Antioxidant activity of small grain cereals caused by phenolics and lipid soluble antioxidants

In this study, the content of soluble, free forms of phenolic compounds (total phenolics, flavonoids, PVPP (polyvinylpolypyrrolidone) bound phenolics, proanthocyanidins and phenolic acids), as well as the content of carotenoids and tocopherols, were determined in whole grains of bread and durum wheat, rye, hull-less barley and hull-less oat, each represented with four genotypes. Antioxidant activity was evaluated as radical scavenging activity with DPPH (2,2-diphenyl-1-picrylhydrazyl) reagent, as well as by hydrogen transfer reaction (reduction power) based on the reduction of Fe³⁺. Generally, a considerable variation in antioxidant activities and phytochemical contents was observed between the cereals. Remarkably higher DPPH radical scavenging ability and reducing power were detected in hull-less barley, followed by rye and hull-less oat and durum and bread wheat, indicating that small grain species have different major antioxidants with different properties. Hull-less barley had the highest content of total free phenols, flavonoids, PVPP bound phenolics and contained flavan-3-ols, not found in other species. Hull-less oat had the highest content of tocopherols, very high content of yellow pigments and PVPP bound phenolics. Ferulic acid was the major free phenolic acid in small grain cereals tested. The relationship between the content of soluble phenols, as well as reducing power and DPPH^• scavenging activity are also considered.     

Nutritional components and antioxidant properties of seven kinds of cereals fermented by the basidiomycete Agaricus blazei

The aim of this work was to evaluate the effects of solid-state fermentation (SSF) by basidiomycete Agaricus blazei Murrill (ABM) on the nutritional components and antioxidant properties of wheat, rice, oat, corn, millet, broomcorn millet and sorghum.The results showed that the contents of nutritional components in the fermented cereals varied with the fermentation time. After SSF of ABM, the enhancement rates of millet in total phenols, amino acid nitrogen and water-soluble protein content were the highest, which were respectively 4.03, 12.04 and 10.37 times higher than that of the control; the enhancement rates of wheat in total protein and reducing sugar content were the highest, which were 0.32 and 100.77 times higher than that of control. According to 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity, reducing power, ferrous ion chelating ability and superoxide anion radical scavenging ability of ethanolic extracts from the fermented cereals, it was shown that the antioxidant properties of the cereals were significantly stronger than that of control after fermented by ABM. The improvement degrees of sorghum in DPPH radical scavenging capacity and superoxide anion radical scavenging ability were the highest, the improvement degrees of wheat in reducing power and ferrous ion chelating ability were the highest.     

苦丁茶冬青粗多糖的分离表征及其抗氧化活性研究

水提醇沉法分离制备苦丁茶冬青粗多糖样品,对其进行初步分离表征（包括总糖、糖醛酸、蛋白质、氨基酸含量和红外光谱分析）和体外抗氧化活性（清除DPPH·自由基、·OH自由基清除能力和还原能力）研究。结果表明,苦丁茶冬青粗多糖中总糖含量为30.67％、糖醛酸含量为12.72％、蛋白质含量为9.35％;含有16种氨基酸成分,总含量为7.72％,其中含有7种人体必需氨基酸,占氨基酸总量的40.41％;红外光谱显示该粗多糖样品中含有α-吡喃糖环结构;此外,苦丁茶冬青粗多糖具有较强的体外抗氧化活性,且其抗氧化活性与多糖浓度之间存在良好的量效关系。     

Cell wall composition and degradability of stem tissue from lucerne divergently selected for lignin and in vitro dry-matter disappearance

