Showing papers on "Ascorbic acid published in 2010"
TL;DR: It is demonstrated that the individual graphene oxide sheets can be readily reduced under a mild condition using L-ascorbic acid (L-AA), which should find practical applications in large scale production of water soluble graphene.
2,113 citations
TL;DR: The role of redox metals Fe and Cu and non-redox metal zinc (Zn) in oxidative stress-related etiology of AD and PD is discussed and several individual antioxidants or their combinations can be neuroprotective and decrease the risk of AD or slow its progression.
Abstract: The neurodegenerative diseases, Alzheimer's disease (AD) and Parkinson's disease (PD), are age-related disorders characterized by the deposition of abnormal forms of specific proteins in the brain. AD is characterized by the presence of extracellular amyloid plaques and intraneuronal neurofibrillary tangles in the brain. Biochemical analysis of amyloid plaques revealed that the main constituent is fibrillar aggregates of a 39-42 residue peptide referred to as the amyloid-β protein (Aβ). PD is associated with the degeneration of dopaminergic neurons in the substantia nigra pars compacta. One of the pathological hallmarks of PD is the presence of intracellular inclusions called Lewy bodies that consist of aggregates of the presynaptic soluble protein called α-synuclein. There are various factors influencing the pathological depositions, and in general, the cause of neuronal death in neurological disorders appears to be multifactorial. However, it is clear, that the underlying factor in the neurological disorders is increased oxidative stress substantiated by the findings that the protein side-chains are modified either directly by reactive oxygen species (ROS) or reactive nitrogen species (RNS), or indirectly, by the products of lipid peroxidation. The increased level of oxidative stress in AD brain is reflected by the increased brain content of iron (Fe) and copper (Cu) both capable of stimulating free radical formation (e.g. hydroxyl radicals via Fenton reaction), increased protein and DNA oxidation in the AD brain, enhanced lipid peroxidation, decreased level of cytochrome c oxidase and advanced glycation end products (AGEs), carbonyls, malondialdehyde (MDA), peroxynitrite, and heme oxygenase-1 (HO-1). AGEs, mainly through their interaction with receptors for advanced glycation end products (RAGEs), further activate signaling pathways, inducing formation of proinflammatory cytokines such as interleukin-6 (IL-6). The conjugated aromatic ring of tyrosine residues is a target for free-radical attack, and accumulation of dityrosine and 3-nitrotyrosine has also been reported in AD brain. The oxidative stress linked with PD is supported by both postmortem studies and by studies showing the increased level of oxidative stress in the substantia nigra pars compacta, demonstrating thus the capacity of oxidative stress to induce nigral cell degeneration. Markers of lipid peroxidation include 4-hydroxy-trans-2-nonenal (HNE), 4-oxo-trans-2-nonenal (4-ONE), acrolein, and 4-oxo-trans-2-hexenal, all of which are well recognized neurotoxic agents. In addition, other important factors, involving inflammation, toxic action of nitric oxide (NO·), defects in protein clearance, and mitochondrial dysfunction all contribute to the etiology of PD. It has been suggested that several individual antioxidants or their combinations can be neuroprotective and decrease the risk of AD or slow its progression. The aim of this review is to discuss the role of redox metals Fe and Cu and non-redox metal zinc (Zn) in oxidative stress-related etiology of AD and PD. Attention is focused on the metal-induced formation of free radicals and the protective role of antioxidants [glutathione (GSH), vitamin C (ascorbic acid)], vitamin E (α-Tocopherol), lipoic acid, flavonoids [catechins, epigallocatechin gallate (EGCG)], and curcumin. An alternate hypothesis topic in AD is also discussed.
956 citations
TL;DR: It would be timely to develop a range of iron bioavailability factors based not only on diet composition but also on subject characteristics, such as iron status and prevalence of obesity.
949 citations
TL;DR: It is reported that a natural compound, vitamin C (Vc), enhances iPSC generation from both mouse and human somatic cells, acts at least in part by alleviating cell senescence, a recently identified roadblock for reprogramming.
913 citations
TL;DR: The synthesis of graphene using a modified Hummer's method and its application for the electrochemical detection of dopamine was reported and the capacity of graphene modified electrode for selective detection of serotonin was confirmed in a sufficient amount of ascorbic acid.
