ANTIOXIDANT ACTIVITY AND TOTAL PHENOLIC CONTENTS IN PEEL AND PULP OF CHINESE JUJUBE (ZIZIPHUS JUJUBA MILL) FRUITS

Total phenolic contents in peel and pulp of the fruits of three Chinese jujube cultivars ( Ziziphus jujuba cv. mayazao, Z. jujuba cv. dongzao and Z. jujuba cv. yuanzao) were determined. The antioxidant activities in peel and pulp of the jujube fruits were measured by different methods, including 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity, ferric reducing antioxidant power (FRAP) and Trolox equivalent antioxidant capacity (TEAC). The total phenolic content in peel was five to six times higher than that in the pulp of all the three cultivars. The phenolics contents in the jujube were different with cultivars. The EC₅₀ ( Concentration of lyophilized samples needed to decrease the initial DPPH radical concentration by 50% ), FRAP and TEAC values of the peel and pulp were remarkably correlated to their total phenolic contents (R  = − 0.922, R  =  0.985 and R  =  0.997, respectively). The results indicated that the high capacity of antioxidant of Chinese jujube fruit could be attributed to the high phenolic contents in the fruit.

PRACTICAL APPLICATIONS

There was an expanding quest surrounding the use of antioxidant because they have the capacity to protect from the damage because of free radicals and reactive oxygen species. However, the safety of synthetic antioxidant was challenged. Much attention has been focused on the use of natural antioxidant. Interest in food phenolics had increased greatly because of their antioxidant and possible promoting-health role in human health. In this study, total phenolic contents and antioxidant capacities in vitro of Chinese jujube ( Ziziphus jujuba Mill) peel and pulp were researched. The work would help to explore a natural antioxidant for possible application in food and dietary supplemental products for health promotion.     

Antioxidant properties in vitro and total phenolic contents in methanol extracts from medicinal plants

In order to find out new sources of safe and inexpensive antioxidants, the antioxidant capacities of 45 selected medicinal plants were evaluated using ferric reducing antioxidant power (FRAP) and Trolox equivalent antioxidant capacity (TEAC) assays, respectively, and the total phenolic contents of these plants were measured by the Folin-Ciocalteu method. Most of these plants were analyzed for the first time for their antioxidant activities. It was found that the plants Sargentodoxa cuneata Rehd. Et Wils, Fraxinus rhynchophylla Hance, Paeonia lactiflora Pall, Paeonia suffruticosa Andr and Scutellaria baicalensis Ceorgi possessed the highest antioxidant capacities and thus could be potential rich sources of natural antioxidants. A strong correlation between TEAC values and those obtained from FRAP assay implied that antioxidants in these plants were capable of scavenging free radicals and reducing oxidants. A high correlation between antioxidant capacities and their total phenolic contents indicated that phenolic compounds were a major contributor of antioxidant activity of these plants.     

Antioxidant actions and phenolic and vitamin C contents of common Mauritian exotic fruits

Seventeen commonly consumed exotic fruits from Mauritius were analysed for their antioxidant capacity, total phenolics, proanthocyanidins, flavonoids and vitamin C content. Two independent methods were used to evaluate the antioxidant potential of total fruit extracts. The antioxidant activities of the fruits ranged from 1 to 47 µmol Trolox equivalent antioxidant capacity (TEAC) g^?1 fresh weight and from 0.3 to 34 micro/mol g fresh weight (FRAP) g^?1 fresh weight. Total phenolics in the fruits ranged from 118 to 5638 µg g^?1 fresh weight, proanthocyanidins from 7 to 2561 µg g^?1 fresh weight, flavonoids from 21 to 712 µg g^?1 fresh weight and vitamin C content from 8 to 1426 µg g^?1 fresh weight. There were strong correlations between antioxidant activity (assessed by both TEAC and FRAP) and total phenolics and proanthocyanidins. Flavonoids seemed to contribute less to the antioxidant potential of the fruits, while very poor correlations were observed between ascorbate content and antioxidant activity. The highest antioxidant capacities were observed in red and yellow Psidium cattleianum Sabine ‘Chinese guava’, sweet and acid Averrhoa carambola L ‘starfruit’, Syzygium cumini L Skeels ‘jamblon’ and white Psidium guajava L ‘guava’. These fruits were also characterised by high levels of total phenolics. Mauritian exotic fruits are thus a significant source of phenolic antioxidants, which may have potential beneficial effects on health. Copyright © 2003 Society of Chemical Industry     

