67 research outputs found

    Effect of thermal treatment and storage on bioactive compounds, organic acids and antioxidant activity of baobab fruit (Adansonia digitata) pulp from Malawi

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    Bioactive compounds of baobab (Adansonia digitata) pulp from Malawi were investigated. The effect of thermal treatment and storage on selected quality attributes of the juice was also evaluated. Organic compounds were analysed by HPLC; total phenol content (TPC) and total antioxidant activity (FRAP, ABTS and DPPH) were measured by spectrophotometry. Malawi baobab pulp contains high levels of procyanidin B2 (533 ± 22.6 mg/100 g FW), vitamin C (AA + DHA) (466 ± 2.5 mg/100 g FW), gallic acid (68.5 ± 12.4 mg/100 g FW) and (−)-epicatechin (43.0 ± 3.0 mg/100 g FW) and showed a maximum TPC of 1.89 × 103 ± 1.61 mg GAE/100 g FW. The maximum antioxidant activity was 2.81 × 103 ± 92.8 mg TEAC/100 g FW for FRAP, 1.52 × 103 ± 17.1 mg TEAC/100 g FW for ABTS and 50.9 ± 0.43% DPPH for DPPH. Thermal pasteurisation (72 °C, 15 s) retained vitamin C which further showed extended half-life under refrigeration temperature (6 °C). Procyanidin B2, (−)-epicatechin, TPC and antioxidant activity fluctuated during storage. Antioxidant activity was significantly correlated (p ≤ 0.05) with bioactive compounds and TPC

    Effects of cranberry powder on serum lipid profiles and biomarkers of oxidative stress in rats fed an atherogenic diet

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    This study investigated that the antioxidative effect of freeze-dried cranberry powder against protein and lipid oxidation and ameliorative effect of serum lipid profile in rat fed atherogenic diet. Six weeks old male Sprague-Dawley rats were divided into the following four groups: normal diet group with 5% corn oil (control), atherogenic diet group with 5% corn oil, 10% lard, 1% cholesterol, and 0.5% sodium cholate (HFC), atherogenic plus 2% cranberry powder diet group (HFC + C2), and atherogenic plus 5% cranberry powder diet group (HFC + C5), and respective diet and water were fed daily for 6 weeks. After the experimental period, the serum lipid profile, such as total cholesterol, HDL-cholesterol, LDL-cholesterol, and triglyceride, ferric reducing ability of plasma (FRAP), plasma phenolics content, superoxide dismutase (SOD) activity, serum protein carbonyl and thiobarbituric acid reactive substances (TBARS) levels were examined. Total phenolic compound and total flavonoid levels in freeze-dried cranberry powder were 9.94 mg/g and 8.12 mg/g, respectively. Serum total cholesterol and LDL-cholesterol levels were not significantly different for cranberry powder treatment, but serum HDL-cholesterol level was significantly increased in HFC + C5 group compared with HFC group. Plasma FRAP value tended to be increased by cranberry powder treatment though there was no significant difference. Plasma total phenol concentrations and SOD activities were not significantly different among all groups. Serum protein carbonyl and TBARS levels were significantly decreased in HFC + C5 group compared with HFC group. Overall results suggested that freeze-dried cranberry powder might have the serum lipid improving effect, as well as antioxidative effect demonstrated by its protective effect against protein and lipid oxidation

    High catechin concentrations detected in Withania somnifera (ashwagandha) by high performance liquid chromatography analysis

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    <p>Abstract</p> <p>Background</p> <p><it>Withania somnifera </it>is an important medicinal plant traditionally used in the treatment of many diseases. The present study was carried out to characterize the phenolic acids, flavonoids and 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) scavenging activities in methanolic extracts of <it>W. somnifera </it>fruits, roots and leaves (WSFEt, WSREt and WSLEt).</p> <p>Methods</p> <p>WSFEt, WSREt and WSLEt was prepared by using 80% aqueous methanol and total polyphenols, flavonoids as well as DPPH radical scavenging activities were determined by spectrophotometric methods and phenolic acid profiles were determined by HPLC methods.</p> <p>Results</p> <p>High concentrations of both phenolics and flavonoids were detected in all parts of the plant with the former ranging between 17.80 ± 5.80 and 32.58 ± 3.16 mg/g (dry weight) and the latter ranging between 15.49 ± 1.02 and 31.58 ± 5.07 mg/g. All of the three different plant parts showed strong DPPH radical scavenging activities (59.16 ± 1.20 to 91.84 ± 0.38%). Eight polyphenols (gallic, syringic, benzoic, p-coumaric and vanillic acids as well as catechin, kaempferol and naringenin) have been identified by HPLC in parts of the plant as well. Among all the polyphenols, catechin was detected in the highest concentration (13.01 ± 8.93 to 30.61 ± 11.41 mg/g).</p> <p>Conclusion</p> <p>The results indicating that <it>W. somnifera </it>is a plant with strong therapeutic properties thus further supporting its traditional claims. All major parts of <it>W. somnifera </it>such as the roots, fruits and leaves provide potential benefits for human health because of its high content of polyphenols and antioxidant activities with the leaves containing the highest amounts of polyphenols specially catechin with strong antioxidant properties.</p

