Oxygen Radical Scavenging Capacity Research Articles

Dietary total antioxidant capacity in relation to disease severity and risk of mortality in cirrhosis; results from a cohort study

Liver Cirrhosis, defined as the final stage of chronic liver disease, may become more prevalent in the lower level of body defense against oxidation and inflammation. Therefore, we assessed the association of dietary total antioxidant capacity (DTAC) with the severity and mortality of cirrhosis in a cohort study. 120 newly diagnosed cirrhosis patients from Tehran, Iran, participated in this study. The patients’ habitual diet was assessed using a 168-item validated food frequency questionnaire. Both ferric-reducing antioxidant potential (FRAP) and oxygen radical scavenging capacity (ORAC) methods were computed to achieve DTAC scores. The association between DTAC with disease severity and mortality was estimated by multivariate linear regression and cox proportional hazards regression models. Dietary total antioxidant capacity-ORAC had a significant inverse association with disease severity in both crude and adjusted models (P for trend: <0.001 and 0.016 respectively). The risk of mortality in the first and second tertiles of ORAC was 5.56 (95 % CI: 2.25–13.75; P = 0.002) and 3.20 (95 % CI: 1.25–8.19; P = 0.015) higher than those in the third category, respectively. In conclusion, a higher antioxidant capacity of diet is associated with less disease severity and mortality risk in cirrhosis.

Correlation analysis of phenolic compounds, antioxidant potential, oxygen radical scavenging capacity, and alkaloid content in ripe and unripe Areca catechu from major cultivation areas in Sri Lanka

This study was conducted to compare the correlation between phenolic compounds, antioxidant potential, and the total alkaloid content in Sri Lankan areca nuts based on the maturity stage and varying conditions in growing areas including, climate, altitude, temperature, and soil conditions. The total polyphenol content (TPC), total flavonoid content (TFC), total tannin content (TTC), and the total alkaloid content (TAC) of ripe areca nuts from selected five major growing areas (Kalutara, Kandy, Kegalle, Kurunegala, and Badulla) ranged from 113.24 ± 0.92 to 224.40 ± 26.50 mg GAE/g, 60.25 ± 7.04 to 180.90 ± 15.71 mg QE/g, 73.11 ± 3.77 to 120.78 ± 2.16 mg TE/g, 4.47 ± 0.31 to 18.27 ± 0.02 mg/g respectively. Whereas, TPC, TFC, TTC, and TAC content of unripe areca nuts ranged between 121.59 ± 6.01 to 349.10 ± 29.70 mg GAE/g, 35.81 ± 4.73 to 88.41 ± 1.79 mg QE/g, 54.89 ± 2.25, 75.33 ± 3.22 mg TE/g, and 27.22 ± 0.19 to 52.72 ± 0.36 mg/g respectively. The IC50 DPPH, IC50 ABTS, IC50 FRAP, EC50 hydroxyl radicals, and EC50 nitric oxide radicals of ripe areca nuts of five major growing areas ranged from 73.86 ± 1.06 to 197.46 ± 8.66 mg GAE/g, 50.52 ± 2.12 to 94.24 ± 2.67 mmol TEAC/ml, 195.26 ± 7.22 to 275.00 ± 7.01 mg TEAC/g, 73.00 ± 14.80 to 98.51 ± 37.80 mg/ml, and 62.99 ± 11.25 to 87.70 ± 1.65 mg/ml respectively. The IC50 DPPH, IC50 ABTS, IC50 FRAP, EC50 hydroxyl radicals, and EC50 nitric oxide radicals of ripe areca nuts ranged from 67.23 ± 0.91 to 77.29 ± 0.18 mg GAE/g, 41.91 ± 3.20 to 55.78 ± 0.00 mmol TEAC/ml, 288.40 ± 25.00 to 386.40 ± 16.90 mg TEAC/g, 112.60 ± 17.60 to 257.88 ± 12.20 mg/ml 102.77 ± 0.77 to 245.10 ± 20.40 mg/ml respectively. TPC, TFC, and TTT of ripe areca nuts strongly correlated with their free radical antioxidant capacities whereas; the alkaloid content of unripe areca nuts correlated negatively with the TPC, TFC, and TTT content. Both ripe and unripe nuts exhibit a weak correlation with hydroxyl radical scavenging assay.

