Antioxidant capacity, phenolic content, and polysaccharide content of Lentinus edodes grown in whey permeate-based submerged culture

ABSTRACT:  Total antioxidant capacity (TAC), phenolic content, and crude water-soluble polysaccharide (WSP) were determined for Lentinus edodes mycelia grown on both whey permeate (WP)-based medium with lactose content of 4.5% and controlled medium, and harvested after 5, 10, 15, or 20 d of fermentation at 25 °C. Both methanol extracts and water extracts of L. edodes in this study were found to exhibit high free radical scavenging capacity. The harvesting time was found to contribute to most of the variability in the free radical scavenging capacity. High levels of antioxidant capacities (0.28 ± 0.03 and 0.29 ± 0.06 mmol TAE/g dry weight for methanol and water extracts, respectively) were observed in mycelia grown on whey permeate and harvested on day 10. Harvesting time and the type of media can interact to alter the chemical content of mycelia. Mycelia grown in whey permeate had greater ( P < 0.05) WSP than mycelia grown in the synthetic media. High levels of WSP (4.1 × 10²± 71 mg polysaccharide/g dried mycelia) were found in mycelia grown in whey permeate and harvested on day 10. Whey permeate grown mycelia had phenolic compounds ranging from 4.2 ± 0.1 to 8.0 ± 0.8 mg GAE/g dried mycelia. The overall means of total phenolic contents of mycelia grown in whey permeate were 5.9 ± 0.5 and 6.2 ± 0.6 mg GAE/g dried mycelia for methanol and water extracts, respectively.     

Antioxidant properties of solid-state fermented adlay and rice by Phellinus linteus

Phellinus linteus (Berkeley & Curtis) Teng (Hymenochaetaceae) was inoculated into cooked grains, and new products were formed after the colonisation of fungal mycelia. Our objective was to evaluate the antioxidant properties of ethanolic and hot water extracts from fermented products [Phellinus-fermented adlay (PFA) and rice (PFR)] as compared to uninoculated controls [polished adlay (PA) and rice (PR)]. PFA and PFR were more effective than were PA and PR in antioxidant activity by the conjugated diene method, reducing power, scavenging ability on 1,1-diphenyl-2-picrylhydrazyl radicals and chelating ability on ferrous ions. Total phenols were the major antioxidant components found in both extracts (1.31–9.10 mg/g). Flavonoid contents were in the range of 0.07–1.26 mg/g. Total phenols and flavonoids of two extracts were associated with antioxidant properties. Based on the results obtained, Phellinus-fermented products possessed effective antioxidant properties.     

Radical scavenging and antimicrobial activity of horsetail (Equisetum arvense L.) extracts

A reversed-phase high performance liquid chromatography (RP-HPLC) separation on C₈ column and quantitative method were developed to analyse hydroxyl derivatives of benzoic and cinnamic acid and flavonoids in horsetail ( Equisetum arvense L.) extracts. Total phenolic content of n -butanol, ethyl acetate and water extracts, determined by the Folin-Ciocalteu method, was 96.4, 26.4 and 15.4 mg g⁻¹ of dry extracts, respectively. The antioxidative activity of horsetail extracts was tested by measuring their ability to scavenge stable 2,2-diphenyl-1-picrylhydrazyl (DPPH) and reactive hydroxyl radicals by electron spin resonance spectroscopy. The results demonstrated that the free radical scavenging activity (versus both DPPH and hydroxyl radicals) depended on the type and concentration of applied extracts; the highest DPPH (EC₅₀ = 0.65 mg mL⁻¹) and hydroxyl radical scavenging activities (EC₅₀ = 0.74 mg mL⁻¹) were obtained in the case of n -butanol extract. The radical scavenging activity of extracts significantly correlated with total phenolic content. The antimicrobial tests showed that ethyl acetate and n -butanol extracts inhibited the growth of tested bacteria.     

