不同加热方式对丙二酰基人参皂苷降解的影响及抗氧化活性的变化

Effects of Different Heating Methods on Degradation of Malonyl-ginsenosides and Changes in Antioxidant Activity

采用高效液相色谱法,测定了丙二酰基人参皂苷Rb_(1)、Rc、Rb_(2)和Rd在水浴加热、微波加热、高温蒸制和烘焙条件下的降解情况,并研究其体外抗氧化活性的变化。结果表明:在水浴加热和微波加热条件下,丙二酰基人参皂苷会降解成相应的中性皂苷(Rb_(1),Rc,Rb_(2),Rd);在高温蒸制条件下,丙二酰基人参皂苷不仅降解成相应的中性皂苷,同时还有稀有皂苷20(S)-Rg_(3),20(R)-Rg_(3),RK_(1),Rg_(5)的生成;而在烘焙加热条件下,丙二酰基人参皂苷非常稳定,不发生降解。此外,体外抗氧化试验结果表明,不同加热方式下人参皂苷对DPPH·和OH·的清除能力大小为高温蒸制>烘焙>水浴和微波。此结果可为人参产品在高温加工过程中丙二酰基人参皂苷的降解规律和抗氧化能力提供基础数据,同时也为丙二酰基人参皂苷的开发利用提供了科学依据。

The contents of malonyl-ginsenosides-Rb_(1),-Rc,-Rb_(2) and-Rd,and their degradation products during water bath heating,microwave heating,steaming and baking were simultaneously quantified with HPLC,and their antioxidant activities in vitro were also studied.The results showed that malonyl-ginsenosides degraded gradually under water bath heating and microwave heating,and transformed into corresponding neutral ginsenosides-Rb_(1),-Rc,-Rb_(2) and-Rd.Under the condition of steaming,malonyl-ginsenosides were not only converted to neutral ginsenosides,but also degraded to rare ginsenosides 20 S-Rg_(3),20(R)-Rg_(3),RK_(1) and Rg_(5).However,malonyl-ginsenosides did not undergo any degradation during baking process.In addition the results of antioxidation test in vitro showed that the scavenging ability of ginsenosides to DPPH and OH under different heating methods was as follows:high temperature steaming>baking>water bath heating and microwave heating.This study provides basic data for the degradation and antioxidant capacity of malonyl-ginsenosides in ginseng products during high temperature processing,and provides a scientific basis for the development and utilization of malonyl ginsenosides.