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1.
Phenolic compounds were extracted from three wild grapevine species: Vitis californica, V. riparia and V. amurensis seeds using 80% methanol or 80% acetone. The total content of phenolic compounds was determined utilizing the Folin-Ciocalteu’s phenol reagent while the content of tannins was assayed with the vanillin and BSA precipitation methods. Additionally, the DPPH free radical scavenging activity and the reduction power of the extracts were measured. The RP-HPLC method was applied to identify the phenolic compounds in the extracts, such as phenolic acids and catechins. The seeds contained large amounts of tannins, catechins and gallic acid and observable quantities of p-coumaric acid. The total content of phenolic compounds and tannins was similar in the extracts from V. californica and V. riparia seeds. However, the total content of total phenolic compounds and tannins in the extracts from V. californica and V. riperia seeds were about two-fold higher than that in the extracts from V. amurensis seeds. Extracts from seeds of the American species (V. californica and V. riparia) contained similarly high concentrations of tannins, whereas extracts from seeds of V. amurensis had approximately half that amount of these compounds. The content of catechin and epicatechin was similar in all extracts. The highest DPPH anti-radical scavenging activity was observed in the acetonic and methanolic extracts of V. californica and V. riparia seeds— while the acetonic extract from the V. californica seeds was the strongest reducing agent.  相似文献   

2.
Free phenolic (FP), conjugated phenolic (CP), and insoluble-bound phenolic (IBP) acids were extracted from the seeds of seven species of oil-tea camellia and their antioxidant activities were evaluated. The results indicated that Camellia vietnamensis has the highest total phenolic content (TPC) (31.84 ± 0.11 g of gallic acid equivalent [GAE] kg−1) and that Camellia polyodontia has the lowest TPC (12.34 ± 0.22 g GAE kg−1) in the kernel. The average TPC among the species is similar in both the kernels and in the shells, and the content order of the three forms of phenolic compounds is FP > IBP > CP. HPLC-MS analysis showed the presence of 9–11 phenolic compounds in the FP, CP, or IBP extracts of the seven species of oil-tea camellia seed. Among the phenolics identified, ferulic acid, catechin, and epicatechin were the major contributors of antioxidant activity. Hierarchical cluster analysis conducted based on the phenolic properties showed that C. vietnamensis and Camellia semiserrata belong to the group characterized by high antioxidant capacities (FRAP, ferric-ion-reducing antioxidant power; ABTS assay), and Camellia chekiangoleosa and Camellia oleifera are arranged in a group with moderate phenolic properties. The other species constitute the third cluster with low phenolic content and antioxidant activity. The study demonstrated that oil-tea camellia seed contains significant amounts of phenolic acids. In addition, extracts from various parts of the seed could be interesting novel sources of natural antioxidants.  相似文献   

3.
This study was designed to examine physicochemical composition, antioxidant activities and heat stability of corn oil enriched with bitter orange peel. Volatile compounds composition of corn oil flavored with Citrus aurantium peel was investigated. Flavored oil total aroma content (2.6 mg/mg oil) was mainly represented by monoterpene hydrocarbons and limonene was the major one (2.49 mg/mg oil). Flavored oil methanolic extract was characterized by total phenol content of 1.22 mg GAE/kg. Chlorogenic, ferulic and p-coumaric acids were the major phenolic components of the flavored oil extract (34.33, 30.24 and 19.39 %, respectively). It was also characterized by a higher chlorophylls and carotenoids contents than the refined one. Antioxidant activities of methanolic extracts of both samples were determined using four assays: DPPH, reducing power, β-carotene bleaching and metal chelating tests. In β-carotene bleaching and DPPH radical scavenging assays, flavored oil methanolic extract showed higher activities than the control. It was characterized by a total antioxidant activity of 4.08 mg GAE/kg and an EC50 value of 3.14 mg/mg oil. Its concentration providing 50 % inhibition (IC50) was 0.53 mg/mg oil in the DPPH test and 4.08 mg/mg oil in the β-carotene bleaching test. However, refined corn extract showed significantly lower antioxidant activities (p < 0.05). Results of the oxidative stability index showed bitter orange peel effectiveness against thermal oxidation based on the increased induction time observed in flavored oil (5.95).  相似文献   

