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1.
Antioxidant Activity of Seaweed Extracts: In Vitro Assays,Evaluation in 5 % Fish Oil‐in‐Water Emulsions and Characterization 下载免费PDF全文
K. H. Sabeena Farvin Charlotte Jacobsen 《Journal of the American Oil Chemists' Society》2015,92(4):571-587
In this study the antioxidant activity of absolute ethanol, 50 % ethanol and water extracts of two species of seaweeds, namely Fucus serratus and Polysiphonia fucoides, were evaluated both in in vitro assays and in 5 % fish oil‐in‐water (o/w) emulsions. The 50 % ethanolic extracts of P. fucoides showed higher antioxidant activity both in in vitro assays and in 5 % oil‐in‐water emulsion in the presence or absence of iron. In spite of the higher phenolic content and very good antioxidant activity in some of the in vitro assays, the absolute ethanol extracts of both the species showed a pro‐oxidative tendency in 5 % fish oil‐in‐water emulsion in the presence or absence of iron. In order to investigate the reason for the higher antioxidant activity of 50 % ethanolic extracts of P. fucoides, these extracts were further fractionated into polyphenol‐rich, protein‐rich, polysaccharide‐rich and low‐molecular‐weight fractions. These fractions were tested both in in vitro and in 5 % oil‐in‐water emulsions. The results of the present study showed that the main effect was due to the phenolic compounds. In conclusion, the 50 % ethanolic extracts of P. fucoides can be a potential source of natural antioxidants as these extracts have antioxidant activities similar to those of synthetic antioxidants such as BHT. 相似文献
2.
Kostas Kiritsakis M. G. Kontominas C. Kontogiorgis D. Hadjipavlou-Litina A. Moustakas A. Kiritsakis 《Journal of the American Oil Chemists' Society》2010,87(4):369-376
The olive leaf phenolic composition of the Greek cultivars koroneiki, megaritiki and kalamon was determined using LC/MS. Furthermore, the antioxidant activity of olive leaf extracts from the above three cultivars,
using solvents of increasing polarity (petroleum ether, dichloromethane, methanol and methanol/water: 60/40) was evaluated
using the stable free radical diphenylpicrylhydrazyl (DPPH) test. Furthermore the oxidative stability index (OSI) was compared
to that of the synthetic antioxidant TBHQ and commercial oleoresin (rosemary extract). The ability of phenolic compounds to
inhibit the lipoxygenase (LOX) activity was also investigated. The ten main components determined in the olive tree leaf extracts
for the cultivars koroneiki and kalamon were: secologanoside, dimethyloleuropein, oleuropein diglucoside, luteolin-7-O-glucoside, rutin, oleuropein, oleuroside, quercetin, ligstroside and verbascoside. Respective compounds for the cultivar
megaritiki were: secologanoside, dimethyloleuropein, oleuropein diglucoside, luteolin7-O-glucoside, oleuropein, oleuroside, quercetin and ligstroside. In all three cultivars, oleuropein represented the main phenolic
component. The solvent polarity influenced the total amount of the phenolic compounds determined. When methanol/water (60/40)
was used, as solvent, more phenolic compounds were determined. The total amounts of phenols determined in the extracts, obtained
by successive extractions using the above solvents, were 6,094, 5,579 and 6,196 mg/kg (mg gallic acid/kg dried olive leaves)
for the cultivars megaritiki, kalamon and koroneiki, respectively. Among all extracts, methanol/water extracts exhibited the highest antioxidant activity as shown through the
application of the DPPH and OSI methods. The OSI antioxidant activity followed the sequence: synthetic antioxidant TBHQ > commercial
oleoresin > olive tree leaf extracts > control. Likewise, methanol/water olive leaf extracts significantly inhibited soybean
lipoxygenase, although some small differences in the activity among the olive leaf extracts of the different cultivars were
observed. The solvent polarity as well as the amount of the extract influenced the inhibitory activity. A positive correlation
was shown between the antioxidant activity of leaf extracts and the total phenol content. 相似文献
3.
