1016/j.foodchem.2011.04.083. Epub 2011 May 1.
Yellow camellia (section Nitidissima Chang) is a subgroup of tea plant with golden yellow flowers. It is a very rare species with potential as antioxidant rich plant as it is closely related to tea. We found, for the first time, that the antioxidant capacity and polyphenolic constituents of six yellow camellia species varied widely. Among them, the dry leaf of Camellia impressinervis had the highest level of oxygen radical absorbance capacity (ORAC, 2270.9μmolTE/g), total phenolic content (TPC, 475.6μmolGAE/g), and proanthocyanidin content (PAC, 66.1μmolCE/g). The ORAC level correlated well with TPC (R=0.9402), and PAC (R=0.9954). The compounds responsible for antioxidant activities were further profiled by HPLC and LC-MS analysis. Compared to the commonly consumed tea leaves, yellow camellia leaves contain more diverse phenolic compounds, including ellagitannins, proanthocyanidins, taxifolin deoxyhexose, apigenin derivatives, kaempferol derivative, quercetin derivatives, glucosyl isorhamnetin, (epi)catechin-(epi)afezelechin polymers and platphyllosides. Unlike tea leaves, no caffeine is detected in the yellow camellia leaves. The antioxidant activity of the polyphenolic compounds were further verified by precolumn treatment of the extracts with a stable radical 2,2-diphenyl-1-picrylhydrazyl (DPPH).
金花茶（金花茶组 张宏达）是茶树中开金黄色花朵的一个亚组。它是一种非常稀有的物种，因其与茶密切相关，具有作为富含抗氧化剂植物的潜力。我们首次发现，六种金花茶物种的抗氧化能力和多酚成分差异很大。其中，凹脉金花茶的干叶具有最高水平的氧自由基吸收能力（ORAC，2270.9μmolTE/g）、总酚含量（TPC，475.6μmolGAE/g）和原花青素含量（PAC，66.1μmolCE/g）。ORAC水平与TPC（R = 0.9402）和PAC（R = 0.9954）相关性良好。通过HPLC和LC-MS分析进一步剖析了具有抗氧化活性的化合物。与常见的食用茶叶相比，金花茶的叶子含有更多样化的酚类化合物，包括鞣花单宁、原花青素、 taxifolin deoxyhexose、芹菜素衍生物、山奈酚衍生物、槲皮素衍生物、葡萄糖基异鼠李素、（表）儿茶素-（表）阿夫儿茶素聚合物和platphyllosides。与茶叶不同，金花茶的叶子中未检测到咖啡因。通过用稳定自由基2,2-二苯基-1-苦基肼（DPPH）对提取物进行柱前处理，进一步验证了多酚化合物的抗氧化活性。
