Ascorbic Acid In Aqueous Solution Research Articles

Effects of Foliar Spraying with some Antioxidants on Growth, Dry Seed Yield and Chemical Constituents of Common Bean (Phaseouls vulgaris L.) Plants Grown under Water Stress Levels

The current study was carried out at Qaha Vegetable Research Farm (Qalubia Governorate), Horticulture Research Institute, Agriculture Research Center (A. R. C.), Egypt, during the two successive summer seasons of 2017 and 2018 on common bean cv Nebraska. The aim of this study was to investigate the effect of applied antioxidants (ascorbic acid at 100, 200 mg/L and putrescine at 25, 50 mg/L) under water regimes at three levels i.e. 100%. (control), 75% (moderate stress) and 50% (severe stress) of ETo(Evapotranspiration) respectively of water requirements of common bean plants in the two seasons and their interactions on vegetative growth characteristics, dry seed yield and its components and chemical compositions as well as seed quality. The experimental design was split-plot, the water regimes were arranged in the main plots, while foliar spraying with ascorbic acid and putrescine were adopted in the sub-plots. The obtained results of the treatments showed that foliar spraying with the aqueous solution of putrescine or ascorbic acid at the highest rate of 50 mg/ L or 200 mg/ L respectively under irrigated common bean plants with the moderate water level (75% ETo) markedly increased all of the vegetative growth parameters and dry seed yield and its components. In additions, the same mentioned treatments showed obvious increment in the chemical composition in leaves and dry seeds in both seasons. And led to save a part of the irrigation water (about 25 %) especially under the condition of water stress or drought

A highly sensitive, fast responsive and reversible naphthalimide-based fluorescent probe for hypochlorous acid and ascorbic acid in aqueous solution and living cells.

It is very important to exploit real-time, ultrasensitive and specific visualization detection methods for hypochlorous acid/hypochlorite (HOCl/ClO-) in biological systems as they are the guardians of the human immune system against pathogens invasion. In our work, we designed a novel reversible naphthalimide-based fluorescent probe NAP-OH to recognize HClO/ClO- with a unique selective colorimetric and fluorescent response, a short response time (<8 s) and a high sensitivity (10.3nM). In addition, NAP-OH exhibits a novel on-off-on fluorescence response to ClO-/ascorbic acid (AA) with good cycle stability. The fluorescence signal is quenched because HClO/ClO- oxidizes the subunit of NAP-OH to the segment 2,2,6,6-tetramethyl-1-oxo-piperidinium in NAP-O, which can be reduced by AA with the recovery of fluorescence. Finally, the confocal fluorescence imaging has been performed, which proves that NAP-OH can satisfactorily monitor intracellular endogenous and exogenous HClO/AA redox cycles.

The usefulness of ascorbic acid degradation to analyze the effectiveness of water filtration in household water filter jugs

AbstractIntroduction: This study aimed to determine whether the degradation of ascorbic acid in aqueous solutions could be used to compare the filtration efficiency of various household water filter jugs.Materials and methods: Based on absorbance measurements of ascorbic acid, a new water quality coefficient (WQC) parameter was defined. Differences between the WQC were determined for 4 different water filters commonly used in household water filter jugs in Poland. In addition, correlations between the WQC, the amount of filtered water (AFW), and a number of other parameters were examined for all 4 filters.Conclusions: Significant differences were found in WQC among the 4 filters. A decreasing efficiency of calcium ion removal from the water was observed with the ongoing use of all 4 filter cartridges. Overall, this method could be a sensitive, simple, fast, eco-friendly, and relatively inexpensive tool for determining the effectiveness of water purification in household water filter jugs, which of course requires further research.

