不同干燥方法对黑果枸杞中活性成分含量及其抗氧化活性的影响

Effects of different drying methods on content of bioactive component and antioxidant activity in Lycium ruthenicum

比较不同干燥方法对黑果枸杞的外观性状、口感、活性成分含量及其抗氧化活性的影响,指导黑果枸杞生产实践。分别将冷冻干燥、低温干燥和自然烘干的黑果枸杞用福林酚比色法、紫外分光光度法、消光系数法和DPPH法、FRAP法测定总多酚、原花青素、花色苷含量及抗氧化活性。结果表明,干燥方法对黑果枸杞的性状、口感、活性成分含量及抗氧化活性均产生一定程度影响。冷冻干燥后黑果枸杞外观性状及口感均佳,水分含量低,总多酚、原花青素、花色苷含量低于自然晾干者,但其清除DPPH自由基能力最强;自然晾干者外观形状及口感较差,水分含量高,但其3种活性成分含量最高,FRAP法测得的抗氧化活性最强。因此应综合考虑性状、口感、抗氧化活性及生产成本选择黑果枸杞的干燥方法。

To compare the appearances, tastes, contents of bioactive components and antioxidant activity of Lyceum ruthenicum un- der different drying methods, so as to direct its production practice. The folin-phenol colorimetric method, UV, extinction coefficient method and DPPH, as well as fluorescence recovery after photobleaching （FRAP） method to determine the contents of polyphenols, proanthocyanidins, total anthocyanin and antioxidant activity under different drying methods： vacuum freeze drying, low-temperature oven drying and air drying for L. ruthenicum. The results showed that the drying methods had certain effects on its appearances, tastes, contents of bioactive components and antioxidant activity. The appearances and tastes were best after the L. ruthenicum was dried by vacuum freeze drying, with significantly lower moisture than air drying method. The contents of total polyphenols, anthocyanin and pro- anthocvanidins were hizhest bv air-drving but lowest bv low temperature oven drying in L. ruthenicum. The scavenging ability to DPPH was strongest by freeze-drying and lowest by low temperature oven drying, while the antioxidant activity was strongest by air-drying in the FRAT method. In addition, the appearances and tastes were poor in air drying, with higher moisture but highest contents of the three bioactive components. Therefore, the drying methods for L. ruthenicum shall be comprehensively considered.