Terms Of Antioxidant Activity Research Articles

Preparation of bio-functional textiles by surface functionalization of cellulose fabrics with caffeine loaded nanoparticles.

In recent years transdermal drug delivery has aroused significant interest as a sustained and non-invasive way of administering active substances. The advancements of nanotechnology allowed the development of novel pharmaceutical formulations overcoming skin barrier. Furthermore, such nano-system can be combined with conventional fabrics to pave the way to a new generation of wearable drug delivery devices: bio-functional garments. First the NP were produced by flash nanoprecipitation technique (FNP), the production process was optimized to produce particles with suitable size for transdermal applications. The nanoparticles were characterized in terms of drug content by UV-visible spectroscopy and in term of antioxidant activity by Electron Paramagnetic Resonance spectroscopy (EPR) coupled with spin trapping technique. The NPs were used to functionalize cotton and viscose-micromodal fabrics and the transdermal release properties were tested in vitro by Franz’s Cell experiment. FNP was proven to be an effective technique to produce tunable size particles. Moreover, the nanoencapsulated drug exhibited antioxidant activity. The Franz’s Cell test evidenced a controlled release behavior, providing evidence that the bio-functional textile is suitable for applications where sustained release and antioxidant properties are required.

A comprehensive study about Hibiscus sabdariffa leaves: antioxidant activity, polyphenol profile and macro- and micro-element content

Hibiscus sabdariffa leaves are generally consumed by people in cold drinks and herbal tea. The purpose of this study is to examine in terms of antioxidant activity, polyphenol profile and macro- and micro-element content of H. sabdariffa leaves. Firstly, antioxidant activity studies were carried out by applying antioxidant activity assays to different extracts of the plant leaves. It has been observed that the antioxidant activity results vary depending on the extraction solvent and that the result obtained for one extract in some tests could not be obtained for the same extract in the other tests when solvents are changed. Secondly, the polyphenol profile of this plant was identified with a high-performance liquid chromatography–diode array detector (HPLC–DAD). For this purpose, thirteen polyphenols were examined in leaves of this plant, but only caffeic acid, chlorogenic acid, ellagic acid, p-coumaric acid and quercetin were detected among the studied polyphenols. Finally, macro-element including calcium (Ca), potassium (K), magnesium (Mg), sodium (Na) and micro-element including copper (Cu), iron (Fe), zinc (Zn) analysis was carried out using flame atomic absorption spectrometry (FAAS).

Anti-carcinogenic effect of hesperidin against renal cell carcinoma by targeting COX-2/PGE2 pathway in Wistar rats.

The present study was designed to evaluate the protective effects of hesperidin, a flavonoid on DEN initiated and Fe-NTA promoted renal carcinogenesis in Wistar rats. Renal cancer was initiated by a single i.p. injection of DEN (200 mg/kg b.wt.) and promoted with Fe-NTA (9 mg Fe/kg b.wt. i.p.) twice a week for 16 weeks. Rats were simultaneously administered with hesperidin (100 and 200 mg/kg b.wt.) for 16 consecutive weeks. The chemopreventive effect of hesperidin was assessed in terms of antioxidant activities, renal function, PGE2 level, and the expressions of COX-2 and VEGF. Hesperidin decreased the DEN and Fe-NTA induced lipid peroxidation, improved the renal function (by decreasing the levels of BUN, creatinine, and KIM-1) and restored the renal antioxidant armory (GSH, GPx, GR, SOD, and catalase). Hesperidin was also found to decrease the level of PGE2 and downregulate the expressions of COX-2 and VEGF. Histological findings further revealed the protective effects of hesperidin against DEN and Fe-NTA induced kidney damage. The result of our present findings suggest that hesperidin may be a promising modulator in preventing renal cancer possibly by virtue of its ability to alleviate oxidative stress and inhibit COX-2/PGE2 pathway.

