Changes in Polyphenols and Antioxidant Activities of Yingshan Yunwu Tea during Digestion in Vitro

[Objectives]To explore the change rule of polyphenol content and antioxidant activity of coarse old leaves of Yingshan Yunwu Tea in the process of human digestion.[Methods]The coarse and old leaves of Yunwu tea in Yingshan,Huanggang,Hubei Province were selected as the research object,and their digestion in vitro was simulated.The total polyphenol content was determined by Folin-phenol reagent colorimetric method,and the DPPH radical scavenging activity and total antioxidant activity were determined.[Results]After simulated gastrointestinal digestion in vitro,the polyphenol content and antioxidant activity of coarse old leaf tea soup showed a downward trend.After gastrointestinal digestion,the polyphenol content in tea infusion separately decreased by 31.8%and 8.5%;the scavenging rate of DPPH free radical was 97%before digestion,decreased to 92%after gastric digestion and 65%after intestinal digestion,which decreased by 5%and 27%,respectively;after gastrointestinal digestion,the total antioxidant capacity of tea soup decreased by 4.7%and 3.1%,respectively.[Conclusions]This study provided a reference for the development and application of coarse old leaves of Yingshan Yunwu tea,and provided a reference for the nutritional value evaluation and comprehensive utilization of coarse old leaves,so as to make the best use of coarse tea leaves and reduce the waste of resources.

Correlation between Polyphenol Contents and Antioxidant Activities in Different Echinacea Purpurea Varieties

Objective:Polyphenols are complex compounds containing multiple phenolic hydroxyl groups.They are widely distributed in plants and have antioxidant activities.Whether the antioxidant activities of the cultivated varieties of Echinacea are similar to or better than those of the wild ones and the relationship between the accumulation of polyphenols and their antioxidant activities are still not clear.Methods:Folin-Ciocalteu method,high performance liquid chromatography(HPLC),2,2-diphenyl-1-picrylhydrazyl(DPPH)radical scavenging assay,ferric ion reducing antioxidant power(FRAP)assay,2,2'-azino-bis(3-ethylbenzothiazoline-6)-sulfonic acid(ABTS)radical scavenging assay,and Fe^(2+)chelating ability assay were used,respectively,to detect the total polyphenols and 5 kinds of caffeic acid derivatives(chicoric acid,caffeic acid,caftaric acid,chlorogenic acid,and 1,5-dicaffeoylquinic acid)in the roots,stems,leaves,and flowers,and the antioxidant activities of 3 varieties of Echinacea:E.purpurea L.,cultivar E.purpurea'Aloha',and E.purpurea'White Swan'.Results:E.purpurea L.had the highest contents of total polyphenols,5 caffeic acid derivatives and antioxidant activities,followed by E.purpurea'White Swan'and E.purpurea'Aloha',respectively.E.purpurea'White Swan'had the strongest ability to remove the DPPH,ABTS·^(+)and free radicals,and to chelate Fe^(2+);E.purpurea L.had the strongest ability to reduce FRAP.The correlation analyses revealed that the contents of total polyphenols and caffeic acid derivatives of E.purpurea L.and E.purpurea'White Swan'were correlated with their antioxidant activities.Conclusion:E.purpurea L.was the most appropriate material for the development of medicinal plants.E.purpurea'White Swan'could be used as a substitute for E.purpurea L.in terms of its antioxidant activity.

Effects of different thermal processing methods on bioactive components,phenolic compounds,and antioxidant activities of Qingke(highland hull-less barley)

Qingke(highland hull-less barley)is a grain replete with substantial nutrients and bioactive ingredients.In this study,we evaluated the effects of boiling(BO),steaming(ST),microwave baking(MB),far-infrared baking(FB),steam explosion(SE),and deep frying(DF)on bioactive components,phenolic compounds,and antioxidant activities of Qingke compared with the effects of traditional roast(TR).Results showed that the soluble dietary fiber,beta-glucan and water-extractable pentosans of Qingke in dry heat processes of TR,SE,MB and FB had a higher content compared with other thermal methods and had a better antioxidant activity of hydroxyl radical scavenging and a better reduction capacity,while those in wet heat processes of BO and ST had a better antioxidant activity of ABTS radical scavenging and a better Fe^(2+) chelating ability.DF-and SE-Qingke had a higher content of tocopherol,phenolic,and flavonoid.Overall,6 free phenolic compounds and 12 bound phenolic compounds of Qingke were identified,and free phenolic compounds suffered more damage during thermal processing.Principal component analysis showed that SE had more advantages in retaining and improving the main biological active ingredients of Qingke,and it may be the best method for treating Qingke.