Dora Enith García Torres Dalva Assuno Portari Mancini Rosngela Pavan Torres Jorge Mancini‐Filho 《European Journal of Lipid Science and Technology》2002,104(5):278-281
Macambo is an edible fruit species from the Amazon Region with a high content of lipids (33%). Macambo samples were obtained from the Amazon Region, dried at 60 °C, milled (32 mesh sieve) and submitted to sequential extraction using ether, ethanol and water as solvents. The antioxidant activity of the ether, ethanol and aqueous extracts was 47%, 68% and 67%, respectively, and the antioxidant activity of the control butylated hydroxytoluene (BHT) was 64%. Three phenolic fractions were obtained with tetrahydrofuran: free phenolic acids, soluble and insoluble phenolic esters. The antioxidant activity of these fractions was 83%, 85% and 93% respectively, and the antioxidant activity of the control BHT was 64%. The phenolic acids were identified on the basis of relative retention times as compared with standards. The fractions obtained showed the presence of the following phenolic acids: salicylic, trans‐cinnamic, sinapinic, chlorogenic, protocatechinic, gallic, quinic, and p‐hydroxibenzoic acid. The presence of phenolic compounds in macambo fruit extracts may be responsible for its rather high antioxidant activity and the results obtained suggest that macambo extracts could be used as food antioxidants. Further studies are in progress to analyze the use of its extracts and phenolic fractions in edible oil shelf life. 相似文献
4.
ABSTRACTThis study determined the proximate composition, phytochemical and antioxidant activity of the edible red seaweed, Kappaphycus alvarezii, under different drying conditions, namely, oven dried, sun dried, vacuum dried, and freeze dried. The proximate composition of K. alvarezii has shown no significant difference (p?>?0.05) in macronutrient components except fat content. Phytochemical studies conducted on total phenolic content and total flavonoid content showed that vacuum-dried extracts demonstrated the highest total phenolic content at 12.97?mg?PGE?g?1 DE. In vitro antioxidant activities of seaweed extract by ferric-reducing antioxidant potential and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity proved that oven-dried extracts showed the highest ferric-reducing antioxidant power value, 272.95?µM TE mg?1, and highest scavenging activity, EC50 9.55?mg?mL?1. In general, sun-dried extracts showed lowest antioxidant among all treatments. 相似文献
5.
tefan Schmidt Ivana Niklov Jan Pokorný Pavel Farka Stanislav Sekretr 《European Journal of Lipid Science and Technology》2003,105(8):427-435
Crude ethanol/ethyl acetate extracts of industrial evening primrose (Oenothera biennis L.) seed meal were separated into six fractions using the Sephadex LH‐20 column chromatography and 96% aqueous ethanol as a mobile phase. Their antioxidant activities were tested in sunflower and rapeseed oils by using an Oxidograph apparatus at a temperature of 110 °C. Only the fractions III and IV displayed a pronounced antioxidant activity while the other fractions were either inactive or even pro‐oxidative. The active fractions contained phenolic acids and their esters; gallic acid, methyl and ethyl gallates, protocatechuic acid and its methyl ester were identified by GC/MS. Catechin was present, too, but exhibited only moderate antioxidant activity in sunflower oil. 相似文献
6.
Distribution and Antioxidant Activities of Free,Conjugated, and Insoluble-Bound Phenolics from Seven Species of the Genus Camellia 总被引:1,自引:0,他引:1
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
7.
Sushama Gomare Hyun A. Kim Jeong Hyub Ha Min Woo Lee Jong Moon Park 《Korean Journal of Chemical Engineering》2011,28(5):1252-1259
This study was conducted to isolate microorganisms from the gut of the marine turban shell, Batillus cornutus, which inhabits the mainland of South Korea and primarily feeds on brown algae. We were interested in isolating such gut
bacteria by considering their potential to produce the polysaccharidases required for digestion of brown seaweeds and isolated
three different bacteria from the gut of Batillus cornutus. The isolated bacteria were identified as Bacillus sp. JMP-A, Bacillus sp. JMP-B and Staphylococcus sp. JMP-C. The organisms were evaluated for their ability to produce polysaccharidases such as cellulase, alginate lyase,
laminarinase and kelp-lyase. Bacillus sp. JMP-A and Bacillus sp. JMP-B showed a clear zone of CMC hydrolysis with a radius 1.10 (±0.057) and 3.88 cm (±0.088), respectively, whereas Staphylococcus sp. JMP-C showed no zone of CMC hydrolysis. SEM analysis confirmed that the ability of the bacterial isolates to degrade
kelp differs and is correlated with kelp-lyase production. The cell free extract of the Bacillus sp. JMP-A isolate showed the highest activities of CM-cellulase, α-cellulase, laminarinase and kelp-lyase, which were 22.76, 27.10, 66.59 and 64.36 U/mg, respectively. Meanwhile, the amount
of sugars released was higher during the saccharification of kelp by dialyzed intracellular enzymes of the bacterial isolates
than when dialyzed extracellular enzyme was used. Experimental results of dialyzed enzymatic saccharification of the kelp
demonstrated that use of partially purified enzymes was effective for glucose production. 相似文献
8.
