桑叶总黄酮提取纯化工艺及抗氧化性研究

本文通过单因素实验和响应面分析优化得到超声辅助提取桑叶总黄酮最佳工艺,并通过过氧化氢清除试验测定了桑叶总黄酮的抗氧化活性。结果表明,最佳提取工艺参数是:乙醇浓度80%,料液比1:30 g/mL,超声时间75 min,超声温度40 ℃,得率达2.7%。桑叶总黄酮的含量经过AB-8大孔树脂处理后由12.3%提高至33.8%。抗氧化实验结果表明,桑叶总黄酮的抗氧化能力大于抗坏血酸,是一种潜在的天然抗氧化剂。     

微波辅助提取牛蒡叶多酚及其抗氧化、抗菌活性研究

利用微波辅助法提取多酚。结果表明,微波功率、提取时间、料液比的增加显著提高多酚提取率。微波辅助法提取牛蒡叶多酚的较佳条件为:提取时间3min,微波功率160W,料液比1g:20mL,提取2次。在此条件下,多酚提取率平均值为93.93%。DPPH自由基试验、羟自由基清除能力试验结果表明,牛蒡叶提取物具有较强的抗氧化活性,牛蒡叶提取物浓度为0.90mg/mL时,提取物对DPPH自由基的清除率为51.73%。抑菌试验结果表明,牛蒡叶微波提取物对革兰氏阳性菌与阴性菌都具有很强的抗菌活性,对金黄色葡萄球菌、大肠杆菌、志贺氏菌的最低抑菌浓度(MIC)分别为2.20,2.80,3.00mg/mL。     

桑白皮总黄酮的抗氧化与镇痛活性研究

目的:研究桑白皮总黄酮的抗氧化和镇痛活性。方法:分别采用DPPH自由基法、羟自由基(.OH)法研究桑白皮总黄酮的抗氧化性活性,另外通过小鼠醋酸扭体、热板、甲醛致痛(分别代表3种不同的疼痛模型)研究桑白皮总黄酮的镇痛活性。结果:与VC相比,在体外实验中,桑白皮总黄酮对DPPH自由基和.OH具有良好的清除能力;在体内实验中,桑白皮总黄酮可显著降低由腹腔注射醋酸引起的小鼠扭体次数,同时也可减少热刺激和甲醛诱导的小鼠舔足次数,说明桑白皮总黄酮对化学物质和炎症引起的疼痛均具有一定的缓解作用。结论:桑白皮总黄酮具有显著的抗氧化和镇痛活性。     

Antioxidant Activity,Total Phenolic Content and Selected Physicochemical Properties of White Mulberry (Morus Alba L.) Fruits

In this study, total phenolic content, antioxidant activity, mineral content and selected physicochemical properties of three white mulberry phenotypes (Morus alba L.) grown in Turkey were measured. Moisture, total soluble solids, total sugar, sucrose, reducing sugar, protein, ash, pH, titratable acidity, color (L, a, b), vitamin C, total phenolic, antioxidant activity of fruits were determined between 72.85–79.75 g/100 g fresh fruit, 21.25–28.50 g/100 g fresh fruit, 12.18–17.02 g/100 g fresh fruit, 1.57–4.36 g/100 g fresh fruit, 9.42–15.46 g/100 g fresh fruit, 0.82–0.89 g/100 g fresh fruit, 2.20–2.65 g/100 g fresh fruit, 5.70–5.86, 0.25–0.28 g/100 g fresh fruit, 31.24–68.69, ?2.46 to 15.68, 4.58–21.74, 10.15–21.50 mg/100 g fresh fruit, 18.16–19.24 μg gallic acid equivalent/mg of sample, and 33.96–38.96%, of sample respectively. Fruits were generally found high in P and low in Ca.     