Разработка технологии получения соево-тыквенных десертов функционального назначения

Abstract. Introduction. Domestic food production based on the regional market characteristics can expand the range of functional foods. The research objective was to develop a new technology for desserts based on soy and pumpkin. &#x0D; Study objects and methods. The research featured soybeans of the “Yurna” variety and pumpkin of the “Nadezhda” variety. Soaked soybeans were mixed with mashed pumpkin and drinking water. The mass was heated and kept at 100°C for 30 min with simultaneous grinding and extraction of soluble dry matter. The soy and pumpkin liquid fraction was separated by filtration. A 2.5% aqueous solution of ascorbic acid was added to the liquid fraction at 75–80°C to coagulate protein and other substances. The soy and pumpkin coagulate had a moisture content of 75.0 ± 1%. It was mixed with sea buckthorn syrup and homogenized. The finished product was called “Nadezhda+”. The “Nezhnyi” dessert consisted of gelling solution mixed with soy and pumpkin coagulate and sea buckthorn syrup, after which the mass was homogenized. &#x0D; Results and discussion. The expert assessment helped to identify the most significant indicators of the sensory evaluation of the desserts, namely taste and consistency. The sensory evaluation also made it possible to define the optimal homogenization time for the mix: 60 s for “Nadezhda+” and 90 s for “Nezhnyi”. The developed desserts contained protein (5.75 and 4.70 g/100 g), phosphatides (334 and 102 mg/100 g), β-carotene (2.86 and 1.62 mg/100 g), vitamin E (28.60 and 16.00 mg/100 g) and vitamin C (35.10 and 10.60 mg/100 g), respectively. &#x0D; Conclusion. The content of β-carotene and vitamin E exceeded 15 % of the daily intake in one portion (100 g) of the desserts, as well as vitamin C in “Nadezhda+”. According with State Standard R 52349-2005, the new desserts could be referred to functional foods.

Fabrication and assessment of milk phospholipid-complexed antioxidant phytosomes with vitamin C and E: A comparison with liposomes

Evidences have shown that phytosome assemblies are novel drug delivery system. However, studies of phytosomes in food applications are scarce. The characteristics of milk phospholipid assemblies and their functionality in terms of in vitro digestibility and bioavailability of encapsulated nutrients (ascorbic acid and α-tocopherol) were studied. The phytosomes were fabricated using ethanolic evaporation technique. Spectral analysis revealed that polar parts of phospholipids formed hydrogen bonds with ascorbic acid hydroxyl groups, further, incorporating ascorbic acid or α-tocopherol into the phospholipid assembly changed the chemical conformation of the complexes. Phospholipid-ascorbic acid phytosomes yielded an optimal complexing index of 98.52 ± 0.03% at a molar ratio of 1:1. Phytosomes exhibited good biocompatibility on intestinal epithelial cells. The cellular uptake of ascorbic acid was 29.06 ± 1.18% for phytosomes. It was higher than that for liposomes (24.14 ± 0.60%) and for ascorbic acid aqueous solution (1.17 ± 0.70%).

Structural, magnetic and dielectric studies of siderite nano-particles synthesized by hydrothermal method

Siderite or ferrous carbonate [Formula: see text] is a well-known mineral and finds applications in various fields such as dietary supplement to treat anemia and in petroleum drilling fluids for [Formula: see text] removal. The FeCO3 nano-particles are synthesized by hydrothermal method using aqueous solutions of iron sulfate, ascorbic acid and ammonium carbonate with a molar ratio of 1:1:3, respectively, and heating at [Formula: see text]C for 1.5 h in Teflon-lined stainless steel autoclave. The recovered sample is characterized by several techniques. The powder XRD indicates the hexagonal crystal system and the average crystallite size of 17.32 nm are obtained from the Scherrer’s formula and 18.98 nm is obtained from the Williamson and Hall formula. The TEM images suggest the spherical nature of the nano-particles. The EDX confirms the elemental presence of iron, carbon and oxygen. The impedance and dielectric studies are carried out within 20 Hz–2 MHz range at room temperature. The complex impedance plot, i.e. the Nyquist plot, is composed of one semicircle indicating the contribution from the grain only. The Jonscher’s power-law is applied to AC conductivity data. The VSM data at room temperature and at low temperature, i.e. 20–300 K range, suggests a weak antiferromagnetic nature of the sample.

