Zhejiang University, College of Biosystems Engineering and Food Science, Key Laboratory of Agro-Products Postharvest Handling of Ministry of Agriculture and Rural Affairs, Zhejiang Key Laboratory for Agri-Food Processing, Hangzhou 310058, People's Republic of China.
Institute of Food Science and Engineering, Hezhou University, Hezhou, People's Republic of China.
Food Chem. 2019 Jun 15;283:59-67. doi: 10.1016/j.foodchem.2019.01.017. Epub 2019 Jan 14.
Purple sweet potatoes are known for its vibrant purple color due to high level of anthocyanins. A polyethylene glycol based ultrasonic-assisted green extraction (PEG-UAE) of anthocyanins from purple sweet potato was proposed. Different types of PEG were tested for anthocyanin extraction along with PEG concentration, liquid-to-solid ratio, ultrasonic temperature and time were investigated for its impact on viscosity and extraction efficiency. The optimum extraction condition, 42 mL/g of ratio, 83% of PEG 200 concentration, 64 °C of ultrasonic temperature and 80 min of sonication time, resulted in better extraction of anthocyanins (83.78 mg CE/100 g DW) and phenolics (994.88 mg GAE/100 g DW). Using UPLC-Triple-TOF/MS, ten anthocyanin and six non-anthocyanin compounds were identified and characterized, with the highest peak area for cyanidin-3-caffeoyl-p-hydroxybenzoyl sophoroside-5-glucoside (25.9%). Moreover, the anthocyanins and phenolics extraction yield along with antioxidant activity were negatively correlated with PEG viscosity, on which ultrasonication has profound effects.
紫薯因其富含花青苷而呈现鲜艳的紫色。本研究提出了一种基于聚乙二醇（PEG）的超声辅助绿色提取紫薯花青苷的方法。测试了不同类型的 PEG 对花青苷提取的效果，并考察了 PEG 浓度、液固比、超声温度和时间对其粘度和提取效率的影响。最佳提取条件为料液比 42 mL/g、PEG 200 浓度 83%、超声温度 64 °C 和超声时间 80 min，在此条件下，紫薯花青苷（83.78 mg CE/100 g DW）和总酚（994.88 mg GAE/100 g DW）的提取效果较好。采用 UPLC-Triple-TOF/MS 鉴定并分析了 10 种花青苷和 6 种非花青苷化合物，其中矢车菊素-3-咖啡酰-对羟基苯甲酰基槐糖苷-5-葡萄糖苷的峰面积最高（25.9%）。此外，花青苷和总酚的提取率及抗氧化活性与 PEG 粘度呈负相关，超声处理对此有显著影响。