Optimization of pectin extraction and antioxidant activities from Jerusalem artichoke

Jerusalem artichoke is an economic crop widely planted in saline-alkaline soil. The use of Jerusalem artichoke is of great significance. In this study, the response surface method was employed to optimize the effects of processing variables （extraction temperature, pH, extraction time, and liquid-to- solid ratio） on the yield of Jerusalem artichoke pectin. Under the optimal extraction conditions： pHl .52, 63.62 min, 100℃ and a liquid-to-solid ratio of 44.4 mL/g, the maximum pectin yield was predicted to be 18.76%. Experiments were conducted under these optimal conditions and a pectin yield of 18.52＋0.90% was obtained, which validated the model prediction. The effects of different drying methods （freeze drying, spray drying and vacuum drying） on the properties of Jerusalem artichoke pectin were evaluated and they were compared with apple pectin. FTIR spectral analysis showed no major structural differences in Jerusalem artichoke pectin samples produced by various drying treatments. The antioxidant activities of pectin dried by different methods were investigated using in vitro hydroxyl and DPPH radical scavenging systems. The results revealed that the activities of spray dried pectin （SDP） and apple pectin （AP） were stronger than those of vacuum oven dried pectin （ODP） and vacuum freeze dried pectin （FDP）. Therefore compared with the other two drying methods, the spray drying method was the best.

Comparative analysis of antioxidant activities of essential oils and extracts of fennel(Foeniculum vulgare Mill.)seeds from Egypt and China

The present study was conducted to assay the antioxidant activities of essential oils and ethanol extracts of fennel(Foeniculum vulgare Mill.)seeds from Egypt and China.The major components of the Egyptian fennel essential oil were estragole(51.04%),limonene(11.45%),l-fenchone(8.19%)and trans-anethole(3.62%)by GC–MS analysis.Whereas,the major constituents of Chinese fennel essential oil were transanethole(54.26%),estragole(20.25%),l-fenchone(7.36%)and limonene(2.41%).The fennel seed extracts from Egypt and China contained appreciable levels of total phenolic contents(42.24 and 30.94 mg PE/g,respectively).The extracts exhibited good DPPH radical scavenging capacity with IC50(6.34 and 7.17 mg/g),respectively.A high variation in free radical scavenging activities of essential oils was observed.The Chinese fennel essential oil showed high activity in DPPH radical scavenging with IC50(15.66 mg/g).The Egyptian fennel essential oil showed very low activity with IC50(141.82 mg/g).The results of the present investigation demonstrated significant variations in the antioxidant activities of fennel essential oils and extracts from Egypt and China.

Purification of Proteins from Ginkgo Biloba Seeds and Their Antioxidant Activities

Ginkgo biloba seeds were widely used for food and traditional medicine in china. In the present study, antioxidant proteins named GP were purified from Ginkgo biloba seeds. The proteins （GP） were purified by homogenization of Ginkgo biloba seeds powder in the saline solution, precipitation with 70% ammonium sulphate, and filtration on DEAE-Cellulose 52 anion exchange column. GP showed protein content of 96%, and they showed three bands with approximate molecular weight of 15 kDa, 17 kDa, 21 kDa respectively by SDS-PAGE electrophoresis analysis. Compositions of amino acids obtained by Amino Acid Analyzer showed GP were rich in Glu, Ser ,His ,Asp, Gly, Ala, Leu and Lys compared with the other fractions. The antioxidant activities of GP were investigated using DPPH （the 1, 1-diphenyl-2-picrylhydrazyl） free radical-scavenging and ferric-reducing antioxidant power assays. The GP showed antioxidant activities higher than α-Tocopherol and BHA. Therefore, the present study demonstrates proteins from Ginkgo biloba seeds （GP） can be excellent antioxidant.