Investigating the Antioxidant Potential of Turkish Dried Fruits

In this study, bio-active molecules of ten different dried fruits, which are widely consumed in Turkey, were investigated in terms of their flavonoid profile, antioxidant capacities, total phenolic, and total flavonoid contents. According to the results, all dried fruits possess an antioxidant activity at a certain level and have a different flavonoid profile with compounds belonging to the groups of flavonols, flavan-3-ols, anthocyanins, as well as chlorogenic acid. Dried cranberries and black raisins were observed to have the highest levels of total phenolics, flavonoids, and total antioxidant capacity. Especially black raisin samples were featured with their high amounts of catechin and epicatechin.     

蓝莓花、茎、叶酚类物质含量及抗氧化活性比较

比较蓝莓花、嫩茎、嫩叶及老叶总多酚、总黄酮、原花青素的含量,并研究其抗氧化性能差异。结果表明:嫩叶中总多酚含量最高,为43.77 mg GAE/g(以干质量计,下同),分别是花、嫩茎和老叶的3.45、1.42、1.12倍;老叶中总黄酮、原花青素含量最高,为68.01 mg RE/g、23.29 mg CAE/g,分别是花的2.57倍和4.61倍、嫩茎的1.79倍和1.23倍、嫩叶的1.03倍和1.98倍。抗氧化性能中,老叶的铁还原能力最大,其次是嫩茎和花,嫩叶较差;清除·OH的能力为嫩茎嫩叶花老叶;清除DPPH自由基能力和总抗氧化能力均为嫩茎嫩叶老叶花甲醇提取物,均高于对照品;蓝莓各部分提取物对DPPH自由基的清除能力最强,总抗氧化能力次之,清除·OH能力和铁还原能力较差。     

Carotenoid Profile,Total Phenolic Content,and Antioxidant Activity of Carrots

Carotenoid profile, antioxidant activity, and total phenolic content of carrot cultivars from three different locations in Turkey were determined during two consecutive years. The major carotenoids determined in carrots were β-carotene (41.60–71.2 mg/kg FW) and α-carotene (13.44–30.11 mg/kg FW). The total phenolic contents of carrots ranged from 114–306 mg catechin/kg FW. The antioxidant activity in carrots determined by the TEAC assay varied between 25.9 and 86.6 μmol TE/100 g FW. There was considerable variation in carotenoid contents between locations and years among cultivars. Significant differences were found between the two consecutive years in total phenolic contents except for only one cultivar. The level of antioxidant activity in carrots varied significantly over the years.     

白骨壤叶总黄酮的超声辅助提取及抗氧化活性研究

在单因素试验基础上,采用响应面分析法研究乙醇体积分数、固液比、超声功率和提取时间4个白骨壤叶总黄酮超声辅助提取因素,并比较白骨壤叶总黄酮的体外抗氧化作用。结果表明:白骨壤叶黄酮超声提取的最佳工艺条件为以粒度40～60目的白骨壤叶干粉为原料、乙醇体积分数64.39%、固液比1:28.20(g/mL)、提取功率293.63W、提取时间40.00min,该条件下白骨壤叶中总黄酮提取率为4.185%。白骨壤叶总黄酮体外清除羟自由基、超氧阴离子自由基和1,1-二苯基苦基苯肼(DPPH)自由基的IC50值分别0.232、0.829、23.692mg/L,其清除3种自由基的能力均高于VC。     

沉香叶黄酮类化合物的提取及其抗氧化活性

以沉香叶为原料,采用溶剂浸提的方法提取黄酮类化合物,利用1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）法、2,2-联氮-双-（3-乙基苯并噻唑啉-6-磺酸）二铵盐（2,2’-azinobis-(3-ethylbenzthiazoline-6-sulphonate),ABTS）法和铁氰化钾还原法测定提取物的抗氧化能力。在单因素试验的基础上,选择乙醇体积分数、提取温度、液料比为自变量,以黄酮类化合物得率为响应值,采用响应面法优化提取工艺。结果表明,沉香叶黄酮类化合物提取的最优工艺为乙醇体积分数60%、提取温度60 ℃、液料比20∶1（mL/g）、提取时间3 h,在此条件下黄酮类化合物的得率为2.88%（m/m）。抗氧化实验结果表明,沉香叶黄酮提取物具有较强的清除DPPH自由基和ABTS＋·能力,其半数有效质量浓度值分别为（1.14±0.08） mg/mL和（0.23±0.01） mg/mL。     