4.
ABSTRACT

Asparagus racemosus root extracts were prepared by supercritical fluid (CO2), soxhlet, and maceration-based methods also with various pretreatments. Thereafter, these root extracts were analyzed by High-Performance Liquid Chromatography, along with the chemometric study of the disparate phenolic groups. Among these, supercritical fluid (CO2) based extract has a larger number of polar compounds and the antioxidant activity (98.54 ± 0.22 µM Trolox equivalent mg?1). It also has the best cell viability (94.37 ± 1.12%) and insulin release (0.82 ± 1.12 ng mL?1) on β-pancreatic RINm-5F cells whereas, the best extractive yield (75.80 ± 3.44% w/w) was observed for pretreated aqueous soxhlet-based extract.  相似文献   

5.
Successive extractions with diethyl ether and methanol of the whole seeds of the spice Aframomum danielli yielded diethyl ether extract (ADEE), 13.9%, and methanol extract (ADM), 3.4%, respectively. Similarly, reextraction of the defatted seeds of A. danielli successively with diethyl ether and methanol yielded extracts DFADEE (7.9%) and DFADM (6.7%), respectively. When these extracts were added to refined peanut oil (PNO) at 200 ppm, they showed good antioxidative effects. The percentage antioxidant effectiveness (AE) values were as follows: DFADM (87.3) > ADM (85.3) > ADEE (83.4)=tert-butyl hydroquinone (83.4) on day 20 of storage in an oven maintained at 65±1°C. Generally, antioxidant extracts prepared from A. danielli were also more effective than butylated hydroxytoluene and α-tocopherol in stabilizing refined PNO. Antioxidant components of A. danielli were tentatively identified as phenolic compounds of the trihydroxy type with reducing properties. All extracts prepared from A. danielli showed strong ultraviolet-absorbing characteristics, and methanol was a good extracting solvent.  相似文献   

6.
《分离科学与技术》2012,47(14):3652-3662
Abstract

Antioxidant and antimicrobial activities of the extracts obtained by classical (maceration) and ultrasonic (40 kHz) extraction from dry Plantago major leaves were compared. The antioxidant activities of extracts obtained by ultrasonic and classical extraction were 0.87±0.02 and 0.85±0.02 µg/µg DPPH, respectively. Ultrasound positively affected the extractive substance yield and the kinetics of extraction, but the extract obtained by classical extraction contained higher total contents of phenolic compounds and flavonoids than that obtained by ultrasonic extraction. Extracts of P. major showed better antimicrobial activity against the yeasts than against the bacteria.  相似文献   

7.
The current research project has been devoted to isolating new low cost and eco-friendly phenolic compounds from fruit seeds, peels and vegetables to reduce the atmospheric pollution. Natural phenolic compounds were extracted from different fruit seeds and agriculture waste: P. armeniaca, P. persica, P. domestica and Triticum aesativum. The total phenolic content was quantified, and the maximum value (1 mL extract having 1,933 μg) was found in P. armeniaca seed extract. Phytochemical screening showed that P. armeniaca seeds contain higher amount of alkaloid, tannins, saponins and flavonoid. P. armeniaca seeds enhanced the biotransformation of reactive yellow dye up to 69.89% with maximum laccase (322.45 IU/mL) production. Biodegradation of reactive yellow was only 23.34% without natural redox mediator at sixth day of incubation. Use of P. armeniaca seed stimulators resulted in maximum laccase activity (894.4 IU/mL) with 99.5% rate of removal. UV-Vis, HPLC & FTIR analysis confirmed the transformation of parent dye into various new products. Phytotoxicity study indicated 0% germination index of Avena sativa seeds with reactive yellow, whereas 83% germination index having 100% seed germination while 83% root elongation with treated sample. Thus, the study revealed that the natural phenolic compounds could serve as high potential redox mediators for enhanced laccase-mediated decolorization of reactive yellow dye.  相似文献   

