Oxidation Of Linoleic Acid Research Articles

Leafy Stems of Phagnalon saxatile subsp. saxatile from Algeriaas a Source of Chlorogenic Acids and Flavonoids with Antioxidant Activity: Characterization and Quantification Using UPLC-DAD-ESI-MSn.

Phagnalon saxatile subsp. saxatile is a wild species widespread in Algeria which is utilized for medicinal purposes as analgesic and anticholesterolemic. However, information is still scarce regarding its phytochemical content. The objective of this study was to identify and quantify the phenolic compounds from different extracts of its leafy stems. For this purpose, the effects of four extracting solvents were investigated on the content of phenolic compounds and the antioxidant activity of this plant. The extracts prepared with polar solvents (methanol and water) contained higher amounts of phenolic compounds and showed better antioxidant activity than the extracts with apolar solvents (hexane, dichloromethane). The methanolic extract, richest in total phenolic and total flavonoid, had significant antioxidant activity as regarded by DPPH° scavenging capacity (IC50 of 5.5 µg/mL), ABTS+° scavenging capacity (IC50 of 63.8 µg/mL) and inhibition of oxidation of linoleic acid (IC50 of 22.7 µg/mL), when compared to synthetic antioxidants. Chlorogenic acids and several flavonoids were identified and quantified by UPLC-DAD-MSn. The di-O-caffeoylquinic acids isomers were the most concentrated phenolics (25.4 mg/g DW) in the methanolic extract.

Antioxidant activities of pomegranate peel methanolic and water extracts by in vitro methods

In this study, the antioxidant activities of pomegranate (Punica granatum) peel extracts were investigated using different antioxidant activity methods. The antioxidant activities of extracts prepared at different concentrations (100-1000 μg/ml) were compared with α-tocopherol, ascorbic acid, BHT, and BHA standards. The methanol extract of peels had the highest yield (45.5%). Chelating activities (Fe2+) of methanol extract at 100-1000 μg/ml concentrations ranged between 16.63 and 46.45%. However, the chelating activities of all test extracts were lower than the standards. The reducing power of all extracts increased concentration-dependent. DPPH˙˙ radical scavenging activity of methanol extract varied in the range of 18.53 to 88.75%. The highest percentage inhibition of linoleic acid oxidation was found in 250 μg/ml concentrations. Trolox equivalent (TEs) antioxidant capacity values of methanol extract ranged from 3.09 to 15.27 µM TEs 10 g-1. It was determined that methanol extract showed a dose-dependent inhibition of the antioxidant activities.

Evaluation of antidiabetic, antioxidant, and cytotoxic potential of maize (zea mays l.) husk leaf extracts.

In current study, Maize (Zea mays L.) husk leave extracts were appraised for biological activities such as cytotoxicity, antidiabetic, antioxidant and antimicrobial. Maceration was performed to collect various fractions of husk leave extracts using a pool of solvents i.e., n-hexane, chloroform, ethyl acetate, butanol and methanol. Antioxidant potential was measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging, reducing power and linoleic acid oxidation assay, using butylated hydroxy toluene (BHT) as a positive control. Total phenolic and flavonoid contents were found to be 18.47-425.11 mg/100 g GAE and 5.83-16.72 mg/100 g CE, respectively. The DPPH scavenging assay was exhibited in the range of 76.36 to 88.53%. The percentage inhibition in linoleic acid oxidation was found from 10.16 to 79.51%. Significant antimicrobial activity was demonstrated by husk leaf extracts against bacterial strains and fungal strains using disc diffusion and minimum inhibitory concentration (MIC) method. Amylase alpha assay was employed to analyze the antidiabetic activity which ranged between 9.52-24.81%. Cytotoxicity was evaluated by % age lysis (0.35-9.54%), while thrombolytic activity ranged between 7.67 to 31.27%. The results presented in this study revealed that maize (Zea mays L.) husk leaf extracts can be a valuable source of biologically active compounds and may be consumed as a source of potent herbal medicine in pharmaceuticals.

Epigallocatechin Gallate During Dietary Restriction - Potential Mechanisms of Enhanced Liver Injury.