板栗叶总黄酮提取工艺的优化及其抗氧化活性

采用响应面法优化板栗叶总黄酮的加压溶剂提取工艺,并考察其抗氧化活性。通过单因素试验考察循环次数、提取温度、提取时间、乙醇体积分数4个因素对板栗叶总黄酮提取率的影响,并采用Box-Behnken设计对提取工艺进行优化,通过DPPH自由基和ABTS+自由基清除以及总抗氧化能力研究其抗氧化活性。结果表明,循环次数为2次,提取温度为73℃,提取时间为7.3 min,乙醇体积分数为40%时总黄酮提取率达到最大值,为(5.18±0.06)%,与预测值(5.20±0.10)%稳合良好。在所设最大板栗叶黄酮提取液浓度下,DPPH自由基清除率为88.44%,ABTS+自由基清除率为82.76%,总抗氧化能力为980.3μmol/L,表明具有很好的抗氧化活性。     

樱桃叶黄酮的体外抗氧化活性

考察樱桃叶黄酮的体外抗氧化活性,为樱桃叶黄酮在医药、食品方面的应用提供理论依据。从樱桃叶中提取黄酮,体外检测樱桃叶黄酮对羟自由基(·OH)和超氧阴离子自由基(O2-·)的清除作用,以及对H2O2诱发小鼠红细胞氧化溶血和肝脂质过氧化反应的抑制作用。结果显示,樱桃叶黄酮对·OH和O2-·具有清除作用,且呈现质量浓度依赖性,30μg/mL的黄酮溶液对·OH和O2-·的清除率分别达到85.67%和72.45%,并且对·OH的清除能力优于维生素C;樱桃叶黄酮对肝匀浆脂质过氧化反应和过氧化氢(H2O2)诱发红细胞氧化溶血具有抑制作用,当终质量浓度为30μg/mL时,抑制率分别为79.82%和75.54%。表明樱桃叶黄酮具有质量浓度依赖性的体外抗氧化活性。     

茼蒿叶中总黄酮的提取纯化及抗氧化活性分析

采用二次回归正交旋转组合设计法优化茼蒿叶总黄酮的提取条件,并利用制备色谱对粗黄酮进行纯化,最后通过不同的方法从4 个方面评价总黄酮的抗氧化活性。结果表明,茼蒿叶总黄酮的最佳提取工艺条件为：微波温度73 ℃、乙醇体积分数68%、液料比30∶1（mL/g）、微波功率400 W和微波时间8 min。在此条件下实际总黄酮提取率为0.554%。优化后的总黄酮提取物在总抗氧化活性、羟自由基和DPPH自由基的清除作用,以及对卵黄脂蛋白脂质过氧化的抑制作用方面表现出较高的活性。     

Total Phenolics,Antioxidant Activities,and Anthocyanins of Different Grape Seed Cultivars Grown in Jordan

The total phenolics, antioxidant activities, anthocyanins, vitamine E, and tert-butylhydroxytoluene (BHT) of different cultivars of grape seed extracts (GSE) grown in Jordan were evaluated. In addition, antioxidant activities of GSE were investigated using olive oil substrate by oxidative stability instrument (OSI). Results of chemical composition showed that Baladi black and Asbani black had the highest amount of fat content 14.52 and 14.22 g /100 g seed, respectively, followed by Baladi green (13.28 g /100 g seed), Ajloni green (12.24 g/100 g seed), and Khudari green (10.92 g/100 g seed), respectively. The total phenolics and anthocyanins of GSE ranged from 4.66 to 5.12 g/100 g extracts and 0.14 to 0.68 g/100 g extracts, respectively. Antioxidant activities of GSE ranged from 66.4 to 81.40%, while vitamin E and BHT were 90.34 and 94.70%, respectively. Antioxidant activity of the extracts using OSI ranged from 3.10 to 41.13 h induction time, while vitamin E and BHT had 16.33 and 17.20 h, respectively. GSE had high amounts of antioxidants and can be used to retard lipid oxidation in a variety of food products.     