8.
In this study, the thermal stability of some phenolic antioxidants including flavonoids (quercetin and catechin) and phenolic acids (gallic acid, tannic acid, ellagic acid and caffeic acid) in tallow olein was investigated. Tallow olein fractionated from sheep tallow fat was used as a medium to study the antioxidant activity at 120, 140, 160 and 180°C. In order to extract tallow olein, a three‐stage fractionation method was performed on sheep tallow fat at the constant temperatures of 25, 15 and 5°C using acetone as a solvent. The results suggested that quercetin and ellagic acid had the highest thermal stability amongst others, while gallic acid and caffeic acid exhibited the least thermal stability. Practical applications: The sheep tallow fat has been primarily used in soap manufacturing and its application as an edible fat has been limited due to its high content of saturated fatty acids. Extraction of the liquid phase of tallow fat (tallow olein) by fractionation reduces its long‐chain saturated fatty acid content to an acceptable level for edible consumption. The fractionation process, as negatively affects the stability to autoxidation, should be followed by stabilisation with antioxidants. The recent interest in natural antioxidants encouraged the authors to investigate the thermal stability of phenolic antioxidants in tallow olein. It is necessary to determine the thermal stability of antioxidants to predict their appropriateness to be used in high‐temperature applications such as deep frying. Fractionation and stabilisation with appropriate antioxidants are the important steps to utilise tallow olein as an edible oil for different applications in salad formulations, cooking and frying.  相似文献   

9.
Four different antioxidant activity assays including 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid (ABTS), 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and oxygen radical absorption capacity (ORAC), and thiobarbituric acid reactive substances were performed on the methanolic and ethyl acetate extracts of Camelina seeds (CS), flaxseeds (FS), Camelina meal low fat (CMLF, 9.9% fat), Camelina meal high fat (CMHF, 24.6% fat), and flaxseed meal (FSM, 2.7% fat). In addition, the fatty acid profile, and phenolic, tocopherol, flavonoid, and glucosinolate contents of CS, FS, CMLF, CMHF, and FSM were studied. The major fatty acid was α‐linolenic acid (C18:3 n‐3) which was 33.2, 29.4, 30.2, 60.1, and 39.3% in CS, CMLF, CMHF, FS, and FSM, respectively. The methanolic extract of CMLF showed the highest values of ABTS, DPPH and FRAP and the highest content of phenolic compounds, flavonoids, and glucosinolates. The methanolic and ethylacetate extracts of CMHF showed the highest values for ORAC and α‐ and γ‐tocopherols. The ethylacetate extracts of seeds and meals of Camelina sativa and flax showed lower values for antioxidant activity, phenolic compounds, and flavonoids than the methanolic extracts. In general, Camelina and FS meals showed higher antioxidant activities, and phenolic and flavonoid contents than their respective seeds. Practical applications: Camelina sativa seeds (CS) and flaxseeds (FS) are rich sources of omega 3 oils. Their by‐products after oil extraction are an attractive source of proteins, lipids, fiber, and natural bioactive compounds such as antioxidants. These by‐products may be used to improve nutritional value and prevent lipid oxidation in feed or food systems.  相似文献   

10.
《分离科学与技术》2012,47(6):841-850
The extraction of biologically active compounds from eggplant pulp by modified supercritical CO2 extraction was investigated. Response surface methodology was used to optimize the extraction of phenolic compounds and antioxidant capacity by assessing the pressure, temperature, and cosolvent percentage. The results demonstrated that the maximum phenolic content (3,530.79 mg CAE/100 g extract) and antioxidant capacity (4,593.22 μmol TE/g extract) were observed at 56.8°C, 280 bar, and 1.22% of ethanol and were higher than those obtained by conventional solvent extraction. Four phenolic acids were identified in the supercritical extracts and not in the conventional extracts using HPLC-DAD analysis, suggesting that modified supercritical CO2 extraction is more efficient and selective.  相似文献   