Green tea extract (GTE) is popular in weight loss, and epigallocatechin gallate (EGCG) is considered as the main active component. However, GTE is the primary cause of herbal and dietary supplement-induced liver injury in the United States. Whether there is a greater risk of liver injury when EGCG is consumed during dieting for weight loss has not been previously reported. This study found for the first time that EGCG could induce enhanced lipid metabolism pathways, suggesting that EGCG had the so-called “fat burning” effect, although EGCG did not cause liver injury at doses of 400 or 800 mg/kg in normal mice. Intriguingly, we found that EGCG caused dose-dependent hepatotoxicity on mice under dietary restriction, suggesting the potential combination effects of dietary restriction and EGCG. The combination effect between EGCG and dietary restriction led to overactivation of linoleic acid and arachidonic acid oxidation pathways, significantly increasing the accumulation of pro-inflammatory lipid metabolites and thus mediating liver injury. We also found that the disruption of Lands’ cycle and sphingomyelin-ceramides cycle and the high expression of taurine-conjugated bile acids were important metabolomic characteristics in EGCG-induced liver injury under dietary restriction. This original discovery suggests that people should not go on a diet while consuming EGCG for weight loss; otherwise the risk of liver injury will be significantly increased. This discovery provides new evidence for understanding the “drug-host” interaction hypothesis of drug hepatotoxicity and provides experimental reference for clinical safe use of green tea-related dietary supplements.

Lipids Oxidized Volatile Compounds Profuced in Pine Pollen as affected by Electron-beam Sterilization and Ultra-high Temperature Sterilization

ABSTRACT Pine pollen is rich in unsaturated fatty acids. However, unsaturated fatty acids are oxidized during processing. The oxidation of lipids may affect the odor of pine pollen. Different sterilization methods have different effects on lipid oxidation. In this study, we found that electron-beam sterilization is superior to ultra-high temperature sterilization in odor preservation. Using gas chromatography–mass spectrometry, volatile components were identified in electron-beam sterilization and ultra-high temperature sterilization processed pine pollen. Furthermore, the loss of vitamin C and polyphenols in the processing aggravated lipid oxidation, which made the odor of pine pollen worse. Moreover, lipid oxidase can accelerate lipid oxidation, thus affecting the odor of pine pollen, which was not conducive to the preservation of pine pollen. The results suggested that the components of unpleasant odor were identified as volatile aldehydes and volatile acids, and the odor was mainly produced by the oxidation of linoleic acid.

Anthocyanins profiling of bilberry (Vaccinium myrtillus L.) extract that elucidates antioxidant and anti-inflammatory effects

ABSTRACTBilberry (Vaccinium myrtillus L.) is a medicinal fruit known for its high content of anthocyanins, flavonoids, vitamins, ascorbic acid, carotenoids, tocopherols and phenolic acid. Bilberry has long been used in oriental medicine for the prevention and treatment of various diseases, such as visual acuity, hyperglycemia, dyslipidemia, diabetes, cancer, obesity, inflammatory and cardiovascular diseases. In this study, we investigated using the antioxidant and anti-inflammatory of 70% ethanol extracts of bilberry in vitro. Antioxidant activities were measured with total phenolic, flavonoid and ascorbic acid contents. The bilberry extract (BE) showed significant free radical scavenging activities and inhibited oxidation of linoleic acid in a dose-dependent manner. BE also suppressed nitric oxide (NO) generation and reversed pro-inflammatory cytokines such as iNOS, COX-2, TNF-α and IL-6 in LPS-induced RAW 264.7 cells. From these results, we suggest that BE is a natural powerful antioxidant, and the anti-inflammatory agent being a rich source of anthocyanins.

Phytochemicals Analysis and Some Bioactive Properties of Erica manipuliflora Salisb. (EMS); Antibacterial, Antiradical and Anti-lipid Peroxidation.