Antioxidant Activities of Exopolysaccharides Produced by Lactic Acid Bacteria Isolated from Commercial Yoghurt Samples

An antioxidant is a substance that inhibits the oxidation of other molecules caused by free radicals. The inbuilt antioxidant systems possessed by living organisms are generally not enough to prevent them from oxidative damages and the uses of synthetic antioxidants also have some harmful effects. This study was aimed at evaluating the antioxidant activities of exopolysaccharides produced by lactic acid bacteria isolated from yoghurt. Lactic acid bacteria (LAB) were isolated from six different brands of commercially available yoghurt using deMan Rogosa Sharpe (MRS) agar. The LAB isolates were identified based on morphological and biochemical analyses and were screened for exopolysaccharide (EPS) production. The LAB isolates screened positive were used for EPS production in a liquid medium and the EPS produced were purified and quantified using standard methods. Antioxidant activities of the EPS were evaluated by determining the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity, ferric ion reducing power, and total phenolic contents. Data obtained were analysed using Analysis of Variance. Total lactic acid bacterial count obtained from the yoghurt samples ranged from 0 - 3.9 × 104 CFU/mL with sample A (Fan Yoghurt) having the highest LAB count (3.9 × 104 CFU/mL). The isolated LAB and their incidence rate were Lactobacillus plantarum (25.49%), L. delbrueckii (19.61%), L. fermentum (15.69%), L. acidophilus (13.73%), Leuconostoc mesenteroides (11.76%), Lactococcus lactis (7.84%), and Lactobacillus casei (5.88%). Fifty-one out of the 64 LAB isolates were screened positive for EPS production and only six were able to produce substantial quantity of EPS ranging from 127.4 - 208.5 mg/L. The exopolysaccharides produced by L. fermentum had the highest DPPH radical scavenging activity (62.90%) while that of L. plantarum had the lowest (23.10%) at a concentration of 1000 μg/mL. Also, the EPS produced by L. fermentum recorded the highest ferric ion reducing power (12.89 mg AAE/mL) at 1000 μg/mL while that of L. plantarum had the lowest (5.62 mg AAE/mL). At 1000 μg/mL, the total phenolic contents of the EPS samples ranged from 1.41 - 1.58 mg GAE/mL, and the EPS produced by L. fermentum had the highest (1.58 mg GAE/mL) while those produced by L. paracasei had the lowest (1.41 mg GAE/mL). This study revealed that the exopolysaccharides produced by the LAB isolates showed high antioxidant activities with respect to their DPPH free radical scavenging activity, ferric ion reducing power and total phenolic contents.

Effects of Wet Superfine Grinding on Polyphenols and Antioxidant Activities of Whole Fruit Pulp of Navel Orange

The navel orange were cleaned and pulverized by a wet superfine grinding and a broken wall cooking machine,then the navel orange whole fruit pulp were obtained by wet superfine grinding once,wet superfine grinding twice,and broken wall cooking machine processing.The particle size distribution,free polyphenols,bound polyphenols and antioxidant activity of whole fruit pulp prepared by the three kinds of pulverization methods were discussed.The results showed that the particle size distribution of the whole fruit pulp by wet superfine grinding was more concentrated compared with the broken-wall cooking machine processing,and the total phenols dissolution rate of the navel orange whole pulp was increased by 6.9%,and the total flavonoid dissolution rate was increased by 13.5%.The results also suggested that wet superfine grinding twice could improve 1,1-diphenyl-2-picrylhydrazyl(DPPH)free radical scavenging activity of polyphenols in the whole fruit pulp,wet superfine grinding once and wet superfine grinding twice also could obviously enhance the reducing power and iron reduction ability of polyphenols in the whole fruit pulp.In conclusion,wet superfine grinding could increase both the polyphenol content and antioxidant activity of navel orange whole fruit pulp,it can be used as a pretreatment processing method for preparing navel orange whole fruit pulp.