Bioactives of fruiting bodies and submerged culture mycelia of Agaricus brasiliensis (A. blazei) and their antioxidant properties

Agaricus brasiliensis is a mushroom native from Brazil largely studied due to its polysaccharide contents, particularly β-glucans. In this study, the phenolics and organic acids contents as well as the antioxidant activities of its fruiting bodies and its mycelia obtained from submerged cultivation were compared. The hydroalcoholic extracts obtained from the fruiting bodies, early stationary mycelia and late stationary mycelia contain at least ten phenolic compounds and ten organic acids. Three phenolic compounds were identified as gallic acid, syringic acid and pyrogallol. Eight organic acids were identified as benzoic, oxalic, malic, acetic, alpha-ketoglutaric, citric, fumaric and trans-aconitic acids. All extracts presented antioxidant properties. The latter were evaluated by four assays: DPPH and ABTS radical scavenging activities, chelating ability for ferrous ions and inhibition of lipid peroxidation. The fruiting body extracts were more effective in the DPPH radical scavenging activity and lipid peroxidation inhibition that the mycelia extracts (P ≤ 0.05). The mycelia extracts were more effective in the ABTS radical scavenging activity and ferrous ion chelating ability (P ≤ 0.05). In conclusion, our results show that the mycelia of A. brasiliensis obtained in submerged cultivation can also be, as its fruiting bodies, valuable sources of antioxidant compounds.     

Comparative Flavonoids Contents of Selected Herbs and Associations of Their Radical Scavenging Activity with Antiproliferative Actions in V79-4 Cells

ABSTRACT:  To elucidate the health benefit of herbal teas on the cytotoxicity induced by H₂O₂ in V79-4 cells, herbal extracts and its flavonoids were tested using lactate dehydrogenase release and determining intracellular reactive oxygen species generation and antioxidant activity with superoxide radical scavenging assay. Significant decrease in cell viability was observed on V79-4 cells treated with H₂O₂ (1 mM), while herbal extracts and its flavonoids including catechin and epigallocatechin gallate prevented the LDH release from H₂O₂ cytotoxicity. Total catechin contents of green tea (65.6 mg/g of dry matter) were significantly higher than other herbal teas (35.8 to 1.2 mg/g of DM). The relative concentration of the 4 major tea catechins ranked EGCG > EGC > EC > C. Green tea exhibited the lowest IC₅₀ values (2 g fresh herb/100 mL) of superoxide radical scavenging activity among the tested herbal tea, which indicates powerful antioxidant activity in O₂^·− radicals scavenging, followed by black tea, dandelion, hawthorn, rose hip, chamomile.     

Natural preservative ingredient from marine alga Ulva lactuca L.

The contents of total chlorophyll (T-Chl), carotenoids and phenolics compounds were quantified in the biomasses of Ulva lactuca grown either in normal or artificial sea water under indoor conditions. The antioxidant and antibacterial activities of U. lactuca crude organic extracts ( Ulva- COEs) were determined. Thirty-four compounds in Ulva- COEs were characterised by thin layer chromatography and high-performance liquid chromatography. The major compounds were chlorophyll a (Chl a ) (15.60–30.90%) and b (Chl b ) (12.20–14.89%) , 9-cis β-carotene (13.12–14.47%), α-carotene (11.44–11.47%) and all-trans β-carotene (6.16–29.70%, of total carotenoids).The Ulva- COEs exhibited remarkable antioxidant activity, with an IC₅₀ (concentration which causes a 50% of DPPH radical scavenging activity) values ranged from 16.5 and 18.7 μg mL⁻¹, which could be compared with the synthetic antioxidants: α-tocopherol (14.4 μg mL⁻¹), butylated hydroxyanisol (13.1 μg mL⁻¹) and butylated hydroxyltoluene (13.1 μg mL⁻¹). Also, Ulva- COEs exhibited great potential antibacterial activities against six bacterial strains, with minimal inhibitory concentration values ranged from 0.40 to 0.35 mg mL⁻¹.     

