發(fā)布時間：2019-01-07 20:34

【摘要】：黑果枸杞作為一種天然果實(shí),有“軟黃金”之稱。國內(nèi)外大量實(shí)驗(yàn)研究發(fā)現(xiàn),黑果枸杞對機(jī)體有一定的保健效能,備受人們的關(guān)注。本論文用青海省黑果枸杞的干果為原料,通過超聲波輔助法提取黑果枸杞多糖,并對黑果枸杞粗多糖進(jìn)行純化,進(jìn)而對純化后的黑果枸杞多糖進(jìn)行初步結(jié)構(gòu)表征以及抗氧化活性的研究。1.超聲波法提取黑果枸杞多糖。研究用料液比、超聲波功率、提取溫度、提取時間作為單因素,并用正交試驗(yàn)優(yōu)化提取工藝。結(jié)果表明最適宜的提取條件是料液比是1:20(g/mL)、超聲波功率是150 w、提取溫度是70℃、提取時間是30 min。此條件下的粗多糖得率為10.74%。2.黑果枸杞多糖的純化。黑果枸杞粗多糖經(jīng)三氯乙酸脫蛋白后,依次采用超濾、大孔樹脂吸附、聚酰胺層析、分級沉淀、DEAE-52纖維素洗脫及流水透析進(jìn)行純化,再次通過DEAE-52纖維素柱來洗脫以及制備型高效液進(jìn)一步對多糖進(jìn)行分離純化。結(jié)果表明:經(jīng)分級沉淀后,黑果枸杞多糖由LPR-60、LPR-70、LPR-80、LPR-90四種多糖組成,含量分別為69.27%、76.07%、78.11%、74.43%。用DEAE-52纖維素柱去對其洗脫后,與制備型高效液相結(jié)果相差甚微,研究結(jié)果表明,黑果枸杞多糖由LPR-80-1、LPR-80-2、LPR-80-3和LPR-80-4四種多糖組成,含量分別為76.68%、78.59%、78.54%和77.43%。選擇多糖組分LPR-80-2做后續(xù)的研究。3.黑果枸杞多糖的初步結(jié)構(gòu)表征。通過紫外光譜、紅外光譜、毛細(xì)管電泳、掃描電鏡、原子力顯微鏡、質(zhì)譜對多糖組分LPR-80-2的結(jié)構(gòu)進(jìn)行初步研究。結(jié)果表明:UV檢測顯示其多糖組分在260-280nm的范圍內(nèi)并沒有明顯的吸收,表明該多糖樣品不含蛋白質(zhì)和核酸等生物大分子;紅外光譜分析表明黑果枸杞多糖含多糖的特征吸收峰,且含有吡喃環(huán)結(jié)構(gòu);而毛細(xì)管電泳結(jié)果發(fā)現(xiàn),該多糖組分由鼠李糖、阿拉伯糖、葡糖糖及半乳糖4種單糖組成。其組成摩爾比為:Rha:Ara:Glc:Gal=0.3:2.2:1.0:1.5;原子力顯微鏡掃描顯示該多糖分子分子間排列緊密,呈圓圈狀堆積結(jié)構(gòu);掃描電鏡顯示其呈現(xiàn)表面粗糙的片狀聚集結(jié)構(gòu)。4.黑果枸杞多糖的抗氧化。研究以DPPH·、OH·和O2-·為體外抗氧化指標(biāo),對比黑果枸杞粗多糖及精制多糖的抗氧化活性,實(shí)驗(yàn)結(jié)果發(fā)現(xiàn),黑果枸杞多糖粗品和和精制樣品均具有清除自由基的能力,具有一定的抗氧化活性,且精制多糖樣品的清除自由基能力略高于粗多糖,而且根據(jù)濃度的增大,抑制自由基的作用效果也隨之加強(qiáng),研究還發(fā)現(xiàn),多糖樣品均對羥基自由基的抑制作用比較顯著,隨濃度的變大,越來越接近于Vc對活性氧自由基的抑制能力。并通過研究黑果枸杞多糖對鎘中毒小鼠肝臟的保護(hù)效果,以肝臟中MDA含量、抗氧化酶CAT和SOD含量以及NO的含量為指標(biāo),結(jié)果發(fā)現(xiàn),黑果枸杞多糖能夠使得MDA含量降低,CAT和SOD活性增強(qiáng),NO的含量下降,證實(shí)了黑果枸杞有一定的體內(nèi)抗氧化作用,能夠?qū)︽k中毒小鼠的肝臟起到保護(hù)效果。
[Abstract]:Black fruit wolfberry as a natural fruit, has a "soft gold" said. A large number of experimental studies at home and abroad found that black fruit wolfberry has a certain health care efficiency, and has attracted people's attention. In this paper, the dried fruit of black fruit Lycium barbarum in Qinghai Province was used as raw material, and the polysaccharides of black fruit Lycium barbarum were extracted by ultrasonic assisted method, and the crude polysaccharide of black fruit Lycium barbarum was purified. The purified Lycium barbarum polysaccharides were characterized and the antioxidant activity was studied. 1. Extraction of Polysaccharide from Lycium barbarum by Ultrasonic method. The ratio of material to liquid, ultrasonic power, extraction temperature and extraction time were used as single factors, and the extraction process was optimized by orthogonal test. The results show that the optimum extraction conditions are 1:20 (g/mL), 150 ww ultrasonic power, 70 鈩，

本文編號：2404128