Dietary Total Antioxidant Capacity and Odds of Breast Cancer: A Case-Control Study

Breast cancer (BC) is the most frequently diagnosed female cancer worldwide. It has been shown that oxidative stress can contribute to cancer development. Therefore, we investigated the association between dietary total antioxidant capacity (TAC) and breast cancer risk in a case-control study. This study was conducted on 136 newly diagnosed breast cancer patients and 272 hospitalized controls in Tehran, Iran. Participant habitual diet was obtained using a 168-item validated food frequency questionnaire. Dietary TAC scores were computed using two different methods: the dietary ferric reducing antioxidant potential (FRAP) method and oxygen radical scavenging capacity (ORAC). The association between dietary TAC and breast cancer risk was estimated by logistic regression. The score of DTAC calculated by ORAC method was associated with lower odds of BC, especially among premenopausal women. However, this association was not significant after controlling potential confounders (ORAC: OR Q4–Q1 = 1.01, 95% CI = 0.42–2.44, p-trend = 0.96). Estimation of DTAC by FRAP method was not associated with the risk of BC (FRAP: OR Q4–Q1 = 1.04, 95% CI = 0.53–2.05, p-trend = 0.8). There were no association detected based on menopausal status. In this study, dietary TAC was not significantly related to the odds of breast cancer.

Quantification of Phytochemicals, Cellular Antioxidant Activities and Antiproliferative Activities of Raw and Roasted American Pistachios (Pistacia vera L.).

The consumption of pistachios has been linked to many potential health benefits. Phytochemicals in pistachios, including phenolics, vitamin E and carotenoids, have been considered to make contributions to the health benefits. The objectives of this study were (1) to explore the phytochemical profiles (total phenolics and total flavonoids, including both free and bound forms), selected phytochemicals, vitamin E and carotenoids of raw and roasted pistachios; (2) to determine total antioxidant activity and cellular antioxidant activity (CAA); and (3) to explore antiproliferative activities of pistachio extracts against human breast, liver and colon cancer cells in vitro. Both raw and roasted pistachios contained high total phenolics, at 479.9 ± 10.2 (raw) and 447.9 ± 9.4 (roasted) mg GAE/100 g, respectively, and high flavonoids, at 178.4 ± 10.6 (raw) and 144.1 ± 7.4 (roasted) mg GAE/100 g, respectively. The contributions of the free form to the total phenolics in pistachios were 82% (raw) and 84% (roasted), respectively, and the contributions of the free form to the total flavonoids in pistachios were 65% (raw) and 70% (roasted), respectively. Gentisic acid and catechin were the major phenolics in raw and roasted pistachios, respectively. Both raw and roasted pistachios had similar total antioxidant activity evaluated by Oxygen-Radical-Scavenging Capacity (ORAC) assay, at 7387.9 ± 467 (raw) and 7375.3 ± 602 (roasted) μmol TE/100 g, respectively. Both raw and roasted pistachio extracts exhibited cellular antioxidant activity inhibiting peroxyradical radical-induced oxidation, with CAA values of 77.39 ± 4.25 (wash) and 253.71 ± 19.18 (no wash) μmol QE/100 g of raw pistachios and 115.62 ± 3.02 (wash) and 216.76 ± 6.6 (no wash) μmol QE/100 g of roasted pistachios. Roasted pistachios contained more vitamin E when compared with raw pistachios, while raw pistachios contained more carotenoids than the roasted pistachios. Additionally, the free form of roasted pistachios extracts exhibited superior antiproliferation activity against HepG2, Caco-2 and MDA-MB-231 cancer cells in a dose-dependent manner, with EC50 34.73 ± 1.64, 36.66 ± 3.3 and 7.41 ± 0.82 mg per mL, respectively. These results provided new knowledge about the phytochemical profiles, antioxidant activity, cellular antioxidant activity and antiproliferative activity of raw and roasted pistachios.