Phenolic Profile,Antioxidant Capacity,and Antimicrobial Activity of Leaf Extracts from Six Vitis vinifera L. Varieties

The phenolic composition, antioxidant activity, and antimicrobial activity of extracts from vine leaves of six grape varieties collected in May, August, and September was studied. The phenolic potential of the extracts was dependent on variety and picking-time. Extracts of leaves collected in September were the richest in total phenols, flavonoids, flavonols, and stilbenes. The antioxidant properties determined by ferric reducing antioxidant power and 2,2-diphenyl-1-picrylhydrazyl assays, and antimicrobial activity against Stapylococcus aureus, Bacillus cereus, Campylobacter jejuni, Escherichia coli, and Salmonella Infantis were good and in correlation with the chemical composition changes of the leaf extracts. The results indicated that leaves remaining on the vine in September after the grape harvest could be especially promising as an inexpensive source of effective antioxidant/antimicrobial agents.     

杨梅叶中总黄酮提取工艺及其抗氧化活性研究

采用用正交试验优化杨梅叶中总黄酮的最佳提取工艺条件。以杨梅叶为原料,在乙醇体积分数65%、料液比1:30(g/mL)、提取时间1.5h、提取次数3次条件下,总黄酮提取率为3.34%。测定杨梅叶中总黄酮的体外抗氧化活性活性,结果表明：杨梅叶总黄酮对羟自由基、超氧阴离子自由基均有较强的清除作用,是一种天然有效的抗氧化剂。     

芦柑叶总黄酮的提取工艺优化及其抗氧化活性研究

为得到芦柑叶总黄酮的最佳提取工艺,利用响应面法对芦柑叶总黄酮的提取工艺进行优化,并测定芦柑叶总黄酮的抗氧化活性。在单因素试验基础上,根据Box-Behnken试验设计原理,以芦柑叶总黄酮为响应值,选取液料比、乙醇浓度、超声温度和超声时间进行四因素三水平的响应面试验,建立二次回归方程模型,并利用总黄酮对·OH和DPPH·的清除作用来评价其抗氧化活性。结果表明,最佳的提取工艺条件为:液料比38∶1(mL/g)、乙醇浓度74%、超声温度71℃和超声时间26 min,在该条件下进行3次重复试验,得到总黄酮的平均提取率为(53.19±0.28)mg/g,与预测值的相对误差为0.6%,说明该二次回归方程模型具有一定的准确性与可靠性。芦柑叶总黄酮对·OH和DPPH·的清除试验表明,芦柑叶总黄酮有一定的抗氧化活性,与·OH和DPPH·的清除率之间存在量效关系,其对·OH和DPPH·清除率的IC50分别为146.41 mg/L和66.56 mg/L,说明芦柑叶总黄酮是一种潜在的天然抗氧化剂。     