Influence of Storage Temperature on the Kinetics of the Changes in Anthocyanins, Vitamin C, and Antioxidant Capacity in Fresh-Cut Strawberries Stored under High-Oxygen Atmospheres

ABSTRACT:  Changes in the main antioxidant properties of fresh-cut strawberries stored under high-oxygen atmospheres (80 kPa O₂) were studied at selected temperatures (5 to 20 °C). The suitability of zero- and 1st-order kinetics as well as a model based on Weibull distribution function to describe changes in experimental data is discussed. A non-Arrhenius approach was used to determine the temperature dependence of the estimated rate constants. A Weibull kinetic model most accurately  ( R ²_adj≥ 0.800)  estimated changes in anthocyanins and antioxidant capacity of fresh-cut strawberries throughout the storage period, whereas a 1st-order model adequately fitted  ( R ²_adj≥ 0.982)  the variation of vitamin C. The temperature dependency of the kinetic rate constants for each antioxidant property was successfully modeled through the non-Arrhenius approach  ( R ²_adj≥ 0.709)  . The T_c obtained for anthocyanins, vitamin C, and antioxidant capacity degradation were 290, 284, and 289 K, respectively, indicating the temperature at which a marked acceleration of the losses in the antioxidant potential of strawberry wedges occurs. These findings will help to describe the variation of the antioxidant potential of fresh-cut strawberries upon storage time and temperature.     

桑黄菌多糖体外抗氧化作用

采用化学模拟体系测定桑黄菌胞内多糖与胞外多糖体外抗氧化能力。结果表明：清除DPPH自由基时,胞内多糖的EC50值为1.09mg/mL,胞外多糖的EC50值为1.52mg/mL;清除 ·OH时,胞外多糖的EC50值为0.23mg/mL,胞内多糖的EC50值为0.78mg/mL;清除O2－ ·时,胞外多糖的EC50值为20.31μg/mL,胞内多糖的EC50值为29.97μg/mL;螯合Fe2+时,胞内多糖的EC50值为1.36mg/mL,胞外多糖的EC50值为1.66mg/mL;实验范围内胞内多糖、胞外多糖还原能力与质量浓度呈很好的线性关系。可见桑黄菌多糖抗氧化能力有明显的量效关系,且胞外多糖与胞内多糖的抗氧化能力不同。     

桑黄菌胞内多糖的理化性质和体外抗氧化活性

研究液体发酵桑黄菌胞内多糖的理化性质和体外抗氧化活性。结果表明：经DEAE-52纤维素离子交换柱层析分离分级得到多个级分,以较大分子质量的中性多糖为主。凝胶渗透色谱分析表明桑黄菌胞内多糖的重均分子质量范围为5.7×103～6.1×106D,由葡萄糖、甘露糖和半乳糖组成,其分子物质的量比为15:4:1,多糖含量为41%,特性黏度为12mL/g。通过体外抗氧化模型,发现桑黄菌胞内多糖均能较好的清除 ·OH、O2－ ·和螯合Fe2+,且对O2－ ·具有明显的清除作用。     

Phenolic compound composition and antioxidant activity of fruits of Rubus and Prunus species from Croatia

Two fraction, one containing flavonols, flavan-3-ols, phenolic acids and the other containing anthocyanins, were isolated from Rubus (red raspberry, blackberry) and Prunus (sweet cherry, sour cherry) fruits to study their phenol content by HPLC and antioxidant activity using the DPPH test. Raspberries and blackberries were characterised by catechins and ellagic acid derivatives; sour and sweet cherries by phenolic acids. All fruits had relatively high anthocyanin content. Anthocyanins contributed more to the antioxidant activity of all fruits (∼90%) than flavonols, flavan-3-ols and phenolic acids (∼10%). A biphasic reaction was observed between DPPH^• radicals and phenols, with 'fast' and 'slow' scavenging rates which might be important in the biological activity of these fruits. Sour cherries and blackberries which stand out with the highest total phenol content (1416 and 1040 mg kg⁻¹) had also the strongest antioxidant activity (EC₅₀ = 807 and 672 g of fruit per gram of DPPH) and can be considered as good source of dietary phenols.     

