USDA-ARS, SAA, Food Science Research Unit, 322 Schaub Hall, Box 7624, North Carolina State University, Raleigh, North Carolina 27695-7624, USA.
J Agric Food Chem. 2010 Jan 13;58(1):404-10. doi: 10.1021/jf902799a.
Purple-fleshed sweetpotatoes (PFSP) can be a healthy food choice for consumers and a potential source for natural food colorants. This study aimed to identify anthocyanins and anthocyanidins in PFSP, and to evaluate the effect of thermal processing on these polyphenolic compounds. Freeze-dried powder of raw and steamed samples of three PFSP varieties were extracted with acidified methanol using a Dionex ASE 200 accelerated solvent extractor. Seventeen anthocyanins were identified by HPLC-DAD/ESI-MS/MS for Stokes Purple and NC 415 varieties with five major compounds: cyanidin 3-caffeoylsophoroside-5-glucoside, peonidin 3-caffeoylsophoroside-5-glucoside, cyanidin 3-caffeoyl-p-hydroxybenzoylsophoroside-5-glucoside, peonidin 3-caffeoyl-p-hydroxybenzoyl-sophoroside-5-glucoside, and peonidin-caffeoyl-feruloylsophoroside-5-glucoside. Okinawa variety showed 12 pigments with 3 major peaks identified as cyanidin 3-caffeoylsophoroside-5-glucoside, cyanidin 3-(6'',6'''-dicaffeoylsophoroside)-5-glucoside and cyanidin 3-(6''-caffeoyl-6'''-feruloylsophoroside)-5-glucoside. Steam cooking had no significant effect on total anthocyanin content or the anthocyanin pigments. Cyanidin and peonidin, which were the major anthocyanidins in the acid hydrolyzed extracts, were well separated and quantified by HPLC with external standards. Cyanidin and peonidin, which contribute to the blue and red hues of PFSP, can be simply quantified by HPLC after acid hydrolysis of the anthocyanins.
紫色果肉甘薯（PFSP）可以成为消费者的健康食品选择，也是天然食用色素的潜在来源。本研究旨在鉴定 PFSP 中的花色苷和花色素苷，并评估热加工对这些多酚化合物的影响。使用 Dionex ASE 200 加速溶剂提取器，用酸化甲醇从生的和蒸制的三种 PFSP 品种的冷冻干燥粉末中提取。使用 HPLC-DAD/ESI-MS/MS 鉴定 Stokes Purple 和 NC 415 品种的 17 种花色苷，有五种主要化合物：矢车菊素 3-咖啡酰基棉子糖-5-葡萄糖苷、芍药素 3-咖啡酰基棉子糖-5-葡萄糖苷、矢车菊素 3-咖啡酰基对羟基苯甲酰基棉子糖-5-葡萄糖苷、芍药素 3-咖啡酰基对羟基苯甲酰基槐糖苷-5-葡萄糖苷和芍药素咖啡酰基阿魏酰基棉子糖-5-葡萄糖苷。冲绳品种显示 12 种色素，其中 3 种主要峰鉴定为矢车菊素 3-咖啡酰基棉子糖-5-葡萄糖苷、矢车菊素 3-（6''，6'''-二咖啡酰基棉子糖）-5-葡萄糖苷和矢车菊素 3-（6''-咖啡酰基-6'''-阿魏酰基棉子糖）-5-葡萄糖苷。蒸汽烹饪对总花色苷含量或花色苷色素没有显著影响。通过 HPLC 外标法可以很好地分离和定量酸水解提取物中的主要花色苷元矢车菊素和芍药素。在花色苷酸水解后，通过 HPLC 可以简单地定量对 PFSP 蓝色和红色色调有贡献的矢车菊素和芍药素。