不同可食阶段蚕豆结合酚抗氧化活性的研究

本文研究了五个蚕豆品种（凤豆6号、13号、15号、17号和18号）在三个可食阶段S1（138 DAS）、S2（156 DAS）、S3（173 DAS）（DAS,days after seeding,播种后的天数）种皮和胚结合酚提取物的抗氧化活性。采用Folin-酚法、亚硝酸钠-氯化铝法和香草甲醇法分别测定总酚、黄酮和缩合单宁含量,并通过DPPH自由基清除能力、Trolox等量抗氧化活性（TEAC）和铁还原抗氧化能力（FRAP）评价抗氧化活性,同时对酚类化合物含量和抗氧化活性进行相关性分析。结果显示,种皮总酚、黄酮、缩合单宁含量和抗氧化活性均高于胚;S2采收的凤豆18号酚含量和抗氧化活性在种皮和胚中均最高,S1采收的凤豆17号酚含量和抗氧化活性在种皮中最低,S3采收的在胚中最低;不同品种在整个采收过程中酚含量和抗氧化活性存在差异;在种皮中,总酚含量（TPC）和黄酮含量（FC）与DPPH、FRAP呈极显著相关（P<0.01）,缩合单宁含量（CTC）与DPPH、TEAC、FRAP呈极显著相关（P<0.01）,在胚中,TPC和FC与DPPH、TEAC、FRAP均呈极显著相关（P<0.01）。     

Total phenol,flavonoid, proanthocyanidin and vitamin C levels and antioxidant activities of Mauritian vegetables

Ten Mauritian vegetables, broccoli, cauliflower, white cabbage, lettuce, Chinese cabbage, mugwort, carrot, onion, tomato and chilli pepper, were analysed for their total phenol, flavonoid, proanthocyanidin and vitamin C contents and antioxidant capacity. Antioxidant activities of the vegetables ranged from 0.43 to 3.68 µmol g^?1 fresh weight Trolox equivalent antioxidant capacity (TEAC) and from 0.60 to 8.47 µmol g^?1 fresh weight ferric reducing antioxidant power (FRAP). Levels of total phenols in the vegetables varied between 132 and 1189 µg g^?1 fresh weight and those of total flavonoids between 45 and 944 µg g^?1 fresh weight, while proanthocyanidins were detected at very low levels in only a few vegetables. Vitamin C contents varied between 25 and 748 µg g^?1 fresh weight. Quercetin was the dominant flavonoid aglycone in the hydrolysed vegetable extracts, with values in the range of 15–390 µg g^?1 fresh weight. There were strong correlations between antioxidant capacity and total phenols (TEAC, r = 0.91; FRAP, r = 0.83) and total flavonoids (TEAC, r = 0.89; FRAP, r = 0.82). Vitamin C contents showed poor correlation with TEAC values (r = 0.33), while no correlation was observed with FRAP values. Highest antioxidant capacities were observed in Chinese cabbage (Brassica chinensis L), onion (Allium cepa L), mugwort (Artemisia vulgaris Cantley) and broccoli (Brassica oleracea L var botrytis L subvar cymosa). Mauritian vegetables therefore represent a significant source of phenolic antioxidants, with quercetin derivatives being most abundant, and this may contribute to their potential health benefits. Copyright © 2004 Society of Chemical Industry     

Characterization of Red Raspberry (Rubus idaeus L.) Genotypes for Their Physicochemical Properties

