薏米中酚类提取物测定及抗氧化能力指数分析

选取3种薏米样品,经提取获得游离型和结合型多酚类化合物,采用改进的Folin-Ciocalteu比色法及硼氢化钠/氯醌(SBC)比色法,用酶标仪测定其多酚和黄酮含量;采用抗氧化能力指数(ORAC)方法,于荧光酶标仪中测定提取物中的总抗氧化活性。研究表明,游离型多酚含量中龙薏1号薏米显著性高于贵州黑谷薏米和辽宁5号薏米,结合型多酚含量中龙薏1号薏米显著性高于贵州黑米薏米和辽宁5号薏米,所有样品中其平均结合型多酚含量占总多酚含量的45.28%;游离型黄酮含量中辽宁5号薏米显著高于贵州黑谷薏米和辽宁5号薏米,结合型黄酮含量中龙薏1号薏米高于辽宁5号薏米和贵州黑谷薏米,总黄酮含量最高的是辽宁5号薏米。总抗氧化能力指数(ORAC)最高的是龙薏1号薏米,其值是(668.0 ± 32.7)mg Trolox /100g样品(以干质量计),其次是贵州黑谷薏米和辽宁5号薏米,所有样品中平均结合型ORAC值占总ORAC值的48.08%;3个品种的薏米其总多酚含量与总抗氧化能力指数之间相关系数为0.933,有显著相关性(P＜0.05)。     

Antiproliferative and antioxidant activities of common vegetables: A comparative study

Epidemiological studies have consistently linked abundant consumption of fruits and vegetables to a reduction of the risk of developing several types of cancer. In most cases, however, the identification of specific fruits and vegetables that are responsible for these effects is still lacking, retarding the implementation of effective dietary-based chemopreventive approaches. As a first step towards the identification of foods endowed with the most potent chemopreventive activities, we evaluated the inhibitory effects of extracts isolated from 34 vegetables on the proliferation of 8 different tumour cell lines. The extracts from cruciferous vegetables as well as those from vegetables of the genus Allium inhibited the proliferation of all tested cancer cell lines whereas extracts from vegetables most commonly consumed in Western countries were much less effective. The antiproliferative effect of vegetables was specific to cells of cancerous origin and was found to be largely independent of their antioxidant properties. These results thus indicate that vegetables have very different inhibitory activities towards cancer cells and that the inclusion of cruciferous and Allium vegetables in the diet is essential for effective dietary-based chemopreventive strategies.     

不同产地尖顶羊肚菌多酚组成及抗氧化活性研究

为研究不同产地羊肚菌多酚的抗氧化活性及组成,以3 种不同产地（云南、西藏、新疆）尖顶羊肚菌为原料,提取羊肚菌游离酚和结合酚,测定其1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基清除能力、还原力、2,2’-联苯-二（3-乙基-苯并噻唑-6-磺酸）二铵盐（2,2’-azinobis-（3-ethylbenzthiazoline-6-sulphonate）,ABTS）自由基清除能力和抗氧化能力指数（oxygen radical absorbance capacity,ORAC）值,并通过高效液相色谱（high performance liquid chromatography,HPLC）分析其组分。结果表明,3 种尖顶羊肚菌平均总酚含量为5.958 mg GAE/g,游离酚约为结合酚的25 倍;云南尖顶羊肚菌游离酚、结合酚含量最高（（6.157±0.192）、（0.250±0.018） mg GAE/g）,西藏尖顶羊肚菌游离酚、结合酚含量最低（（4.928±0.045）、（0.188±0.026） mg GAE/g）。3 种尖顶羊肚菌多酚组分主要为酚酸和黄酮,组成较一致,但含量差异显著。体外抗氧化结果表明：3 种尖顶羊肚菌多酚均具有一定的抗氧化活性,其中对DPPH自由基的清除能力最强;西藏尖顶羊肚菌多酚的DPPH自由基清除能力和还原力最强;新疆尖顶羊肚菌多酚的ABTS＋·清除能力最强,ORAC值也最高。     