In the present study, the phenolic content by using LC MS/MS method, anticholinergic, antioxidant (metal reduction, radical and removal of lipid peroxidation), and antibacterial activities of Erica manipuliflora Salisb. (EMS) extract were determined. The amount of vanillic acid, fumaric acid, catechin hydrate, quercetin, and phloridzin dihydrate were found higher than other compounds. The ethanol extract of the EMS showed an inhibition effect on the Acetylcholinesterase (AChE) enzyme with IC50 value of 0.124 ± 0.008 mg mL-1. Also, this extract of the EMS indicated radical (DPPH and ABTS) scavenging activity (about 20%) and the reducing capacity for Cu(II) and Fe(III) close to trolox, and inhibited the oxidation of linoleic acid with 40.5% at 20 μg mL-1. Antibacterial activity of the extracts was investigated against Staphylococcus aureus, Escherichia coli, and Salmonella Typhimurium using agar disc diffusion and minimum inhibitory concentration (MIC) methods. The EMS extract was found to be effective when used at least 312 mg mL-1 concentration on the pathogenic microorganisms. Consequently, it has an important non-synthetic natural content that can be used in the treatment of many diseases due to its many bioactivities such as anticholinergic, antioxidant (radical removal, lipid peroxidation prevention, etc.) and antibacterial.

Evaluation of Antioxidant Activity of Sour Cherry Stalk Extracts by in Vitro Methods

In this study, the antioxidant activities of sour cherry (Prunus cerasus L.) stalk extracts were investigated using β-caroten/linoleic acid, metal chelating, reducing power, DPPH radical scavenging, ABTS method and TEAC method. For this purpose the stalks were extracted separately by using distilled water, methanol, ethyl acetate and hexane solvents following dried and ground to fine powder. The antioxidant activities of extracts prepared at the different concentration (100-1000 μg/mL) were compared with α-tocopherol, ascorbic acid, BHT and BHA standards. The methanol extract of stalk had the highest yield (22%). Chelating activities (Fe2+) of methanol extract at 100-1000 μg/mL concentrations ranged between 18.45 and 67.75%. However, chelating activities of all test extracts were found lower than standards. The reducing power of all extracts except hexane increased depending upon the increase in concentration. DPPH radical scavenging activity of methanol extract varied in the range of 14.57 to 85.78%. The lowest EC50 value was determined as 0.494 µg/mL for methanol extract. But, the highest inhibition percentage of linoleic acid oxidation was found in hexane extract (57.22%). TEAC values of methanol extract ranged from 15.43 to 20.54 µM Trolox equivalent/10 g. It was determined that methanol extract showed a dose-dependent inhibition on the antioxidant activities.

Antilipoxygenase and Anti-Inflammatory Activities of Streblus asper Leaf Extract on Xylene-Induced Ear Edema in Mice

Streblus asper (SA) belonging to the Moraceae family is well known as a folk medicinal plant in Asian countries. This study aimed to investigate the antilipoxygenase activity and the anti-inflammatory effects of the SA leaf extract. An in vitro antilipoxygenase study was performed using a lipoxygenase assay, and the oxidation of linoleic acid into 13-hydroperoxy linoleic acid (HPODE) was detected with a UV spectrophotometer at a wavelength of 234 nm. In the animal study, twenty-five male ICR mice were induced as ear edema by topical xylene, and the ear thickness of the mice was measured. The lipoxygenase assay results showed that the IC50 values of diclofenac sodium and SA were 0.0015 and 37.96 μg/mL, respectively. In the animal study, mice that received diclofenac sodium exhibited significantly reduced ear edema induced by xylene from 30 min onward, while mice that received 250 mg/kg and 500 mg/kg SA exhibited significantly reduced ear edema compared with the control group 45 min after induction with xylene. These results suggested that the SA leaf extract had anti-inflammatory activity. However, further studies are required to evaluate these effects and the additional potential of the plant that might be beneficial for the development of pharmaceutical products that prevent and treat inflammation.

Antioxidants activity and cholesterol regulation effect of Caralluma flava N.E.Br extract in HepG2 cells

