超临界CO2萃取牡丹籽粕多酚工艺 及其抗氧化性评价

为充分利用牡丹籽粕中的多酚资源,采用响应面法优化超临界CO_2萃取牡丹籽粕多酚工艺,以多酚提取量为响应值,得到了乙醇(夹带剂)体积分数、萃取温度和萃取压力的最优条件;通过测定牡丹籽粕多酚对DPPH和ABTS自由基的清除能力,对其抗氧化活性进行评价。结果表明,超临界CO_2萃取最佳工艺条件为乙醇体积分数83%、萃取温度52℃、萃取压力32 MPa,此条件下牡丹籽粕多酚提取量可达18.58 mg/g;牡丹籽粕多酚和VC对DPPH·清除率的IC_(50)分别为128.22μg/mL和147.72μg/mL,对ABTS~+·清除率的IC_(50)分别为109.18μg/mL和142.66μg/mL,牡丹籽粕多酚对DPPH·和ABTS~+·的清除能力均显著强于VC。     

辣椒碱体外抗氧化作用研究

以辣椒碱标准品为原料,Vc为阳性对照,采取体外抗氧化试验模型研究其抗氧化活性。通过分析辣椒碱的还原力和清除DPPH自由基(DPPH·)、超氧阴离子自由基(O_2~-·)、亚硝基以及羟自由基(·OH)的能力,探讨辣椒碱的体外抗氧化性能。结果表明,辣椒碱的还原能力以及对DPPH·、亚硝基以及·OH的清除率随质量浓度的增加而升高,且清除效果与Vc基本相近,但对O_2~-·的清除率较低;辣椒碱对DPPH·、亚硝基以及·OH的IC_(50)分别为0.02,0.15,0.28mg/mL,说明辣椒碱清除DPPH·的效果较好。     

超临界CO_2萃取奇亚籽油工艺优化及抗氧化活性的研究

为高效地提取奇亚籽油,采用单因素及正交实验优化超临界CO_2萃取奇亚籽油最佳工艺条件,考察物料粒度、萃取压力、萃取温度以及萃取时间4个因素对奇亚籽油萃取率的影响,并对奇亚籽油进行抗氧化活性的测定。结果表明:超临界CO_2萃取奇亚籽油最佳工艺条件为物料粒度60目、萃取压力25 MPa、萃取温度50℃、萃取时间2.5 h,奇亚籽油萃取率为85.50%。奇亚籽油中富含不饱和脂肪酸,占总脂肪酸的88.22%,其中亚麻酸高达69.86%。抗氧化实验表明,奇亚籽油对DPPH自由基和ABTS~+自由基具有较强的清除作用,对超氧阴离子自由基也显示出一定清除效果。     

香茅精油的超临界CO_2萃取及其抗氧化活性的研究

采用超临界CO_2萃取法提取香茅草中的精油,通过简单比较法优化萃取条件,并以香茅精油对DPPH自由基(DPPH·)、超氧阴离子自由基(O_2-·)和羟基自由基(OH·)的清除能力来研究其抗氧化活性。结果:在萃取压力为15MPa、萃取温度为45℃、萃取时间为90min的超临界CO_2萃取条件下香茅精油的得率最高,可达_2.13%。香茅精油在一定的浓度范围内其浓度与DPPH·、O_2-·和OH·清除率呈良好的线性关系,量效关系明显,对DPPH·、O_2-·和OH·的半抑制浓度(IC50)分别为3._237mg/m L、0._27_24mg/m L和0.6615mg/m L。表明:香茅精油具有良好的抗氧化活性,是一种开发潜力较高的天然抗氧化剂。     

百香果籽油超临界CO2萃取工艺优化及其体外抗氧化活性

以百香果为原料,在单因素试验基础上,采用Box-Behnken响应面分析,优化超临界CO_2萃取百香果籽油的工艺,并对百香果籽油的体外抗氧化活性进行研究。结果表明,超临界CO_2萃取百香果籽油的最佳工艺为萃取温度53.1℃,萃取压力33.9 MPa,萃取时间3.6h,百香果籽出油率值为26.95%,所得百香果籽油具有较好的还原力,且呈量效关系,对DPPH·的清除能力达80%。超临界CO_2萃取百香果籽油工艺稳定可行,提取的百香果籽油具有抗氧化活性,是一种潜在可用的天然抗氧化资源。     