Lucerne populations that had previously been divergently selected for acid detergent lignin (ADL) concentrations of whole herbage were additionally divergently selected for in vitro dry-matter disappearance (IVDMD) of basal stems. Parental plants of the four selected populations were intercrossed and the half-sib progeny evaluated in a replicated field trial in 1988 over two harvests. Cell wall composition of basal stems was determined for detergent fibre components and neutral sugars, uronic acids, Klason lignin and esterified and etherified phenolic acids of the total fibre fraction. Lignin polymer composition was measured by nitrobenzene oxidation. Degradability of cell wall polysaccharide components was determined by a 48-h in vitro ruminal fermentation. Cell wall composition was changed by both selection criteria. Klason lignin proportion of the total fibre did not differ as a result of selection, whereas the ADL concentration of neutral detergent fibre was different among selection groups. The cell wall polysaccharides of lucerne basal stems shifted towards more cellulose (glucose residues) and less hemicellulose (xylose residues) with selection for either low ADL or high IVDMD. While degradability of the cell wall polysaccharides was correlated with various measures of lignin composition and concentration, the results were variable and inconclusive. Surprisingly, Kiason lignin and ADL were positively correlated with cell wall polysaccharide degradability, and esterified ferulic acid was negatively correlated with degradation of the cell wall. Selection for herbage ADL and basal stem IVDMD of lucerne did alter cell wall degradation, but the associated changes in cell wall lignification were not consistently correlated with cell wall degradability.     

Chemical composition of the essential oil and antioxidant activity of methanolic extracts from fruits and flowers of Hypericum lydium Boiss.

This study was conducted to evaluate the essential oil composition and antioxidant activity of methanolic extracts from fruits and flowers of Hypericum lydium Boiss., a wild growing species of the Turkish flora. The antioxidant activities were determined through several biochemical assays. Both extracts showed an inhibitory effect against the formation of TBARS in a phosphatidylcholine liposome model system, moderate scavenging effect on DPPH and superoxide radicals, prominent reducing power and inhibitory effect on deoxyribose degradation in both the nonsite and site-specific assay, but a greater hydroxyl radical scavenging activity was observed in the non-site specific assay, suggesting that the extracts were better at scavenging hydroxyl radicals than at chelating iron. Correlation analysis indicated that there was a linear relationship between antioxidant potency, free-radical scavenging activity, reducing power and the content of flavonoids of fruits and flowers extracts. The essential oils obtained by hydrodistillation were analyzed by GC and GC-MS. In total forty-three compounds were identified. The most abundant components were monoterpenes hydrocarbons represented principally by α-pinene. The tested oil showed no antioxidant activity.     

Phenolics,Sugars, Antimicrobial and Free-Radical-Scavenging Activities of <Emphasis Type="Italic">Melicoccus bijugatus</Emphasis> Jacq. Fruits from the Dominican Republic and Florida

Edible fruits of the native South American tree Melicoccus bijugatus Jacq. are consumed fresh or in traditional food, drink and medicinal preparations. Some therapeutic effects of these fruits may be due to phenolics and sugars. Aqueous acetone, methanol or ethanol tissue extracts of different cultivars or collections of M. bijugatus fruits from the Dominican Republic and Florida were analyzed for total phenolics and free radical scavenging activity by UV-vis spectroscopy, sugars by gas chromatography, and antimicrobial activity by the disc diffusion assay. Total phenolics and free radical scavenging activities ranked: seed coat > embryo > pulp extracts. Montgomery cultivar fruits had the highest total phenolics. For sugars: pulp > embryo and highest in Punta Cana fruit pulp. In all extracts: sucrose > glucose and fructose. Glucose:fructose ratios were 1:1 (pulp) and 0.2:1 (embryo). Pulp extracts had dose-response antibacterial activity and pulp and embryo extracts had antifungal activity against one yeast species. Phenolics and sugars were confirmed with thin-layer chromatography and nuclear magnetic resonance. Sugar-free pulp fractions containing phenolics had slightly more antimicrobial activity than H₂O-soluble pulp fractions with sugars. Results indicate M. bijugatus fruits contain phenolics, sugars and other H₂O-soluble compounds consistent with therapeutic uses. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