Rapid Fruit Extracts Antioxidant Capacity Determination by Fourier Transform Infrared Spectroscopy

ABSTRACT: The antioxidant content of fruits have made them a desirable component of the human diet. Several wet chemistry techniques, including the oxygen radical absorbance capacity (ORAC_FL) assay, have been reported for measuring the antioxidant activities of fruit. In this study, we investigated the use of Fourier transform infrared spectroscopy (FTIR) to measure fruit antioxidant activity. Flavonoid-rich extracts from 5 blueberry, 5 grape, and 6 blackberry genotypes were obtained by methanol-water-formic acid (60:37:3, v/v/v) solvent. The total antioxidant capacities of the fruit extracts were determined by the ORAC_FL assay, and the FTIR spectra of the fruit extracts were collected. Partial least squares (PLS) regressions with cross-validation was conducted on 128 spectra of extracts and their corresponding ORAC_FL values to obtain a calibration model for predicting the antioxidant activity of the extracts. Spectra from an additional 16 extracts were used as an external validation set for the model. A good calibration model ( R ²= 0.97) for antioxidant activity was obtained with satisfactory predictive ability (root mean standard error [RMSE] = 5.35) using the spectral region 2000/cm to 900/cm. Cross-validation procedures indicated good correlations ( R ²= 0.94) between ORAC_FL assay values and FTIR estimates. The ratio of the standard deviation of the data to the standard error of validation (RPD) values were above 5.0 for blueberry, grapes, and the combined extracts in the external validation set indicating that the calibration model was suitable for quantifying fruit extracts antioxidant activities. This study shows that an FTIR technique would be suitable for rapidly measuring fruit extract antioxidant activity.     

POTENTIAL ANTIOXIDANT ACTIVITY OF MARINE RED ALGA GRATELOUPIA FILICINA EXTRACTS

Grateloupia filicina is an important alga cultivated as a source of food in Korea and Japan. In order to examine its potential antioxidant activity, crude extracts of G. filicina were evaluated for their effect on scavenging of reactive oxygen species (DPPH, H, H₂O₂ and O₂) and inhibition of lipid peroxidation. The activities of these extracts were compared with those of commercial antioxidants such as BHA, BHT and α-tocopherol. The methanolic extract (2 mg/mL) of G. filicina scavenged 82% of DPPH radicals which is almost three times higher than that of BHT. The same methanolic extract scavenged 65% of superoxide onion which is almost two times higher than that of BHT and α-tocopherol. In contrast, the extracts in chloroform and carbon tetrachloride inhibited lipid peroxidation more effectively than all commercial antioxidants tested in a linoleic acid model system.     

Oxidative stability of brined anchovies (Engraulis encrasicholus) with plant extracts

The effect of brining with plant extracts on the oxidative stability of anchovies was investigated during storage. The brining process was done in 15 g 100 mL⁻¹ of sodium chloride solution with water, and with myrtle, rosemary and nettle extracts. Brined anchovies were stored at 4 ± 1  ° C for 28 days. Brining with plant extracts slowed down the lipid oxidation of anchovies. The highest antioxidant effect was observed in brined anchovies with rosemary and myrtle extracts during storage as indicated by peroxide value (POV), thiobarbituric acid reactive substance and oxidative rancidity (OR) scores. Furthermore, OR scores in brined anchovies were well correlated with thiobarbituric acid reactive substance ( r ² = 0.66, P  < 0.01) and POV ( r ² = 0.87; P  < 0.01). The fatty acid profiles were similar among the brined anchovies with plant extracts. These results suggest that brining with rosemary, myrtle and to a lesser extent, nettle extracts prevents development of oxidation in lipids of anchovies during storage.     

马兰提取物抗氧化性研究

目的：考查马兰中水提取物和乙醇提取物抗氧化活性。方法：分别以水和乙醇为提取液,探讨马兰中水提取物和乙醇提取物的抗氧化活性,包括还原能力以及清除DPPH自由基、羟自由基、超氧阴离子自由基和H2O2的能力。 结果：提取物主要成分为黄酮类化合物。马兰水提取物的抗氧化活性为：超氧阴离子自由基(IC50 2.2μg/mL)＞H2O2(IC50 2.8μg/mL)＞羟自由基(IC50 5.6μg/mL)＞DPPH自由基(IC50 8.5μg/mL) ＞金属螯合性(IC50 28.0μg/mL)。而马兰乙醇提取物的抗氧化活性为：H2O2(IC50 2.0μg/mL) ＞超氧阴离子自由基(IC50 2.1μg/mL)>羟自由基(IC50 2.5μg/mL)> DPPH自由基(IC50 5.6μg/mL) ＞金属螯合性(IC50 51.2μg/mL)。结论：马兰提取物具有较强的抗氧化活性。     