茴香精油微胶囊在辣椒丝中的应用

利用总抗氧化能力、DPPH·清除率和羟自由基(·OH)清除率评价茴香种子精油的体外抗氧化活性,采用复凝聚法制备茴香精油微胶囊,并将之用于辣椒丝的防腐保鲜。采用模糊数学综合评价法确定茴香精油微胶囊在辣椒丝中的添加量。结果表明:茴香种子精油清除DPPH·自由基的IC_(50)为13.5612 mg/mL(TBHQ为7.5235 mg/mL),清除·OH自由基的IC_(50)为11.6433 mg/m L(TBHQ为6.1404 mg/mL),总抗氧化能力清除率为58.9%。茴香精油微胶囊在辣椒丝中最适添加量为3%。     

水酶法提取冬瓜籽油工艺优化及体外抗氧化活性研究

以冬瓜籽为原料,采用水酶法提取冬瓜籽油。通过单因素试验设计研究酶的种类、pH、酶解时间、酶解温度、料液比对冬瓜籽油提取率的影响,并利用Box-Behnken试验设计确定冬瓜籽油的最佳提取条件。由响应面分析得出冬瓜籽油的最佳提取条件为:以葡聚糖酶为酶解用酶,料液比1∶6,酶解时间6.1 h,酶添加量3%,酶解温度60℃,pH 4.22。在最佳提取条件下,冬瓜籽油提取率达90.67%。体外抗氧化活性研究表明:冬瓜籽油对DPPH自由基、羟基自由基清除率及铁离子还原能力随其质量浓度增加而增大;对DPPH自由基清除率IC_(50)为10.23 mg/mL,对羟基自由基清除率IC_(50)为0.39 mg/mL,冬瓜籽油质量浓度为1.0 mg/mL时,其对羟基自由基清除率为98.84%,与V_C的清除效果相当。     

椪柑籽油提取工艺优化及其抗氧化活性的研究

本研究以椪柑籽为原料,采用响应面法优化压榨及亚临界丁烷萃取工艺,得到椪柑籽油最佳提取条件,并对所得椪柑籽油进行抗氧化活性研究。结果表明压榨法最佳工艺条件为加热时间2 min、微波功率900 w和喷水比例2.10%,出油率达到27.12%；亚临界丁烷萃取最佳工艺条件为萃取次数4次、萃取温度45 ℃、萃取时间43 min,出油率达到10.02%。高效液相色谱分析结果表明,亚临界椪柑籽油中橙皮苷含量(49.60 μg/g)和柚皮苷含量(30.07 μg/g)分别高于压榨椪柑籽油中橙皮苷含量(17.29 μg/g)和柚皮苷含量(28.30 μg/g)。当样品质量浓度为50 mg/mL,亚临界椪柑籽油DPPH自由基清除率为71.81%,ABTS自由基清除率为48.66%,总抗氧化能力为0.123 mmol/L。压榨椪柑籽油DPPH自由基清除率为24.34%,ABTS自由基清除率为15.11%,总抗氧化能力为0.102 mmol/L。因此,亚临界椪柑籽油比压榨椪柑籽油具有更强的抗氧化活性。     

大鲵油体外抗氧化活性研究

采用体外抗氧化实验研究大鲵油抗氧化活性,测定大鲵油对DPPH自由基、羟基自由基、超氧自由基清除能力和还原能力、Fe~(2+)螯合能力。以V_C为阳性对照,评价大鲵油的体外抗氧化活性。结果表明:大鲵油抗氧化能力强于鲐鱼油,添加复合抗氧化剂后抗氧化能力更强,对Fe~(2+)的螯合能力表现最好,相同质量浓度条件下强于V_C;对DPPH自由基、羟基自由基清除能力和还原能力与V_C相当。大鲵油对DPPH自由基、羟基自由基和Fe~(2+)螯合能力的半抑制质量浓度(IC_(50))分别为3.523、0.493、0.559 mg/m L,添加了复合抗氧化剂的大鲵油的相应IC_(50)分别为0.572、0.099、0.062 mg/m L。     