脱脂椰肉中多酚化合物抗氧化性的研究

从脱脂椰肉中提取多酚化合物,然后研究该多酚化合物对脂质过氧化的抑制作用,DPPH自由基的清除作用,羟基自由基的清除作用,Fe2+的络合能力以及Fe3+的还原能力,并以BHT、没食子酸,VE做为对照。结果表明脱脂椰肉中多酚类物质(DCP)对Fe2+具有很强的络合能力,对DPPH.和.OH有较强的清除能力,DCP也具有一定的还原能力,但其抑制脂质体过氧化作用的能力较弱。这说明脱脂椰肉中多酚有显著的抗氧化性。     

人工疏果对龙眼果实大小、内源激素和细胞壁成分的影响

在花后1个月内分2次对储良龙眼(Dimocarpus Longan Lour.cv.Chuliang）进行人工疏果处理（总疏果幅度50%左右）。结果表明,人工疏果可以促进果实的生长（与对照相比,横径和果实重量至采收分别增加了7.1%和22.5%）。果实中GA4 7和ZRs含量均表现为疏果处理大于对照,其差异在出现含量高峰时增大,而IAA含量也是疏果处理大于对照,但其差异主要出现在花后45d和花后100d。在整个果实发育期间,疏果处理与对照果皮中细胞壁成分变化的趋势基本相似,处理只是在后期才增加了果皮细胞壁中果胶,半纤维素和纤维素的含量,分别出现在花后90d后、60d和75d后,疏果处理对可溶性糖的含量无影响。根据试验结果推测：在果实发育前期,疏果处理显增加的内源细胞分裂素类水平,可能有利于促进细胞分裂和细胞数量;而在果实发育后期,增加的果皮细胞壁成分则为人工疏果促进果实生长（主要表现为细胞的膨大）提供了物质基础。     

不同仓储期普洱茶(生茶)中酚类成分差异及其对体外抗氧化能力的影响

为探究普洱茶仓储陈化过程中酚类物质等品质成分变化及其对抗氧化能力的影响,采用高效液相色谱(HPLC)等方法对6个系列3个不同仓储期共18款普洱茶(生茶)中的17种酚类化合物、3种嘌呤碱等品质成分进行定量检测.并对普洱茶(生茶)的铁离子还原/抗氧化能力、DPPH自由基清除能力、ABTS自由基清除能力、羟基自由基清除能力和...     

普洱茶挥发性成分抗氧化活性研究

用同时蒸馏萃取法（SDE）富集普洱茶挥发性物质,并用GC-MS分析其化学组成,采用DPPH和FRAP法对不同发酵阶段普洱茶挥发性物质的抗氧化活性进行评价,分析抗氧化活性与主要成分含量的关系。结果表明,普洱茶在发酵过程中甲氧基苯类化合物的相对含量大幅增加;挥发性物质的DPPH自由基清除能力和FRAP总抗氧化能力随发酵程度的加深呈显著上升趋势,发酵出堆后分别提高了100%和296%;挥发性物质的DPPH自由基清除能力和FRAP总抗氧化能力与甲氧基苯类化合物和芳樟醇氧化物的相对含量具有显著正相关性。     

Radical Scavenging Activity and Stability of Betalains from <Emphasis Type="Italic">Beta vulgaris</Emphasis> Hairy Root Culture in Simulated Conditions of Human Gastrointestinal Tract

Stability and radical scavenging activity of betalains, biosynthesized by Beta vulgaris hairy root culture were investigated at different pH values, bile salts concentration, as well as at the in vitro conditions of gastrointestinal tract. It was established that pH below 3 and concentrations of the bile salts up to 4% had no great influence on betalains stability. At the in vitro conditions of gastrointestinal tract betalains are relatively stable, as their radical scavenging activity decrease from 75% inhibition of 2,2-diphenyl-1-picrylhydrazyl (DPPH•) to about 38%.     

原生态椰子油体外抗氧化活性

对原生态椰子油(VCO)的体外抗氧化活性进行了评价,分析了VCO中总酚酸的含量及其对DPPH自由基和ABTS+自由基的清除能力,对Fe~(2+)的络合能力以及对花生油的抗氧化能力.结果表明,VCO中总酚酸的含量为(0.180±0.003)mg/mL;对DPPH自由基的清除率为31.95%.低于Trolox、BHT和没食子酸;对ABTS~+自由基的清除能力为67.49 μmol/L Tmlox当量(TEAC值);对Fe~(2+)的络合能力优于Tmlox和BHT,但显著低于没食子酸;VCO对花生油具有一定的抗氧化能力.     