小叶薜荔茎叶提取物的抗氧化活性研究

用95%乙醇对小叶薜荔茎叶进行浸提,浸膏分别用石油醚、乙酸乙酯、氯仿、正丁醇和水进行萃取,最后用大孔吸附树脂进行梯度洗脱,得到11种粗提物。采用Folin-Ciocalteu比色法、ORAC（氧自由基吸收能力）分析法和DPPH（1,1-二苯基-2-三硝基苯肼）法对粗提物进行总酚含量和抗氧化能力评价。同时测定了粗体物的羟基自由基的清除能力。结果表明,小叶薜荔茎叶粗提物的总酚含量在14.1%～68.6%之间,同时粗提物具有较强的抗氧化能力,它们的ORAC值在1.01×103～1.82×104μmolTE/g之间。粗提物的总酚含量与抗氧化能力之间具有明显的相关性。      

Preliminary characterisation of peach cultivars for their antioxidant capacity

Eleven peach cultivars (white‐ and yellow‐flesh peaches, nectarines and canning clingstone peaches) were assayed for their antioxidant capacity and their content of some important organic compounds as well as vitamin C, carotenoids and phenols. Antioxidant capacity, determined by FRAP assay, varied between genotypes. Those with the highest value of Ferric Reducing Antioxidant Power (FRAP) were Federica and Springcrest. Antioxidant capacity was correlated to the amount of organic components with significant differences among the cultivars. In some case, antioxidant capacity was related to phenol content, as in yellow–flesh peaches. These results suggest the importance of genotype for determining antioxidant capacity, which, in turn, is related to the organic constituents, such as phenols, vitamin C and carotenoids.     

基于HepG2细胞模型的褐赭色羊肚菌多酚抗氧化及抗增殖活性研究

本实验研究了褐赭色羊肚菌游离酚和结合酚体内抗氧化能力以及对HepG2细胞的毒性和抗增殖作用。采用HPLC对褐赭色羊肚菌多酚组分进行鉴定,测定多酚抗氧化能力指数(ORAC);以人肝癌细胞HepG2为模型,测定多酚细胞抗氧化活性(CAA值)及抗增殖活性(EC50值)。结果显示:褐赭色羊肚菌游离酚和结合酚含量分别为(4.27±0.07)、(0.14±0.01)mg GAE/g DW;其ORAC值分别为(4624.52±400)、(429.41±60)μmol TE/100 g DW;CAA值分别为(15.33±0.60)、(0.37±0.01)μmol QE/100 g DW(PBS清洗)和(51.84±0.83)、(1.27±0.04)μmol QE/100 g DW(不经PBS清洗)。游离酚和结合酚浓度为125μg/m L和70μg/m L时,对HepG2细胞增殖抑制率分别为77.28%、66.31%,且试验浓度范围内,羊肚菌多酚对HepG2基本无细胞毒性。褐赭色羊肚菌多酚具有一定的细胞抗氧化及抗增殖活性,可将褐赭色羊肚菌作为开发此类功能营养食品的原料,为羊肚菌的进一步综合利用提供理论依据。     

新疆12种干果的营养品质及抗氧化分析

为了解新疆主要干果的营养品质及抗氧化能力,选取新疆常见的12种干果,对其水分、葡萄糖、果糖、蔗糖、有机酸、总黄酮、总酚及抗氧化活性进行分析。结果表明,新疆干果种类和品种间均存在显著差异(P<0.05)。新疆干果水分含量普遍偏低,除骏枣(23.11%)和灰枣(19.37%)外,其余10种干果的水分含量均在14%以下;在营养品质方面,12种干果的主要营养成分含量:果糖114.28～540.67 mg/g DW,葡萄糖103.20～286.04 mg/g DW,蔗糖13.07～350.79,总糖388.67～826.71 mg/g DW,总酸6.56～19.01 mg/g DW,总黄酮0.39～3.04 mg RE/g,总酚0.56～0.73 mg GAE/g,其中7种葡萄干的果糖、葡萄糖、总糖、酒石酸、总酸、总黄酮含量高,骏枣和灰枣中蔗糖、总酚含量高,吊干杏中苹果酸、柠檬酸含量高;在抗氧能力方面,12种干果的抗氧化能力为:DPPH 2.65～9.75μmol TE/g,ABTS 8.22～51.82μmol TE/g,FARP 5.01～40.52μmol TE/g,ORAC 32.36～76.16μmol TE/g,其中黄提、黑加仑、吊干杏和小无花果的DPPH、FARP和ORAC较高,而骏枣和灰枣的ABTS较高。     