Lucía Cassani Catarina Loureno-Lopes Marta Barral-Martinez Franklin Chamorro Pascual Garcia-Perez Jesus Simal-Gandara Miguel A. Prieto 《International journal of molecular sciences》2022,23(4)
Algae are underexplored resources in Western countries and novel approaches are needed to boost their industrial exploitation. In this work, eight edible seaweeds were subjected to their valorization in terms of nutritional characterization, thermochemical properties, and bioactive profile. Our results suggest that seaweeds present a rich nutritional profile, in which carbohydrates are present in high proportions, followed by a moderate protein composition and a valuable content of ω-3 polyunsaturated fatty acids. The thermochemical characterization of seaweeds showed that some macroalgae present a low ash content and high volatile matter and carbon fixation rates, being promising sources for alternative biofuel production. The bioactive profile of seaweeds was obtained from their phenolic and carotenoid content, together with the evaluation of their associated bioactivities. Among all the species analyzed, Porphyra purpurea presented a balanced composition in terms of carbohydrates and proteins and the best thermochemical profile. This species also showed moderate anti-inflammatory activity. Additionally, Himanthalia elongata extracts showed the highest contents of total phenolics and a moderate carotenoid content, which led to the highest rates of antioxidant activity. Overall, these results suggest that seaweeds can be used as food or functional ingredient to increase the nutritional quality of food formulations. 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.
C. Ciavatta M. Govi L. Vittori Antisari P. Sequi 《Nutrient Cycling in Agroecosystems》1990,25(3):167-174
An enzymatic approach to assess the stability of organic matter extracted from organic fertilizers and amendments is proposed. The use of 0.1M NaOH plus 0.1M Na4P2O7 previously suggested as a suitable extractant solution for soil organic matter was also found satisfactory for the extraction of organic matter from organic fertilizers and amendments, especially when the temperature was raised to 65°C. The presence of nonhumified compounds in the extracts from organic fertilizers may interfere considerably during fractionation of organic carbon. An enzymatic hydrolysis with lipase, lysozyme and pronase, added sequentially to the extracts, led to an appreciable reduction in the interference. The interference was further reduced by carrying out a successive acid hydrolysis with 3N H2SO4; in this case the DH values (percentage of humified fractions with respect to total extractable carbon) were reduced to less than 10% in all organic fertilizers, but remained higher than about 70% in organic amendments. 相似文献
11.
This study compared algal palatability and chemical defenses from subtropical green algae that may use different types of defense systems that deter feeding by the rock-boring sea urchin Echinometra lucunter. The potential defense systems present include (1) the terpenoid caulerpenyne and its activated products from Caulerpa spp., and (2) dimethylsulfoniopropionate (DMSP)-related defenses in Ulva spp. Secondary metabolites from these chemical groups have been shown to deter feeding by various marine herbivores, including tropical and temperate sea urchins. Live algal multiple-choice feeding assays and assays incorporating algal extracts or isolated metabolites into an artificial diet were conducted. Several green algae, including Ulva lactuca, Caulerpa prolifera, and Cladophora sp., were unpalatable. Nonpolar extracts from U. lactuca deterred feeding, whereas nonpolar extracts from C. prolifera had no effect on feeding. Polar extracts from both species stimulated feeding. Caulerpenyne deterred feeding at approximately 4% dry mass; however, dimethyl sulfide and acrylic acid had no effect at natural and elevated concentrations. E. lucunter is more tolerant than other sea urchins to DMSP-related defenses and less tolerant to caulerpenyne than many reef fish. Understanding the chemical defenses of the algae tested in this study is important because they, and related species, frequently are invasive or form blooms, and can significantly modify marine ecosystems. 相似文献
12.