Enzyme inhibitory and antioxidant activity of Melia azedarach L. naturalized in Anatolia and its phenolic acid and fatty acid composition

In the present study, acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and tyrosinase inhibitory and antioxidant activities of the fruit and leaf extracts of Melia azedarach L. (Meliaceae) of Turkish origin were evaluated. Enzyme inhibitory activity of the extracts was tested in vitro using ELISA microplate reader. Antioxidant activity of the extracts was tested using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, ferrous ion-chelation, and ferric-reducing antioxidant power (FRAP) assays. Phenolic composition of the extracts was elucidated by high performance liquid chromatography (HPLC) and fatty acid compositions of the fatty oils of the fruits and leaves were elucidated by gas chromatography-mass spectrometry (GC-MS). The ethyl acetate extract from the leaves showed the highest inhibition against AChE (33.63 ± 1.40%) and BChE (92.89 ± 3.05%). The methanol extract from the leaves exerted the best antioxidant activity in DPPH radical scavenging and FRAP assays, while the ethyl acetate extracts of the fruits and leaves had the most notable effect in metal-chelation assay.     

视频扫描测定油菜饼粕自由基清除活力方法的研究

用视频扫描平板色谱和稳定自由基1，1－二苯基－2－间三硝苯基偕腙肼（DPPH）检测油菜饼粕自由基清除活力的方法，研究抗坏血酸，维生素E，酚酸和类黄酮等17种常见酚类化合物对自由基的清除活力，发现自由基清除面积与样品量的相关系数为0．947－0．996，检测下限为40－690ng，以维生素E指数为清除活力指标，视频扫描法与常规标准比色法的测定结果具有良好的相关性，测定油菜饼粕提取液自由基清除活力发现，68－75％的化合物具有自由基清除能力，Rf值为0．41的化合物清除活力最高，占总活力的38％。     

Hydrothermal and biotechnological treatments on nutraceutical content and antioxidant activity of rice bran

The effect of processing such as steaming, germination and parboiling on nutraceuticals and in vitro bioactive properties of rice bran from three different rice varieties namely Jyothi (pigmented), IR64 and Sona masuri (non-pigmented) were investigated. Within the varieties envisaged, pigmented Jyothi variety contained higher levels of vitamin E, soluble, bound and total polyphenol, flavanoids, free radical scavenging activity and total antioxidant activity. Direct steam exposure of bran resulted in an increase in, ether extractives and oryzanol, as well as retention of all the vitamin E components, bound polyphenols, flavonoids and decrease in soluble and total polyphenol content, free radical scavenging activity and total antioxidant activity compared to native. Parboiling as well as germination of paddy resulted in an increase, in the content of ether extractives and oryzanol, whereas other bioactive properties decreased compared to native. Hence it may be concluded that bioactive components and antioxidant properties were significantly higher in Jyothi bran compared to the other two paddy brans, and processing leads to changes in bioactive properties with maximum retention of bioactive components in the steamed bran.     

Preparation and bioactivity evaluation of low salt peptide from sunf lower seed meal