The influence of the extraction temperature on polyphenolic profiles and bioactivity of chamomile (Matricaria chamomilla L.) subcritical water extracts

The main goal of this research was to determine the relationship among chemical structure, bioactivity and temperature of chamomile during subcritical water extraction in isobaric conditions (45 bar) at seven different temperatures (65–210 °C). The influence of temperature on phenolic profiles was defined by UHPLC-HESI-MS/MS. The overall results indicate that the presence of conjugated double bonds, side chains, glucose moiety or ether moiety in molecules influence the efficiency of polyphenols’ extraction in subcritical water. In terms of antioxidant activity, the extracts were the most active towards ABTS radicals (IC50 = 7.3–16.8 µg/mL), whereby temperature of 150 °C was optimal. On the other hand, the extracts obtained at 115 °C showed highest cytotoxicity. Inhibition of α-amylase and α-glucosidase was the highest at 65 and 85 °C, i.e. 0.51 and 4.13 mmolAE/g, respectively. Activity against tyrosinase was the highest at 210 °C (17.92 mgKAE/g). The data showed that different non-phenolic compounds may also participate in bio-activities of the extracts.

Highly stable gold nanoparticles green-synthesized by upcycling cartilage waste extract from yellow-nose skate (Dipturus chilensis) and evaluation of its cytotoxicity, haemocompatibility and antioxidant activity

Skate (Dipturus chilensis) cartilage extract was utilized as a green reducing agent for the synthesis of spherical gold nanoparticles with an average size of 16.7 ± 0.2 nm. The gold nanoparticle solution showed a surface plasmon resonance at 543 nm with a wine-red colour. A strong X-ray diffraction pattern and clear lattice structure in high-resolution transmission electron microscopy indicated a face-centred cubic structure of the gold nanoparticles. The gold nanoparticles retained excellent colloidal stability. Gold nanoparticles showed strong antioxidant activity in terms of 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity. In vitro cytotoxicity was observed for seven cancer cells assessed by the water-soluble tetrazolium assay. Among the seven cancer cells, the highest cytotoxicity was observed for MDA-MB-231 (human breast adenocarcinoma cell) followed by HeLa (human epithelial cervix adenocarcinoma cell) and lastly by HT-29 (human colorectal adenocarcinoma cell). Furthermore, gold nanoparticles showed excellent haemocompatibility, indicating the possibility of their use as a future nanomedicine. These results strongly suggest that gold nanoparticles green-synthesized by upcycling skate cartilage waste extract will be valuable carriers or vehicles for the delivery of drugs or bioactive molecules, such as anti-cancer agents, for the treatment of cancers.

Lasiosan, a new exopolysaccharide from Lasiodiplodia sp. strain B2 (MTCC 6000): Structural characterization and biological evaluation

Abstract Ascomycete fungi are promising biofactories producing bioactive compounds exhibiting diverse biological activities. In an ongoing search for bioactive potential of microorganisms from different ecological niches, a promising Lasiodiplodia sp. strain B2 (MTCC 6000) was identified as a producer of exopolysaccharide (designated as Lasiosan). The exopolysaccharide was purified and structurally characterized as glucomannan having glucose and mannose residues (ratio 1:1) with average molecular mass of 29.3 kDa. Lasiosan demonstrated promising antimicrobial and anti-biofilm activities by inhibiting the growth of different Gram-negative, Gram-positive, drug-resistant bacteria and different Candida strains. The purified exopolysaccharide exhibited potential antioxidant activity in terms of good reducing power and scavenging of DPPH free radicals, superoxide anions and lipid peroxyl radicals. Further, the in vitro immune responses of Lasiosan were demonstrated in mouse RAW 264.7 macrophages. Lasiosan inhibited the LPS-stimulated reactive oxygen species (ROS) and nitric oxide (NO) generation in RAW 264.7 macrophages without affecting cell proliferation. Furthermore, Lasiosan significantly down-regulated the production of LPS stimulated proinflammatory mediators such as TNF-α and IL-6 from RAW 264.7 macrophages. This is the first report on Lasiosan exhibiting broad spectrum antimicrobial, anti-biofilm, antioxidant and immunomodulatory activities, which could be explored as a promising candidate for application in biotechnological and biomedical fields.