11.
The bark of trees is an abundant material for chemical by-products. The combination effects of different concentrations of Acer saccharum var. saccharum inner (IB) and outer (OB) bark acetone extracts with citric acid (CA) applied to Leucaena leucocephala wood were evaluated against the growth of three common molds (Trichoderma viride, Fusarium subglutinans, and Aspergillus niger). IB, OB, and CA solutions were prepared at 0.25% and 0.5% and their combinations were formulated in equal amounts. Acetone extracts of IB and OB were analyzed for their chemicals composition and phenolic compounds using GC/MS and PHLC, respectively. The IB acetone extract contained 4-hydroxy-4-methyl-2-pentanone (31.67%), palmitic acid (15.52%), and linoleic acid (11.14%), while the OB acetone extract contained 1,2-benzenedicarboxylic acid, bis(2-ethylhexyl) ester (9.34%), (Z,E)-9,12-tetradecadien-1-ol (8.86%), and cis-tetrahydro-6-methoxy-2H-pyran-3-ol (5.72%). The HPLC analysis indicated the presence of 14 phenolic compounds in IB extract with major constituents caffeine (362.88?µg/g extract), and p-hydroxy benzoic acid (358.06?µg/g extract), while OB contained 12 compounds with major constituents p-hydroxy benzoic acid (8950.5?µg/g extract), gallic acid (5261?µg/g extract) and salicylic acid (572.38?µg/g extract). High total phenolic content in OB (292.67?mg GAE/g) was associated with high antioxidant activity with an IC50 values of 1.77 and 4.14?μg/mL, as measured by DPPH and β-Carotene-linoleic acid, respectively. The combination treatment of IB0.25%+ OB0.25%+CA0.25% produced the highest antifungal effects against growth of T. viride with an inhibition percentage (IP) of 10.37%, IB0.5%+CA0.5% (IP 16.66%) with F. subglutinans, while CA0.5% and OB0.25%, showed IP of 27.77% and 23.70% with A. niger, respectively. The combination effects of IB, OB and CA could be used as biocide agents for preventing mold growth on wood.  相似文献   

12.
《分离科学与技术》2012,47(11):1665-1674
The effects of ultrasonic-assisted extraction factors for the main phenolic compound (quercetin) from Hypericum perforatum L. were optimized using the Box–Behnken design (BBD) combined with response surface methodology. The BBD was employed to evaluate the effects of extraction temperature (30–70°C), extraction time (20–80 min), methanol concentration (20–80%, v/v), and HCl concentration (0.8–2.0 M) on the content of one of the major phenolic compounds of quercetin. The extracts were analyzed by high performance liquid chromatography (HPLC). The major phenolic compounds of H. perforatum were isolated and the antioxidant capacity and total phenol content were determined in crude extract and fractions. The optimum conditions were determined as extraction temperature 67°C, extraction time 67 min, methanol concentration 77% (v/v), and HCl concentration 1.2 M. The predicted content of quercetin was 10.81 mg/g dried plant under the optimal conditions and the subsequent verification experiment with 11.09 mg/g dried plant confirmed the validity of the predicted model. The isolated compounds were identified as quercetin, cyanidin, protocatechuic acid, and kaempferol.  相似文献   

13.
Phenolic compounds were extracted with 80% (v/v) aqueous acetone from buckwheat seeds and groats. Tannin fractions were obtained from the crude extracts by Sephadex LH-20 column chromatography. Total phenolic contents of isolated fractions from buckwheat seeds and groats were 477 and 371 mg catechin equiv/g, respectively. The analyzed samples were characterized by electrophoretic separations using capillary zone electrophoresis. Both fractions exhibited strong antioxidant activity. The tannin fraction of buckwheat seeds reduced 1,1-diphenyl-2-picrylhydrazyl radicals (DPPH·) and [2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)] diammonium salt radical cations (ABTS·+) stronger than the fraction of buckwheat groats. The EC50 values amounted to 0.019 and 0.020 mg while Trolox equivalent antioxidant capacity values were 4.06 and 3.55 mmol Trolox equiv/g for tannin fractions of buckwheat seeds and groats, respectively. Similarly, antioxidant activity of the tannin fraction of buckwheat seeds measured by photochemiluminescence assay, was higher than antioxidant activity noted for the fraction obtained from groats. However, both fractions inhibited oxidation to the same extent in applied lipid models: β-carotene-linoleic acid emulsion and l-α-lecithin liposomes. In β-carotene-linoleic acid emulsion system, 1 mg of tannin fractions exhibited similar antioxidant activity to 0.5 mg butylated hydroxyanisole (BHA).  相似文献   