ORAC法测定保健食品抗氧化能力体内外实验对比分析

目的：探讨ORAC(oxygen radical absorbance capacity)荧光法测定保健食品抗氧化能力的体内体外实验结果的相关性。方法：以VC和3种保健食品为样品,用ORAC荧光法作为检测方法,用抗氧化能力(即Trolox当量)作为定量依据,通过体内体外实验测定保健食品的抗氧化能力。结果：ORAC荧光法测定保健食品抗氧化能力体内体外的实验结果存在一定相关性。当体外检测样品抗氧化值折合小鼠灌胃剂量大于25μmol Trolox/kg时,用该样品连续灌胃小鼠30d,动物体内抗氧化实验结果呈现阳性。结论：通过ORAC荧光法体外实现测定保健食品抗氧化能力,能够推测用同样方法检测动物体内抗氧化实验的结果。     

菜籽蛋白水解物体外和细胞内抗氧化性评价及氨基酸分析研究

以“双低”油菜籽秦优7号为原料,碱溶酸沉法获得菜籽分离蛋白后进一步用Alcalase2.4L酶解得到菜籽蛋白水解物（rapeseed protein hydrolysates,RPHs）;采用聚丙烯酰胺葡聚糖凝胶柱（Sephacryl S-100HR）对RPHs进行分离纯化,得到3 个组分;采用抗氧化能力指数（oxygen radical absortion capacity,ORAC）方法以及细胞抗氧化活性（cellular antioxidant capacity,CAA）的方法分析筛选得到抗氧化性最好的组分3。结果表明组分3的ORAC值为（1610.38±112.51）μmol TE/g;CAA值为（124.66±2.18）μmol QE/g,EC50值为（57.84±3.38）μg/mL;在此基础之上,对组分3进行氨基酸分析以及电泳分析,表明其抗氧化性与分子质量分布及氨基酸组成可能存在一定关系。     

Effects of addition of egg ovotransferrin-derived peptides on the oxygen radical absorbance capacity of different teas

Ovotransferrin-derived peptides showed synergistic effects with vitamin C, epigallocatechin gallate (EGCG), and caffeic acid, but not quercetin in our previous report. In this study, we further investigated the interactions between ovotransferrin-derived peptides and teas, based on the oxygen radical absorbance capacity (ORAC) assay. Our results showed that there was no significant difference in ORAC values among green, oolong, and black teas. For all the samples, 80% methanol extracts possessed better antioxidant capacity than hot water extracts. The antioxidant capacity of teas were improved by adding either ovotransferrin hydrolysate or its purified peptide IRW; however, adding hydrolysate did not improve antioxidant stability of teas. ORAC values of both teas and hydrolysate added teas were decreased during 22weeks of storage, while samples stored at 4°C exhibited higher antioxidant capacity than those stored at room temperature. This suggested that ovotransferrin hydrolysate could be used as functional food ingredients in enhancing antioxidant capacities of foods, which would benefit human nutrition and health.     

模拟体外消化对蓝靛果提取物花色苷组成及抗氧化能力的影响

研究体外消化前后蓝靛果提取物的总酚和花色苷含量、花色苷组成以及抗氧化能力的变化。实验分别采用福林-酚法和pH示差法测定总酚和花色苷含量,利用高效液相色谱-电喷雾二级质谱联用技术结合分子质量,离子碎片,出峰顺序及参考文献分析花色苷组成;采用总抗氧化能力（total antioxidant capacity,T-AOC）和氧自由基吸收能力（oxygen radical absorbance capacity,ORAC）法测定体外消化前后提取物的抗氧化能力。结果表明：模拟体外消化后样品总酚含量增加了48.2%,花色苷含量降低了67.6%,单体花色苷由11 种降为8 种,此外,ORAC值和T-AOC值分别下降了80.0%和55.6%。综上,与未经消化提取物相比较,模拟体外消化处理的蓝靛果提取物的多酚含量增加,花色苷含量和种类均减少,抗氧化能力下降。     

