紫薯多酚的提
發(fā)布時(shí)間：2019-05-18 12:00
【摘要】：紫薯(Purple sweet potato)屬旋花科,多分布于中國(guó)南方大部分地區(qū)。紫薯所含營(yíng)養(yǎng)成分豐富,塊莖除含有植物多糖、蛋白質(zhì)、維生素等多種營(yíng)養(yǎng)成分外,還富含花色苷、綠原酸、類黃酮等多酚類物質(zhì),這類物質(zhì)是天然的抗氧化劑,具有降血脂、抗腫瘤、有效清除自由基、抗衰老等增強(qiáng)機(jī)體免疫的功能。目前關(guān)于多酚的研究主要是對(duì)某種原料的游離酚進(jìn)行的提取測(cè)定,而自然界的各類物種,尤其是在植物原料中,除了游離酚外,還有一部分酚類物質(zhì)是以結(jié)合態(tài)的形式存在的,這部分酚類物質(zhì)即為結(jié)合酚。目前國(guó)內(nèi)外對(duì)植物中結(jié)合酚提取純化及活性研究方面的系統(tǒng)報(bào)道較少,本文以"遼薯20"這一品種的紫薯凍干粉為原料,對(duì)其游離酚和結(jié)合酚分別進(jìn)行提取和純化,采用高效液相色譜技術(shù)、液質(zhì)聯(lián)用技術(shù)對(duì)其酚酸類物質(zhì)組成進(jìn)行了分析,采用DPPH自由基清除法和α-葡萄糖苷酶活性抑制法初步研究了其抗氧化活性和降血糖活性,并利用體外模擬消化試驗(yàn)研究了其體外模擬消化釋放和在胃腸道消化過(guò)程中的穩(wěn)定性,研究結(jié)果如下:1、經(jīng)篩選后采用體積分?jǐn)?shù)為60%的乙醇水溶液提取紫薯游離酚,在單因素試驗(yàn)的基礎(chǔ)上,利用響應(yīng)面分析法優(yōu)化相關(guān)參數(shù),得出了紫薯游離酚提取的最優(yōu)預(yù)測(cè)值,即當(dāng)提取溫度50.12℃,液料比55.43:1(mL/g),提取時(shí)間2.12h時(shí),提取率可達(dá)到1.08g/100g,結(jié)合實(shí)際操作,優(yōu)化工藝參數(shù)確定為溫度50℃,液料比55:1(mL/g),提取時(shí)間2h.在此參數(shù)下,提取率為(1.06±0.001)g/100g,達(dá)到了預(yù)測(cè)值的98.88%。用堿水解法對(duì)充分提取游離酚后的紫薯渣中結(jié)合酚進(jìn)行水解提取,單因素試驗(yàn)基礎(chǔ)上采用響應(yīng)面分析法優(yōu)化工藝參數(shù),得出紫薯結(jié)合酚提取的最優(yōu)預(yù)測(cè)值為:液料比32.2:1(mL/g),NaOH濃度1.87mol/L,水解時(shí)間5.22h時(shí),多酚提取率達(dá)到0.58g/100g.結(jié)合實(shí)際操作優(yōu)化工藝參數(shù)為液料比30:1(mL/g),NaOH濃度2mol/L,水解時(shí)間5h,結(jié)合酚提取率為(0.57±0.008)g/100g,達(dá)到預(yù)測(cè)值得97.34%。2、AB-8型大孔樹脂純化紫薯游離酚較為理想,吸附時(shí)最適上樣濃度是1.0mg/mL,上樣液pH為3.0,最大上樣體積120mL即5.4BV,此時(shí)的吸附率可以達(dá)到(80.29±0.44)%,解吸時(shí)最適洗脫劑為pH為7.0的體積分?jǐn)?shù)為50%的乙醇水溶液,洗脫體積150mL即6.8BV,此時(shí)的解吸率達(dá)到(85.59±0.38)%;結(jié)合酚的純化使用的是HPD-100型號(hào)的大孔樹脂,吸附時(shí)最適上樣濃度是0.25mg/mL,上樣液pH為3.0,最大上樣體積80mL即3.6BV,此時(shí)的吸附率可以達(dá)到(73.88±0.40)%,解吸時(shí)最適洗脫劑為pH為5.0的體積分?jǐn)?shù)為50%的乙醇水溶液,洗脫體積150mL即6.8BV,此時(shí)解吸率可以達(dá)到(84.64±0.10)%。酚類化合物在純化前后含量差異顯著,說(shuō)明大孔樹脂對(duì)紫薯多酚的純化效果較好。3、液質(zhì)聯(lián)用鑒定結(jié)果表明紫薯游離酚由單咖啡�？鼘幩�(綠原酸)、甲基化咖啡酰奎寧酸、二咖啡�？鼘幩岷图谆Х弱？鼘幩岬耐之悩�(gòu)體構(gòu)成,紫薯結(jié)合酚主要包含羥基苯甲酸和咖啡酸,進(jìn)一步利用高效液相色譜對(duì)照法確定了游離酚中二咖啡酰奎寧酸為綠原酸、異綠原酸A、異綠原酸B和異綠原酸C和結(jié)合酚中對(duì)羥基苯甲酸的存在。對(duì)樹脂純化后的紫薯多酚樣品進(jìn)行體外清除DPPH自由基及抑制α-葡萄糖苷酶活性的檢測(cè),結(jié)果表明,游離酚和結(jié)合酚清除DPPH自由基的半數(shù)抑制濃度(IC50)分別為0.014mg/mL和2.02mg/mL;α-葡萄糖苷酶活性抑制的IC50分別為0.16mg/mL和0.98mg/mL,說(shuō)明紫薯的多酚清除DPPH自由基的能力和抑制α-葡萄糖苷酶活性的能力總體來(lái)說(shuō)較好。4、通過(guò)體外模擬機(jī)體消化方式來(lái)研究紫薯消化過(guò)程中多酚的釋放量、吸收量及多酚的穩(wěn)定性,結(jié)果表明:紫薯在體外模擬消化過(guò)程中,多酚釋放的最佳時(shí)間為:胃消化1h、腸消化2h.總酚、黃酮、花色苷和酚酸的生物利用率分別為(18.42±0.33)%、(15.00±0.21)%、(0.46±0.006)%和(12.87±0.12)%。游離酚在消化過(guò)程中除酚酸外,總酚、黃酮和花色苷的濃度持續(xù)降低,但結(jié)合酚在腸消化時(shí)黃酮、花色苷和酚酸的含量升高,由此說(shuō)明結(jié)合酚穩(wěn)定性好于游離酚;經(jīng)過(guò)體外模擬消化的紫薯,其游離酚各物質(zhì)的濃度均明顯下降,但在結(jié)合酚中總酚、黃酮和酚酸的濃度明顯上升,說(shuō)明在體外消化過(guò)程中有一部分游離酚與大分子結(jié)合,轉(zhuǎn)化成結(jié)合酚。
[Abstract]:Purple sweet potato is a kind of spinning machine, which is mostly distributed in most parts of the south of china. The purple sweet potato contains rich nutrient components, and the tuber is rich in various nutrient components such as plant polysaccharide, protein, vitamin and the like, and is rich in polyphenol substances such as flower color, chlorogenic acid, and flavonoid, And has the functions of resisting aging and the like and enhancing the immunity of the body. At present, the research on polyphenol is mainly the extraction and determination of the free phenol of some kind of raw material, and the various