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The antioxidant activities of anthocayanin from purple sweet potato(yan 176)were studied with three methods: scavenging activity against diphenylpicrylhydrazyl radical, superoxide anion radical and hydroxyl radica1, and compared with Vc. As the result: the anthocayanin from purple sweet potato showed high scavenging effects on ·OH, O2．- and DPPH·. But the antioxidant activities of crude pigment obviously lower pure pigment and Vc. When the concentration reached to 5mg/mL, the antioxidant activities of pure pigment are closed to Vc. Key word:purple sweet potato anthocyanin; extraction; purification; component analysis; stability; antioxidant activities
河北农业大学 硕士学位论文 紫甘薯花青素的提取纯化、稳定性及抗氧化活性研究 姓名：姚钰蓉 申请学位级别：硕士 专业：农产品加工及贮藏工程 指导教师：张伟；木泰华 2009-06-18
摘要
天然花青素是一类广泛存在于植物中的水溶性色素，属于类黄酮化合 物。因其安全、色泽亮丽兼具抗氧化及其它保健功能，已投入工业化生产， 以丰富人们的工作和生活。紫甘薯产量高，容易栽培，成为经济地获取天 然花青素的理想途径，因此，近年来从紫甘薯中提取花青素成为国际上热 门研究项目。
紫甘薯花青素在清除·OH，O2．-和 DPPH·自由基 3 个抗氧化体系中表现出较 强的自由基清除能力，且随着浓度增大，紫甘薯花青素抗氧化活性增强，当浓度 达到 5mg/mL 时，紫甘薯花青素纯品自由基清除能力与抗坏血酸（Vc）接近。但 粗品的抗氧化能力明显低于纯品和 Vc。
关键词：紫甘薯花青素；提取纯化；构成成分；稳定性；抗氧化活性
Abstract
Inartificial anthocyanin is a kind of water-solubility coloring matter which is widely indwelled in plant, and it belongs to flavones compound. AS a result of its vivid color and luster, anti-oxidation and other function of health care, in order to making people’s works and lives better, it has been put into industrialization produce. Purple sweet potato is high output, easy planted, become a inexpensive way to obtain anthocyanin, so recently years, the anthocyanin distilling from it has become a very hot research study.
The optimum extraction conditions have been obtained, which included extraction temperature was 60℃, the concentration of extraction reagent was 5% formic acid, the ratio of purple sweet potato powder to the extraction reagent was 1:10, extraction time was 2 hour for 3 times, after the crude anthocyanin pigments was purified by AB-8 Macro-porous Resin, the color value increased to 20.4.
The purple sweet potato anthocyanins had a better heat stability. Under 60℃,the stability very good, and the save ratio next to 100%. The purple sweet potato anthocyanins had a strong compression resistance characteristic, at the pressure is 500MPa, disposal 15min, the anthocyains still hold the line. At the different pH value, anthocyanins stabilities are different, at a strong acidity condition（pH≤3）, the change of colour and characteristic absorb spectrum are unconspicuous, however, at the alkalescence condition, the anthocayanins showed a instability characteristic.
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The study on the extraction and purification and stability and dant activitiesof anthocyanins from purple sweet potato
Author: Yao Yu-rong Adviser: Prof. Zhang Wei Researcher.Mu Tai-hua Specialty: Processing and Storage of Agriculture Products
The chemical components in extraction of purple sweet potato were analyzed by HPLC-electrosprary ionization-mass spectrometry(ESI-MS) and the structure was elucidated accoding to mass-to-charge ratio (m/z) of molecule ionic peak, the fragmental and reference. The major anthocayanin is 3-O-(6-O-trans-caffeyl-2-O-β-glucopyranosyl-β-glucopyranoside)-5-O-β-glucoside peonidin.
Tris(Hydroxymethyl)aminomethane Mega-Pascal Microgramme Milligram Mole Millimeter Gramme Milliliter Hour Second Minue Cetimeter Vitamine C Nanometer
中文名称 美国食品和药物管理局 联合国粮食及农业组织
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紫甘薯花青素具有较好的热稳定性，在60℃以下稳定性很好，保存率可达到 100%。紫甘薯花青素具有较强的耐压特性。在压力500 MPa处理15 min后花青素 的保存率仍保持不变。不同pH值下紫甘薯花青素稳定性不同，在较强的酸性条 件下（pH≤3），颜色及特征吸收光谱变化不太明显。但在碱性条件下，花青素稳 定性较差。
The present thesis was focused on the anthocyanins from purple sweet potato cultivated in Hebei Academy of Agricultural Sciences, including technology conditions of extractiom and purification, component analysis, stabilities and antioxidant activities.
本课题收集了河北和北京密云两地的四种紫甘薯品种，通过对其色彩色度差 及吸光值的测定，结果发现由河北农林科学院提供的紫甘薯品种烟176具有更好 的色调，故选用烟176作为本试验的原料，对其花青素的提取纯化工艺、构成成 分、稳定性和抗氧化活性进行了研究。
通过单因素和正交试验得到紫甘薯花青素最佳提取条件为：甲酸浓度 5%， 提取温度 60℃，提取时间 1h，料液比 1：10，提取 3 次。
在提取工艺和纯化工艺的基础上，得到了一套制备紫甘薯花青素的生产工 艺，在此工艺下制备的紫甘薯花青素的色价为 20.4。
采用HPLC-ESI-MS联用技术对紫甘薯花青素构成成分进行分析,结合紫甘 薯花青素化学成分的相关文献报道,得出紫甘薯（烟176）花青素主要构成成分为 3-O-(6-O-trans-caffeyl-2-O-β-glucopyranosyl-β-glucopyranoside)-5-O-β-glucoside peonidin。