不同黑茶提取物功能性成分分析及活性评价

探究不同黑茶提取物(天尖茶、茯砖茶、百两茶、六堡茶及普洱茶)中主要功能性组分的差异,评价其功能性活性1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除能力、氧自由基的吸收能力(oxygen radical absorbance capacity,ORAC)及对PC12神经细胞保护作用,并建立功能性组分与其活性的相关性。结果表明,湖南产的茯砖、天尖和百两茶,其提取物中的茶多酚、茶多糖及儿茶素总含量均显著高于普洱和六堡茶提取物,而咖啡碱、没食子酸及茶氨酸含量则以普洱茶提取物最高。茯砖、天尖和百两茶提取物对DPPH自由基的清除能力及对氧自由基的吸收能力均较强,而在PC12神经细胞损伤保护实验中,茯砖、普洱及六堡茶提取物效果明显。通过相关性分析,发现茶多酚(特别是酯型儿茶素表儿茶素没食子酸酯(epicatechin gallate,ECG)和表没食子儿茶素没食子酸酯(epigallocatechin gallate,EGCG))是黑茶提取物DPPH自由基和ORAC活性的主要影响因素,而茶氨酸含量则与PC12细胞保护作用正相关。     

Contributions of phenolics and added vitamin C to the antioxidant capacity of pomegranate and grape juices: synergism and antagonism among constituents

The aim of this study was to examine the contribution of sugar, organic acid, neutral phenol, and anthocyanin fractions and added ascorbic acid to grape and pomegranate‐nectarine juice total phenol, oxygen radical absorbance capacity (ORAC), ferric reducing antioxidant power (FRAP) and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) values. Neutral phenol and anthocyanin fractions contributed ≥75% of the total antioxidant capacity (TAC) for both juices. Intrinsic synergy and antagonism among the fractionated constituents occurred inconsistently in each assay. Sugars and organic acids antagonised pomegranate juice neutral phenols and anthocyanins in the DPPH assay by 50% and the grape juice ORAC value by 21%, but were synergistic to the grape juice FRAP value. The added ascorbic acid was dose‐dependently synergistic with pomegranate and grape juice total phenol, DPPH and FRAP assays, but less so in the ORAC assay. Thus, the interactions between grape and pomegranate juice constituents determine TAC and total phenol values, and synergy in these assays could not be attributed solely to polyphenols.     

Antioxidant activity of minor components of tree nut oils

The antioxidative components of tree nut oils were extracted using a solvent stripping process. Tree nut oil extracts contained phospholipids, sphingolipids, sterols and tocopherols. The chloroform/methanol extracted oils had higher amounts of phenolic compounds than their hexane extracted counterparts. The antioxidant activity of tree nut oil minor component extracts were assessed using the 2,2-azino-bis (3-ethylbenzthiazoline sulphonate) (ABTS) radical scavenging activity, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity, β-carotene bleaching test, oxygen radical absorbance capacity (ORAC) and photochemiluminescence inhibition assays. Results of these studies demonstrated that extracts of chloroform/methanol extracted oils possessed higher antioxidant activities than extracts of their hexane extracted counterparts. Meanwhile the extract of chloroform/methanol extracted pecan oil possessed the highest antioxidant activity.     

模拟物流对不同浆果提取物抗氧化活性变化的影响

该研究旨在探究在模拟物流条件下蓝莓、树莓和接骨木莓提取物多酚含量及其抗氧化活性的变化,采用循环变温法模拟陆地物流运输条件[30 ℃（7 h）→35 ℃（6 h）→45 ℃（5 h）→55 ℃（5 h）→60 ℃（1 h）→30 ℃（7 h）],Folin酚法测定不同物流时间下浆果提取物多酚含量,2,2-联苯基-1-苦基肼基（2,2-Diphenyl-1-picrylhydrazyl,DPPH·）清除活性和氧自由基吸收能力（Oxygen Radical Absorbance Capacity,ORAC）评价不同物流时间下浆果提取物抗氧化活性的变化。结果表明,接骨木莓提取物、蓝莓提取物和树莓提取物初始多酚质量分数分别为14.96%、5.11%和2.53%,随着循环时间的积累,仅接骨木莓提取物多酚含量显著升高;三者DPPH·清除活性均降低,总IC50增长率均超过20%;接骨木莓提取物、树莓提取物和蓝莓提取物ORAC波动较大,其Trolox当量分别下降62.76%、32.74%和19.72%。模拟物流温度变化与时间积累会影响蓝莓提取物、树莓提取物和接骨木莓提取物抗氧化活性,DPPH·清除活性稳定性依次为树莓<蓝莓<接骨木莓,ORAC稳定性依次为蓝莓<接骨木莓<树莓。