Effect of thermal processing on the phenolic profiles, antioxidant capacity, and volatile compounds of fig wines

No systematic studies have been conducted on the manufacture and quality control of fig wines. In the present work, the effect of thermal processing on phytochemical profiles, antioxidant capacity, and volatile compounds of fig wines was investigated. The results show that varieties of detected volatiles and the content of anthocyanins in fig wines decreased significantly owing to fig drying, while individual phenolic concentration increased. The drying process exhibited no significant effect on the contents of total polyphenols and flavonoids, 1, 1-diphenyl-2-picrylhydrazyl radical (DPPH) and oxygen radical-scavenging capacities, whereas prefermentation heating showed a negative effect on the antioxidant capacity and phenolic compositions, and resulted in a significant decrease of the contents of acetaldehyde and acetoin. Overall, fig drying showed a stronger effect on the flavor profile of fig wines compared with prefermentation heating. Choosing an appropriate thermal processing procedure is essential to preserve the antioxidant capacity and flavor of fig wines. Practical applications Figs are sodium-, fat-, and cholesterol- free, while they are rich in fibers and antioxidants compounds. Our previous study indicates that figs are excellent raw materials for winemaking attributing to their high sugar and polyphenol contents. At present, there is a lack of studies on systematical investigation of the manufacture and the quality control of fig wines. The phytochemical compounds, antioxidant capacity, and volatiles in fig wines as well as the effect of thermal processing during prefermentation were investigated in this study. We expect our study will provide guidance for producing innovative and high quality products in the wine industry. In addition, we hope it could bring huge economic benefits to smallholder farmers and agricultural cooperatives in fig cultivation.

Chemical profile and in vitro gut microbiota modulatory, anti-inflammatory and free radical scavenging properties of chrysanthemum morifolium cv. Fubaiju

Hot-water and ethanol extracts of Chrysanthemum morifolium cv. Fubaiju were investigated for their chemical compositions, effects on gut microbiota, anti-inflammatory, and free radical scavenging capacities. UPLC-IMS-QTOF-MS analysis detected tuberonic acid glucoside and tasumatrol B in the Fubaiju for the first time. The hot-water extract had greater anti-inflammation and free radical scavenging activities than its counterpart ethanol extract under the experimental conditions. The total phenolic content, relative ABTS+, DPPH and oxygen radical scavenging capacities of the hot-water extract were 33.48 mg gallic acid equivalents/g, and 121.57, 110.11 and 1638.99 µmol Trolox equivalents/g, respectively. In addition, the hot-water extract enhanced the abundance of Bacteroidetes, Firmicutes, Bifidobacteria and Precotella, suggesting that drinking chrysanthemum tea may modulate gut microbiota. The results from this research could be used to improve the production and consumption of C. morifolium cv. Fubaiju as a functional food ingredient and promote local agricultural economics.

Characterization and Comparison of Unfermented and Fermented Seed-Watermelon Juice

Fermented juice was prepared with byproducts (pulp and rind) of seed watermelon (Citrullus lanatus sp. vulgaris var. megalaspermus) for the first time, and its radical scavenging capacity and aroma were compared with those of the corresponding unfermented juice. The 2,2-diphenyl-1-picryhydrazyl and hydroxyl radical scavenging capacities of the fermented juice were significantly stronger than those of the unfermented juice. The oxygen radical scavenging capacity of the fermented juice was 60 µM trolox equivalent/mL, which was 7.14% higher than that of the unfermented juice. Gas chromatography-mass spectrometer analysis showed a total of 26 and 29 volatiles in unfermented juice and fermented juice, respectively. The content of typical watermelon aroma, including 1-nonanol, 3,6-nonadien-1-ol, nonanal, trans-2-nonenal, and trans,cis-2,6-nonadienal, was reduced from 92.08 mg/L in the unfermented juice to 26.41 mg/L in the fermented juice. Furthermore, isoamylol, ethyl octanoate, ethyl acetate, and ethyl laurate contributed a typical grape-wine bouquet to the fermented juice. Sensory evaluation further confirmed the attractive appearance and watermelon aroma of the fermented juice. Therefore, the fermented seed-watermelon juice showed a strong radical scavenging capacity and presented the typical watermelon aroma with a grape-wine bouquet.

Lithium Salts of Krebs Cycle Substrates as Potential Normothymic Antioxidant Agents.