ABSTRACT:  The worldwide tendency for growing more small fruits, including raspberries, shows permanent increase because this group of fruits has a relatively higher content of bioactive nutrients. To study the health benefits of red raspberry fruits, 11 preselected wild-grown and 1 well-known cultivar, Heritage, were evaluated for some of their physicochemical properties such as fruit weight, total antioxidant capacity (measured by β-carotene bleaching and FRAP assays), total phenolics, ascorbic acid, soluble solid content (SSC), and acidity. Fruit weight, SSC, and ascorbic acid contents were between 1.47 and 2.32 g, 10.87% and 13.60%, and 21 and 36 mg/100 g, respectively. Antioxidant activity and total phenolic content varied among genotypes and the ERZ5 genotype had the highest antioxidant capacity as ascertained by both methods. This genotype also had the highest total phenolic (2031 μg GAE/g FW) content. There are linear relationships between antioxidant capacities and total phenols. The present study demonstrates the potential of certain wild genotypes, notably ERZ5, for improving the nutritional value through germplasm enhancement programs.     

Evaluation of the effects of thermal treatments on color, polyphenol stability, enzyme activities and antioxidant capacities of innovative pasty celeriac (Apium graveolens L. var. rapaceum (Mill.) DC.) products

Initial heating was applied as the first processing step in the production of innovative pasty celeriac products. For this purpose, celeriac was converted into a paste and subsequently heated at 90 and 100 °C for 5–10 min. Alternatively, the fresh plant material was blanched prior to mincing. For the first time, phenolic compounds in celeriac were characterized by high-performance liquid chromatography coupled with mass spectrometry (LC–MSⁿ). Among the 14 phenolics detected, several caffeic, ferulic and quinic acid derivatives as well as malonylated and acetylated flavonoid derivatives were newly identified. Upon thermal treatment, the antioxidant capacities (TEAC assay) and the total phenolic contents remained virtually unchanged. The antioxidant capacities of heated samples determined by the FRAP assay were even higher than those of the unheated control. The contents of the main phenolic compound apiin decreased upon heat treatment, whereas the levels of the minor compounds malonylapiin A and B increased. Only by extended steam- and water-blanching at 100 °C, respectively, complete inactivation of peroxidase and polyphenol oxidase was achieved. The obtained celeriac products were characterized by their bright white color. Consequently, blanching is recommended as the initial operation in the processing of celeriac into novel pasty products.     

Antioxidant properties of domesticated and wild Rubus species

The antioxidative capacities of a number of Rubus species of varied pigmentation have been investigated. In addition, total phenol, anthocyanin and ascorbic acid contents have been determined. Two methods to assess the antioxidant potential of fruit juices have been used. The antioxidant capacities of the fruit ranged from 0 to 25.3 µmol Trolox equivalents g⁻¹ (TEAC) or from 190 to 66 000 µmol l⁻¹ ferric reducing antioxidant power (FRAP). Ascorbic acid contributes only minimally to the antioxidant potential of Rubus juices (<10%, TEAC). There are apparent linear relationships between antioxidant capacity (assessed as both TEAC and FRAP) and total phenols (r_xy = 0.6713 and 0.9646 respectively). Also, anthocyanin content has a minor influence on antioxidant capacity (r_xy = 0.3774, TEAC; r_xy = 0.5883, FRAP). The sample with the highest antioxidant capacity (Rubus caucasicus) had the highest phenol content, but only a low percentage was represented by anthocyanins. The present study demonstrates the potential of certain wild Rubus species, notably R caucasicus, for improvement of nutritional value through germplasm enhancement programmes. © 2000 Society of Chemical Industry     

Systematic evaluation of natural phenolic antioxidants from 133 Indian medicinal plants