Herbal medicine has a long-standing history in many locations in Yemen and continue to provide useful and applicable tools for treating ailments. The objectives of the present study are to investigate antioxidant activity and cholesterol regulatory effect of Caralluma flava N.E.Br methanolic extract (CFM) through chemical and molecular approaches. CFM afforded the yield of 18 % (w/w) through methanolic extraction and contained considerable amount of phenolic and flavonoid compounds (9.22 ± 1.4 mg/g) and 3.35 ± 0.16 mg/g respectively). Antioxidant activity assays revealed that CFM are effective antioxidant with 76.8% DPPH scavenging activity bleaching inhibitory activity. Result from s-carotene–linoleic acid assay shows that CFM efficiently retarded the oxidation of linoleic acid in the reaction system compared to control. CFM regulate the expression of cholesterol metabolism genes in HepG2 cells in a dose-dependent manner. The low-density lipoprotein receptor (LDLR) mRNA level was significantly up-regulated by 1.3, 2.4 and 3.2 fold compared to control cells. The mRNA level of 3-Hydroxy-3-Methylglutaryl-CoA Reductase (HMGCOA) was significantly suppressed by 12, 30 and 50% in a dose dependent manner compared to the control cells treated with 20, 50 and 100 µg/ml of CFM respectively. Apolipoprotein A-1 (Apo A-1) gene was up-regulated by 1.7 and 2.2 fold and apolipoprotein B100 (Apo B100) gene was suppressed by 11% and 24% in HepG2 cells treated with 50 and 100 µg/ml of CFM respectively, compared to control cells. In conclusion, CFM is a potential cardioprotector through enhancement of cholesterol regulation and exertion of antioxidant activity.

Linoleate diol synthase related enzymes of the human pathogens Histoplasma capsulatum and Blastomyces dermatitidis

Histoplasma capsulatum is an ascomyceteous fungus and a human lung pathogen, which is present in river valleys of the Americas and other continents. H. capsulatum and two related human pathogens, Blasmomyces dermatitidis and Paracoccidioides brasiliensis, belongs to the Ajellomycetaceae family. The genomes of all three species code for three homologous and tentative enzymes of the linoleate diol synthase (LDS) family of fusion enzymes with dioxygenase (DOX) and cytochrome P450 domains. One group aligned closely with 8R-DOX-5,8-LDS of Aspergilli, which oxidizes linoleic acid to 5S,8R-dihydroxylinoleic acid; this group was not further investigated. The second group aligned with 10R-DOX-epoxy alcohol synthase (EAS) of plant pathogens. Expression of this enzyme from B. dermatitidis revealed only 10R-DOX activities, i.e., oxidation of linoleic acid to 10R-hydroperoxy-8E,12Z-octadecadienoic acid. The third group aligned in a separate entity. Expression of these enzymes of H. capsulatum and B. dermatitidis revealed no DOX activities, but both enzymes transformed 13S-hydroperoxy-9Z,11E-octadecadienoic acid efficiently to 12(13S)epoxy-11-hydroperoxy-9Z-octadecenoic acid. Other 13-hydroperoxides of linoleic and α-linolenic acids were transformed with less efficiency and the 9-hydroperoxides of linoleic acid were not transformed. In conclusion, a novel EAS has been found in H. capsulatum and B. dermititidis with 13S-hydroperoxy-9Z,11E-octadecadienoic acid as the likely physiological substrate.

Physicochemical and Structural Characteristics of Soybean Protein Isolates Induced by Lipoxygenase-Catalyzed Linoleic Acid Oxidation during In Vitro Gastric Digestion.

The effects of oxidation on the gastric digestion properties of soybean protein isolates (SPIs) in a model of lipoxygenase (LOX)-catalyzed linoleic acid (LA) oxidation system and the multiscale structural characterization of SPI hydrolysate were investigated. Results indicated that the feature of SPI hydrolysate is dependent upon the degree of oxidation. Pepsin hydrolysis caused a red shift in fluorescence intensity and a reduction in surface hydrophobicity and diminished the particle size of SPI hydrolysate during gastric digestion. Compared with the control, mild oxidation was beneficial to protein unfolding and gastric digestibility, as manifested by minimal molecular weight (MW) distribution >50 kDa (32.34%) and smaller peptide fragments under scanning electron microscopy. However, severe oxidation brought about 39.47% loss of free amino acids. It was interesting to find that glycinin was more vulnerable to pepsin hydrolysis after oxidation as compared to the native SPI. Overall, the moderately oxidized SPI appeared to be digested to a greater extent.