Objective:Aim of the present work was to study the antioxidant properties of lithium salts of Krebs cycle substrates and their influence on immune cells. Lithium is a well-known and widely used mood stabilizer. These lithium-based substances have a lot of potential properties because of the anionic component of the Krebs cycle substrates, which take part in basic intracellular biochemical process.Materials and Methods:Lithium salts of fumarate, pyruvate, malate, succinate, and citrate (as reference drug) were investigated in this study as antioxidants and immunomodulators. The antioxidant properties were studied by the voltammetry method, which evaluates oxygen radical scavenging capacity of lithium substances. Influence of the lithium compounds on the immune cells of human blood was indicated by the reaction of blast transformation of lymphocytes.Results:All tested substances and their mixes possessed antioxidant properties, more expressed in maximal therapeutic concentration. Lithium compounds showed no toxic influence on human blood immune cells and caused no significant changes in both spontaneous and stimulated proliferation.Conclusion:The results allow considering lithium salts of Krebs cycle substrates as potential normothymic agents (mood stabilizer) with antioxidant properties and low toxicity.

Polyphenol content, in vitro bioaccessibility and antioxidant capacity of widely consumed beverages.

Beverages prepared from antioxidant-rich plants are sources of polyphenols, the bioactivity of which depends on bioaccessibility in the gastrointestinal tract. This work evaluated the polyphenol content and antioxidant capacity of widely consumed beverages such as chamomile tea, yerba mate, a coffee blend (65% roasted: 35% green), and coffee-like substitutes such as chicory, malt and a soluble cereal mixture. Additionally, the bioaccessibility of the two beverages with the highest antioxidant capacity was evaluated using an in vitro digestion model. Total phenolic content ranged from 11.15 mg 200 mL-1 in chamomile tea, up to 154.53 mg 200 mL-1 in mate or 215.05 mg 200 mL-1 in the blend. These results correlated with the antioxidant capacity analysed by ferric reducing antioxidant power, oxygen radical scavenging capacity and 2,2'-azinobis-3-ethylbenzothiazoline-6-sulphonic acid methods. Yerba mate and the coffee blend showed an average polyphenol recovery after in vitro gastrointestinal digestion of 57% and 78%, respectively. Although both beverages showed similar phenolic composition, polyphenols in coffee were more stable than in yerba mate. Alkaline pH in the intestinal digestion stage was responsible for the observed reduction in polyphenol stability. Regular consumption of the studied beverages provides considerable amounts of antioxidants which are relatively stable after simulated digestion, and thus have the potential to prevent oxidative stress-related disorders. © 2017 Society of Chemical Industry.

Antioxidant and anti-cancer activities of proanthocyanidins-rich extracts from three varieties of sorghum (Sorghum bicolor) bran

ABSTRACTHepatocellular carcinoma is the fifth frequently diagnosed cancer in humans. Proanthocyanidins was reported to be an excellent dietary botanical supplement for its antioxidant and anticancer effects. In this study, proanthocyanidins-rich extracts (PREs) were prepared from three varieties (Jinza No. 12, Jinza No. 15 and Jinza No. 18) of sorghum bran. Their proanthocyanidins profiles were characterized. Antioxidant assay showed that PRE samples from Jinza No. 12 and Jinza No. 15 had significant higher (p < .05) hydroxyl radical, 1-diphenyl-2-picrylhydrazyl radical and oxygen radical-scavenging capacities compared to PRE from Jinza No. 18. Stronger anti-proliferation and inhibition of cell migration (p < .05) in HepG2 cancer cells were also demonstrated among the PRE samples from Jinza No. 12 and Jinza No. 15. Intracellular signaling array analysis demonstrated an up-regulated level of phosphorylated 5’AMP-activated protein kinase α and down-regulated levels of phosphorylated extracellular signal-regulated kinase 1/2 (ERK1/2) and p38.