Total antioxidant capacities of 133 Indian medicinal plant species sampled from 64 families were assessed by ABTS, DPPH and FRAP assays, and their total phenolic contents measured by Folin–Ciocalteu assay. These species exhibited a broad range of antioxidant activities, varying from 0.16 to 500.70 mmol TEAC/100 g DW in the ABTS assay. The antioxidant activity values similarly varied with the DPPH and FRAP assays. Significant and positive linear correlations were found between total antioxidant capacities and phenolic contents (R = 0.89–0.97), indicating that phenolics were the dominant antioxidant constituents in the tested medicinal plants. Preliminary identification of the major phenolic compounds from 83 selected medicinal plants by reversed-phase HPLC revealed phenolic acids, tannins, flavonoids, curcuminoids, coumarins, lignans, and quinines. The fruit of Terminalia chebula, pericarp of Punica granatum and gall of Rhus succedanea showed very high levels of hydrolysable tannins, and the gum of Acacia catechu presented very high levels of catechin and epicatechin in addition to tannins. Major phenolics in many of the medicinal plants were identified for the first time (e.g., Euphorbia lathyrus, Ipomoea turpethum, and Picrorrhiza kurroa). This systematic investigation of a large number of Indian medicinal plants proved important for understanding their chemical constituents and functionality in Ayurvedic medicine, and contributes to the search for natural sources of potent antioxidants.     

Impact of processing and storage on the phenolic profiles and contents of pomegranate (Punica granatum L.) juices

Juices were obtained on pilot-plant scale from untreated, steamed and peeled pomegranate fruits (Punica granatum L.), respectively, by applying increasing pressures and various juice treatments, i.e., enzymatic treatment, filtration, clarification and pasteurization, to determine the influence of process technology on the phenolic profiles and contents of the juices. Polyphenols were characterized and quantified by HPLC-DAD-ESI/MSⁿ, and total phenolics and antioxidant capacity of the juices were determined by Folin–Ciocalteu, FRAP and TEAC assays, respectively. The total amounts of anthocyanins and colorless phenolics in the juices significantly differed depending on the applied technology. Highest phenolic recoveries were obtained from steamed fruits without further treatment. In contrast, lowest phenolic contents were determined in the juices produced from peeled fruits, i.e., the isolated seeds with adherent arils. With increasing pressures, polyphenol recoveries were enhanced, whereas juice treatments such as microfiltration and fining lowered phenolic contents of the juices. Furthermore, the amounts of individual phenolics were determined by HPLC-DAD with ellagitannins dominating the phenolic profiles. Juices solely produced from the edible parts of pomegranate exhibited lower amounts of ellagitannins compared with the juices from entire fruits. In contrast, the former juices were characterized by the highest amounts of gallotannins, hydroxybenzoic acids, hydroxycinnamic acids and dihydroflavonols. These results were consistent with the astringency of the juices. Additionally, storage experiments were performed at 4 °C and 20 °C in the dark and 20 °C under light exposure, revealing significant pigment degradation and concomitant color loss, especially at elevated temperatures and upon illumination, whereas the contents of non-anthocyanin phenolics and antioxidant capacity remained virtually unchanged throughout storage.     

Antioxidant capacity and hydrophilic phytochemicals in commercially grown native Australian fruits

Hydrophilic phytochemicals and antioxidant capacities of eight commercially grown native Australian fruits were determined. Kakadu plum (Terminalia ferdinandiana) contained a 6-fold higher level of total phenolic compounds and quandong (Santalum acuminatum) a 1.9-fold higher level of total phenolic compounds (TP, Folin–Ciocalteu assay) than blueberry (Vaccinum sp., cv. Biloxi). Both fruits displayed superior oxygen radical-scavenging capacity (ORAC-H assay) that was, respectively 4.1-fold and 6.5-fold of that of blueberry. The total reducing capacity (TRC; ferric reducing antioxidant power (FRAP) assay) of Kakadu plum and quandong exceeded the TRC of blueberry, respectively, 13.1- and 2.3-times. The primary sources of antioxidant capacities in the evaluated fruits were phenolic acids (benzoic and cinnamic) and flavonoids (flavonols, flavanones and anthocyanins) tentatively detected by liquid chromatography–mass spectrometry (LC–PDA–MS/MS). A high level of vitamin C was recorded for Kakadu plum and Australian citrus fruits. The major organic acids detected were citric and malic acid.     