Purification and Antioxidant Activities of Phycocyanin from Spirulina Platensis

This study aimed to purify and determine antioxidant activities of different fractions obtained during the purification process of phycocyanin from Spirulina platensis. The dried powder of Spirulina platensis, after ground with sands, was extracted with 50 mM sodium phosphate buffer at pH 6.8 before centrifuged to precipitate unwanted proteins. Then the supernatant was separated by celit column to obtain semi-pure phycocyanin and further purified by treated with ammonium sulfate. The purity of phycocyanin was monitored by measuring the absorbance spectrum from 200 to 700 nm. Its purity ratio A620A280 was determined. The antioxidant activities of the obtained phycocyanin were determined by 2,2＇-azino-bis（3-ethylbenzthiazoline-6-sulphonic acid） （ABTS） assay and lipid peroxidation （linoleie acid） assay. The purity ratio of phycocyanin in the Spirulina crude extract was 0.36 and increased to 2.68 after purification. The fraction with the highest purity ratio of phycocyanin demonstrated the hightest antioxidant activities. For ABTS assay, it presented the Vitamin C Equivalent Antioxidant Capacity （VCEAC） value of 0.0405 ±0.0002 mg of ascorbic acid/mg of sample and the Trolox Equivalent Antioxidant Capacity （TEAC） value of 0.0485 ±0.0002 mg oftrolox/mg of sample respectively. The result from lipid peroxidation assay exhibited IC50 value of 5.9336 ±0.2565 mg/mL. The purification of Spirulinaplatensis crude extract obtained from this study increased the purity ratio of phycocyanin and its antioxidant activities. This will be further investigated for the development into anti-aging cosmetic products.

Chemical components from Crotalaria pallida Ait. and their antioxidant activities

Nine compounds were isolated from the 95%ethanol extract of the dried seeds of Crotalaria pallida.The structures of all compounds were identified through the analysis of spectral data.All compounds were isolated for the first time from Crotalaria genus.Compounds 1-5 were evaluated for their antioxidant abilities by ABTS,DPPH and FRAP assays.Results showed that compounds 1-5 had moderate antioxidant activities。

Antioxidant Activities of Crude Phlorotannins from Sargassum hemiphyllum

Brown algae are well known as a source of biologically active compounds, especially those having antioxidant activities, such as phlorotannins. In this study we examined the antioxidant activities of crude phlorotannins extracts（CPEs） obtained from Sargassum hemiphyllum（SH） and fractionated according to the molecular weights. When CPEs were administrated at a dose of 30 mg/kg to Kunming mice pre-treated with carbon tetrachloride（CCl4）, the levels of oxidative stress indicators in the liver, kidney and brain were significantly reduced in vivo. All the components of various molecular weight fractions of CPEs exhibited greater scavenging capacities in clearing hydroxyl free radical and superoxide anion than the positive controls gallic acid, vitamin C and vitamin E. Particularly, the components greater than 30 k D obtained from ethyl acetate phase showed the highest antioxidant capacities. These results indicated that SH is a potential source for extracting phlorotannins, the algal antioxidant compounds.

Determination of contents of eight alkaloids in fruits of Macleaya cordata (Willd) R. Br. from different habitats and antioxidant activities of extracts

A reliable ultrasound-assisted extraction （UAE） method combined with HPLC-UV for quantification of eight active alkaloids in fruits of Macleaya cordata （Willd） R. Br. was developed. The optimization conditions of UAE were obtained by using Box-Behnken design of response surface methodology. Chromatography was carried out using a Kromasil C18 column by gradient elution with 0.1% phosphoric acid aqueous solution for HPLC-UV. All calibration curves showed good linear correlation coefficients （R^2〉0.999 6） and recoveries （from 97.3% to 104.9%） were acceptable. 1,1-diphenyl-2-picrylhydrazyl （DPPH） method was employed to test the antioxidant activity of the extract from the samples. The proposed method was successfully applied to quantifying eight components in nine samples of M.cordata, and significant variations of alkaloid contents and antioxidant aetivity of the samples from different habitats were demonstrated. It presents a powerful proof for the selection of the best sources to extract eight kinds of alkaloids.

Phenolic compounds and its antioxidant activities in ethanolic extracts from seven cultivars of Chinese jujube

Phenolic compounds and its antioxidant activity of extracts from seven cultivars of Chinese jujubes were investigated by high performance liquid chromatography(HPLC)with standards and different antioxidant evaluation methods,such as phosphomolybdenum assay,superoxide radical scavenging activity(SRSA),hydroxyl radical scavenging activity(HRSA),antihemolytic activity and inhibition of lipid peroxidation in rat liver homogenate,respectively.The results showed the components of the extracts are comprised of total phenols and flavonoids,and its content ranges from 454.3 to 1298.9(GAE mg/100 g dry weight).Phlorizin,catechin,gallic acid,chlorogenic acid,caffeic acid were the predominant phenolic compounds.All the extracts had significant antioxidant activities either in vitro or in vivo.Correlation analysis indicated that the antioxidant capacities of Chinese jujube extracts demonstrated a good positive relationship with some phenolic acids,which was higher in Xiao and Goutou.The results indicated that Xiao and Goutou could be attributed to a potential source of natural antioxidants for food applications.