665 citations
TL;DR: It is shown that the F-C reagent is significantly reactive toward other compounds besides phenols, which should be seen as a measure of total antioxidant capacity rather than phenolic content.
Abstract: A thorough study was done to test the reactivity of the Folin−Ciocalteu (F-C) reagent toward various compound classes. Over 80 compounds were tested. Compound classes included phenols, thiols, vitamins, amino acids, proteins, nucleotide bases, unsaturated fatty acids, carbohydrates, organic acids, inorganic ions, metal complexes, aldehydes, and ketones. All phenols, proteins, and thiols tested were reactive toward the reagent. Many vitamin derivatives were also reactive, as were the inorganic ions Fe+2, Mn2+, I−, and SO32−. Other compounds showing reactivity included the nucleotide base guanine and the trioses glyceraldehyde and dihydroxyacetone. Copper complexation enhanced the reactivity of salicylate derivatives toward the reagent, whereas zinc complexation did not. Several amino acids and sugars that were reported to be reactive toward the F-C reagent in earlier studies were found not to be reactive in this study, at least in the concentrations used. Reaction kinetics of each compound with the F-C rea...
635 citations
TL;DR: Co3O4 nanofibers have great potential applications in the development of sensors for enzyme-free detection of glucose and are demonstrated to have good reproducibility and selectivity in alkaline solution.
623 citations
TL;DR: The CuO/MWCNTs electrode exhibits an enhanced electrocatalytic property, low working potential, high sensitivity, excellent selectivity, good stability, and fast amperometric sensing towards oxidation of glucose, thus is promising for the future development of nonenzymatic glucose sensors.
592 citations
TL;DR: More efforts are required to understand the role of proximate composition of fish, post harvest histor y, environmental conditions, initial microbial load, t ype and nature of bacteria and their interaction in order to optimize the shelf-life of fish.
Abstract: Problem statement: Spoilage of food products is due to chemical, enzymatic or microbial activities One-fourth of the world’s food supply and 30% of landed fish are lost through microbial activity alone. With the ever growing world population and the need to store and transport the food from one place to another where it is needed, food preservation becomes necessary in order to increase its shelf life and maintain its nutritional value, texture and flavor. The freshness and quality of fish have always gained the attention by Food Regulatory Agencies and Food Processing Industry. Proper handling, pretreatment and preservation techniques can improve the quality fish and fish products and increase their shelf life. Methodology: Historically salting, drying, smoking, fermentation and canning were the methods to prevent fish spoilage and extend its shelf life. In response to consumer demand for texture, appearance and taste, new methods were developed including: Cooling, freezing and chemical preservation. A comprehensive review of the literature on the subject of fish spoilage and modern preservation techniques was carried out. Conclusion: Fish spoilage results from three basic mechanisms: Enzymatic autolysis, oxidation, microbial growth. Low temperature storage and chemical techniques for controlling water activity, enzymatic, oxidative and microbial spoilage are the most common in the industry today. A process involving the addition of an EDTA (1 mM)-TBHQ (0.02%) combination and ascorbic acid and storage at refrigerated temperatures (5°C) in darkness can be the most positive for controlling the spoilage of fish and fish product. The suggested process would address antimicrobial activity as well as destructive oxidation of the desired lipids and fats. However, more efforts are required to understand the role of proximate composition of fish, post harvest history, environmental conditions, initial microbial load, type and nature of bacteria and their interaction in order to optimize the shelf-life of fish.
473 citations
TL;DR: It is demonstrated that the stem cell redox status is regulated during differentiation and postulate that the highly unsaturated metabolome sustained by stem cells makes them particularly attuned to differentiate in response to in vivo oxidative processes such as inflammation.
Abstract: Metabolites offer an important unexplored complementary approach to understanding the pluripotency of stem cells. Using MS-based metabolomics, we show that embryonic stem cells are characterized by abundant metabolites with highly unsaturated structures whose levels decrease upon differentiation. By monitoring the reduced and oxidized glutathione ratio as well as ascorbic acid levels, we demonstrate that the stem cell redox status is regulated during differentiation. On the basis of the oxidative biochemistry of the unsaturated metabolites, we experimentally manipulated specific pathways in embryonic stem cells while monitoring the effects on differentiation. Inhibition of the eicosanoid signaling pathway promoted pluripotency and maintained levels of unsaturated fatty acids. In contrast, downstream oxidized metabolites (for example, neuroprotectin D1) and substrates of pro-oxidative reactions (for example, acyl-carnitines), promoted neuronal and cardiac differentiation. We postulate that the highly unsaturated metabolome sustained by stem cells allows them to differentiate in response to in vivo oxidative processes such as inflammation.