Chemical Composition and Antimicrobial and Antioxidant Activities of Essential Oils and Various Extracts of Juniperus phoenicea L. (Cupressacees)

ABSTRACT:  GC-FID and GC-MS analysis of essential oils of  Juniperus phoenicea  resulted in the identification of 30 compounds, representing more than 98% of the total composition. α-pinene (55.7% and 80.7%), δ-3-carene (10.7% and 4.5%), and γ-cadinene (2.9% and 5.1%) were the main components, respectively, in leaves and berries essential oil. Extracts of  J. phoenicea  were obtained by different extraction solvents: methanol, ethanol, ethyl acetate, and dichloromethane and evaluated composition for polyphenols (gallic acid equivalent 52 to 217 g/kg), tannins (catechin equivalent 6.5 to 60.2 g/kg), antocyanins (cyanidin equivalent 84 to 373 mg/kg), and flavonoids (quercetin equivalent 6.4 to 29.3 g/kg). The samples (essential oils and extracts) were subjected to a screening for their antioxidant activity by using DPPH and ABTS assays; antimicrobial activity was tested with 6 bacteria (3 Gram-positive and 3 Gram-negative), 1 yeast, and 2 fungi. The strongest antioxidant activity was obtained by the methanolic extract ( IC ₅₀= 6.5 ± 0.3 mg/L). Flavonoids are likely to contribute to the antifungal activity against  Saccharomyces cerevisiae.  Correlations were studied between chemical composition and antioxidant and antimicrobial activities.     

不同体积分数乙醇沉淀桑黄胞内多糖的理化性质及抗氧化活性

研究桑黄胞内多糖醇沉过程中乙醇体积分数对多糖得率、纯度、理化性质和抗氧化活性等的影响。结果表明：随着乙醇体积分数的增加,沉淀粗多糖的得率增加,而粗多糖中多糖含量呈现不规则的变化;不同体积分数乙醇沉淀获得的桑黄多糖中均含有木糖、甘露糖、半乳糖和葡萄糖。扫描电镜图像显示,低体积分数（65%、75%、85%）乙醇沉淀的多糖呈现均匀球状,高体积分数（95%)乙醇沉淀的多糖连成大块片状。桑黄胞内多糖体外抗氧化能力存在明显的量-效关系,95%乙醇沉淀的多糖对1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基、羟自由基、2,2’-联氮-双（3-乙基苯并噻唑啉-6-磺酸）二铵盐（2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid),ABTS）自由基的清除效果最好,对Fe3＋的还原能力最强,抗氧化活性最高。     

Antioxidant Activity of Mycelia from Aspergillus candidus

The antioxidant activity of mycelia extracts produced from the submerged cultures of Aspergillus candidus CCRC 31543 was investigated. Inhibition of peroxidation (IP%) of mycelia acetone extracts (MAE) in linoleic acid peroxidation was equal to that of BHA and significantly (p < 0.05) higher than that of α-tocopherol. As measured by the Rancimat method in lard, MAE showed marked antioxidant activity with an induction time of 8.4 h at a concentration of 200 μg/mL. MAE also exhibited strong scavenging effect on α,α-diphenyl-β-picrylhydrazyl radicals and marked reducing power. HPLC-DAD analysis suggested that MAE possessed the antioxidant components 3,3"-dihydroxyterphenyllin, 3-hydroxyterphenyllin, and candidusin B.     