species of the natural world, in particular in the plant raw material, in addition to the free phenol, a part of the phenolic substance is present in the form of the bound state, and the phenolic substance is the combined phenol. At present, there are few systematic reports on the extraction and purification of the combined phenol in plants and the research on the activity of the combination of phenol in plants, and the free phenol and the combined phenol are respectively extracted and purified by using the purple sweet potato freeze-dried powder as the raw material, and the high-performance liquid chromatography technology is adopted. The composition of phenolic acids was analyzed by liquid-mass spectrometry, and the anti-oxidative activity and the hypoglycemic activity were studied by the method of DPPH free radical scavenging and the inhibition of the enzyme activity of the yeast-grape. The results of this study were as follows:1. The free phenol of purple sweet potato was extracted with 60% ethanol aqueous solution after screening, and on the basis of single factor test, The optimum predicted value of the extraction of the free phenol of purple sweet potato was obtained by using the response surface analysis method, that is, when the extraction temperature is 50.12 鈩，
本文編號(hào)：2479974
[Abstract]:Purple sweet potato is a kind of spinning machine, which is mostly distributed in most parts of the south of china. The purple sweet potato contains rich nutrient components, and the tuber is rich in various nutrient components such as plant polysaccharide, protein, vitamin and the like, and is rich in polyphenol substances such as flower color, chlorogenic acid, and flavonoid, And has the functions of resisting aging and the like and enhancing the immunity of the body. At present, the research on polyphenol is mainly the extraction and determination of the free phenol of some kind of raw material, and the various species of the natural world, in particular in the plant raw material, in addition to the free phenol, a part of the phenolic substance is present in the form of the bound state, and the phenolic substance is the combined phenol. At present, there are few systematic reports on the extraction and purification of the combined phenol in plants and the research on the activity of the combination of phenol in plants, and the free phenol and the combined phenol are respectively extracted and purified by using the purple sweet potato freeze-dried powder as the raw material, and the high-performance liquid chromatography technology is adopted. The composition of phenolic acids was analyzed by liquid-mass spectrometry, and the anti-oxidative activity and the hypoglycemic activity were studied by the method of DPPH free radical scavenging and the inhibition of the enzyme activity of the yeast-grape. The results of this study were as follows:1. The free phenol of purple sweet potato was extracted with 60% ethanol aqueous solution after screening, and on the basis of single factor test, The optimum predicted value of the extraction of the free phenol of purple sweet potato was obtained by using the response surface analysis method, that is, when the extraction temperature is 50.12 鈩，
本文編號(hào)：2479974
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