471 citations
Book•
21 May 2010
TL;DR: Physical and Chemical Data Recommendations for Nomenclature and Tables in Biochemical Thermodynamics Standard Transformed Gibbs Energies of Formation for Biochemical Reactants Enthalpy, Entropy, and Free Energy Values for Bi biochemical Redox Reactions Oxidation-Reduction Potentials, Absorbance Bands and Molar Absorption Characteristics.
Abstract: Amino Acids, Peptides and Proteins Properties of Amino Acids Data on the Naturally Occurring Amino Acids Structures and Symbols for Synthetic Amino Acids Incorporated Into Synthetic Polypeptides Unnatural Amino Acids for Incorporation into Proteins Properties of the alpha-Keto Acid Analogs of Amino Acids alpha,ss-Unsaturated Amino Acids Amino Acid Antagonists Coefficients of Solubility Equations of Certain Amino Acids in Water Heat Capacities, Absolute Entropies, and Entropies of Formation of Amino Acids and Related Compounds Heat of Combustion, Enthalpy and Free Energy of Formation of Amino Acids and Related Compounds Solubilities of Amino Acids in Water at Various Temperatures Heats of Solution of Amino Acids in Aqueous Solution at 25 C Free Energies of Solution and Standard Free Energy of Formation of Amino Acids in Aqueous Solution at 25 C Far Ultraviolet Absorption Spectra of Amino Acids UV Absorption Characteristics of N-Acetyl Methyl Esters of the Aromatic Amino Acids, Cystine and of N-Acetylcysteine Numerical Values of the Absorbances of the Aromatic Amino Acids in Acid, Neutral and Alkaline Solutions Luminescence of the Aromatic Amino Acids Luminescence of Derivatives of the Aromatic Amino Acids Luminescence of Proteins Lacking Tryptophan Luminescence of Proteins Containing Tryptophan Hydrophobicities of Amino Acids and Proteins Chemical Specificity of Reagents for Protein Modification Reagents for the Chemical Modification of Proteins Protein pK Values Protease Inhibitors and Protease Inhibitor Cocktails Assay of Solution Protein Concentration Spectrophotometric Determination of Protein Concentration in the Short-Wavelength Ultraviolet Lipids A Comprehensive Classification System for Lipids Properties of Fatty Acids and Their Methyl Esters Densities, Specific Volumes, and Temperature Coefficients of Fatty Acids from C8 to C12 Composition and Properties of Common Oils and Fats Androgens Bile Acids Corticoids Estrogens Progestogens Sterols Prostaglandins and Related Fatty-Acid Derived Materials Vitamins and Coenzymes Properties of Vitamins Biological Characteristics of Vitamins Properties for Ascorbic Acid and Ascorbate-2-Sulfate Vitamers Vitamin Names Discarded Nucleic Acids UV Spectral Characteristics and Acidic Dissociation Constants of 280 Alkyl Bases, Nucleosides, and Nucleotides Ultraviolet Absorbance of Oligonucleotides Containing 2'-O-Methylpentose Residues Spectrophotometric Constants of Ribonucleotides Purines, Pyrimidines, Nucleosides, and Nucleotides: Physical Constants and Spectral Properties Chemical Modification of Nucleic Acids Transfection Technologies Carbohydrates Introduction to Carbohydrates Natural Alditols, Inositols, Inososes, and Amino Alditols and Inosamines Natural Acids of Carbohydrate Derivation Natural Aldoses Natural Ketoses Carbohydrate Phosphate Esters The Naturally Occurring Amino Sugars Oligosaccharides (Including Disaccharides) Mucopolysaccharides (Glycosaminoglycans) Physical and Chemical Data Recommendations for Nomenclature and Tables in Biochemical Thermodynamics Standard Transformed Gibbs Energies of Formation for Biochemical Reactants Enthalpy, Entropy, and Free Energy Values for Biochemical Redox Reactions Oxidation-Reduction Potentials, Absorbance Bands and Molar Absorbance of Compounds used in Biochemical Studies Calorimetric DELTAH Values Accompanying Conformational Changes of Macromolecules in Solution Free Energies of Hydrolysis and Decarboxylation Deci-Normal Solutions of Oxidation and Reduction Reagents Guidelines for Potentiometric Measurements in Suspensions Part A. The Suspension Effect Ionization Constants of Acids and Bases Guidelines for NMR Measurements for Determination of High and