Effect of fatty acids on the flavor formation of fish sauce

An appropriate fish model helps track changes of lipid and fatty acid during fermentation. Here we selected three freshwater fish (Culter alburnus, Carassius auratus and Ietalurus Punetaus) as the fermentative materials of fish sauce due to their significantly different contents of lipid and unsaturated fatty acid. The electronic nose showed that the flavor profiles of sauce samples prepared with different fish were dramatically different. A total of 71 volatile compounds of fish sauce were detected by solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC/MS). Then nine key flavor compounds, including 3-methylbutanal, 3-methyl-1-butanol, 3-(methylthio)propanal, 1-octen-3-ol, phenylacetaldehyde, nonanal, dimethyl trisulfide, decanal and hexanol, were screened based on odor activity values. According to correlation analysis between fatty acid profiles and fish sauce aroma, possible pathways of oleic acid (C18:1) and linoleic acid (C18:2) oxidation were suggested: oleic acid undergone the auto-oxidation to mainly form 10- hydroperoxide and 11- hydroperoxide, and (or) secondary form 8-hydroperoxide, then converted to nonanal, octanal and decanal; linoleic acid undergone the enzymatic oxidation to form 10-L(S)-hydroperoxy-cis-9, trans-11-octadecadieuoic acid, then converted to 1-octen-3-ol.

Comparative performance analysis of enzyme inactivation of soy milk by using RSM and ANN

AbstractThe presence of antinutritional factors as trypsin inhibitors (TIA) and lipoxygenase (LOX) in soy milk produces indigestion and off‐flavor due to oxidation of linoleic acid to hyperoxide. The objective of the study was to determine the prediction capacity of response surface methodology (RSM) and artificial neural network (ANN) for enzyme inactivation of soy milk. The microwave and thermo‐sonication method were used to prepare and treat the sample. Statistical parameters like NRMSE and %MAE were used to compare and evaluate the final result. NRMSE value had shown five times better results in the case of ANN (0.015) compared to RSM (0.082). Similarly, the % MAE value was also fivefold better in the case of ANN. In the case of RSM, Chi‐square values for TIA and LOX were 317.32 and 146.73, respectively. Whereas for ANN, the value was 4.68 and 2.69, respectively. So, it can be concluded that the prediction capacity of ANN is better than RSM.Practical ApplicationsThis modeling has a tremendous potential contributing to prediction of enzymes inactivation without real‐time experiments with great accuracy. Moreover, a number of industries are producing soy milk nowadays, and it could be helpful in elimination of beany flavor with desirable inactivation of lipoxygenase and enhancing the digestibility by removing trypsin inhibitors with appropriate environmental conditions. In addition, it can also pave the way for a number of food processing technology in which enzymatic inactivation is prominent and the prediction of percentage inactivation is crucial. This technique could be applied to predict the yield of any process after maintaining a certain treatment and process condition. Process engineering of any industry and biochemical processes are very sensitive to small changes in parameters and their effects could be predicted by using the modern approach of artificial neural network with more preciseness without running the actual experiments.

Amino acid composition and antioxidant properties of the enzymatic hydrolysate of calabash nutmeg (Monodora myristica) and its membrane ultrafiltration peptide fractions.

The aim of this work was to determine amino acid composition and in vitro antioxidant activities of Monodora myristica protein hydrolysate and its membrane ultrafiltration peptide fractions. The Alcalase hydrolysate was fractionated using ultrafiltration membranes to produce peptide sizes of <1, 1-3, 3-5, and 5-10kDa. The results showed that sequential fractionation resulted in higher glycine and glutamic acid and glutamine contents. Analysis of in vitro antioxidant properties showed that fractionation of the M. myristica hydrolysate led to significant (p<.05) improvements in 2,2-diphenyl-1-picrylhydrazyl radical scavenging, metal chelation activity, ferric reducing antioxidant power (FRAP), and hydroxyl (OH) radical scavenging activity. Linoleic acid oxidation was significantly (p<.05) attenuated by the peptide fractions. We conclude that peptide antioxidant activities were significantly (p<.05) improved by membrane fractionation, especially the 3-5kDa fraction. PRACTICAL APPLICATIONS: The use of protein hydrolysate fractions with potential to prevent oxidation, which can reduce shelf life of foods and cause degenerate diseases due to cell damage is proposed for Monodora myristica. The demand for natural products and negative health issues associated with artificial food ingredients have led to increased consumer preference for natural sources of antioxidants. The protein hydrolysate and membrane fractions produced in this work showed high antioxidant ability that could qualify them to replace toxic synthetic antioxidants in foods. Peptide fractions had better metal chelation than the hydrolysates, which is important because chelation of metal ions can decrease the amount of free iron available to participate in the Fenton reaction and ultimately decrease the formation of toxic free radicals. Incorporation of the peptides into foods will enhance scavenging of toxic free radicals that may form during storage, thereby improving product freshness and shelf life in addition to preventing human degenerative diseases.