FOLKLORE MEDICINAL ORCHIDS FROM SOUTH INDIA: THE POTENTIAL SOURCE OF ANTIOXIDANTS

Objective: Orchids are widely used the economically important ornamental plant. Conventionally, they were also used for the treatment of several diseases. In the present study, five species of medicinal Orchids from South India were selected to evaluate their antioxidant potential.Methods: The selected species were extracted by Soxhlet method using 70% ethanol. The extracts obtained were analyzed for various quantitative and antioxidant assays followed by correlation analysis in between quantitative and antioxidant activity.Results: Antioxidant data revealed that among the extracts of five orchids, Coelogyne breviscapa was proved to be superior in terms of antioxidant activities, followed by Aerides maculosum, Dendrobium macrostachyum, Pholidota pallida, and Vanda testacea. Correlation analysis was performed, and the results proved simple positive correlation and highest average value of “r” (correlation coefficient) for antioxidant activities with quantitative were the total antioxidants, total phenolics, total flavonoids, and ascorbic acid content. Among the qualitative antioxidant activities, the highest average value of “r” was shown by 2, 2-diphenyl-1-picrylhydrazyl, iron chelating, 2,2-azinobis-3-ethyl-benzothiazoline-6-sulfonic acid, and superoxide radical.Conclusion: The study documents that orchid plants have significant antioxidant potential which can contribute to human health.

Supercritical carbon dioxide extraction of quinoa oil: Study of the influence of process parameters on the extraction yield and oil quality

The supercritical CO2 extraction of oil from four different quinoa varieties has been studied in this work. For this purpose, the influence of extraction temperature (40–60 °C), pressure (20–40 MPa) and raw material size (250–1000 μm) on the extraction rate has been considered. The extraction rate resulted to be faster the higher the pressure whereas the temperature had less influence on the extraction kinetics. The experimental data were modelled using the Sovova’s kinetic model.The quality of the oil extracted has been evaluated in terms of antioxidant activity (AA), fatty acid profile and tocopherol content. The highest AA was obtained for quinoa oil extracted at 40 MPa and 40 °C; this oil presented high content of polyunsaturated fatty acids (63% of the total) and significant amount of tocopherols (2.5 mg/g oil).Quinoa oil extracted using CO2 presented higher antioxidant capacity and tocopherol content than quinoa oil extracted with hexane, regardless the quinoa variety used.

Photocatalytic activity of CuO/Cu(OH)2 nanostructures in the degradation of Reactive Green 19A and textile effluent, phytotoxicity studies and their biogenic properties (antibacterial and anticancer)

In this study, CuO/Cu(OH)2 (denoted as CuONs) nanostructures were synthesized relying to a cheap and rapid chemical co-precipitation method using copper sulfate and liquid ammonia as precursors. Results obtained from X-ray diffraction, and field emission scanning electron microscopy analysis revealed the crystalline nature of synthesized CuONs. Fourier transform infrared spectroscopy and energy dispersive spectroscopy studies showed interactions between copper and oxygen atoms. Synthesized CuONs showed the size in the range of 20–30 nm using high resolution transmission electron microscopy analysis. The photocatalytic degradation performance of Reactive Green 19A (RG19A) dye using CuONs was evaluated. The results showed that CuONs exhibited 98% degradation efficiency after 12 h and also complete mineralization in form of reducing chemical oxygen demand (COD) (84%) and total organic carbon (TOC) (80%). The nanocatalyst was recovered from the dye containing solution and its catalytic activity can be reused up to four times efficiently. CuONs was also able to decolorize actual textile effluent (80% in terms of the American Dye Manufacturers' Institute (ADMI) value) with significant reductions in COD (72%) and TOC (69%). Phytotoxicity studies revealed that the degradation products of RG19A and textile effluent were scarcely toxic in nature, thereby increasing the applicability of CuONs for the treatment of textile wastewater. Additionally, the CuONs showed a maximum antibacterial effect against human pathogens which also displayed synergistic antibacterial potential related to commercial antibiotics. Moreover, CuONs displayed strong antioxidant activity in terms of ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (IC50: 51 μg/mL) and DPPH (1,1-diphenyl-2-picrylhydrazyl) (IC50: 60 μg/mL) radical scavenging. The CuONs exhibited dose dependent response against tumor rat C6 cell line (IC50: 60 μg/mL) and may serve as anticancer agents.