Low pKa Values Measurement and Interpretation of Electrokinetic Phenomena Measurement of pH Definition, Standards, and Procedures General Comments on Buffers List of Buffers Bronsted Acidities Measurement of pH Buffer Solutions Amine Buffers Useful for Biological Research Preparation of Buffers for Use in Enzyme Studies Buffer for Acrylamide Gels (Single-Gel Systems) Starch Gels Indicators for Volumetric Work and pH Determinations Acid and Base Indicators Specific Gravity of Liquids Viscosity and Density Tables A Listing of Log P Values, Water Solubility, and Molecular Weight for Some Selected Chemicals Chemicals Commonly Used in Biochemistry and Molecular Biology and Their Properties Common Detergents Used in Biochemical Research Some Properties of Detergents and Surfactants Used in Biochemistry and Molecular Biology Some Biological Stains and Dyes Mordant Dyes Metal Chelating Agents Water Stability of Solutions for GLP and cGMP Use General Information on Spectroscopy Microplates Plastics Chemical and Physical Properties of Various Commercial Plastics Generic Source-Based Nomenclature for Polymers Definitions of Terms Relating to Reactions of Polymers and to Functional Polymeric Materials Definitions of Terms Related to Polymer Blends, Composites, and Multiphase Polymeric Materials Organic Name Reactions Useful in Biochemistry and Molecular Biology Enzymes in Synthetic Organic Chemistry Therapeutic Enzymes Weights of Cells and Cell Constituents Particle Diameter Appendix A: Abbreviations and Acronyms Appendix B: Glossary of Terms Useful in Biochemistry Index
TL;DR: In this paper, the physicochemical and antioxidant properties of some commercial brands of Indian honeys have been investigated with respect to their level of total phenolics, protein, radical scavenging activity, ascorbic acid equivalent antioxidant content (AEAC) and ferric reducing antioxidant potential (FRAP).
TL;DR: A versatile method for selectively synthesizing single-crystalline rhombic dodecahedral, cubic, and octahedral palladium nanocrystals, as well as their derivatives with varying degrees of edge- and corner-truncation, was reported for the first time.
Abstract: A versatile method for selectively synthesizing single-crystalline rhombic dodecahedral, cubic, and octahedral palladium nanocrystals, as well as their derivatives with varying degrees of edge- and corner-truncation, was reported for the first time. This is also the first report regarding the synthesis of rhombic dodecahedral palladium nanocrystals. All the nanocrystals were readily synthesized by a seed-mediated method with cetyltrimethylammonium bromide as surfactant, KI as additive, and ascorbic acid as reductant. At the same ascorbic acid concentration, a series of palladium nanocrystals with varying shapes were obtained through manipulation of the concentration of KI and the reaction temperature. The formation of different palladium facets were correlated with their growth conditions. In the absence of KI, the 100 palladium facets are favored. In the presence of KI, the concentration of KI and the reaction temperature play an important role on the formation of different palladium facets. The 110 palladium facets are favored at relatively high temperatures and medium KI concentrations. The 111 palladium facets are favored at relatively low temperatures and medium KI concentrations. The 100 palladium facets are favored at either very low or relatively high KI concentrations. These correlations were explained in terms of surface-energy and growth kinetics. These results provide a basis for gaining mechanistic insights into the growth of well-faceted metal nanostructures.
TL;DR: Several monofloral Cuban honeys were analyzed to determine their total phenolic, flavonoid, ascorbic acid, amino acid, protein and carotenoid contents as well as their radical-scavenging activity and antimicrobial capacities.
TL;DR: The antioxidant properties of lyophilized aqueous extract of propolis (LAEP) from Erzurum province of Turkey is determined and correlated the values with total levels of polyphenolic compounds.