    Postharvest stability of antioxidant compounds in hawthorn and cornelian cherries at room and refrigerator temperatures – comparison with blackberries, white and red grapes

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    Antioxidant capacity (DPPH, ABTS and FRAP assays), as well as total phenol (TP), total flavonoid (TF) and total anthocyanin (TA) contents of hawthorn (Crataegus pentagyna L.), cornelian cherries (Cornus mas), blackberries (Rubus fruticosus) and white and red grapes (Vitis vinifera L.) were monitored during postharvest storage at room and refrigerator temperatures. Hawthorn exhibited the highest initial TP (891.15±10.83 mg GAE/100g FW) and TF contents (536.76±15.52 mg CE/100g FW) as well as antioxidant capacity using FRAP (6.33±0.10 mmol Fe2+/100g FW) and ABTS (7.27±0.04 mmol TEAC/100g FW) essays, while cornelian cherries exhibited the highest antioxidant capacity measured by the DPPH assay (2.88±0.02 mmol TEAC/100g FW). Storage at 25 ºC facilitated faster spoilage of all analyzed fruits. Significant fluctuations in TP, TF and TA contents were observed for all fruits during storage, except for the TP content of blackberries stored at 4 ºC and TF content of blackberries stored at 25 ºC, which remained relatively stable. Storage at 4 ºC did not adversely influence the content of phytochemicals in analyzed fruits, expect for hawthorn, which showed a 15.1% lower TA content at the end of storage (37 days). As evidenced from the high degree of positive correlations between antioxidant assay results and phytochemical content determinations, antioxidant capacity paralleled the fluctuations in phytochemical content and depended greatly on the type of fruit in question

    Antioxidant stability of small fruits in postharvest storage at room and refrigerator temperatures

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    Strawberries (Fragaria ananassa), raspberries (Rubus idaeus) and red currants (Ribes rubrum), as well as two drupes, cherries (Prunus avium), and sour cherries (Prunus cerasus), were subjected to two storage temperatures (4°C and 25°C) and phytochemicals concentrations (total phenols, flavonoids and anthocyanins) as well as antioxidant capacity (DPPH, ABTS and FRAP assays) were monitored until the fruit visually spoiled. Red currants and strawberries exhibited the highest initial total phenol (TP) contents (322.40 ± 5.56 and 335.47 ± 6.12 mg GAE/100 g FW, respectively) and maintained the highest TP contents throughout storage at both temperatures. Storage of at 25°C as opposed to 4°C, facilitated faster spoilage of analyzed fruits. In addition, most fruits stored at 4°C, exhibited slightly higher antioxidant activity values at the end of storage according to all three antioxidant activity assays as opposed to fruits stored at 25°C. The dynamic evolution of antioxidant capacity at both temperatures reflected the transient changes in phytochemical composition of small fruits in storage

    Fluctuations in the levels of antioxidant compounds and antioxidant capacity of ten small fruits during one year of frozen storage

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    The fluctuations in antioxidant capacity (DPPH, ABTS and FRAP assays), total phenol (TP), total flavonoid (TF) and total anthocyanin (TA) contents of ten small fruits (sweet cherries, sour cherries, strawberries, red currants, raspberries, blackberries, hawthorn, cornelian cherries, and red and white grapes) were monitored during storage at -20 °C. After one year in storage all varieties exept hawthorn and white grapes retained equal or slightly greater TP content in comparison to the initial values. The TF and TA levels also remained stable or even increased after 12 months in all fruits exept hawthorn and strawberries. Red currants and raspberries exhibited optimal preservation of antioxidant capacity, while hawthorn showed a decrease in the antioxidant capacity during different time points in storage as well as at the end of storage. Analyzed fruits were classified into four main groups based on hierarchical cluster analysis (HCA)

    Antioxidant Properties of Extracts of Wild Medicinal Mushroom Species from Croatia

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    Antioxidant activity and total phenol (TP) content of methanol and water extracts of three wild Croatian mushroom species Auricularia auricula-judae (Bull.) Quél., Sarcoscypha austriaca (Sacc.) Boud, and Strobilurus esculentus (Wulfen) Singer were determined and compared with the values obtained for extracts of four cultivated mushrooms Agaricus bisporus (J.E. Lange) Imbach (brown and white variant), Pleurotus ostreatus (Jacq.) P. Kumm. and Lentinula edodes (Berk.) Pegler. Spectrophotometric determination of the TP content was performed using the Folin-Ciocalteu method, while antioxidant activity was measured in a reaction with 1, 1-diphenyl-2-picrylhydrazyl radical (DPPH assay) and ferric-tripyridyltriazine (Fe3+-TPTZ) complex (FRAP assay). On the average, 5.8-fold higher TP content was observed for water in comparison to methanol extracts of all analysed mushrooms. Consequently, antioxidant activity was also higher for water extracts, which is evident from the obtained higher values in the FRAP assay and lower EC50 values in the DPPH assay. Among the three tested wild species, the water extract of S. esculentus exhibited the highest concentration of TP, 8.12 mg/g gallic acid equivalents (GAE), the highest reducing power, 19.42 mmol Fe2+/kg, and the best radical scavenging properties, EC50 = 13.5 mg/mL
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