茶树花萃取物降血脂及抗氧化性能研究

利用超临界CO2萃取得到茶树花浸膏,将超临界萃取后的茶树花渣用乙醇提取,得茶树花渣萃取物,研究二者的降血脂及抗氧化能力。以样品的体外结合胆酸盐能力衡量降血脂能力,以样品体外对超氧阴离子、羟基自由基与DPPH自由基的清除率衡量抗氧化能力。结果表明:茶树花浸膏及茶树花渣萃取物在本实验的最高浓度32mg/mL时对牛磺胆酸钠和甘氨胆酸钠的吸附率最大。茶树花渣乙醇萃取物对两种胆酸的吸附率与螯合胆酸型降血脂药物考来烯胺的吸附率更加接近。渣萃取物与考来烯胺对胆酸盐的吸附率均高于茶树花浸膏的胆酸盐吸附率。与抗氧化剂2,6-二叔丁基-4-甲基苯酚(BHT)相比,茶树花渣乙醇萃取物对超氧阴离子、羟基自由基的清除率更高,对DPPH自由基的清除率略低。茶树花渣萃取物与BHT对三种自由基的清除率均高于茶树花浸膏的清除率。     

西瓜籽油脂肪酸成分分析及抗氧化活性研究

目的：研究西瓜籽油脂肪酸成分及抗氧化活性。方法：采用索氏回流法对西瓜籽进行提油,对西瓜籽油进行酯化处理,用气相色谱—质谱联机（GC-MS）对其脂肪酸的成分、含量进行分析,通过其对铁离子的还原能力和对DPPH自由基、羟基自由基及超氧阴离子自由基清除能力的测定。结果：西瓜籽油中含有6种脂肪酸,其中不饱和脂肪酸相对含量达到50%以上;西瓜籽油对铁离子具有还原能力,对DPPH自由基的IC₅₀值为3.7 mg/mL,对超氧阴离子自由基的IC₅₀值为0.031 mg/mL,对羟基自由基的IC₅₀值为12.04 mg/mL。结论：西瓜籽油富含不饱和脂肪酸,有较好的抗氧化活性。     

改良的DPPH与ABTS自由基法评价不同葡萄籽油抗氧化能力

本研究采用改良的1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picryhydrazyl,DPPH)法和2,2'-联氮双-(3-乙基苯并噻唑林-6-磺酸)二胺盐[2,2'-azinobis(3-ethylbenzothi azoline-6-sulfonic acid)ammonium salt,ABTS]法测定不同方法提取葡萄籽油极性部分、非极性部分及全油的抗氧化能力,测定不同葡萄籽油多酚含量,研究多酚与葡萄籽油极性部分抗氧化能力的相关性。热榨毛油与溶剂法毛油在经过精炼后多酚含量和抗氧化能力显著降低;在溶剂法精炼油、热榨法精炼油、低温压榨油、超临界CO_2萃取葡萄籽油中,低温压榨油极性部分清除DPPH与ABTS自由基的能力最强,低温压榨油的多酚含量最高,超临界CO_2萃取葡萄籽油非极性部分与低温压榨油全油的DPPH与ABTS自由基清除能力最强;各不同葡萄籽油总酚含量与极性部分DPPH和ABTS自由基的清除能力具有显著的正相关性。     

Supercritical CO2 cell breaking extraction of Lycium barbarum seed oil and determination of its chemical composition by HPLC/APCI/MS and antioxidant activity

The extraction parameters for oil extraction from Lycium barbarum seed including extraction pressure, temperature and time were optimized using an orthogonal test design. The optimum conditions for supercritical CO₂ extraction were as follows: extraction pressure, 30 MPa; extraction temperature, 45 °C; dynamic extraction time, 60 min; CO₂ flow, 25 kg/h. The oil yield under the conditions proposed was 19.28 g/100 g. The effect of cell wall breakage pretreatment was investigated by supercritical CO₂ rapid depressurization, and results indicated this pretreatment could result in a rapid and efficient extraction. A sensitive fluorescent reagent 2-(11H-benzo[a]carbazol-11-yl) ethyl 4-methylbenzenesulfonate (BCETS) was utilized as pre-column labeling regent to determine fatty acids (FA) from Lycium barbarum seed oils obtained by different extraction methods. The main FA were: C18:2, C18:1, C16, C20:6, C18:3, and C20. The oil from L. barbarum seed exhibited excellent antioxidant activity in 2,2-diphenyl-1-picrylhydrazyl（DPPH）radical scavenging assay and β-carotene bleaching test, and its antioxidant activity compared well with the references ascorbic acid and α- tocopherol.     