TL;DR: In this paper, composite-hydroxide-mediated and composite-molten-salt-based nanostructures have been applied to modify the graphite substrates for nonenzymatic glucose detection.
Abstract: CuO flowers and nanorods have been synthesized for the first time by the composite-hydroxide-mediated and the composite-molten-salt method, respectively, with advantages of one-step, ambient pressure, low temperature, template-free and low cost. Both nanostructures have been applied to modify the graphite substrates for nonenzymatic glucose detection. Compared with bare graphite electrode, the new electrodes exhibit excellent catalysis to direct glucose oxidation. Though the electrode based on the CuO flowers has higher sensitivity than that of the CuO nanorods modified electrode, the latter presents a much better linear range of glucose concentration and a shorter response time. Both electrodes exhibit the same detection limit of glucose as low as 4 μM. In addition, the detection of dopamine and ascorbic acid has also been carried out on these CuO nanostructure modified electrodes, indicating good selectivity for glucose detection.
TL;DR: African leafy vegetables such as Arachis hypogea and Bidens pilosa are good sources of dietary fibre, while Nasturtium aquatica, Urtic dioica and Xanthosoma mafaffa are excellent free radical scavengers.
TL;DR: In this paper, tomato juice was sonicated at different amplitude levels (24.4-61.0 μm) at a constant frequency of 20 kHz for treatment times (2-10 min) and pulse durations of 5 s on and 5 s off.
TL;DR: The main findings observed to date from the European Prospective Investigation into Cancer and Nutrition on dietary factors associated with the most frequent cancer sites contribute to scientific evidence for appropriate public health strategies and prevention activities aimed at reducing the global cancer burden.
University of Pittsburgh1, University of Cincinnati2, National Institutes of Health3, George Washington University4, University of Alabama at Birmingham5, University of Texas at Austin6, Columbia University7, University of Utah8, University of North Carolina at Chapel Hill9, Case Western Reserve University10, Northwestern University11, University of Texas Health Science Center at Houston12, Brown University13, Ohio State University14, Drexel University15, Wake Forest University16, Oregon Health & Science University17, University of Texas Medical Branch18, University of Texas Southwestern Medical Center19, Wayne State University20
TL;DR: Vitamin C and E supplementation initiated in the 9th to 16th week of pregnancy in an unselected cohort of low-risk, nulliparous women did not reduce the rate of adverse maternal or perinatal outcomes related to pregnancy-associated hypertension.
Abstract: Background Oxidative stress has been proposed as a mechanism linking the poor placental perfusion characteristic of preeclampsia with the clinical manifestations of the disorder. We assessed the effects of antioxidant supplementation with vitamins C and E, initiated early in pregnancy, on the risk of serious adverse maternal, fetal, and neonatal outcomes related to pregnancy-associated hypertension. Methods We conducted a multicenter, randomized, double-blind trial involving nulliparous women who were at low risk for preeclampsia. Women were randomly assigned to begin daily supplementation with 1000 mg of vitamin C and 400 IU of vitamin E or matching placebo between the 9th and 16th weeks of pregnancy. The primary outcome was severe pregnancy-associated hypertension alone or severe or mild hypertension with elevated liver-enzyme levels, thrombocytopenia, elevated serum creatinine levels, eclamptic seizure, medically indicated preterm birth, fetal-growth restriction, or perinatal death. Results A total of ...
TL;DR: In this paper, a study was carried out for identification of the phytochemicals present in the Vitex negundo leaves and also evaluate the total phenols, total flavonoids and antioxidant activity of the leaf extract.
Abstract: The present study was carried out for identification of the phytochemicals present in the Vitex negundo leaves and also evaluate the total phenols, total flavonoids and antioxidant activity of the leaf extract. Total phenols was carried out by Folin Ciocalteu method and the phenolic content was 27.72 mg/100 of gallic acid equivalent (GE). Antioxidant activity was evaluated by DPPH method and the leaves of V. negundo showed 23.21 mg/100 of ascorbic acid equivalent antioxidant capacity (AEAC). The GC-MS study also carried out and it showed the presence of phytochemicals like 4H-Pyran-4-one, 2,3-dihydro-3,5-dihydroxy-6-methyl-(RT:6.17), Phytol (RT:19.67) and Vitamin E (RT:25.11).
Key words: Total Phenols, total flavonoids, antioxidant activity, DPPH, GC-MS.