Ascorbate,not urate,modulates the plasma antioxidant capacity after strawberry intake

The consumption of antioxidant-rich foods has already been associated with acute significant increases in plasma total antioxidant capacity (TAC) in humans, but there is no consensus among different literature reports. Furthermore, the acute rise in plasma TAC observed after consumption of several non-berry fruits seems not to be necessarily related to the absorption of dietary antioxidants, such as micronutrients and phenolic substances, but is attributed to the relevant increase of endogenous urate in serum. In this study, we first compared the nutritional quality of strawberry fruits from different genotypes, all cultivated in the same experimental field. Significant genotype-to-genotype differences were observed in the antioxidant capacity and in the vitamin C, folate and phenolic contents of the fruits. Second, in order to investigate the individual effects of the selected strawberry genotypes on the post-prandial plasma antioxidant status in humans, we assessed the acute effects of a single dose of strawberries in healthy subjects. The variation of plasma TAC through the FRAP and TEAC assays, and any eventual changes in ascorbate and urate levels in serum, were measured during the three hours following the strawberry intake. The acute intake of strawberries resulted in a significant increase in plasma FRAP values in all the subjects, independently of the individual TAC baseline levels. Interestingly, the lowest increases in plasma TAC and in serum ascorbate levels were associated with consumption of the nutritionally-poorest cultivars. In addition, significant increases in ascorbate, but not in urate, concentrations were observed in serum. These findings suggested that the fructose-dependent hyperuremic effect, observed after the intake of non-berry fruits, is not responsible for the plasma antioxidant changes following strawberry consumption.     

Total phenolics and antioxidants profiles of commonly consumed edible flowers in China

Edible flowers are referred to the non-toxic flowers that can be consumed by human beings for their additional nutritional or medical properties. These flowers are rich source of natural antioxidants, thus exert specific positive health effects on chronic diseases and act as a potential function food. This research paper is focused on the determination of total phenolic content (TPC), total flavonoids content (TFC), and antioxidant capacities of different kinds of edible flowers in China and compared systematically. Sixty-five flower samples were collected from parks in Guangzhou and also purchased from Qingping Market. TPC, TFC, and three anti-oxidative assays (DPPH free radical scavenging activity, ABTS radical scavenging activity, and Ferric reducing antioxidant capacity (FRAP) assay) were conducted. Different flowers presented diverse range of antioxidant capacities, phenolic contents, and flavonoid contents. A high correlation between TPC and antioxidant activity (as accessed using three different methods) was reported. However, a low relationship was observed between TFC value and antioxidant capacities. This study revealed that five Rosa species exhibited strong antioxidant capacities among other samples, and these can be used as potential functional foods to counterbalance the effect of reactive oxygen species (ROS) and oxidative stress.     

A comprehensive study of polyphenols contents and antioxidant potential of 39 widely used spices and food condiments

Spices and condiments are rich sources of potent antioxidants. In the present investigation, total equivalent antioxidant capacities (TEAC) of 39 spices were studied using 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) scavenging, and cupric reducing antioxidant capacity (CUPRAC) assays. Their total phenolic contents (TPC) and total flavonoid contents (TFC) were also determined. TEAC, TPC, and TFC varied significantly (P?<?0.05) among these spices. ABTS, DPPH, and CUPRAC assay values of studied spices ranged from 1.42 to 112.94 mg ascorbic acid equivalents (AAE)/g, 1.14 to 91.09 mg Trolox equivalents (TE)/g, and 0.52 to 54.47 mg TE/g, respectively (dry weight basis; DW). Based on Folin–Ciocalteu assay, TPC ranged from 2.93 to 160.55 mg of gallic acid equivalents (GAE)/g DW. Strong correlations between TPC and TEAC values (R?=?0.966, 0.825, and 0.954 for ABTS, DPPH, and CUPRAC, respectively) were found. This indicates that phenolic compounds are potent antioxidants in these spices. Principal component analysis (PCA) indicated that cloves (flower buds of Syzygium aromaticum) had the most distinct and potent antioxidant capacity, followed by allspice (fruits of Pimenta dioica) and cinnamon (bark of Cinnamomum verum). Results of the present study provide adequate evidence that polyphenols are responsible for their compelling antioxidant capacities of studied spices. Thus, consumption of antioxidant-rich spices such as cloves, allspice, and cinnamon can significantly prevent oxidative stress in the human body.     

