基于抗氧化活性分析的蓝莓多酚提取工艺

基于对蓝莓不同极性溶剂(水、正丁醇、甲醇、70%乙醇、乙酸乙酯)提取物以及甲醇提取、大孔树脂纯化后的乙酸乙酯、正丁醇和水萃取物抗氧化活性(DPPH和ABTS)的分析测定,优化并确定了蓝莓多酚的提取工艺。实验结果显示,蓝莓不同溶剂提取物对DPPH、ABTS自由基具有良好的清除能力,其活性成分主要集中在大极性的70%乙醇、甲醇和正丁醇部位,经过大孔树脂纯化后萃取得到蓝莓不同极性多酚抗氧化活性强弱顺序为:正丁醇水乙酸乙酯。蓝莓提取物和萃取物的抗氧化能力与多酚含量有显著的相关性,与花色苷含量无关。较大极性的提取和萃取溶剂有利于蓝莓强效多酚的获取。以抗氧化活性为导向的蓝莓多酚提取工艺为:蓝莓果实以含0.3%三氟乙酸的70%乙醇提取,提取液经LS-305大孔树脂吸附,先用0.3%三氟乙酸水溶液冲洗去杂,再用含0.3%三氟乙酸的甲醇溶液洗脱,洗脱液在40℃下减压浓缩除去甲醇后用水溶解,以乙酸乙酯萃取去杂,再以正丁醇萃取,萃取液在60℃下减压浓缩后冷冻干燥。     

溶剂法萃取茶多酚的工艺研究

本实验通过对绿茶叶的提取,确定溶剂法萃取茶多酚的工艺条件,最佳温度为80℃;最佳乙醇水溶液浓度为65%;最佳萃取次数为3次;最佳萃取时间为60min。儿茶素含量最高的是利用乙醇萃取后再用乙酸乙酯和氯仿萃取,然后旋转蒸发干燥,此时茶多酚制品中功能成分儿茶素的含量可达24.19%,可以直接应用于食品加工工业。     

肉桂中肉桂醛及肉桂酸的微波辅助萃取及HPLC测定

利用聚焦式微波辅助萃取系统,结合HPLC分析,对肉桂 中的肉桂醛和肉桂酸进行微波萃取分离和分析,并比较 了水及乙醇等溶剂作为萃取溶剂的效果。研究发现,极性 强的溶剂,如水、乙醇容易吸收微波,温升较快,而石油醚 和正己烷等极性较弱的溶剂,对微波的吸收较弱,温升较 慢。比较极性溶剂在微波场温升效应得,无水乙醇≥80％ 乙醇>纯水>0.1NNaOH>0.1NHCl。以乙醇为溶剂进行肉 桂醛的微波萃取,得率为2.37％,以水为溶剂的萃取得率 为2.04％;溶剂之间的差别不大。而对肉桂酸的微波萃取, 以乙醇为溶剂的萃取得率为0.96％,以水为溶剂的萃取得 率为2.91％,溶剂之间的微波萃取效果差别较大。     

蜂胶不同溶剂萃取物组成和抗氧化性的研究

以蜂胶为原料,分别以甲醇、乙醇、氯仿、蒸馏水为溶剂进行萃取,测定各萃取物总酚与黄酮类物质的含量,通过测定还原能力,清除DPPH 自由基能力的测定来比较4 种不同萃取物的抗氧化性。结果表明：甲醇萃取物具有较强的抗氧化性。甲醇萃取物浓度为0.25mg/ml 时还原力高达1.162,且浓度为0.05mg/ml 时对DPPH 自由基清除率为64.676%。乙醇萃取物通过石油醚、氯仿、乙酸乙酯、丙酮依次分级萃取后所得到4 种萃取物各项指标测定结果表明,氯仿萃取了蜂胶乙醇萃取物中主要成分,但乙酸乙酯和丙酮萃取物的还原能力及清除DPPH 自由基清除能力较佳,在浓度为0.05mg/ml 时还原力分别为2.087 和1.798,DPPH自由基清除率达87.724% 和88.013%。     