TL;DR: Obese women are at increased risk of gestational diabetes, pregnancy induced hypertension and pre-eclampsia, and babies of women who were obese were more likely to be large for gestational age and macrosomic compared with those of women with a normal BMI.
Abstract: The prevalence of obesity amongst women bearing children in Australia is rising and has important implications for obstetric care. The aim of this study was to assess the prevalence and impact of mothers being overweight and obese in early to mid-pregnancy on maternal, peripartum and neonatal outcomes. A secondary analysis was performed on data collected from nulliparous women with a singleton pregnancy enrolled in the Australian Collaborative Trial of Supplements with antioxidants Vitamin C and Vitamin E to pregnant women for the prevention of pre-eclampsia (ACTS). Women were categorized into three groups according to their body mass index (BMI): normal (BMI 18.5-24.9 kg/m2); overweight (BMI 25-29.9 kg/m2) and; obese (BMI 30-34.9 kg/m2). Obstetric and perinatal outcomes were compared by univariate and multivariate analyses. Of the 1661 women included, 43% were overweight or obese. Obese women were at increased risk of pre-eclampsia (relative risk (RR) 2.99 [95% confidence intervals (CI) 1.88, 4.73], p < 0.0001) and gestational diabetes (RR 2.10 [95%CI 1.17, 3.79], p = 0.01) compared with women with a normal BMI. Obese and overweight women were more likely to be induced and require a caesarean section compared with women of normal BMI (induction - RR 1.33 [95%CI 1.13, 1.57], p = 0.001 and 1.78 [95%CI 1.51, 2.09], p < 0.0001, caesarean section - RR 1.42 [95%CI 1.18, 1.70], p = 0.0002 and 1.63 [95%CI 1.34, 1.99], p < 0.0001). Babies of women who were obese were more likely to be large for gestational age (LFGA) (RR 2.08 [95%CI 1.47, 2.93], p < 0.0001) and macrosomic (RR 4.54 [95%CI 2.01, 10.24], p = 0.0003) compared with those of women with a normal BMI. The rate of overweight and obesity is increasing amongst the Australian obstetric population. Women who are overweight and obese have an increased risk of adverse pregnancy outcomes. In particular, obese women are at increased risk of gestational diabetes, pregnancy induced hypertension and pre-eclampsia. Effective preventative strategies are urgently needed. Current Controlled Trials ISRCTN00416244
TL;DR: The antioxidant capacity (AOC) of black currants, blueberry, raspberry, red currant, and cranberry extracts was determined using the FRAP assay and the contribution of polymeric proanthocyanidins to the AOC of the five berries was not determined as when analyzed by reversed-phase HPLC these high molecular weight flavan-3-ols are either retained by the column or eluted as a broad unresolved band.
Abstract: The antioxidant capacity (AOC) of black currant, blueberry, raspberry, red currant, and cranberry extracts was determined using the FRAP assay. In addition, the vitamin C content of the berries was determined and phenolic and polyphenolic compounds in the extracts were analyze by reversedphase HPLC-PDA-MS 3 and by reversed-phase HPLC-PDA with an online antioxidant detection system. A complex spectrum of anthocyanins was the major contributor to the AOC of black currants and blueberries, whereas the lower AOC of red currants and cranberries was due mainly to a reduced anthocyanin content. Raspberries also had a lower anthocyanin content than black currants and blueberries, but there was only a slight decline in the AOC because of the presence of the ellagitannins sanguin H-6 and lambertianin C, which were responsible for 58% of the HPLCAOC of the berries. Vitamin C was responsible for 18-23% of the HPLC-AOC of black currants, red currants, and cranberries and for 11% of that of raspberries but did not contribute to the AOC of the blueberry extract that was examined. Seven percent of the HPLC-AOC of the cranberry extract was attributable to procyanidin dimers. However, the contribution of polymeric proanthocyanidins to the AOC of the five berries was not determined as when analyzed by reversed-phase HPLC these high molecular weight flavan-3-ols are either retained by the column or eluted as a broad unresolved band.
TL;DR: This procedure extends the application of this fastest of azide-based bioorthogonal reactions to the exterior of living cells to protect the cells from damage by oxidative agents produced by the Cu-catalyzed reduction of oxygen by ascorbate, which is required to maintain the metal in the active +1 oxidation state.