Dwiecki K Siger A Czubiński J Nogala-Kałucka M Lampart-Szczapa E 《Journal of the American Oil Chemists' Society》2012,89(3):379-387
The focus of the present research was to study inhibition of lipoxygenase activity by rapeseed native polyphenols and the
interactions between those compounds and the enzyme. The enzyme and polyphenolic compounds (polyphenols, phenolic acids) were
extracted from rapeseed (Brassica napus) varieties Aviso and PR45DO3. The total phenolic compounds concentration in tested rapeseed was 1,485–1,691 mg/100 g d.m. (dry matter) and the free phenolic
acids content in both rapeseed varieties was about 76 μg/100 g d.m. The isolated proteins showed lipoxygenase activity. Prooxidant
properties of phenolic compounds in the presence of lipoxygenase and linoleic acid were observed rather in the case of extracts
containing a relatively high concentration of miscellaneous polyphenols. Antioxidant properties were recorded in the case
of phenolic acid extracts which contain only 1.4–1.9% of phenolics present in raw phenolic extracts. We propose that the prooxidant
effect of phenolic compounds comes from quinone and oxidized polyphenols formation. The observed antioxidant activity of phenolic
acid extracts is probably due to their ability to scavenge free radicals formed from linoleic acid. However, reduction of
lipoxygenase ferric to ferrous ions, which prevent the activation of the enzyme and inhibited its activity, was also observed. 相似文献
13.
David A. Pereira de Abreu Karen Villalba Rodríguez José Manuel Cruz Freire 《European Journal of Lipid Science and Technology》2011,113(11):1395-1401
The capacity of the natural antioxidant from barley husks to retard oxidation of PUFA in cod liver oil (Gadus morhua) was investigated and compared to synthetic antioxidants. The results confirm the efficacy of a natural antioxidant derived from barley husks to slow down the progress of lipid hydrolysis and increase oxidative stability in cod liver oil. The rates of lipid hydrolysis and lipid oxidation were slowed down with increasing concentration of natural antioxidant used. Using 100 mg of the natural antioxidant was more effective than some synthetic antioxidants (BHA 200 mg and BHT 200 mg) against primary and secondary oxidation. The use of propyl gallate (PG) as an antioxidant (200 mg/kg in cod liver oil) was the most effective antioxidant employed in reducing the production of primary and delaying secondary oxidation products. The formation of free fatty acids (FFA) was significantly lower in samples with natural antioxidant (BE200 and BE100) than in the control samples. BHA and BHT were the most effective antioxidants employed to delay the lipid hydrolysis. Practical applications: The use of barley husks, which are residues of the brewing process, was optimized to obtain a crude antioxidant extract. Natural extracts of phenolic compounds with high antioxidant activity were obtained after prehydrolysis and delignification of barley husks. The raw extracts show more than two‐fold antioxidant capacity compared to BHT in terms of EC50. The results demonstrate the efficacy of a natural antioxidant derived from barley husks. The extract could be used in fatty foods (such as butter, oil, etc.) to prevent rancidity. 相似文献
14.
Abdalbasit Adam Mariod Ramlah Mohamad Ibrahim Maznah Ismail Norsharina Ismail 《Journal of the American Oil Chemists' Society》2010,87(1):35-43
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
15.
Sanjit Kanjilal Kaki Shiva Shanker Kotte Sagar Rao Kunduru Konda Reddy Bhamidipati V. S. K. Rao Kota B. Shiva Kumar Mannepalli L. Kantam Rachapudi B. N. Prasad 《European Journal of Lipid Science and Technology》2008,110(12):1175-1182
An efficient chemo‐enzymatic synthesis of ferulic acid‐based structured lipids mimicking triacylglycerol with a pendant phenolic moiety was carried out for the first time. Initially, ferulic acid was reduced to coniferyl alcohol, followed by its esterification with fatty acids. The key step in the synthesis was dihydroxylation of the olefinic side chain of coniferyl ester, which was eventually esterified with fatty acids to generate phenolic structured lipids. Two such compounds of varying fatty acid chain lengths were synthesized in good yield. Structural confirmation of both compounds is based on IR, 1H and 13C NMR, and MS techniques. The synthesized compounds were tested for in vitro antioxidant and antimicrobial activities. Both compounds exhibited moderate to good antioxidant activity. The phenolic structured lipid with only shorter‐chain fatty acids showed antibacterial activity. Both compounds did not show any antifungal activity. 相似文献
16.