橡子仁萃取物成分分析及对α-淀粉酶、α-葡萄糖苷酶的抑制作用

为探索橡子仁萃取物的成分组成及对α-淀粉酶、α-葡萄糖苷酶的抑制作用,以栓皮栎橡子仁为材料,采用超声波辅助乙醇提取和有机溶剂萃取,制备橡子仁乙酸乙酯、正丁醇、水萃取物,通过紫外吸收光谱、高效液相色谱分析各萃取物的化学成分组成,通过抑制率测定、抑制动力学和荧光猝灭试验分析各萃取物的体外抑酶效果及作用机制。结果表明:三种橡子仁萃取物结构高度相似,主要为单宁类物质;乙酸乙酯萃取物含表儿茶素没食子酸酯、没食子酸、没食子儿茶素没食子酸酯等9种物质;正丁醇萃取物含表儿茶素没食子酸酯、儿茶素、没食子儿茶素没食子酸酯等16种物质;水萃取物含没食子酸、绿原酸等21种物质。三种橡子仁萃取物均可有效抑制α-淀粉酶、α-葡萄糖苷酶活性,乙酸乙酯、正丁醇、水萃取物对α-淀粉酶的半抑制浓度（IC₅₀）分别为1.047、1.122、4.031 mg/mL,对α-葡萄糖苷酶的IC₅₀值分别为0.014、0.028、0.037 mg/mL。三种萃取物对两种酶的酶抑制类型多为混合型抑制,荧光猝灭类型多是以静态猝灭为主,动态猝灭为辅的混合猝灭。     

蒸汽爆破甘蔗渣中抗氧化物质的提取及评价

以蒸汽爆破甘蔗渣(SESB)为原料,乙醇、甲醇、水及乙酸乙酯为溶剂,对其中的多酚和糖进行提取并评价了提取液的抗氧化能力。其中甲醇提取液中酚类物质含量最高((1.5174±0.0140)mg/mL),水次之((1.2382±0.0025)mg/mL),乙酸乙酯最低。提取液中的总糖含量以水中最多,其次为甲醇,乙酸乙酯中最低。四种提取液对DPPH自由基均具有很强的清除能力。水、乙醇和甲醇提取液具有较强的还原力,呈明显的量效关系。采用溶剂对SESB中抗氧化物质提取是可行的。综合经济效益、环境问题及水提取液中酚类含量、总糖含量以及抗氧化能力,认为以水作为溶剂最佳。     

银桦叶不同溶剂提取物的抗氧化活性

研究银桦叶不同溶剂提取物的体外抗氧化活性。药材采用甲醇超声提取,分别用不同极性溶剂进行萃取分离,得正丁醇、乙酸乙酯、石油醚和水4个不同极性部位,采用普鲁士蓝法、DPPH自由基清除法和ABTS自由基清除法测定评价银桦叶提取物的体外抗氧活性。结果表明,银桦叶不同溶剂提取物均表现出较好的抗氧化活性,且与样品浓度呈良好量效关系,其中甲醇提取物和乙酸乙酯萃取物抗氧化活性最强,是天然抗氧化剂的良好来源。     

不同溶剂提取乳苣的抗氧化作用研究

以乳苣全草为原料,75%乙醇为溶剂提取乳苣,提取液用不同极性溶剂依次萃取,得石油醚萃取物、乙酸乙酯萃取物、正丁醇萃取物和水萃取物,同时测定了各相提取物对羟自由基、超氧阴离子自由基、DPPH自由基的清除能力,并与VC进行比较。结果表明:各萃取物均具有一定的抗氧化活性,且随着浓度的增加而增强;对羟自由基的清除能力大小依次为乙酸乙酯萃取物>正丁醇萃取物>VC>水萃取物>石油醚萃取物;对超氧阴离子自由基清除能力大小依次为VC>正丁醇萃取物>乙酸乙酯萃取物>石油醚萃取物>水萃取物;对DPPH自由基清除能力大小依次为VC>乙酸乙酯萃取物>正丁醇萃取物>水萃取物>石油醚萃取物;各萃取物还原能力大小依次为VC>正丁醇萃取物>乙酸乙酯萃取物>水萃取物>石油醚萃取物。     