壶瓶碎米荠富硒油脂理化特征及体外抗氧化活性的研究

为研究壶瓶碎米荠种子中富硒油脂的理化特征及体外抗氧化能力,采用索氏提取法提取壶瓶碎米荠种子中富硒油脂,参照国家标准对酸价、过氧化值等指标进行评价,利用HS-SPME-GC-MS和GC-MS法鉴定油脂组成及其油脂挥发性物质,微波消解-原子荧光法测定油脂中硒的含量,福林酚法测定油脂中总酚含量;以该油脂对DPPH、超氧阴离子...     

提取方法对奇亚籽油品质特性的影响

以奇亚籽为原料,分别采用压榨法、溶剂浸提法、水酶法和超临界CO₂萃取法提取奇亚籽油,对比分析不同方法提取奇亚籽油的理化性质、脂肪酸组成、油脂氧化稳定性、酚类物质含量及体外抗氧化能力等品质特性。结果表明:4种方法中,超临界CO₂萃取法的油脂得率最高(85.5%),其次是溶剂浸提法(65.8%)和压榨法(40.9%),水酶法最低(33.2%)。超临界CO₂萃取的奇亚籽油品质最佳,色泽为黄值70红值4.3灰值0.3,酸价为1.10 mg KOH/g、过氧化值为0.0137 g/100 g,含有不饱和脂肪酸总质量分数为88.22%,其中亚油酸18.36%,亚麻酸69.86%;其氧化速度最慢在30 h后过氧化值达到0.25 g/100 g;总酚含量为106.45 mg/kg,黄酮含量为222.09 mg/kg。超临界CO₂萃取的奇亚籽油在相同质量浓度下的DPPH自由基清除能力(IC₅₀ 28.04 mg/mL)与ABTS+·清除能力(IC₅₀ 33.70 mg/mL)优于压榨法、溶剂浸提法和水酶法;对超氧阴离子自由基清除能力(IC₅₀ 10.08 mg/mL)优于溶剂浸提法、水酶法,略低于压榨法。     

Polyphenolic Composition and Antioxidant Activities of Grape Seed Extract

Grape seed extracts (GSEs,) obtained from Italian and Rhine Rieslings, were examined for polyphenolic composition and antioxidant activities using HPLC and ESR spectrometry. The seed extraction was carried out with ethyl acetate and ethanol. The contents of polyphenols, flavan-3-ols and antioxidant activities were found to be higher in ethyl acetate than in ethanolic extracts. IC₅₀ values were 0.1045 mg/mL and 0.0599 mg/mL for the stable DPPH radical in ethanolic and ethyl acetate extracts, respectively. The values for the short-lived OH radical were 0.1989 mg/mL and 0.0362 mg/mL, in the given order. The significant correlations between the antioxidant activities of GSEs and polyphenols were established (P < 0.05). Owing to their antioxidant activities, the cultivars could be used as a source to produce a GSE.     

Antioxidant and tyrosinase inhibitory activities of different parts of guava (<Emphasis Type="Italic">Psidium guajava</Emphasis> L.)

The antioxidant and the tyrosinase inhibitory activities of 4 different solvents (acetone, ethanol, methanol, and water) for preparation of extracts from guava (branch, fruit, leaf, and seed) were evaluated by measuring total phenolic contents (TPC), DPPH radical scavenging activity, ABTS radical scavenging activity, reducing power (RP), and tyrosinase inhibitory activity. The extracts of branch and leaf showed relatively higher antioxidant properties than those of fruit and seed. The highest TPC (141.28 mg/g gallic acid equivalents), DPPH radical scavenging activity (IC₅₀=34.01 μg/mL), ABTS radical scavenging activity (IC₅₀=3.23 μg/mL), and RP (IC₅₀= 75.63 μg/mL) were found in acetone extract of leaf, while water extract of seed had the lowest antioxidant activity. The tyrosinase inhibitory activity of ethanol extract from guava leaf was 69.56%, which was the highest activity among the extracts. These results indicate that useful bioactive substances exist in the guava branch as well as leaf extracts.     