Comparison of Antioxidant Activities in Black Soybean Preparations Fermented with Various Microorganisms

Black soybeans [Glycine max（L.） Merrill] were fermented with various GRAS（generally recognized as safe） microorganisms,including Aspergillus sp.,Bacillus sp.and yeast（Issatchenkia orientalis） at 30°C for 3 d.The antioxidant contents,including total phenolics and total flavonoids,and the antioxidant activities of 1,1-diphenyl-2-picrylhydrazine（DPPH）,ferric reducing antioxidant power（FRAP） and HO.scavenging were analyzed in preparations of fermented black soybeans.Fermented cultures proved to yield significant levels of antioxidants compared with non-fermented cultures（P 〈 0.05）.Fermented black soybean preparations possessed antioxidant activities could be attributed to the total phenolics and flavonoids present.

Identification and Evaluation of Antioxidant Activities of Bamboo Extracts

The antioxidant activity of solvent extracts from two main bamboo species, moso bamboo (Phyllostachys pubescens) and madake bamboo (P. bambusoides) in Japan, was first evaluated by scavenging free radical of 1,1-diphenyl-2-picrylhydrazyl (DPPH), the inhibition activity for peroxidation of linoleic acid, and the reduction power. The methanol-extracts of moso bamboo culms and madake bamboo leaves presented stronger antioxidant activity compared with DPPH scavenging activity. Methanol-extract of moso bamboo culms was further fractionated by different solvents and n-butanol soluble fraction exhibited the most significant activity in the DPPH scavenging assay. The fractionation of n-butanol soluble extract was isolated by silica gel column with gradient mixture solvent of chloroform and methanol. The isolated fractions were directed by the antioxidant activity measured by scavenging the stable DPPH free radical. It was observed that most of the eluted fractions showed the antioxidative activity. Fractions acquired from elution with the mixture solvent of chloroform and methanol (10:1–5:1) showed stronger antioxidant activity than the other fractions.

Antioxidant Activities of Nine Selected Culinary Spices from China

The antioxidant activities and the total phenolic contents of the water and/or ethanol extracts of the nine selected culinary spices from China were systematically investigated. Both ethanol extracts and water extracts had high ability of 1, 1-diphenyl-2-picrylhydrazyl（DPPH） radical scavenging, 2, 2＇-azinobis（3-ethylbenzthiazoline-6-sulphonic acid）（ABTS） radical scavenging and ferric reducing antioxidant power（FRAP）. The ethanol extract of Sichuan pepper showed the highest ability of DPPH radical scavenging. The extract with the highest ABTS radical scavenging effect was that of ethanol extract of cinnamon. Both ethanol and water extracts of cinnamon possessed the high ferric reducing antioxidant power（FRAP） with the values of 4 541.87 and 1 134.52 μmol of Fe（Ⅱ）/g. The extracts with high hydroxyl radical-mediated deoxyribose degradation were all the ethanol extracts as follows： cinnamon, bay leaf, Sichuan pepper, star anise and fennel. The extracts with high antioxidant activities also had the high contents of the phenols. The study indicated that these spices might be potentially be used as natural antioxidants in food.

Quantification and analysis of anthocyanin and flavonoids compositions,and antioxidant activities in onions with three different colors

Onion（Allium cepa L.） is a very important vegetable crop widely cultivated throughout the world. In this study, we measured total anthocyanins and flavonols of onions of three colors. The fresh weight（FW） of total anthocyanins were（29.99±1.19）,（9.64±1.30） and（0.75±0.40） mg 100 g^–1 fruit in red, yellow and white onions, respectively. Likewise, the FW of total flavonoids were（111.10±5.98）,（36.64±3.59）, and 0 mg 100 g^–1 in red, yellow and white, respectively. Four types of anthocyanins（delphinidin 3,5-diglycosides, cyanidin 3,5-diglycosides, cyanidin 3-glycosides and cyanidin 3-（6′′-malonyl）-glucopyranoside） and two kinds of flavonoids（quercetin and quercetin 3-glycosides） were identified in two varieties（red and yellow bulb） of onions by HPLC/DAD-ESI/MS. The total polyphenol contents were also measured by means of Folin-Ciocalteu method. Moreover, all the concentrations of anthocyanins, flavonoids and polyphenols showed significantly positive correlations with antioxidant activities measured by DPPH˙, ABTS˙＋ and FRAP assays. This study provided information on anthocyanin and flavonoids compositions that will be useful for onion breeding.