Comments on “Assorted interactions of amino acids prevailing in aqueous vitamin C solutions probed by physicochemical and ab-initio contrivances”

A polemic is given regarding several of the calculated numerical values given in the published paper. The authors’ calculated apparent molal volumes for tryptophan and tyrosine dissolved in aqueous-ascorbic acid solutions cannot be obtained from the experimental density data and amino acid molalities given in the published paper. Moreover, the authors’ calculations show tyrosine to have the larger apparent partial molal volume, which is just opposite to what has been reported in the published literature.

Snowflake-like gold nanoparticles as SERS substrates for the sensitive detection of organophosphorus pesticide residues

Representing tremendous enhancement effect for the Raman signal of trace chemicals, branched gold nanoparticles (Au NPs) are particularly attractive as surface-enhanced Raman spectroscopy (SERS) substrates, though precise morphology control during synthesis might remain challenging. Herein, snowflake-like gold nanoparticles served as SERS substrates were successfully prepared by reducing chloroauric acid (HAuCl4) with ascorbic acid in aqueous solutions of tetradecylpiperidinium (C14PDB) surfactant. At a C14PDB/HAuCl4 molar concentration ratio of 4.2/1 and a reaction time of 6 h, the Au NPs resembled hexagonal snowflakes were produced. The snowflake-like Au NPs substrates performed great SERS activity and afforded limits of detection around 3 × 10−9 mol L−1 in aqueous rhodamine 6G (R6G) solutions and 1 × 10−8 mol L−1 for organophosphorus pesticides in solution. And applying these SERS substrates for practical detection on five fruit or vegetable peels, the detection limit of parathion-methyl, triazophos and phosmet on apple peels was 0.026 ng cm−2, 0.031 ng cm−2 and 0.032 ng cm−2, respectively. SERS results suggest that snowflake-like Au NPs used as SERS substrates hold great promise for the detection of organophosphorus pesticides at trace concentrations.

Detection of ascorbic acid using green synthesized AgInS2 quantum dots

We herein report green synthesis of water-soluble AgInS2 (AIS) quantum dots (QDs) for the detection of ascorbic acid (AA). The optical analysis showed that addition of AA increased the photoluminescence (PL) intensity of the QDs by suppressing the surface defects via the chelating action of AA. The relationship between the PL intensity and AA concentration was found to be linear over a range of 0.66 μM–99 μM. The AIS QDs exhibited excellent limit of detection (LOD = 26 nM) and can be employed as optical sensor for rapid detection of AA in aqueous solutions.

MOLECULAR INTERACTION STUDIES OF ZWITTER- ION IN AQUEOUS SUCROSE AND ASCORBIC ACID AT CONSTANT TEMPERATURE

Density and viscosity of L-Arginine in aqueous sucrose and ascorbic acid solutions have been determined experimentally at 298 K. The results obtained from density and viscosity measurement have been used to calculate the Hydration number Hn, apparent molar volume фv, partial molal volume ф0v , at infinite dilution, transfer volume ∆ф0tr and B- coefficient. It has been observed that there exist strong solute-solvent interaction and complex formation between in these ternary systems. The properties of this amino acid in water and aqueous sucrose and ascorbic acid systems are discussed in terms of the charge, size and hydrogen bonding effect.

Exploring the effect of PVP on the spherical agglomeration process and micromeritic properties of ascorbic acid

Spherical agglomerated crystals of ascorbic acid (AA) have been prepared with a trace of polyvinylpyrrolidone (PVP) by a spherical agglomeration method. The process of spherical crystallization has been monitored online with a particle vision and measurement (PVM) probe. The effect of PVP on the metastable zone width of ascorbic acid in aqueous solutions has been characterized by a laser method. Hydrogen bonding interactions between AA and PVP have been identified by Fourier-transform infrared spectroscopy and 1H nuclear magnetic resonance. Differential scanning calorimetry and powder X-ray diffraction measurements have shown that the prepared spherical crystals still exhibited a crystallin nature. The micromeritic properties, namely flowability, packability, and compressibility, were significantly improved compared to those of the pure drug crystals. In this study, we have explored the mechanism of the spherical crystallization process in the presence of the polymer, and the beneficial effect of the polymer on the micromeritic properties of crystals of ascorbic acid.

