竹荪多糖提取工艺及抗氧化活性

Extraction process of polysaccharide from Dictyophora indusiata and antioxidant activity

采用缓冻协同微波法对竹荪中的多糖成分进行提取并进行工艺研究,依次考察缓冻时间、微波功率、液料比、提取时间对多糖得率的影响,在单因素试验基础上,运用响应面设计优化得到最佳提取工艺。利用1,1二苯基2三硝基苯肼(DPPH)自由基清除法、2,2'联氮双(3乙基苯并噻唑啉6磺酸)二铵盐(ABTS)自由基清除法、羟自由基清除法、总还原能力4种试验,对比缓冻协同微波法提取得到的竹荪多糖(PW 1)和单一微波法获得的竹荪多糖(PW 2)的抗氧化活性,并借助高效液相色谱联用多角度激光散射(HPSEC MALLS RI)技术和红外光谱分析多糖初步结构。结果表明:最佳提取条件为缓冻时间16 h、微波功率260 W、液料比53 mL/g、提取时间8 min,在最佳提取条件下,PW 1的得率为11.87%。在4种抗氧化活性试验中,PW 1表现的抗氧化活性比PW 2更强。初步结构分析发现PW 1与PW 2分别是由4个主色谱峰和3个主色谱峰构成,并以α糖苷键连接为主的吡喃型糖,重均分子量均为1.018×10^(6)~14.980×10^(6)g/mol。

The extraction process of Dictyophora indusiata polysaccharides by slow freezing-microwave assisted method was studied.The factors of slow freezing time,microwave power,liquid-solid ratio,extraction time was investigated,and then the response surface design was used to obtain the optimal extraction process based on the single-factor experiment.The antioxidant activity of 1,1-diphenyl-2-picrylhydrazyl(DPPH),2,2'-bis(3-ethylbenzothiazoline-6-sulfonic acid)diamimium salt(ABTS)and hydroxyl radical scavenging and total reducing capacity were compared with the polysaccharide(PW-1)extracted by slow freezing-microwave assisted method and the polysaccharide(PW-2)obtained by microwave assisted method.The preliminary structure of polysaccharides was analyzed by high-performance liquid chromatography multi-angle laser scattering(HPSEC-MALLS-RI)technology and infrared spectroscopy.Results showed that the optimum extraction conditions for the 11.87%extraction yield of polysaccharide(PW-1)was slow freezing time of 16 h,microwave power of 260 W,liquid-solid ratio of 53 mL/g,and extraction time of 8 min.PW-1 exhibited stronger antioxidant activity than PW-2 in four tests of antioxidant activity.PW-1 and PW-2 were composed of four main chromatographic peaks,and three main chromatographic peaks respectively.The molecular weights of pyranose connected byα-glycosidic bonds ranged from 1.018×10^(6) to 14.980×10^(6) g/mol.