Sunflower seed meal peptide as one sort of bioactive peptide has intensively application prospects. However, preparation of low salt peptide from sunflower seed meal with high efficiency remains a challenge. In this study, single and compound proteases were optimized to hydrolyze protein. Results showed that hydrolysis at pH 7.0 by proteases resulted in ash content in the range of 5.66%-7.37% and small peptides. Among all hydrolysis processes, sequential hydrolysis of Alcalase with Flavourzyme and Alcalase with Protamex showed higher nitrogen recovery ratio (67.66% and 66.49%, respectively). Furthermore, biological activities of peptides were investigated by testing their ABTS (2,2-azinobis (3-ethylben-zothiazoline-6-sulfonic acid) diammonium salt) radical scavenging activity, DPPH (2,2-diphenyl-1-picrylhydrazil) radical scavenging activity and angiotensin converting enzyme (ACE) inhibitory activity. Peptide hydrolyzed by Alcalase with Papain presented the highest antioxidant activity, followed by Alcalase with Protamex, with ABTS scavenging rate as 63.01% and 31.75%, and DPPH scavenging rate as 56.04% and 28.06%, respectively. Synchronously, peptide hydrolyzed by Alcalase with Protamex and Alcalase with Alcalase had the highest ACE inhibitory activity (56.74%, 56.76%). In conclusion, hydrolysis by proteases Alcalase with Protamex at pH 7.0 was the most effective method for the preparation of low salt peptide from sunflower seed meal, which could be an alternative for anti-oxidants and anti-vasoconstrictor.     

The binding of bile salts by vegetable fibre

The binding of bile salts by dietary fibre plays an important role in cholesterol metabolism in man. In most of the adsorption studies of bile salts in vitro, the chemical composition of the fibre preparations has not been described, even broadly, nor has the effect of co-precipitated compounds (e.g. proteins) been considered. Hence, it seemed useful to investigate the adsorption of Na cholate (NaC) and Na taurocholate (NaTC) by well-defined cell wall material (CWM) from parenchymatous, lignified and cutinised tissues of mature runner bean pods as well as leeks under a variety of experimental conditions. This study was to identify the groups of polymers which are responsible for adsorption. The results showed dramatic differences in the adsorption characteristics of the wall preparations at different pH values. Some of the findings are reported below. The CWM from the various tissues was prepared by sequentially extracting the wet ball-milled tissues with 1% aq. Na deoxycholate and phenol/acetic acid/water (2:1:1, w/v/v). Experiments with labelled deoxycholate showed that the final preparations contained negligible amounts of adsorbed deoxycholate. Since the amount of residual starch in the preparations was small, no attempt was made to remove it; however, if required, this could be completely removed by extraction with 90% aq. dimethyl sulphoxide. The particle size of the preparations varied from 25–50 μm. For adsorption studies the following preparations were used: (1) whole-, depeetinated-and delignified-CWM from parenchymatous and lignified tissues of runner beans, together with the H and Na forms; (2) CWM of runner beans at different stages of maturity; (3) CWM of whole-and decutinised-leaves and cutinised tissues of leeks and (4) carboxymethyl cellulose and amberlite resin. The binding of bile salts was measured by a modified isotope-dilution procedure. The neutral sugars from the polysaccharides were determined as alditol acetates by GLC and an estimate of the uronic acid content of the preparations was obtained by a modified carbazole method. Experiments on the effect of pH on the binding of cholate by the various preparations showed that the adsorption capacity was very much dependent on the pH. The binding increased as the pH decreased. These experiments were complicated by the precipitation cholic acid at a pH value of <4. Nevertheless, an interaction between cholate and CWM persisted in acid solutions. Removal of pectic substances and lignin from the runner bean preparations resulted in a decrease of the adsorption capacity. The results suggested that the adsorption is greatest under conditions in which the ionization of cholic acid and the acidic groups of the cell wall polymers is at its lowest. Following these studies, determinations were made of the adsorption of cholate from an aqueous solution (without buffer) by wall preparations in the H and Na forms. With all the preparations the adsorption was greatest when these were in the H form. Adsorption studies with the preparations from leeks showed that the adsorption capacity of the parenchymatous tissues was considerably more than that of cutinised tissues. Hence, pectic substances in the H form (an not lignin or cutin) are probably the principal binding agents of cholate. The adsorption of Na taurocholate by the various preparations was independent of pH value. The implications of these results are discussed.     