Oregano: chemical analysis and evaluation of its antimalarial, antioxidant, and cytotoxic activities

Abstract: GC‐FID and GC‐MS analysis of essential oil from oregano leaves (Origanum compactum) resulted in the identification of 46 compounds, representing more than 98% of the total composition. Carvacrol was the predominant compound (36.46%), followed by thymol (29.74%) and p‐cymene (24.31%). Serial extractions with petroleum ether, ethyl acetate, ethanol, and water were performed on aerials parts of Origanum compactum. In these extracts, different chemical families were characterized: polyphenols (gallic acid equivalent 21.2 to 858.3 g/kg), tannins (catechin equivalent 12.4 to 510.3 g/kg), anthocyanins (cyanidin equivalent 0.38 to 5.63 mg/kg), and flavonoids (quercetin equivalent 14.5 to 54.7 g/kg). The samples (essential oil and extracts) were subjected to a screening for antioxidant (DPPH and ABTS assays) and antimalarial activities and against human breast cancer cells. The essential oil showed a higher antioxidant activity with an IC₅₀= 2 ± 0.1 mg/L. Among the extracts, the aqueous extract had the highest antioxidant activity with an IC₅₀= 4.8 ± 0.2 mg/L (DPPH assay). Concerning antimalarial activity, Origanum compactum essential oil and ethyl acetate extract showed the best results with an IC₅₀ of 34 and 33 mg/mL, respectively. In addition, ethyl acetate extract (30 mg/L) and ethanol extract (56 mg/L) showed activity against human breast cancer cells (MCF7). The oregano essential oil was considered to be nontoxic.     

核桃仁皮不同极性提取物的体外抗氧化活性分析

采用乙酸乙酯、正丁醇、氯仿、石油醚对核桃仁皮多酚进行提取,通过清除DPPH自由基、OH自由基、ABTS自由基法与铁离子还原能力初步评价其体外抗氧化活性。结果表明,不同极性溶剂对核桃仁皮多酚提取能力为乙酸乙酯>正丁醇>氯仿>石油醚;乙酸乙酯提取物具有最强的DPPH自由基清除能力和ABTS自由基清除能力,其IC₅₀值分别为5.004和29.654 μg/mL,其次为正丁醇(9.596、23.681 μg/mL)、氯仿提取物(62.719、144.475 μg/mL)以及石油醚提取物(48.316、146.424 μg/mL);正丁醇提取物具有最强的OH自由基清除能力,其IC₅₀值为393.578 μg/mL,其次为乙酸乙酯(510.186 μg/mL)、氯仿提取物(627.003 μg/mL)与石油醚提取物(840.315 μg/mL);在铁离子还原能力实验中,当样品浓度均为100 μg/mL时,各提取物的吸光度为乙酸乙酯(0.821)>正丁醇(0.509)>氯仿(0.406)>石油醚(0.142)。总之,不同极性提取物其抗氧化能力有差异,依次为乙酸乙酯>正丁醇>氯仿>石油醚,且与质量浓度呈正相关。     

沙枣不同部位提取物体外抗氧化作用的研究

以沙枣为研究对象,选用不同溶剂对沙枣花、沙枣叶、沙枣果肉、沙枣核进行提取,测定提取液对DPPH自由基的抗氧化能力。实验结果表明,不同溶剂提取物均对DPPH自由基有清除能力,清除能力大小顺序为80%乙醇>纯水>石油醚。沙枣果肉在石油醚中清除能力较好,半清除率浓度为(32.33±0.8)mg/mL;沙枣核在80%乙醇中清除能力较好,半清除率浓度为(0.21±0.01)mg/mL;沙枣花在水中清除能力较好,半清除率浓度(1.82±0.06)mg/mL。