高通量筛选研究茯砖茶对FXR模型的作用

将茯砖茶水提液分别用三氯甲烷、乙酸乙酯、正丁醇萃取,制得三氯甲烷层、乙酸乙酯层、正丁醇层及水层样品,茶渣用95%的乙醇提取,制得乙醇提取物,通过高通量药物筛选测定各样品对法尼酯衍生物X受体(FXR)模型的激活和抑制作用,研究茯砖茶的降脂减肥功效,结果显示茯砖茶各部份对FXR都有抑制作用,乙酸乙酯层样品激活作用较明显,从中分离制得儿茶素EGCG及ECG单体对FXR模型有很好的激活作用,证明茯砖茶有较强的降脂功能,有望开发成天然的降脂药物。茯砖茶中其他活性成分的分离有待进一步进行。     

不同溶剂及辅助方法对花生壳提取物中木犀草素含量及抗菌作用的影响

研究了不同溶剂及辅助方法对花生壳提取物木犀草素含量及金黄色葡萄球菌抗菌作用的影响。结果表明提取物中木犀草素绝对含量和抗菌效果与提取溶剂和辅助方法有关,提取物中木犀草素的绝对含量及在同一浓度时抗菌效果分别是丙酮乙醇甲醇乙酸乙酯水、水浴回流法微波法恒温震荡法超声波法,同时对于同种溶剂或辅助方法提取物而言,随着提取物浓度的增加,抗菌作用越显著。相关性分析表明对金黄色葡萄球菌的抗菌效果与提取物中木犀草素绝对含量呈正显著相关,与花生壳提取物得率之间无显著相关。辅助方法有助于提高花生壳提取物木犀草素绝对含量和抗菌效果。     

A systematic approach for extraction of phenolic compounds using parsley (Petroselinum crispum) flakes as a model substrate

The impact of extraction methodology and polarity of extraction solvents on the assay of phenolic compounds was investigated using parsley (Petroselinum crispum) flakes as a model substrate. This systematic study was undertaken to address substantial variations in the extraction procedures, solvents and conditions as described in the recent literature. Five different extraction procedures [shaking, vortex mixing, sonication, stirring and pressurized liquid extraction (PLE)] and three different solvents (methanol, ethanol and acetone), with five different solvent to water ratios per solvent, were used for extraction. Extracts were analyzed for phenolic content by high‐performance liquid chromatography and Folin–Ciocalteu assays. The yields of phenolic compounds extracted with a pressurized liquid extractor were comparable to or better than those of four classical extraction procedures. Optimum extraction efficiency with PLE was obtained when extractions were performed with four extraction cycles using ethanol–water (50:50, v/v). The amount of apiin (4,5,7‐trihydroxyflavone 7‐apiosylglucoside) and malonylapiin (apigenin malonylapiosylglucoside) isolated from parsley varied with the composition of extraction solvent. Apiin extractability was found to be a maximum when the solvent (ethanol, methanol or acetone) to water ratio was 30:70 (v/v), whereas higher amounts of malonylapiin were isolated with a reverse solvent to water ratio (70:30, v/v). Malonylapiin was not detected when parsley samples were extracted with organic solvent to water ratios of 10:90 (v/v) and 30:70 (v/v). Published in 2006 by John Wiley & Sons, Ltd     

Tea extraction methods in relation to control of epimerization of tea catechins

Effect of water temperature and ethanol concentration on epimerization and extractability of tea catechins was investigated. The results showed that epigallocatechin gallate (EGCG) and epicatechin gallate (ECG) were partially epimerized into gallocatechin gallate (GCG) and catechin gallate (CG), respectively, when tea catechins extract was heated in water solution at 100 °C for 2 h or dry tea was extracted in water at 100 °C. The epimerization of the catechins was inhibited if the tea catechins extract was heated as solid powder and the dry tea was extracted in 50% (v/v) ethanol or in water at 80 °C or below. When the dry tea was extracted in water, the extractability of catechins increased with the increase of extraction temperature up to 100 °C, but there was no statistically significant difference in total catechins between 80 °C and 100 °C. When teas were extracted using ethanol solutions, the highest extractability of total catechins was obtained in 50% (v/v) ethanol for dry tea and in 75% (v/v) ethanol for fresh tea leaf. In order to reveal the real profiles of tea catechins in teas to be tested, dry tea should be extracted in 50% (v/v) ethanol for 10 min, while fresh tea leaf should be extracted in 75% (v/v) ethanol for 10 min. For commercial extraction, temperature should be controlled at 80 °C if water is used as the solvent. Copyright © 2007 Society of Chemical Industry     