14.
The objective of this work was to extract water‐soluble compounds from different seed and nut cakes under the same conditions and compare the phenolic content and antioxidant activity of the cake extracts. Seed cakes of sunflower, pumpkin, flaxseed and defatted sesame, and nut cakes of almond, pecan, macadamia and hazelnut were used in the experiments. Extracts were obtained by solid–liquid extraction with a water/ethanol solution (20:80, v/v). Total phenolic content, flavonoids, flavan‐3‐ols and condensed tannins in the extracts were determined using spectrophotometric analysis. Antioxidant properties of the extracts were determined by the DPPH and ABTS radical scavenging methods, and by determination of the reducing power and chelating activity. The extract from pecan nut cake presented the highest amounts of all compounds analyzed, followed by sunflower seed and hazelnut cake extracts. These samples also had the highest effects on the ABTS and DPPH radicals, as well as the uppermost reducing powers. The extracts from pecan nut and sunflower and sesame seeds were analyzed using HPLC and individual phenolics were further characterized.  相似文献   

15.
Olive oil composition has been investigated using chemical approaches, since the composition has a direct impact on its quality and safety and it may be used for certification purposes. In this paper, eleven monovarietal and twelve commercial Portuguese olive oils were analyzed to determine spectrophotometrically their total polyphenol content, ortho-diphenols and antioxidant activity. The phenolic profiles of these olive oils were also studied by high performance liquid chromatography. The lowest phenolic content and antioxidant activity were observed for monovarietal olive oils, however, among these group, ‘Cobrançosa’ and ‘Redondil’ cultivars showed the highest values of these two chemical parameters. In commercial olive oils, the concentration of polyphenols, determined according to the Folin–Ciocalteu method, and the antioxidant activity (ABTS method) ranged from 97.37 ± 1.10 to 219.7 ± 1.50 mg GAE/kg of oil and from 387.2 ± 20.00 to 997.5 ± 30.90 µmol Trolox/kg, respectively. The study of the phenolic profile demonstrated that the highest concentrations of the most abundant compounds in olive oil (tyrosol, hydroxytyrosol and oleuropein) are present in commercial olive oils. The correlation coefficient between total phenolics and antioxidant activity was statistically significant (r = 0.95, p < 0.0001). The same was observed for ortho-diphenol content and antioxidant capacity (r = 0.94, p < 0.0001).  相似文献   

16.
Possible use of canola hulls as a source of natural anti-oxidants was explored. Cyclone canola hulls were extracted with methanol (30 to 80%, vol/vol) and acetone (30 to 80%, vol/vol). The free radical-scavenging activity of phenolic extracts so prepared was evaluated using the 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS) radical ion (ABTSo−), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, and chemiluminescence assays. The total content of phenolics in prepared extracts from canola hulls ranged from 15 to 136 mg sinapic acid equivalents per gram of extract. Higher levels of condensed tannins were detected in the acetone extracts than in the corresponding methanolic counterparts. Seventy and 80% (vol/vol) acetone extracts displayed markedly stronger antioxidant activity than any of the other extracts investigated. Statistically significant linear correlations were found between TEAC (Trolox equivalent antioxidant capacity) values (expressed in mM of Trolox equivalents per gram of extract) and total pehnolics, TEAC and total condensed tannins (i.e., determined using the modified vanillin and pronthocyanidin assays), as well as TEAC and protein precipitation activity of phenolic extracts (i.e., measured using the dye-labeled assay). The antioxidant activities of extracts as determined by the ABTSo− radical ion assay correlated highly with those of the chemiluminescence and DPPH radical assays.  相似文献   