Biorefining of blackcurrant pomace into high value functional ingredients using supercritical CO2, pressurized liquid and enzyme assisted extractions

This study reports valorisation of blackcurrant pomace using multistep processes for its biorefining into valuable food-grade ingredients. Firstly, supercritical carbon dioxide extraction (SFE-CO2) was optimized for effective isolation of lipophilic fraction using response surface methodology based on central composite design. Afterwards pressurized liquid (PLE) and enzyme assisted (EAE) extractions were applied for the isolation of higher polarity substances. The yield of SFE-CO2 at optimal parameters (60°C, 45MPa, 120min) were up to 14.6%, while PLE and EAE with acetone, ethanol or water enabled additionally obtain 12.3–39.9% of extracts from SFE-CO2 residues. Lipophilic extracts were rich in polyunsaturated fatty acids (linoleic 46.89%, γ-linolenic 14.02%) and tocopherols (in total 2468μg/g oil), while polar fractions demonstrated strong antioxidant capacity as it was evaluated by the total phenolic content, DPPH radical and ABTS cation radical scavenging, ferric reducing antioxidant power and oxygen radical scavenging capacity assays.

Synthesis and Antioxidant Activity of Alkyl Nitroderivatives of Hydroxytyrosol.

A series of alkyl nitrohydroxytyrosyl ether derivatives has been synthesized from free hydroxytyrosol (HT), the natural olive oil phenol, in order to increase the assortment of compounds with potential neuroprotective activity in Parkinson’s disease. In this work, the antioxidant activity of these novel compounds has been evaluated using Ferric Reducing Antioxidant Power (FRAP), 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), and Oxygen Radical Scavenging Capacity (ORAC) assays compared to that of nitrohydroxytyrosol (NO2HT) and free HT. New compounds showed variable antioxidant activity depending on the alkyl side chain length; compounds with short chains (2–4 carbon atoms) maintained or even improved the antioxidant activity compared to NO2HT and/or HT, whereas those with longer side chains (6–8 carbon atoms) showed lower activity than NO2HT but higher than HT.

Comparison of phytochemical profiles, antioxidant and cellular antioxidant activities of seven cultivars of Aloe

SummaryA comparative assessment of the phytochemical profiles and antioxidant activities of seven cultivars of Aloe was conducted to evaluate the potential health benefits of Aloe. Aloe arborescens contained the highest levels of phenolic content, total antioxidant capacity by the oxygen radical scavenging capacity assay and cellular antioxidant activity assay. Aloe vera showed the highest levels of flavonoid content and antioxidant capacity by the peroxyl radical scavenging capacity assay. Aloe greenii had the highest CAA value with a PBS wash before adding ABAP. There were no significant differences observed between Aloe arborescens and Aloe greenii. Aloin, aloe‐emodin‐8‐O‐beta‐D‐glucopyranoside, catechin, epicatechin, sinapic acid and chlorogenic acid were identified in Aloe samples by the HPLC analysis. Aloin, aloe‐emodin‐8‐O‐beta‐D‐glucopyranoside and catechin showed strong relationships with antioxidant activity. Significant levels of aloin, aloe‐emodin‐8‐O‐beta‐D‐glucopyranoside and catechin were determined in Aloe greenii, Aloe vera and Aloe saponaria, respectively.

Evaluation of the antioxidant properties of tryptophan and its metabolites in in vitro assay.