Evaluation of antioxidant and antibacterial activities of Crotalaria pallida stem extract

BackgroundAntioxidants play an important role in protecting cellular damage by reactive oxygen species. The aim of the present study is to assess the phytochemical nature, antioxidant and antibacterial activities of petroleum ether, chloroform, methanol, and aqueous extracts of Crotalaria pallida stem.MethodsThe preliminary screening of the various extracts was carried out using standard methods. Total phenolic content (TPC) was determined by the modified Folin-Ciocalteu method and antioxidant activities were assayed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, reducing power assay, total antioxidant capacity (TAC) and reduction of ferric ions. Antibacterial activity of different extracts were assayed against Gram-positive and Gram-negative bacterial strains by observing the zone of inhibition using disc diffusion method, where Staphylococcus aureus, Bacillus cereus, Escherichia coli and Pseudomonas aeruginosa were used as bacterial strains.ResultsPetroleum ether, chloroform, methanol and aqueous extracts of stem exhibited remarkable antioxidant activity in terms of all the assays tested. Petroleum ether extract (PEE) showed DPPH radical scavenging activity with IC50 value of 126.96 µg/ml. In antibacterial assay, the PEE and chloroform extract (CE) showed mild to moderate antibacterial activity against all the bacterial strains except B. cereus while methanol extract (ME) showed no inhibitory effect against any of the tested bacteria.ConclusionPEE, CE and ME of C. pallida stem were found to be the most effective free radical quencher and a potent source of natural antioxidants as well as antibacterial activity. Thus justifying their traditional use in green therapeutics.

Effect of drying techniques on drying behaviour and physico-chemical properties of marigold

In the present study, the flowers of the three cultivars of marigold, namely, Pusa Narangi, Pusa Basanti and Solan I were dried using different drying methods viz. solar drying, fan drying and cabinet drying using different time-temperature combinations. The study revealed that the least time taken to achieve the final moisture content was in the solar drying followed by cabinet drying and fan drying respectively. The maximum moisture removal was obtained in the solar drying method. The study revealed that solar drying was economical method in the tropical regions as this method resulted in the maximum loss of moisture and the best quality preservation in terms of antioxidant activity, β-carotene, fibre content, ash and protein content.

Insight into DNA protection ability of medicinal herbs and potential mechanisms in hydrogen peroxide damages model

DNA damage is one of the most important consequences of oxidative stress in the cells. If DNA repair is unable to modify these inducible DNA damages, genomic instability may lead to mutation, cancer, aging and many other diseases. Single cell gel electrophoresis or comet assay is a common and versatile method to quantify these types of DNA damages. DNA damages induced by hydrogen peroxide (H2O2) are one of the proper models for measurement of protective ability of different compounds. So the main aim of this review is to provide an overview about protection ability of medicinal plants and their potential mechanism against H2O2 induced DNA damages. In this review, relevant researches on the effect of medicinal plants on DNA damages induced by H2O2 and possible molecular mechanisms are discussed. It seems that, medicinal plants are considered as therapeutic key factors to protect DNA from consequences caused by oxidative stress. Sufficient in vitro evidences introduce them as DNA protective agents through different mechanisms including antioxidant activity and some other cellular mechanisms. Moreover, in order to correlate the antigenotoxicity effects with their potential antioxidant property, most of medicinal plants were evaluated in term of antioxidant activity using standard methods. This review highlights the preventive effects of herbal medicine against oxidative DNA damages as well as provides rational possibility to engage them in animal studies and future clinical investigations.