The antioxidant activity of crude tannins of canola and rapeseed hulls was evaluated by β-carotene-linoleate, α,α-diphenyl-β-picrylhydrazyl
(DPPH) radical, and reducing power assays. Crude tannins were extracted from three samples of Cyclone canola (high-tannin)
hulls and Kolner, Ligaret, and Leo Polish rapeseed (low-tannin) hulls with 70% (vol/vol) acetone. The total phenolic content
in crude tannin extracts ranged between 128 and 296 mg of sinapic acid equivalents per 1 g of extract. The ultraviolet spectra
of methanolic solution of canola extracts showed two absorption maxima (282 and 309 nm), whereas those of rapeseed extracts
exhibited a single maximum (326 nm). Crude tannins isolated from canola hulls exerted significantly (P<0.025) greater antioxidant activity than those from rapeseed in all three assays. The scavenging effect of all crude tannins,
at a dose of 1 mg, on the DPPH radical ranged from 35.2 to 50.5%. The reducing power of Cyclone canola hull extracts on potassium
ferricyanide was significantly (P≤0.0025) greater than that of rapeseed hull extracts, and the observed data correlated well (r=0.966; P=0.002) with the total content of phenolics present. 相似文献
17.
In the forest industry, bark is an abundant residue, predominantly converted into calorific energy. As the antioxidant potential of phenolic compounds from sugar maple (Acer saccharum Marsh.) and red maple (Acer rubrum L.) bark has previously been established, the present study focused on the hot-water extraction optimization of these barks. Several process parameters (maple species, temperature, duration, ratio bark/water, particle size) were thus studied and large disparities were found between the two species. Extraction yield, phenolic content, and antioxidant capacity of red maple extracts were several times higher than those of sugar maple extracts. Principal component analysis, applied to the selected best extraction conditions, identified 3–4 clusters depending on the maple species. These groups were sorted from the highest extraction yield and energy consumption combined with the lowest phenolic content and antioxidant capacity, to moderate extraction yield and energy consumption with the highest phenolic content and antioxidant capacity. 相似文献
18.
Ultrasonic-assisted enzymatic extraction (UEAE) and response surface methodology (RSM) were used to isolate polysaccharides from Setaria viridis (SVP). Optimal extraction conditions in the enzymatic hydrolysis process were: extraction duration, 68 min; extraction temperature, 51°C; ratio of enzyme to raw material, 1.6%; and ratio of liquid to raw material, 20 mL/g. Then, following ultrasonic treatment (180 W, 60°C, 60 min), the experimental yield was 8.94 ± 0.38%. Crude SVP was purified by DEAE cellulose-52 chromatography and Sephadex G-100 chromatography, resulting in the isolation of three fractions (designated SVP-1, SVP-2 and SVP-3). These SVPs were mainly composed of glucose residue, and SVP-3 had a significantly higher uronic acid content than the other two fractions. Additionally, all fractions showed strong antioxidant activities in vitro. 相似文献
19.
Magdalena Karamać 《Journal of the American Oil Chemists' Society》2010,87(5):559-566
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
20.
Fumiko Hara Toshimitsu Nakashima Hideki Fukuda 《Journal of the American Oil Chemists' Society》1997,74(9):1129-1132
Nineteen commercial lipase preparations were compared with respect to their ability to hydrolyze phosphatidylcholine (PC)
in a reverse micellar system. In terms of the source organism, lipases from Mucor or Rhizopus species showed comparatively high reactivity, while those from Aspergillus and Humicola sp. exhibited little PC hydrolysis activity. Almost no hydrolysis reaction was observed by positionally nonspecific lipases
derived from Candida sp. The results suggest that particular attention should be paid to the source organism in selecting lipases for use in the
enzymatic conversion of phospholipids. 相似文献