17.
Effect of Accelerated Storage on Microencapsulated Kenaf Seed Oil   总被引:1,自引:0,他引:1  
In order to improve the quality and protect against degradation, kenaf (Hibiscus cannabinus L.) seed oil was microencapsulated by using spray drying. The microencapsulated kenaf seed oil (MKSO) was then stored at 65 °C for 24 days, the changes of fatty acids and bioactive compounds were examined every six days. Bulk (unencapsulated) kenaf seed oil was used as a control and was compared to the MKSO. The fatty acids and phytosterols compositions were determined by using gas chromatography, while tocopherols and phenolic acids of microencapsulated kenaf seed oil were determined by using high performance liquid chromatography. The results showed that there was a significant decrease (p < 0.05) in bioactive compounds in kenaf seed oil while the bioactive compounds in MKSO were maintained in a stable condition upon accelerated storage. Microencapsulation was shown to protect kenaf seed oil against oxidation, as well as preventing the degradation and/or loss of bioactive compounds in kenaf seed oil.  相似文献   

18.
The aim of this study was to investigate the chemical composition of acetone extracts of the lichens Toninia candida and Usnea barbata and in vitro antioxidant, antimicrobial, and anticancer activities of these extracts together with some of their major metabolites. The chemical composition of T. candida and U. barbata extracts was determined using HPLC-UV analysis. The major phenolic compounds in these extracts were norstictic acid (T. candida) and usnic acid (U. barbata). Antioxidant activity was evaluated by free radical scavenging, superoxide anion radical scavenging, reducing power and determination of total phenolic compounds. Results of the study proved that norstictic acid had the largest antioxidant activity. The total content of phenols in the extracts was determined as the pyrocatechol equivalent. The antimicrobial activity was estimated by determination of the minimal inhibitory concentration using the broth microdilution method. The most active was usnic acid with minimum inhibitory concentration values ranging from 0.0008 to 0.5 mg/mL. Anticancer activity was tested against FemX (human melanoma) and LS174 (human colon carcinoma) cell lines using the microculture tetrazolium test. Usnic acid was found to have the strongest anticancer activity towards both cell lines with IC50 values of 12.72 and 15.66 μg/mL.  相似文献   

19.
Multi response optimisation conditions were investigated in grape seeds’ phenolic compounds extraction by using ultrasound-assisted extraction (UAE) methodology. The effect of independent process variables such as EtOH concentration (0–100%), extraction time (0–40 min), solvent:solid ratio (4.5–38.5 mL/g) and extraction temperature (20–60°C) on total phenolic content (TPC) and total antioxidant activity (TAA) of the extracts were studied. The optimum conditions of UAE were determined as follows: EtOH concentration, 61.76%; extraction time 20 min., solvent:solid ratio, 30 mL/g; extraction temperature 50°C. The estimation results of the model and the experimental results for TPC and TAA showed a great similarity.  相似文献   

20.
The total phenolic content and the antioxidant potential of methanolic extract (ME), ethyl acetate extract (EAE), and hexane extract (HE) from Monechma ciliatum leaves (MCL) were evaluated. The Folin-Ciocalteu, β-carotene bleaching, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and the accelerated oxidation methods were used for evaluation. Both the extraction yield and the antioxidant activity (AOA) were strongly dependent on the solvent. Among the extracts, ME exhibited highest total phenolic compounds (TPC) and IC50 values for DPPH, followed by EAE and HE, respectively. Peroxide value (PV), anisidine value (AV) conjugated dienes (CD), and thiobarbituric acid reactive substances (TBARS) were taken as the parameters for evaluation of stabilization efficacy of MCL extracts and results revealed MCL to be a potent antioxidant for the stabilization of corn oil. As a general trend, increased AOA was observed for increased extract concentration. The predominant phenolic compounds identified by HPLC-DAD in MCL extracts were p-coumaric acid, vanillin and ferulic acid.  相似文献   

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