Antioxidant capacities of phenolic compounds and tocopherols from Tunisian pomegranate (Punica granatum) fruits

This article aims to determine the phenolic, tocopherol contents, and antioxidant capacities from fruits (juices, peels, and seed oils) of 6 Tunisian pomegranate ecotypes. Total anthocyanins were determined by a differential pH method. Hydrolyzable tannins were determined with potassium iodate. The tocopherol (α-tocopherol, γ-tocopherol, and δ-tocopherol) contents were, respectively, 165.77, 107.38, and 27.29 mg/100 g from dry seed. Four phenolic compounds were identified and quantified in pomegranate peel and pulp using the high-performance liquid chromatography/ultraviolet method: 2 hydroxybenzoic acids (gallic and ellagic acids) and 2 hydroxycinnamic acids (caffeic and p-coumaric acids). Juice, peel, and seed oil antioxidants were confirmed by ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC) methods. The highest values were recorded in peels with 25.63 mmol trolox equivalent/100 g and 22.08 mmol TE/100 g for FRAP and ORAC assay, respectively. Results showed that the antioxidant potency of pomegranate extracts was correlated with their phenolic compound content. In particular, the highest correlation was reported in peels. High correlations were also found between peel hydroxybenzoic acids and FRAP ORAC antioxidant capacities. Identified tocopherols seem to contribute in major part to the antioxidant activity of seed oil. The results implied that bioactive compounds from the peel might be potential resources for the development of antioxidant function dietary food.     

Antioxidant capacities and total phenolic contents of 56 vegetables

The antioxidant capacities and total phenolic contents of lipophilic and hydrophilic extracts of 56 commonly consumed vegetables were studied. The resulted showed that antioxidant capacities and total phenolic contents in the lipophilic fraction were higher than those in hydrophilic fraction. The different vegetables had diverse antioxidant capacities. The highest antioxidant capacities and phenolic contents were found in Chinese toon bud, loosestrife, perilla leaf, cowpea, caraway, lotus root, sweet potato leaf, soy bean (green), pepper leaf, ginseng leaf, chives, and broccoli, while the values were very low in marrow squash and eggplant (purple). Furthermore, several phenolic compounds were detected, and chlorogenic acid, gallic acid and galangin were widely found in these vegetables. The results provide support for dietary guidelines as well as epidemiological research.     

Antioxidant capacity,phenolics and isoflavones in soybean by-products

This study aimed to determine proximate composition, antioxidant capacity, total phenolic content, isoflavones and free phenolic compounds in soy by-products. High carbohydrate and protein contents were found in grade A soymilk powder (GASP) compared to grade B soymilk powder (GBSP) and soy husk powder (SHP). Ash, moisture and total dietary fibre contents were reported to be the highest in soy husk, while GBSP had the highest fat content. Antioxidant capacity as assessed using β-carotene bleaching assay was in the order of SHP ≈ GBSP > GASP, and the ranking order of the Trolox Equivalent Antioxidant Capacity (TEAC) value was GASP ≈ GBSP > SHP, while the Ferric Reducing Antioxidant Power (FRAP) value was GASP > GBSP > SHP. The total phenolic content was in the range of 62.44–103.86 mg GAE/100 g wet weight, and the major phenolic compounds in free form were ferulic, vanilic as well as gallic acids. Acid hydrolysis increased the amount of total extractable isoflavone in all soy samples.     