TL;DR: In this article, nanocomposite LDPE films containing Ag and ZnO nanoparticles were prepared by melt mixing in a twin- screw extruder and then filled with fresh orange juice and stored at 4 °C.
Abstract: article i nfo Nanocomposite LDPE films containing Ag and ZnO nanoparticles were prepared by melt mixing in a twin- screw extruder. Packages prepared from the films were then filled with fresh orange juice and stored at 4 °C. Microbial stability, ascorbic acid (AA) content, browning index, color value, and sensory attributes of them were evaluated after 7, 28, and 56 days of storage. Packages containing the nanomaterials, expect 1% nano- ZnO, kept the microbial load of fresh juice below the limit of microbial shelf life (6 log cfu/ml) up to 28 days The least degradation of AA (80.50 mg/100 g), development of brown pigments (OD=0.23) and losing of color (ΔE=6.0) were observed in pouches containing 0.25% nano-ZnO, after the same time. Sensory attributes were also ranked highest for the juice thus packed in the recent packages after 28 days (pb0.05). Packages containing nanosilver increased shelf life of fresh juice although part of its sensory attributes were lost. Industrial relevance: Compared with pure packaging materials, antimicrobial nanocomposite packages containing Ag and ZnO as an alternative non-thermal technology can extend the shelf life of fresh orange juice up to 28 days. However, a certain concentration of nano-ZnO in the packages showed less adverse effects on sensory characteristics. © 2010 Published by Elsevier Ltd.
TL;DR: In vitro and in vivo bioactivities of these polyphenol metabolites and catabolites are assessed, and the current evidence for their involvement in the protective effects of dietary polyphenols, within the gastrointestinal tract and other parts of the body to which they are transported by the circulatory system is reviewed.
Abstract: Berries contain vitamin C and are also a rich source of phytochemicals, especially anthocyanins which occur along with other classes of phenolic compounds, including ellagitannins, flavan-3-ols, procyanidins, flavonols and hydroxybenzoate derivatives. This review examines studies with both human subjects and animals on the absorption of these compounds, and their glucuronide, sulphate and methylated metabolites, into the circulatory system from the gastrointestinal tract and the evidence for their localisation within the body in organs such as the brain and eyes. The involvement of the colonic microflora in catabolising dietary flavonoids that pass from the small to the large intestine is discussed along with the potential fate and role of the resultant phenolic acids that can be produced in substantial quantities. The in vitro and in vivo bioactivities of these polyphenol metabolites and catabolites are assessed, and the current evidence for their involvement in the protective effects of dietary polyphenols, within the gastrointestinal tract and other parts of the body to which they are transported by the circulatory system, is reviewed.
TL;DR: One important application of nutrient profile models is to help consumers identify foods that provide optimal nutrition at an affordable cost.
TL;DR: In this paper, the authors applied 10% gum arabic as an edible coating to green-mature tomatoes stored at 20°C and 80-90% RH for 20 days.
TL;DR: In this article, the authors synthesize quasi-spherical silver nanoparticles by using ascorbic acid as reductant and citrate as stabilizer in a 30°C water bath.
TL;DR: Live-cell confocal microscopy experiments show that RCS1 is membrane-permeable and can sense changes in the levels of labile Cu(+) pools within living cells by ratiometric imaging, including expansion of endogenous stores of exchangeable intracellular Cu(+ triggered by ascorbate stimulation in kidney and brain cells.
Abstract: We present the synthesis, properties, and biological applications of Ratio-Coppersensor-1 (RCS1), a new water-soluble fluorescent sensor for ratiometric imaging of copper in living cells. RCS1 combines an asymmetric BODIPY reporter and thioether-based ligand receptor to provide high selectivity and sensitivity for Cu+ over other biologically relevant metal ions, including Cu2+ and Zn2+, a ca. 20-fold fluorescence ratio change upon Cu+ binding, and visible excitation and emission profiles compatible with standard fluorescence microscopy filter sets. Live-cell confocal microscopy experiments show that RCS1 is membrane-permeable and can sense changes in the levels of labile Cu+ pools within living cells by ratiometric imaging, including expansion of endogenous stores of exchangeable intracellular Cu+ triggered by ascorbate stimulation in kidney and brain cells.