Alcalase-generated proteolysates of stone fish (Actinopyga lecanora) flesh as a new source of antioxidant peptides

ABSTRACTIn the present study, the alcalase-generated proteolysates obtained after 8 h of proteolysis of stone fish flesh showed the most potent antioxidant activity in terms of DPPH• radical scavenging activity (77.43%, IC50 of 0.5 mg/mL), ABTS• radical scavenging activity (92.73%, IC50 of 0.33 mg/mL) and FRAP value (39.2 mmol/100 mL FeSO4). These proteolysates profiled and characterized as antioxidative peptides. The proteolysates were initially subjected to ultrafiltration using MWCO Spin-X UF. Potent fractions were further characterized based on hydrophobicity using reversed-phase high-performance liquid chromatography (RP-HPLC) and isoelectric point using an OFFGEL isoelectric focusing fractionator. Results indicated that most of the antioxidative peptides found in fractions with a molecular weight (MW) of less than 2 kDa, hydrophilic (hydrophilicity >80%) and basic (pI = 9.7). The final purified fraction with the highest antioxidant activity was selected for peptide identification and sequencing using Q-TOF mass spectrometry. A total of four peptides were identified, from which Peptide 1 (GVSGLHID) showed the highest antioxidant activity and this has potential as a novel bioingredient of nutraceuticals and functional foods to promote human health.

The use of macro- and microalgae as functional ingredients in diets for meagre (Argyrosomus regius, Asso 1801)

The use of macro- and microalgae as functional ingredients in diets for meagre (Argyrosomus regius, Asso 1801)

Investigation of in vitro Antioxidant and Anti-inflammatory Activities of Selected Siddha Polyherbal Formulations

Abstract: Objective: This study deals with the antioxidant and anti-inflammatory activities of selected Siddha polyherbal formulations such as Amukkara choornam, Thirikadugu choornam, Eladi choornam and Thiripala choornam. Amukkara choornam consist of seven herbals (withania, ginger, black pepper, long pepper, mesua, cardamom and clove). Thirikadugu choornam has three herbal ingredients ginger, black pepper and long pepper. Eladi choorna has seven raw drugs like cardamom, ginger, arrow root, yew leaves, Mesua, black pepper and clove. Thiripala choornam comprises of three dry fruits amla, chebulla and bellerica. Methods: Even though all these medicines have been used as analgesic for joint pain in Siddha system of medicine, their antioxidant and anti-inflammatory activities were not yet proved scientifically. In the present work, we have evaluated the antioxidant and anti-inflammatory properties of aqueous extract of the above-mentioned herbal formulations. Results: Among the investigated formulations, has six folds higher level of total phenolic content (1248 mf GAE/100 g) when compared to other formulations (190.42 – 199.78 mg GAE/100 g). Similarly, \ exhibited promising antioxidant activity in terms of radical scavenging potential against DPPH (IC-50: 156 mg/L), superoxide (IC-50: 2303 mg/L), hydrogen peroxide (IC-50: 294 mg/L) and hydroxyl radical (IC-50: 587 mg/L) and anti-inflammatory activity (IC-50: 24 mg/L). Conclusion: Among the investigated samples, Thiripala choornam was found to exhibit high antioxidant and anti-inflammatory potential and thus could be used as more effective analgesic formulation. Key words: Aqueous extract, Polyphenols, Antioxidant, Anti-inflammatory, Amukkara choornam, Thirikadugu choornam, Eladi choornam, Thiripala choornam.

Structural and Functional Properties of Exopolysaccharide Excreted by a Novel Bacillus anthracis (Strain PFAB2) of Hot Spring Origin.