Bioprocessing of Brewers' Spent Grain Enhances Its Antioxidant Activity: Characterization of Phenolic Compounds and Bioactive Peptides.

Brewers’ spent grain (BSG) is the major by-product of the brewing industry which remain largely unutilized despite its nutritional quality. In this study, the effects of fermentation on BSG antioxidant potential were analyzed. A biotechnological protocol including the use of xylanase followed by fermentation with Lactiplantibacillus plantarum (Lactobacillus plantarum) PU1, PRO17, and H46 was used. Bioprocessed BSG exhibited enhanced antioxidant potential, characterized by high radical scavenging activity, long-term inhibition of linoleic acid oxidation and protective effect toward oxidative stress on human keratinocytes NCTC 2544. Immunolabelling and confocal laser microscopy showed that xylanase caused an extensive cell wall arabinoxylan disruption, contributing to the release of bound phenols molecules, thus available to further conversion through lactic acid bacteria metabolism. To clarify the role of fermentation on the antioxidant BSG potential, phenols were selectively extracted and characterized through HPLC-MS techniques. Novel antioxidant peptides were purified and identified in the most active bioprocessed BSG.

Modeling of Ultrasound Assisted Extraction, Chemical Composition, Antioxidant Activity, Rheological Aspects, and Biological Properties of “Barhang-e-Kabir” Mucilage

In this study, response surface methodology (RSM) was used to investigate the influence of independent process parameters including water to seed ratio (g/g), temperature (°C), time (min) and ultrasonic intensity (%) on extraction yield of “Barhang-e-kabir”. Chemical composition, monosaccharide composition (using HPAEC-PAD), molecular conformation, molecular weight properties, Surface tension, ζ-potential, particle size distribution, Fourier transform infrared spectroscopy (FTIR), color measurement, total phenol content (TPC), total flavonoid content (TFC), antioxidant activity (AA), antimicrobial and dilute-solution and steady-state behavior were evaluated. The optimum condition to obtain maximum extraction yield (13.1 %) was extraction temperature 70 ᵒC, extraction time 40 min, water to seed ratio of 1:10, ultrasonic power of 90 %. Plantago major gum (PMG) had 89.24% carbohydrate, 4.53% ash, 4.11% moisture and 2.12% protein. Viscometric molecular weight and average molecular weight were found to be 1.13 ×105 g/mol and 9.9 ×105 g/mol, respectively. The intrinsic viscosity of PMG was 12.56 dL/g in deionized water at 25 oC. Steady shear measurement demonstrated that PMG is a shear thinning fluid with high viscosity at low concentration. TPC, TFC and AA (IC50) tests of PMG showed 89.80 ± 1.23 mg GAE g−1dry sample, 123.25 ± 1.32 mg g−1dry sample and 470.45 ± 0.35 µg/ml, respectively. Prevention of the linoleic acid oxidation in the system of s-Carotene-linoleic acid was equal to 32.45 %. The results showed that Streptococcus pyogenes and Pseudomonas aeruginosa the most sensitive and highest resistance strain to PMG, respectively.

Antifungal, antitoxigenic, and antioxidant activities of the essential oil from laurel (Laurus nobilis L.): Potential use as wheat preservative.

Essential oils (EOs) are widely used in the food industry as natural food preservatives to extend product shelf life and as flavoring agents. The aim of this work was to study the chemical profile of the EO from laurel (Laurus nobilis) and its antifungal, antitoxigenic, and antioxidant activities. The extractive yield of the EO from Algerian laurel was 1.13% being 1,8‐cineole the most dominant compound (35.5%) by gas chromatography–mass spectrometry analysis. The values of minimum inhibitory concentration and minimum fungicidal concentration (MFC) against Aspergillus flavus were 1.75 and 2 mg/ml, respectively. The production of aflatoxin B1 was inhibited by EO concentrations between 0.25 mg/ml (15% decrease) and 1.50 mg/ml (86% decrease), and it was totally inhibited at the MFC value. The EO showed a wide antifungal spectrum against other species in a dose‐dependent manner. In a food‐model study, the L. nobilis EO showed remarkable efficacy in fumigated wheat grains, providing from 51.5% to 76.7% protection against A. flavus during 6‐month storage. The L. nobilis EO showed good free radical scavenging activity by DPPH assay (IC50 value of 602 μg/ml) and moderate antioxidant activity in the β‐carotene bleaching assay (46% inhibition of linoleic acid oxidation). The conclusions of this study justify future research for the application of EO from laurel as a natural preservative to improve food safety and extend shelf life by controlling spoilage and toxigenic molds as well as oxidative damage.