Effect of Chelating Agents and Spice-Derived Antioxidants on Myoglobin Oxidation in a Lipid-Free Model System

ABSTRACT:  This study compared myoglobin (Mb) oxidation in lipid-free model systems containing iron and Type I (radical quenching) or Type II (metal chelating) antioxidants. Oxidation was measured as loss of oxymyoglobin (MbO₂) during 0 to 24 h holding at 22 °C. Sodium tripolyphosphate (STPP) demonstrated iron-binding ability at all concentrations tested (88% and 21% added iron bound at 1 and 0.05 mg/mL, respectively). Iron chelation was observed for phytic acid only at the highest concentration (9.5% bound at 1 mg/mL phytate). Neither Type I antioxidant (rosmarinate or eugenol) demonstrated any iron chelating ability (<0.5% bound). In presence of iron, Type I antioxidants had a significant ( P < 0.05) prooxidant effect (54.7% retention of MbO₂ in control, 9.5% and 37.5% retention in rosmarinate and eugenol samples, respectively). The Type II antioxidants (STPP and phytate) were more effective inhibitors ( P < 0.05) of Mb oxidation than Type I antioxidants, (68.7% and 61.1% for STPP and phytate, respectively). Type I antioxidants were capable of rapid reduction of ferric iron to the ferrous form, as measured by the ferrozine assay. This strong reducing ability accounted for the prooxidant effects of rosmarinic acid and eugenol, since ferrous iron is the form associated with generation of oxygen radicals, and subsequent Mb oxidation. Type II antioxidants chelated and thus prevented the oxidizing effect of added ferrous iron. Mb oxidation can proceed rapidly (within 15 min) in the presence of iron and the absence of lipid, especially if reducing compounds such as rosmarinic acid or eugenol are also present to maintain iron in an active ferrous form.     

Antioxidant properties of methanolic extracts from Agrocybe cylindracea

Agrocybe cylindracea (DC: Fr.) Mre. (Bolbitiaceae) was available in the form of fruit bodies, mycelia and fermentation filtrate. From these three forms, methanolic extracts were prepared and their antioxidant properties studied. The methanolic extract from fruit bodies showed high inhibitory ability on lipid oxidation (90.0-97.3%) at 5-20 mg/ml and had an EC₅₀ value of 0.94 mg extract/ml. EC₅₀ values in reducing power were 2.36, 6.89 and 5.00 mg extract/ml for fruit bodies, mycelia and filtrate, respectively. The scavenging ability of the methanolic extract from fruit bodies on 1,1-diphenyl-2-picrylhydrazyl radicals was 89.0% at 1 mg/ml whereas those from mycelia and filtrate was 91.4% and 94.9% at 10 mg/ml, respectively. The chelating abilities of methanolic extracts from fruit bodies, mycelia and filtrate on ferrous ions were 90.6%, 84.6% and 96.3% at 5 mg/ml, respectively. Total phenols were the major detected naturally occurring antioxidant components found in methanolic extracts from A. cylindracea and in the range of 15.55-23.47 mg/g. Based on EC₅₀ values, A. cylindracea was good in antioxidant properties, except for the scavenging ability on hydroxyl radicals.     

Comparison of hot air-drying and freeze-drying on the physicochemical properties and antioxidant activities of pumpkin (Cucurbita moschata Duch.) flours

Freeze-drying and hot air-drying were applied in the preparation of pumpkin flours to investigate the effects of drying methods on the antioxidant activities and physicochemical properties. The antioxidant activities of methanol extracts from pumpkin flours were studied in terms of total antioxidant activity, reducing power, free radical scavenging, superoxide anion radical scavenging and metal chelating activities. Hot air-dried pumpkin flour showed stronger antioxidant activities than freeze-dried flour. The percentage inhibition of peroxidation in linoleic acid system by 15 mg mL⁻¹ extracts from hot air-dried and freeze-dried pumpkin flours was found to be 92.4% and 86.1% after 120 h of incubation, respectively. Hot air-dried pumpkin flour exhibited higher reducing power, free radical scavenging and metal chelating activities than freeze-dried flour. This study also indicated that freeze-drying significantly reduced the browning and preserved the redness of pumpkin flours. Hot air-drying reduced the oil absorption capacity, water absorption and porosity of pumpkin flours, while it markedly increased the water solubility and bulk density.