大孔树脂纯化沉香叶黄酮工艺优化及纯化前后抗氧化性比较

研究沉香叶黄酮的大孔树脂纯化工艺及其抗氧化性。通过静态和动态实验,考察树脂种类、粗提液浓度、洗脱剂、上样流速、洗脱流速对沉香叶黄酮吸附解吸性能的影响,确定最佳纯化工艺条件;采用羟自由基法、DPPH自由基和ABTS自由基法,比较纯化前后沉香叶黄酮的抗氧化性。结果表明,NKA-9大孔树脂纯化沉香叶黄酮效果最好,最佳条件为:以1.5 mL/min速度将5.0 mg/mL粗提液上柱,用70%(v/v)乙醇以2.0 mg/mL速度洗脱,此条件下沉香叶黄酮纯度提高至76.58%±3.46%。沉香叶黄酮纯化后清除羟自由基、DPPH自由基和ABTS自由基IC₅₀值分别为(0.120±0.008)、(0.016±0.009)、(0.042±0.002)mg/mL,远低于纯化前的(0.300±0.015)、(0.170±0.008)、(0.160±0.009)mg/mL,说明沉香叶黄酮纯化前后均具有较强的抗氧化性,纯化后抗氧化性明显增强。NKA-9大孔树脂适合分离纯化沉香叶黄酮。     

Bioactive Compounds and Antioxidant Activity of Tomato Cultivars

The bioactive compounds of 16 tomato cultivars, grown in the same field for 2 years (2003 and 2004) were investigated. Lycopene (5.7–26.3 mg kg^?1) was the predominant carotenoid, while β-carotene (2.1–11.2 mg kg^?1) and a small amount of lutein (0.02–0.49 mg kg^?1) were found in all tomato cultivars. Kagome 77, the richest source of total carotenoids and L-ascorbic acid, also showed the highest antioxidant activity. β-Carotene and lutein contents of tomatoes differed between 2 years statistically. Antioxidant activities of tomatoes were found between 48 and 118 μmol TEAC 100 g^?1. A significant correlation was only observed between L-ascorbic acid (2.2–13.8 mg 100 g^?1) and antioxidant activity using TEAC assay.     

金鸡毛草叶总黄酮大孔树脂的富集及抗氧化活性研究

以金鸡毛草叶总黄酮粗提液为原料,用静态吸附试验对7种大孔树脂进行筛选,选取用最佳大孔树脂进行后续吸附考察,采用单因素试验优选总黄酮的最佳纯化工艺,以维生素C(VC)为对照品,考察金鸡毛草叶总黄酮的抗氧化活性。结果表明最佳大孔树脂为AB-8型,经单因素和正交试验,树脂动态吸附最佳纯化工艺为上样浓度4mg/mL、上样体积1.2BV、上样流速1.5BV/h、上样pH6、洗脱水用量3.5BV、洗脱液乙醇的浓度60%,洗脱用量3BV,在此条件下纯化后总黄酮的保留率为61.1%,纯化后样液纯度提高至5.24倍;抗氧化活性方面,在干浸膏浓度20μg/mL^100μg/mL范围内对1,1-二苯基-2-三硝基苯肼自由基(DPPH·)清除率为23.10%~57.76%,在100μg/mL浓度下对羟基自由基(·OH)的清除率为3.76%,在3.6μg/mL^18.2μg/mL浓度范围内对2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐自由基(ABTS+·)清除率为33.27%~87.90%,表明金鸡毛草叶总黄酮具有一定的抗氧化活性,可为金鸡毛草的深入开发、产业附加值的提高提供参考依据。     

酶解法提取花生壳黄酮及其抗氧化性、抑菌性研究

以花生壳为原料,采用酶解法提取黄酮并对其抗氧化性及抑菌性进行测定。通过单因素试验及正交试验确定最佳提取工艺为:酶添加量1.0%、酶解时间120 min、酶解温度45℃、料液比1∶10,花生壳黄酮提取率为2.593%。通过对羟基自由基和DPPH自由基的清除效果来测定花生壳黄酮的抗氧化性,结果表明,花生壳黄酮对两种自由基的清除率与其浓度呈正相关;在相同浓度下,其清除能力均高于Vc。采用滤纸片法测定花生壳黄酮的抑菌性,发现其浓度为1.25 mg/mL时对大肠杆菌、金黄色葡萄球菌、沙门氏菌、枯草芽孢杆菌均具有明显的抑制作用。酶解法可以有效地提取花生壳黄酮,花生壳黄酮具有抗氧化和抑菌作用,在天然抗氧化剂、抑菌剂的开发及应用方面具有广阔的发展前景。