Human milk contains a number of nutrients and bioactive ingredients which play an important role in the growth and development of infants. One important nutrient and bioactive ingredient of human milk is L-tryptophan. L-Tryptophan is an essential aromatic α-amino acid and is required in the diet of children and adult humans. As an essential amino acid, it is needed for protein synthesis and as a precursor of key biomolecules such as serotonin, melatonin, tryptamine, niacin, quinolinic acid and kynurenic acid, nicotinamide adenine dinucleotide. The aim of the study was to evaluate the antioxidant, anti-inflammatory and antiproliferative properties of tryptophan isolated from enzymatic hydrolysates from human milk and its metabolites on human glioma U251 cells and to evaluate the effects of human recombinant (hrIFNγ) on molecular ions of tryptophan and its metabolites in human glial U251 cells. The cytotoxicity was determined by MTT (3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide) assay. The antioxidant property was assessed by the oxygen radical scavenging capacity (ORAC) method. The anti-inflammatory effect was determined by the enzyme-linked immunosorbent assay (ELISA) against cytokines IL-6 and TNF-α. The effects of recombinant human (rhIFNγ) on molecular ions of tryptophan and its catabolites were evaluated by mass spectrometry. The tryptophan was isolated from milk peptides following enzymatic digestion, followed by separation by chromatographic and mass spectrometric methods. Tryptophan from human milk exhibited profoundly higher oxygen radical absorption capacity (7,986±468 µm Trolox equivalent (TE)/g) than that of whole human milk (80.4±13.3 µm TE/g). Tryptophan showed a moderate degree of anti-inflammatory activity against TNF-α and IL-6. rhIFNγ inhibited tryptophan metabolism. A low concentration of L-tryptophan (10-25 μg/mL) inhibited nearly 25% of cell growth. When U251 cells were treated with 25 μg/mL L-tryptophan and subsequently challenged with 30 ng/mL of human recombinant IFNγ, a significant inhibitory effect on cell growth was observed. Low concentrations of Xanthurenic acid, L-kynurenine, and 3-OH DL kynurenine were found to inhibit cell growth except melatonin and 3-OH anthranilic acid. Melatonin was a strong inducer of TNF-α in RAW cells, whereas 3-OH kynurenine at 25, 50 and 100 µg/mL inhibited IL-6 in RAW cells. No significant change was observed in the IL-8 profile in tryptophan-treated U251 cells except that L-kynurenine at 10 µg/mL produced significantly high level of an inflammatory cytokine IL-8. Melatonin, 3-OH, DL kynurenine at high concentrations (100 µg/mL) induced proliferation of U251 cells. Melatonin seemed to show synergistic effects with recombinant human IFNγ (rhINFγ) in promoting growth of human glioma cells. While treatment of U251 cells with tryptophan alone and subsequent treatment with rhIFNγ inhibited the growth of human cancer glioma cells, and conversely melatonin combined with rhIFNγ promoted growth of the U251 cells. The findings from this study suggest that human milk-derived tryptophan and its metabolites possess strong antioxidant properties. Such effects might play a significant role in regulating the cell proliferation and growth of human cancer cells in a concentration-dependent manner.

Structure and Antioxidant Activities of Proanthocyanidins from Elephant Apple (Dillenia indica Linn.).

Proanthocyanidins were isolated and purified from fruits of elephant apple (Dillenia indica Linn.) and their structural and bioactive properties were examined. Bate-Smith alcoholysis, FTIR, and (13) C NMR spectra revealed that elephant apple proanthocyanidins (EAPs) contained a dominant amount of B-type procyanidins (PC) with a minor amount of B-type prodelphinidins (PD) but no A-type interflavan linkage. (13) C NMR spectrum indicated that the cis isomer was dominant in EAPs. The electron spray ionization and matrix-assisted laser desorption ionization time of flight mass spectra of EAPs showed the clear ion peaks corresponding to B-type PC dimer to B-type PD with degree of polymerization of 11. EAPs had strong antioxidant activity, which was evidenced by the high oxygen radical scavenging capacity at 1.06 × 10(4) μmol TE/g and ferric reducing antioxidant power of 2320 μmol Fe(II)/g. The results suggest that EAPs could be extracted to be used as promising functional food materials. In this study, the elephant apple proanthocyanidins (EAPs) with a yield of 0.23% were identified for the first time as dominant B-type poly(catechin/epicatechin) but no A-type interflavan linkage. EAPs had higher ORAC and FRAP values compared to commercial grape seed proanthocyanidins, suggesting that EAPs may be used as promising functional food materials.

Release of Antioxidant Peptides from the Body Wall Proteins of the Sea Cucumber Isostichopus fuscus.

Proteases from the tentacles of the sea cucumber Isostichopusfuscus were partially purified and used to produce antioxidant peptides from body wall proteins of this marine species. Three proteins (105, 68, and 39 kDa) were identified by SDS-PAGE in the proteolytic extract of the tentacles. Protein hydrolyzates were generated with gelatin and crude protein substrates from body wall, and peptidic fractions lower and higher than 3 kDa were obtained to evaluate their oxygen radical scavenging capacity (ORAC). The 3 kDa-fraction obtained from the crude protein hydrolyzate showed the highest ORAC value (0.92 +/- 0.04 micromol Trolox equivalent/mg protein). This fraction was selected to purify peptides potentially responsible for the activity that might be used as ingredients for development of functional foods.