Exopolysaccharide produced by a unique avirulent Bacillus anthracis strain PFAB2 of hot spring origin has been characterized and its functional properties are investigated which is a first report. Maximum yield of EPS is 7.66g/l with 2% glucose and 1% peptone as optimum carbon and nitrogen source respectively. The EPS is found to be a homopolymer consisting of only glucose as principle monosaccharide component. Through 1H NMR study, different dextran-like proton peaks are observed. Molecular weight of the EPS resembles low molecular weight bacterial origin polysaccharides. Melting transition of the EPS has started after 276°C which indicates good thermal stability. The EPS also shows potent antioxidant activity in terms of DPPH and ABTS mediated free radical scavenging property compared to standard ascorbic acid. Emulsifying property of the EPS is also observed and has shown good emulsification of vegetable oils. The polysaccharide forms a thermo resistant gel during the heating phase, with G' higher than G″ indicating excellent shear-thinning behaviour and viscoelastic nature of the EPS.

Phytochemistry investigation and antioxidant activity of four edible Verbenaceae of Burkina Faso

<p><em>Lantana rhodesiensis</em> Moldenke, <em>Lippia chevalieri</em> Moldenke, <em>Vitex diversifolia </em>Bak and <em>Vitex doniana </em>Sweet are four species of Verbenaceae family widely used in traditional medicines in Burkina. The aim of this investigation was to study the chromatographic profile of phenols acids and that of the flavonoids as well as the antioxidants activities. Then, three types of extraction were made: acetonic (100%), decoction, ethanol-water(80/20 + 20/80); and fractions of ethanol-water which arehexane fraction (HF), ethyl acetate fraction (EAF), butanol fraction (BF) and aqueous fraction (AqF) of each species. These evaluations were supplemented by the quantification of the metal ions and the characterization by atomic absorption and HPLC-DAD methods of totals phenols acids and totals flavonoids.The whole of these proportioning was directed against the antioxidant activity through the anti-DPPH* (free radical scavenging activity), anti-TAC (total antioxidant capacity) and anti-IRP(iron reducing power).36 flavonoids on 41 were highlighted by the HPLC-DAD method. A derivative glycosylate of quercetin was detected in the <em>V. diversifolia</em> extracts. <em>L. chevalieri</em> presented the strongest value in terms of ions content with a 55.88 g/kg of calcium.In terms of antioxidant activity, <em>L. rhodesiensis</em> and <em>L. chevalieri</em> presented the best activities on total antioxidant activity and anti-DPPH, and iron reducing power respectively.It’s arise that decoction extract have the best’s activities and can justify the traditional uses.</p>

Chemical, fatty acid, polyphenolic profile, techno-functional and antioxidant properties of flours obtained from quinoa (Chenopodium quinoa Willd) seeds

In the recent years, quinoa has gained a renewed relevance as an alternative crop to cereals due to its excellent nutritional value. Thus, the aims of this work were to determine the physico-chemical, techno-functional and in vitro antioxidant properties as well as the total phenolic and flavonid contents of six quinoa flours. On the different samples proximal compositions and polyphenolic, sugar and organic acids profiles were also determined. Quinoa flours showed a protein content ranged between 11.62 and 13.66g/100g while the fat content was comprised between 4.87 and 6.48g/100g. The TDF content ranged from 12.71 to 18.59g/100g with ratios IDF:SDF higher than 8:1. In all samples analyzed four organic acids (oxalic, ciltric, malic, and succinic) and three sugars (sucrose, glucose, and fructose) were determined. As regards to techno-functional propreties, all quinoa flours showed lower water and oil holding capacities with values of 1.44–1.80g water/g sample and 0.89–1.04g oil/g sample, respectively. However, all samples showed a high swelling capacity with values ranged from 8.55 to 9.57mL/g. The chemical profiles identification allowed to exposed major concentrations of 4-hydroxibenzoic acid and interesting concentrations of the other phenolic compounds and interesting contents of Ω3 fatty acids, compounds with renewed biological properties in terms of antioxidant activity and control diseases. In addition, the antioxidant activity assessed allowed to establish their antioxidant capacity of this product and the good correlations with total phenolic and flavonoid contents. The results of this study suggested that quinoa flours is a valid source of natural compounds with significant antioxidant activity and biological properties. Further investigations should be undertaken in respect of target product, anyhow the present study allowed to increase the knowledge about this Andean region species.