不同提取方法对蓝莓色素得率及抗氧化活力的 影响研究

目的 研究不同提取方法对蓝莓色素得率、抗氧化活力的影响及得率与抗氧化活力间的关系。方法 分别以乙醇、甲醇、丙酮为浸提溶剂,常规溶剂浸提、超声辅助浸提、微波辅助浸提3种提取方式,测定浸提液色素得率及其清除DPPH.、 、.OH的能力;分析色素得率与抗氧化活力的关系。结果 不同提取溶剂对蓝莓色素得率的影响差异不显著(P>0.05),但不同提取方式对蓝莓色素得率的影响差异显著(P＜0.05);不同提取方法的蓝莓色素清除DPPH.、 、和.OH的能力存在显著差异(P<0.05);蓝莓色素得率与其清除DPPH.与.OH能力间存在显著的正相关。结论 提取方式对蓝莓色素的得率及抗氧化活力有显著影响;蓝莓色素得率与其清除DPPH.和.OH能力呈显著的正相关性;超声辅助乙醇浸提更有助于获取高得率、高抗氧化活性的蓝莓色素。     

黄蘑多糖提取工艺及纯化研究

采用单因素实验和L9(33)正交实验设计,考察了浸提溶剂、料液比、浸提时间、浸提温度和浸提次数对黄蘑多糖提取率的影响,确定最佳提取工艺。采用Sevage法除蛋白,乙醇反复沉淀,AB-8大孔吸附树脂纯化黄蘑多糖。结果表明:影响多糖提取率的主次因素为浸提时间、浸提温度及料液比;黄蘑多糖最佳提取工艺条件:料液比1∶25,浸提温度90℃,浸提时间3h。在此工艺条件下,黄蘑多糖提取率为30.48%。纯化后的多糖含量为91%,分子量约为104356。     

酸浆中木犀草苷提取工艺优化

目的优化酸浆中木犀草苷成分的提取工艺。方法选取干燥的酸浆[Physalisalkekengi L.var.franchetii(Mast.)Makino]宿萼作为实验材料,分别使用甲醇、乙醇和水作为溶剂,考察超声、热回流和渗漉对木犀草苷提取效率的影响。结果以乙醇作为提取溶剂,采用加热回流的提取方式,木犀草苷得率较高。运用单因素考察法及正交实验确定了最佳工艺条件:使用乙醇溶液,料液比1:30(g/mL),加热回流90 min,提取3次,木犀草苷得率可达1.28%。结论经过优化后,酸浆提取所选用试剂安全可靠,木犀草苷得率显著提高。     

Recovery of bioactive compounds from walnut (Juglans regia L.) green husk by supercritical carbon dioxide extraction

In this work, the use of supercritical carbon dioxide, a nontoxic solvent, was proposed to extract bioactive compounds from Juglans regia L. green husk and was compared to other traditional techniques based on solvents such as ethanol, methanol and water. Supercritical CO₂ was combined with ethanol as an organic modifier at a rate of 20% of the total flow to achieve greater extraction of polar compounds. The extracts were characterised in terms of extraction yields, antioxidant activity, total polyphenol content, phenolic acids, juglone, volatile organic compounds and antifungal activity. The results showed that the extracts obtained with supercritical CO₂ were rich in polyphenols (10750 mg GAE/100 g) and juglone (1192 mg/100 g) and exerted high antioxidant activity and antifungal activity compared with the tested fungi. Walnut green husk is not just a food industry waste but also an important economic source of bioactive compounds that could be used for food active packaging.     

低温连续相变萃取灵芝活性成分的工艺优化

本研究利用低温连续相变萃取工艺提取灵芝活性成分,以灵芝提取固形物、总糖、总三萜得率为主要指标,研究提取温度、提取时间、提取溶剂、溶剂浓度等因素对低温连续相变萃取灵芝活性成分的影响,通过正交实验确定最佳低温连续相变醇提灵芝活性成分的最佳工艺条件,并对该最佳工艺水提成分的总糖分子量情况分布进行GPC(凝胶渗透色谱)分析.实...     