Optimization for Production of Intracellular Polysaccharide from Cordyceps ophioglossoides L2 in Submerged Culture and Its Antioxidant Activities in vitro

Cordyceps ophioglossoides is a valuable traditional medicinal material.We have found that intracellular polysaccharide(IPS) is the major biologically active ingredient in Cordyceps ophioglossoides.This study is the first time to optimize the yield of IPS from Cordyceps ophioglossoides.The optimal medium for IPS production consists of glucose 54.50 g·L·1,yeast powder 25.50 g·L·1,NaH2PO4 0.4 g·L·1 and K2HPO4 0.4 g·L·1.The suggested culture conditions are 24 ℃,initial pH 4.5 with a rotary speed of 120 r·min·1 for 168 h.The yield of IPS is 737.93 mg·L·1,which is 50% higher than the yield under the conditions prior to optimization.The anti-oxidative activities of IPS in Cordyceps ophioglossoides L2 are also characterized using various in vitro assay.The anti-oxidative activity may explain the reason why IPS from Cordyceps ophioglossoides can be used to fight against neurodegenerative dis-eases and menopausal symptoms.

Determination of Residual Catechins, Polyphenolic Contents and Antioxidant Activities of Developed Theaflavin-3,3’-Digallate Rich Black Teas

This study was carried out to characterize total residual catechins and their fractions, polyphenolic contents and antioxidant activities of black teas enriched with high levels of theaflavin-3,3’-digallate. The made teas were processed from eleven selected cultivars. A comparative study was carried out between the processed teas and those from commercially grown Kenyan cultivars in relation to the above chemical parameters. A correlation matrix analysis was also conducted to find out whether a relationship existed between the antioxidant activities and the said chemical parameters. The total residual catechins were found to range between 3.10% and 8.08%. The total polyphenol levels varied between 19.00% and 28.90%, while the antioxidant activities of the teas ranged from 82.70% to 91.70%. There was a significant p < 0.001 correlation between the antioxidant activity and total polyphenols (r = 0.8948). There was also a high correlation p < 0.001 between the antioxidant activity and total catechins (r = 0.8878). Out of the four catechin fractions, the antioxidant activity correlated most with EGCG (r = 0.8774). The total polyphenolic contents and antioxidant activities for most of the cultivars were comparable to those of the green tea reference standard. From the figures obtained, it can be concluded that the most of the newly developed black teas of the selected cultivars have higher quality and enhanced antioxidant activities and that they can be recommended for commercial production.

Chemical constituents and antioxidant activities of waste liquid extract from Apostichopus japonicus Selenka processing

Apostichopus japonicus Selenka is an ideal tonic food that is used traditionally in many Asian countries, and it contains many bioactive substances, such as antioxidant, antimicrobial, and anticancer materials. To convert waste liquid generated during production into a useful resource, extract from waste liquid was isolated by column chromatography and studied by the pyrogallol autoxidation and 1,10-phenanthroline-Fe^2＋ oxidation methods. Results show that the extract scavenged about 91% of the superoxide anion radical at a concentration of 1.4 mg/mL and 24% of the hydroxyl radical at 3.3 mg/mL. Four compounds were isolated and identified from the extract： 2,4-dihydroxy-5-methyl-1,3-azine; 2,4-dihydroxy- 1,3-diazine; 3-O-β-D-quinovopranosyl-（1→2）-4-O-sodium sulfate-β-D-xylopranosyl]-holosta-9（11）-ene313,12β,17α-triol; and 24-ethyl-5α-cholesta-7-ene-3β-O-β-D-xylopyranoside. All of these compounds are known in A. japonicus, and were found in the waste liquid for the first time.