Measurement of total phenolic content and antioxidant activity of aerial parts of medicinal plant Coronopus didymus.

To evaluate the total phenolic content and compare the antioxidant activity of various solvent extracts and fractions from the aerial parts of Coronopus didymus through various assays. Total phenolic content was determined using the Folin-Ciocalteu assay and the invitro antioxidant activity of a number of different extracts was investigated in a dose-dependent manner with three different methods: the 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) and ferric reducing antioxidant power (FRAP) assays. A flavone was isolated from the most active ethanolic extract with high antioxidant activity using size exclusion chromatography. IC50 values were calculated for the DPPH and ABTS methods. The FRAP activity was assessed in terms of μM Fe (II) equivalent. The phenolic content was found to be highest in the ethanol extract (CDA Et; 47.8mM GAE) and the lowest in the dichloromethane extract (CDA DCM; 3.13mM GAE). The ethanol extract showed high radical scavenging activity towards DPPH and ABTS radicals with IC50 values of (7.80×102) and (4.32×102) μg/mL, respectively. The most active ethanol extract had a FRAP value of 1921.7μM Fe (II) equivalent. The isolated flavone F10C (5,7,4'-trihydroxy-3'-methoxy flavone) was far more effective for scavenging free radicals in the DPPH and ABTS assays with IC50 of 43.8 and 0.08μg/mL, than the standard trolox, with IC50 values of 97.5 and 21.1μg/mL, respectively. In addition, the flavone F10C and the standard ascorbic acid had FRAP values of 1621.7 and 16038.0μM Fe (II) equivalents, respectively. The total phenolic content of extracts in decreasing order is ethanol extract (CDA Et)>acetone extract (CDA ACE)>phenolic extract (CDA MW)>n-hexane extract (CDA nHX)> chloroform extract (CDA CHL)>dichloromethane extract (CDA DCM). The ordering of extracts in terms of antioxidant activity from highest to lowest is CDA Et>CDA MW>CDA DCM>CDA CHL>CDA ACE>CDA nHX in DPPH, ABTS and FRAP assays. A significant relationship is found between antioxidant potential and total phenolic content, suggesting that phenolic compounds are the major contributors to the antioxidant activity of C. didymus.

Effects of deodorisation methods on volatile compounds, chemical properties and antioxidant activities of fucoidan isolated from brown seaweed (Sargassum sp.)

Fucoidan is a unique marine algae derivative that exhibit many bioactivities. However, the distinct unpleasant odour limits its application in food products. In the present study, fucoidans were deodorised using three different methods; activated carbon, (Fac), ion exchange resin (Fresin) and calcium carbonate (FCaCO3). Subsequently, the effects of deodorisation on the chemical properties (FTIR, fucose and sulphate content), volatile compound compositions (GC-MS) and antioxidant activity (total phenolic content, DPPH, superoxide and hydroxyl radical scavenging) of fucoidan were evaluated. A total of 46 volatile compounds were successfully identified in all samples using headspace-solid phase microextraction (HS-SPME) and analysed using gas chromatography mass spectrometry (GC-MS). It was found that 2,4-bis(1,1-dimethylethyl)phenol was one of the odour active compounds in Fsar, which reduced significantly after deodorisation. All deodorised samples showed no significant (p>0.05) differences in fucose, sulphate content and total phenolic content from that of Fsar except for Fresin. In terms of antioxidant activity, the DPPH scavenging activity in FCaCO3 (3%) was significantly higher, (p<0.05) compared to that of Fsar. All deodorised fucoidans were observed to show significantly higher (p<0.05) superoxide anion scavenging activity compared to that of Fsar. Hydroxyl radical scavenging activity of Fresin (1:100), Fresin (3:100), and FCaCO3 (5%) showed a significant increase (p<0.05) compared to Fsar. Overall results confirm that the deodorisation methods were successful in reducing the odour and did not alter its chemical compositions, while in some cases, enhance the antioxidant activities.