Chemical composition and in vitro antioxidant properties of water-soluble extracts obtained from Bangladesh vegetables.

The aim of this study was to evaluate the nutritional value and antioxidant properties of aqueous extracts of some Bangladesh vegetables using fruits of ash gourd, bitter gourd, brinjal, okra, ridge gourd, snake gourd, and leaves of Indian spinach, kangkong, and stem amaranth. Proximate composition showed that the dried extracts were composed mainly of crude protein (14.6%-46.7%) and non-fibre carbohydrates (26.4%-53.5%). With the exception of stem amaranth, all the extracts had >40% DPPH radical scavenging ability at 0.5mg/ml. In contrast metal chelation was lower, except in Indian spinach with ~46%. The ferric reducing antioxidant power (FRAP) was highest for the kangkong (10.9mM Fe3+ reduced), which is similar to the 9.9mM for butylated hydroxytoluene (BHT). All the extracts suppressed linoleic acid oxidation better than BHT within the first 5days of the incubation period. We conclude that the Indian spinach, kangkong, and okra could be considered as the most promising sources of antioxidant compounds. PRACTICAL APPLICATIONS: Vegetables are commonly consumed as part of a regular diet but the high water and fiber contents usually mean that large quantities are required to provide long-term health benefits. Therefore, in this work, aqueous extracts of nine Bangladesh vegetables were prepared to provide a more concentrated form of nutrients and bioactive compounds. The extracts had strong nutritional value based on the high contents of crude protein, potassium, iron, and non-fibre carbohydrates. The high content of polyphenolic compounds in the extracts can also provide health benefits, which was demonstrated through strong free radical scavenging, metal chelation, ferric iron reduction, and inhibition of linoleic acid oxidation. These vegetable extracts have the potential to be used as sources of bioactive compounds to prevent or treat non-communicable diseases that are associated with high oxidative stress.

Diagnose the Bioactive Compounds in Flaxseed Extract and Its Oil and Use Their Mixture as an Antioxidant

The aim of this study is to extract the important antioxidants components of flaxseed in different ways. The Determination of total phenol content, antioxidant activity and percentage of linoleic acid inhibition by DPPH for the components (Lignan, oil, 80 and 100% ethanolic extract and the deionized water extract). The components of flaxseed oil were identified using GC/MS. The efficiency of the mixture (80% ethanolic extract and oil) was determined by inhibiting the process of oxidation of linoleic acid during storage periods (0, 7, 14 and 21 days) at laboratory temperature, and the following results were obtained: The yield of lignan, oil, ethanol extract (80 and 100)% and deionized water were (0.12,40.52,10.9,9.6 and 13 )g.100g-1 seed respectively, while the total phenolic content of the above components was (700,1165,3315,2098 and 483)mgGAE.100g-1,respectively. Flaxseed oil gave the highest antioxidant activity 79.3% with an inhibition percentage 73.19%, compared with ethanolic extract, lignan and water extract. The diagnosis of GC/MS flaxseed oil showed that the oil was contained in compounds with antioxidant activity, including mono, di and tri-terpens such as Copaene, Monoterpene, ?- Sesquiphellandrene, Squalene, diethyl phthalate ,?-Sitosterol and Hexadecanoic acid, as well as, the presence of ascorbic acid and gamma tocopherol with good concentrations (8.68 and 2.62)% respectively. The mixture of 80% ethanol and oil extract showed an effect in decreasing of peroxide values with an increase of concentration of the added mixture (0.1, 0.4 and 0.10 mg.mg-1). The maximum reduction of the peroxide value at the concentration was 0.6 mg. mg-1, compared with the standard sample during the different durations of storage.