热带水果多酚提取物的抗氧化和抗增殖活性研究

为明确12种热带水果多酚提取物的总酚含量、总抗氧化能力和抗肿瘤细胞增殖活性,分别采用Folin-Ciocalteu法确定了水果提取物的总酚含量,采用ORAC和FRAP的方法确定了其抗氧化能力,采用MTT的方法确定了其抗人肝癌细胞HepG2增殖的活性。结果显示,12种水果提取物的总酚含量为26.17-229.67 mg GAE/100g 鲜重,最高杨桃的总酚含量为最低鳄梨的8.78倍;ORAC和FRAP抗氧化值分别为607.05-2631.17 μmol TE/100g 鲜重和462.12-1067.92 μmol TE/100 g鲜重,杨桃具有最高的ORAC和FRAP抗氧化值,分别是最低木瓜的4.33倍和鳄梨的2.31倍;11种水果提取物抑制肿瘤细胞HepG2增殖的IC50值为31.79-66.93 mg/mL,抑制活性最弱木瓜的IC50值为最强杨桃的2.11倍。水果提取物的总酚含量与其ORAC抗氧化值（R2＝0.7839）、FRAP抗氧化值（R2＝0.7636）和抑制HepG2细胞增殖的IC50值（R2＝0.8847）之间具有显著的相关性。     

Biochemical,biological and histological evaluation of some culinary and medicinal herbs grown under greenhouse and field conditions

BACKGROUND: Increasing evidence supports the potential health benefits of herbal extracts displaying antioxidant, anti‐inflammatory and antitumour activities. Environment can have a pronounced effect on phenolic content and antioxidant capacity. The objectives of this study were to evaluate the total phenolic contents and antioxidant capacities of five different herbs grown under greenhouse and field conditions and to assess their potential anti‐inflammatory effects. RESULTS: High total polyphenolic (TPP) content (measured by the Folin‐Ciocalteu reagent method) and high Trolox equivalent antioxidant capacity (TEAC) were observed in all herbs evaluated. Leaves from thyme, sage, spearmint and peppermint grown in the greenhouse showed significantly higher TPP content and TEAC than those grown under field conditions, with a threefold difference being observed in peppermint. Rosemary, spearmint and peppermint extracts showed stronger inhibition of cyclooxygenase COX‐2 than of COX‐1. CONCLUSION: The results show that producing herbs under greenhouse conditions can improve their biological activities by increasing TPP contents and antioxidant capacities. The selective inhibition of COX‐2 activity by rosemary, spearmint and peppermint suggests that they may be useful as anti‐inflammatory agents with fewer side effects than regular non‐steroidal drugs. Copyright © 2010 Society of Chemical Industry     

提取溶剂对青稞提取物总酚、黄酮含量及其抗氧化活性的影响

以3种不同的青稞为原料,采用不同的提取溶剂(水、60%乙醇、60%甲醇、60%丙酮、95%乙醇、100%甲醇、100%丙酮)对青稞进行提取。对各提取物的总酚、总黄酮进行测定,同时采用3种抗氧化方法:二苯代苦味酰自由基(DPPH)、2,2’-联氨-双(3-乙基苯并噻唑啉-6-磺酸)二胺盐自由基(ABTS)和总抗氧化能力(FARP)评价青稞提取物的抗氧化活性。结果表明,95%乙醇和60%丙酮更有利于青稞多酚的提取。藏青2000的各溶剂提取物的总酚、总黄酮及抗氧化活性普遍高于相应溶剂的循化蓝青稞和香格里拉绿青稞。藏青2000的60%丙酮提取物含有最高的总酚含量,达到211.92mg GAE/100g DW;在60%乙醇提取时具有最高的总黄酮含量,达到60.11mg RT/100g DW;在60%乙醇提取时具有最强的DPPH清除能力,达到80.08%;而用60%丙酮提取时,具有最强的ABTS清除能力和总抗氧化能力,分别达到了1.85,9.28 mmol TEAC/100g DW。总酚含量与抗氧化活性均具有显著的相关性,FRAP法与DPPH、ABTS法具有极显著的相关性。综上表明,青稞富含总酚成分,是一种潜在的天然抗氧化剂资源。