Reutilization of mango byproducts: study of the effect of extraction solvent and temperature on their antioxidant properties

Mango biowastes, obtained after processing, contain large amounts of compounds with antioxidant activity that can be reused to reduce their environmental impact. The present study evaluates the effect of solvent (methanol, ethanol, acetone, water, methanol:water [1:1], ethanol:water [1:1], and acetone:water [1:1]), and temperature (25, 50, and 75 °C) on the efficiency of the extraction of antioxidants from mango peel and seed. Among the factors optimized, extraction solvent was the most important. The solvents that best obtained extracts with high antioxidant capacity were methanol, methanol:water, ethanol:water, and acetone:water (β-carotene test, antioxidant activity coefficient 173 to 926; thiobarbituric acid reactive substances test, inhibition ratio 15% to 89%; 2,2'-azino-bis-(3-ethylbenzothiazoline)-6-sulfonic acid ABTS(·+); and 2,2-diphenyl-1-picrylhydrazyl DPPH· scavenging, 7 to 22 and 8 to 28 g trolox equivalent antioxidant capacity [TE] per 100 g mango biowaste on a dry matter basis [DW]). Similarly, the flavonoid (0.21 to 1.4 g (+)-catechin equivalents per 100 g DW), tannin (3.8 to 14 g tannic acid equivalents per 100 g DW), and proanthocyanidin (0.23 to 7.8 g leucoanthocyanidin equivalents per 100 g DW) content was highest in the peel extracts obtained with methanol, ethanol:water, or acetone:water and in the seed extracts obtained with methanol or acetone:water. From the perspective of food security, it is advisable to choose ethanol (which also has a notable antioxidant content), ethanol:water, or acetone:water, as they are all solvents that can be used in compliance with good manufacturing practice. In general, increasing temperature improves the capacity of the extracts obtained from mango peel and seed to inhibit lipid peroxidation; however, its effect on the extraction of phytochemical compounds or on the capacity of the extracts to scavenge free radicals was negligible in comparison to that of the solvent. PRACTICAL APPLICATION: There are many antioxidant compounds in mango peel and seed, and they could be used as a natural and very inexpensive alternative to synthetic food additives. However, the conditions in which the antioxidants are extracted must be optimized. This work proves that conditions such as extraction solvent or temperature have a crucial impact on obtaining extracts rich in antioxidants from mango biowastes.     

马齿苋不同溶剂提取物的抗氧化活性

研究马齿苋不同溶剂提取物的抗氧化能力。以水、70%甲醇、70%乙醇和70%丙酮为提取溶剂,通过清除DPPH·、ABTS^+、·OH及FRAP法评价马齿苋不同溶剂提取物的抗氧化作用,并测定提取物的总多酚、总黄酮含量。结果表明,马齿苋不同溶剂提取物在4种抗氧化评价体系中均表现出一定的抗氧化活性, 70%丙酮提取物抗氧化活性最强,总多酚含量最高。70%丙酮可作为马齿苋抗氧化活性成分提取的优选溶剂,而总多酚含量可作为马齿苋抗氧化提取物的质量评价指标。     

Selection of the Solvent and Extraction Conditions for Maximum Recovery of Antioxidant Phenolic Compounds from Coffee Silverskin

The extraction of antioxidant phenolic compounds from coffee silverskin (CS) was studied. Firstly, the effect of different solvents (methanol, ethanol, acetone, and distilled water) on the production of antioxidant extracts was evaluated. All the extracts showed antioxidant activity (FRAP and DPPH assays), but those obtained with methanol and ethanol had significantly higher (p?<?0.05) DPPH inhibition than the remaining ones. Due to the lower toxicity, ethanol was selected as extraction solvent, and further experiments were performed in order to define the solvent concentration, solvent/solid ratio, and time to maximize the extraction results. The best condition to produce an extract with high content of phenolic compounds (13 mg gallic acid equivalents/g CS) and antioxidant activity [DPPH?=?18.24 μmol Trolox equivalents/g CS and FRAP?=?0.83 mmol Fe(II)/g CS] was achieved when using 60 % ethanol in a ratio of 35 ml/g CS, during 30 min at 60–65 °C.