Preparation of water‐insoluble and biochemically stable RNA hybrid material

RNA, which plays an important role in the transcription and translation of genetic processes, has novel functional material abilities, such as the complementary interaction with nucleic acid bases, intercalation, and the binding with metal ions. However, because the RNA is a water‐soluble and biochemically unstable biopolymer, RNA cannot be used as a polymer material. Therefore, we prepared a water‐insoluble RNA‐inorganic hybrid material by mixing the RNA and a silane coupling reagent, bis(3‐trimethoxysilylpropyl)amine. The RNA‐inorganic hybrid material did not show complete hydrolysis in spite of the incubation with the RNA hydrolysis enzyme Ribonuclease A for 72 hours. In addition, RNA‐inorganic composite material effectively accumulated various metal ions, such as heavy and rare‐earth metal ions. Furthermore, when the Cu(II) ion‐accumulated RNA‐inorganic hybrid material was incubated in an aqueous ascorbic acid solution, dehydroascorbic acid was produced by the oxidative effect of Cu(II) ions in RNA‐inorganic hybrid material.

Synthesis of Cu Nanowires Using Ascorbic Acid in Aqueous Solution and Their Applications for Flexible Transparent Conductive Films

Cu nanowires (NWs) have been extensively studied to produce flexible, low-cost and high-conductivity transparent films because of their flexibility, low cost and high conductivity. Most synthetic procedures are based on chemical reduction, which often requires high temperature, organic solvents, and toxic reagents such as N2H4. It is desirable to develop a cost-efficient and environmentally friendly synthetic procedure for practical use. Furthermore, Cu NWs with high aspect ratios are required to improve performances of the transparent conductive films. Previously, we synthesized Cu nanoparticles based on chemical aqueous reduction employing ascorbic acid (vitamin C) as a reducing agent instead of commonly used toxic reducing agents. The key to the wire-like morphologies is the adsorption of surface ligands to metal crystal facets during the nucleation of NWs. Surface ligands selectively adsorbs onto {100} facets and consequently the anisotropic growth along the <110> direction occurs. In addition, reaction speed control and additives are also important for syntheses of NWs with high aspect ratios. In this study, we examined to synthesize Cu NWs by chemically reducing aqueous Cu chloride complexes using ascorbic acid as a mild reducing agent instead of the commonly employed toxic reducing agent. We chose polyvinylpyrrolidone (PVP) and NaCl as a surface ligand and an additive, respectively. In addition, we controlled aspect ratios of Cu NWs by changing type of capping agent, optimizing additives and atmosphere. Cu chloride complexes were reduced to Cu metal through CuCl by ascorbic acid. The shape of the Cu metal particles highly depended on pH in the presence of PVP. Cu NWs were synthesized in the pH range of 3 to 4 while Cu nanoparticles were synthesized above pH 4. The reduction speed accelerated with increasing pH because the reduction capability of ascorbic acid increased with increasing pH. In fast reduction, all Cu chloride complexes were reduced to Cu particles before the anisotropic growth. In slow reduction, PVP effectively stabilized {110} facets of Cu rather than {111} facets, resulting in Cu NWs. The length and diameter of the Cu NWs were affected by atmosphere rather than additives and type of PVP. In the case of using ascorbic acid in aqueous solution, dissolved oxygen reacted with ascorbic acid to form hydrogen peroxide. Subsequently, hydrogen peroxide oxidized Cu metal surface and consequently prevented the anisotropic growth, resulting in Cu NWs with low aspect rations. By changing atmosphere from air to N2, we synthesized Cu NWs (length: 36 µm, diameter: 124 nm) from the reaction using ascorbic acid in aqueous solution. In our presentation, detailed results and discussion about the synthesis mechanism and performances as transparent conductive films will be introduced.

