不同品种紫肉甘薯抗氧化能力及花色苷成分分析

Antioxidant Capacity and Anthocyanins of Purple-Fleshed Sweet Potato Cultivars

以广东地区9个不同品种的紫肉甘薯为研究对象,评价紫肉甘薯抗氧化能力,并对花色苷的组成进行定性和定量分析。结果表明:不同品种紫肉甘薯,总酚含量和抗氧化能力也不尽相同,其中广紫9的总酚含量为578 mg GAE/100 g,清除2,2’-联氮基-双-(3-乙基苯并噻唑啉-6-磺酸)二铵盐(2,2’-amino-di(3-ethyl-benzothiazoline sulphonic acid-6)ammonium salt,ABTS)自由基能力、氧自由基吸收能力、还原能力分别为4.36、10.38、11.23μmol TE/g,均高于其他品种的紫肉甘薯。通过高效液相色谱-四极杆飞行时间质谱法共鉴定出16种花色苷,包括8种矢车菊素类和8种芍药素类。紫肉甘薯花色苷含量在77.17~1 125.06 mg/kg之间,以广紫9含量最高,花色苷主要以酰基化的形式存在,其含量是非酰化的89倍,酰基化程度明显高于其他品种。综上所述,不同品种紫肉甘薯具有不同的抗氧化能力,其花色苷含量与结构也有较大差异,其中广紫9花色苷含量最高,抗氧化能力最强。

The antioxidant activities and anthocyanin composition of purple sweet potatoes from nine varieties cultivated in Guangdong were determined.The results indicated that total phenolic contents and antioxidant activities of different varieties were different.The total phenolic content of Guangzi 9 was 578 mg GAE/100 g fresh weight,and the 2,2＇-amino-di（3-ethylbenzothiazoline sulphonic acid-6） ammonium salt（ABTS＋·） radical scavenging activity,oxygen radical absorbance capacity,and reducing power were 4.36,10.38,and 11.23 μmol TE/g fresh weight,respectively,which were superior to those of the other varieties.Sixteen anthocyanins,including 8 cyanidins and 8 peonidins,were identified by high performance liquid chromatography-quadrupole-time of flight mass spectrometry（HPLC-QTOF-MS）.The content of total anthocyanins was in the range of 77.17–1 125.06 mg/kg fresh weight,and Guangzi 9 showed the highest anthocyanin content.Acylated anthocyanins were the main anthocyanin constituents in purple sweet potatoes.Acylated anthocyanins were 89 times more abundant than non-acylated ones in Guangzi 9,which showed a significantly higher content of acylated anthocyanins than the other varieties.Taken together,the antioxidant activities and anthocyanin composition of different purple sweet potato varieties were different with Guangzi 9 exhibiting the highest content of anthocyanins and highest antioxidant capacity.