樱桃李多糖提取工艺优化及单糖组成与抗氧化活性测定

Optimization of Polysaccharide Extraction Process and Analysis of Monosaccharide Composition and Antioxidant Activity of Prunus cerasifera

为确定樱桃李多糖的最佳提取工艺,比较热水提取法、酶解法和超声辅助法对多糖提取率的影响,通过扫描电镜(scanning electron microscope,SEM)观察不同提取方式所得樱桃李纯化多糖(Prunus cerasifera pure polysaccharides,PCPPs)的微观结构。在正交试验确定复合酶质量比的基础上,采用单因素结合正交试验优化复合酶法提取樱桃李粗多糖(Prunus cerasifera crude polysaccharides,PCCPs)的最佳工艺为纤维素酶添加量2.0%、果胶酶添加量2.5%、料液比1∶35(g/mL)、酶解时间2.0 h、酶解温度55℃。以种植的紫果、红果和野生的紫果、红果为原料,将最佳提取工艺下得到的PCCPs经纯化、水解、衍生化后,采用液相色谱(high-performance liquid chromatography,HPLC)分析单糖组成。结果表明,4种樱桃李多糖均由甘露糖、葡萄糖醛酸、鼠李糖、葡萄糖、半乳糖和阿拉伯糖6种单糖组成,但含量存在显著差异(P<0.05)。体外抗氧化试验表明,4种多糖均具有一定的抗氧化能力,其中种植紫果的抗氧化活性最强,对DPPH自由基和ABTS+自由基清除的IC_(50)值分别为0.04 mg/mL和0.21 mg/mL。

In order to determine the optimal extraction process of polysaccharides from Prunus cerasifera,the influence of hot water extraction method,enzymolysis extraction method,and ultrasound⁃assisted extraction method on polysaccharide extraction rate were compared,and the microstructures of pure polysaccharides from Prunus cerasifera(PCPPs)obtained by different extraction methods were observed with scanning electron mi⁃croscope(SEM).Orthogonal experiment determined the compound enzyme mass ratio,and on this basis,single factor experiments,orthogonal experiments,and compound enzyme methods were combined to optimize the ex⁃traction process of crude polysaccharides from Prunus cerasifera(PCCPs)as follows:cellulase dosage of 2.0%,pectase dosage of 2.5%,material⁃to⁃liquid ratio of 1∶35(g/mL),enzymatic hydrolysis time of 2.0 h,and enzy⁃matic hydrolysis temperature of 55℃.With cultivated purple fruits and red fruits,as well as wild purple fruits and red fruits as raw materials,the monosaccharide composition was analyzed by high⁃performance liquid chro⁃matography(HPLC)after purification,hydrolysis,and derivatization of the PCCPs obtained by the optimal ex⁃traction process.The results showed that four polysaccharides from Prunus cerasifera all consisted of six mono⁃saccharides,including mannose,glucuronic acid,rhamnose,glucose,galactose,and arabinose,but the content of these monosaccharides was significantly different(P<0.05).The results of in vitro antioxidant experiments showed that the four polysaccharides had certain antioxidant activity,among which polysaccharides from culti⁃vated purple fruits showed the strongest antioxidant activity,with the half inhibitory concentration value(IC_(50))for DPPH and ABTS+radical scavenging of 0.04 mg/mL and 0.21 mg/mL,respectively.