Free radical scavenging activity of selected medicinal plants of Eastern Botswana

Water and methanol extracts from roots of Ozoroa paniculosa (Anarcardiaceae); seeds of Colophospermum mopane (Caesalpiniaceae) and Cucumis metuliferus (Cucurbitaceae) ripe fruits were assessed for in vitro antioxidant activity. Free radical scavenging activity was measured spectrophotometrically as maximum fading power of DPPH at 525 nm. Water and methanol extracts of Ozoroa paniculosa exhibited higher scavenging potency than extracts of either Colophospermum mopane or Cucumis metuliferus at all tested concentrations. None of the extracts from Cucumis metuliferus exhibited any recognizable free radical scavenging activity. Above 50 microg mL(-1) both water and methanol extracts of Ozoroa paniculosa exhibited 91% scavenging activity similar to the control compounds L-ascorbic acid (91%) and (-) epicatechin (92%). Between 50-100 microg mL(-1), water and methanol extracts of Colophospermum mopane exhibited scavenging potency of < or = 70%. However, above 100 microg mL(-1), both water and methanolic extracts of C. mopane exhibited scavenging activity > 70%. Chloroform extracts of all the tested plants showed poor scavenging activity (< 30%). The order of scavenging potency for the tested samples was as follows: L-ascorbic acid > or = epicatechin > O. paniculosa (methanolic extract) > O. paniculosa (water extract) > O. paniculosa (ethylacetate extract) > C. mopane (methanolic extract) > C. mopane (water extract) > all extracts of C. metuliferus. These findings lend credence to the use of these plants as anti-inflammatory and antioxidant agents in folk medicine.     

不同茶树品种鲜叶多糖的理化性质和抗氧化活性比较研究

选取来自同一茶园且具有代表性的黄金桂、铁观音、祁门种、六堡茶、大红袍、槠叶齐、龙井43、白叶1号、中黄1号和福鼎大白茶10个茶树品种鲜叶为原料,直接进行微波干燥固样,通过水提法制备10个不同茶树品种的多糖,采用化学分析、高效液相色谱、红外光谱、凝胶色谱层析、扫描电镜、测量粒径和Zeta电位等方法比较分析10个茶多糖的主要理化性质,并测定其1,1-二苯基-2-苦肼基（DPPH）、2,2'-联氮-双-3-乙基苯并噻唑啉-6-磺酸（ABTS）自由基清除能力和铁离子还原能力等体外抗氧化活性。理化性质结果表明,茶多糖是一类水溶性的酸性糖蛋白,主要由糖醛酸、中性糖、蛋白质和多酚构成;10个茶多糖的单糖组分主要由半乳糖醛酸、葡萄糖、半乳糖和阿拉伯糖组成;主成分分析（PCA）表明,白叶1号和龙井43与其他茶树品种在多糖的基本组成上具有较大差异。体外抗氧化研究表明,不同茶树品种多糖的体外抗氧化能力存在显著差异,但均随其浓度增加而呈线性增加,其中白叶1号多糖的抗氧化活性整体表现最为优异。理化性质与抗氧化活性的相关性分析结果显示,不同茶树品种多糖的抗氧化能力可能与其所含的多酚和蛋白质含量有关。     

Changes in phytochemical, antimicrobial and free radical scavenging activities of the Peruvian pepper tree (Schinus molle L.) as influenced by fruit maturation

The effect of stage of maturity on total lipids, fatty acids, yields and essential oil composition and their antimicrobial and free radical scavenging activities of the Schinus molle fruits was investigated. The content of total lipids varied from 2.87 to 5.35% (w/w, dw) and were rich in unsaturated fatty acids particularly linoleic acid. As maturation progress, the essential oil yield dropped from 5.18% to 1.15%. Monoterpene hydrocarbons with α-phellandrene (35.15-40.38%), limonene + β-phellandrene (21.47-36.62%), β-myrcene (7.61-24.96%) and α-pinene (1.92-2.58%) were found to be the main components. At the same time, the essential oils were evaluated for their antimicrobial and free radical scavenging activities. They were found to be active against Bacillus subtilis, Bacillus cereus, Salmonella typhymurium and Escherichia coli but they do not inhibit the growth of Candida albicans. Conversely, they showed very weak activity against the DPPH radical. In both assay, the oil derived from the intermediate stage was reported as more efficient.