Release of Antioxidant Peptides from the Body Wall Proteins of the Sea Cucumber Isostichopus Fuscus

Proteases from the tentacles of the sea cucumber Isostichopus fuscus were partially purified and used to produce antioxidant peptides from body wall proteins of this marine species. Three proteins (105, 68, and 39 kDa) were identified by SDS-PAGE in the proteolytic extract of the tentacles. Protein hydrolyzates were generated with gelatin and crude protein substrates from body wall, and peptidic fractions lower and higher than 3 kDa were obtained to evaluate their oxygen radical scavenging capacity (ORAC). The 3 kDa-fraction obtained from the crude protein hydrolyzate showed the highest ORAC value (0.92 ± 0.04 μmol Trolox equivalent/mg protein). This fraction was selected to purify peptides potentially responsible for the activity that might be used as ingredients for development of functional foods.

Effects of storage and cooking on the antioxidant capacity of laying hen eggs

The aromatic amino acids and carotenoids are the major contributors to the antioxidant properties of egg yolk. This study aimed to evaluate the effect of simulated retail storage and domestic cooking on the antioxidant activity as well as on the aromatic amino acid and carotenoid contents in ordinary table eggs, omega 3/lutein (n-3/lutein) enriched eggs, and eggs from heritage chicken breeds. The oxygen radical scavenging capacity (ORAC) was the highest in n-3/lutein enriched eggs (161.4μmolTE/gsample), while eggs from heritage white leghorns (HW) showed the lowest levels (127.6μmolTE/gsample). Six weeks of storage at refrigerated temperature did not change the ORAC values, as well as the contents of free amino acid, carotenoid, and malondialdehyde (MDA) in egg yolk. Boiling and frying however, significantly reduced the ORAC value, and the contents of free amino acid, lutein and zeaxanthin, and increased the MDA content in eggs. Our results showed that the antioxidant activity is stable during six weeks of simulated retail storage.

Comparative Assessment of Phenolic Content and in Vitro Antioxidant Capacity in the Pulp and Peel of Mango Cultivars.

Mango (Mangifera indica L.), also called “the king of fruits”, is one of the most popular fruits in tropical regions. Pulp and peel samples of mango cultivars were analyzed to estimate total phenolic, total flavonoid and total anthocyanin contents. Phenolic acids, hydrophilic peroxyl radical scavenging capacity (hydro-PSC) and oxygen radical scavenging capacity (ORAC) in vitro were also determined. Total phenolics and flavonoid contents were found maximum in the peel of Xiao Tainang and Da Tainang cultivars, respectively, whereas Xiao Tainang also exhibited significant antioxidant capacity. Noteworthy, concentrations of gallic acid, protocatechuic acid, ferulic acid, chlorogenic acid and caffeic acids at 79.15, 64.33, 33.75, 27.19 and 13.62 mg/100 g fresh weight (FW) were quantified for Da Tainang, Xiao Tainang and of Jidan cultivars, respectively. Comparatively, a higher level of phenolics and significant antioxidant capacity in mango peel indicated that it might be useful as a functional food and value-added ingredient to promote human health.

Structure, antioxidant and α-amylase inhibitory activities of longan pericarp proanthocyanidins

Longan pericarp proanthocyanidins (LPPs) were extracted and examined by structural and bioactive analyses. By 1H and 13C NMR spectra, LPPs were identified for the first time containing dominant catechin/epicatechin units with a mean degree of polymerisation of 3.3. Consistent with this result, electron spray ionisation (ESI) mass spectra revealed that the predominant LPPs were poly(epi)catechin with abundant A-type and B-type linkages. Matrix-assisted laser desorption ionisation time of flight (MALDI-TOF) mass spectra of LPPs showed dominant [M + Na]+ peaks that corresponded to procyanidin trimers–octamers. The presence of galloyl group in monomeric units of LPPs was confirmed by FT-IR, NMR, ESI and MALDI-TOF mass spectrometry (MS). Moreover, LPPs had a strong antioxidant activity of 1.23 × 104 µmol TE/g as measured by oxygen radical scavenging capacity (ORAC), and α-amylase inhibitory activity with IC50 for uncompetitive α-amylase inhibition of 0.075 mg/mL. These results indicate LPPs are promising antioxidant which could be applied as potential functional food components.