Quantum dots attached to graphene oxide for sensitive detection of ascorbic acid in aqueous solutions

Water-soluble fluorescent carboxyl-functionalized CdSe-ZnS quantum dots (QDs) were immobilized on graphene oxide (GO) and used for sensitive detection of ascorbic acid in aqueous solutions. QDs were attached to the surface of graphene oxide using the EDC/NHS-sulfo coupling reaction. Ascorbic acid is known as an antioxidant. It plays a crucial role in health maintenance, bio synthetic pathways such as formation of collagen and regulates immune system. The photoluminescence (PL) intensity of as-prepared GO-QD hybrids in water was quenched by ascorbic acid at ambient temperature. Based on this photoluminescence quenching phenomenon, a simple, rapid, and sensitive procedure is developed. In this study we are successful in detecting ascorbic acid due to its biological significance and the limit of detection is 568 pM.

아스코빅애씨드 고함량 안정화 수계 조성물 제조 방법

Ascorbic acid (Vitamin C) has been widely used in skin care formulations. Due to its remarkable effects on anti-oxidation, collagen biosynthesis and whitening, ascorbic acid is considered as an effectible anti-aging active ingredient. But, the instability problems of ascorbic acid in cosmetic formulation such as oxidation, browning and changes in smell is the difficult issue to be overcome for the application of high concentration of ascorbic acid. We tried to stabilize the ascorbic acid in non-aqueous liquid formulation that contains polyol solvent at first. The non-aqueous system was effectible to reduce oxidation. But, ascorbic acid was crystallized in the non-aqueous formulation at the low temperature below 5℃. We tried to develop way to stabilize the ascorbic acid in aqueous solutions to solve the crystallizing problem. In this study, we search the optimal ratio of antioxidant combination, such as zinc sulfate, glutathione and curcuma longa (turmeric) root extract. Formulations were stored at - 16℃, 5℃, 25℃, 40℃, 50℃ and cycle(5 – 40℃) (in incubator) for a period of eight weeks to investigate their stability. In the stability analysis, the test parameters consisted of color, scent, phase separation and sedimentation. Ascorbic acid stability was checked by HPLC analysis.

Effects of ethanol combined with ascorbic acid and packaging on the inhibition of browning and microbial growth in fresh-cut Chinese yam.

The objective of this study was to investigate the effects of aqueous solutions of ethanol (25%, v/v) and ascorbic acid (AA, 1%, m/v) alone and in combination, along with modified atmosphere packaging (MAP) or vacuum packaging (VP), on the physicochemical properties and microbial quality of fresh‐cut Chinese yam slices during 4°C storage. The data showed that ethanol (25%, v/v) combined with AA (1%, m/v) and MAP treatment resulted in the lowest changes for headspace gas composition, color, electrical conductivity, overall visual quality, aerobic plate count population, and mold and yeast population in fresh‐cut Chinese yam over 21 days of 4°C cold storage, which was more effective at both inhibiting microbial growth and delaying browning than ethanol or AA alone or a commonly used sanitizer, sodium hypochlorite. The experiment on packaging demonstrated that samples treated with VP and 25% ethanol with 1% (m/v) AA dip can only preserve the sensory qualities of fresh‐cut Chinese yam slices up to 7 days at 4°C, but 25% (v/v) ethanol in conjunction with 1% (m/v) AA packed with MAP had antibrowning potential and maintained the quality of fresh‐cut Chinese yam slices up to 14 days when stored at 4°C.

Multifunctional carbon dot for lifetime thermal sensing, nucleolus imaging and antialgal activity.

Multifunctional carbon dots (CDs) with lifetime thermal sensing, nucleolus imaging, and antialgal activity properties were synthesized directly from ascorbic acid aqueous solution by a one-step electrochemical method at room temperature. The as-prepared CDs are responsive to temperature and exhibit an accurate linear response of fluorescence intensity vs. temperature (20-100 °C). These CDs can enter a cell and nucleolus, adsorb on the nucleic acids (DNA and RNA) and the fluorescence intensity of CDs is increased by the adsorption of nucleic acids. In addition, the CDs can inhibit the activity of RuBisCO in Anabaena sp., leading to reducing the growth of Anabaena sp. All these properties make the CDs serve as effective fluorescence-based nanothermometers, nucleolus probes, and antialgal agents.

Synthesis of colloidal silver nanoparticle clusters and their application in ascorbic acid detection by SERS

Ascorbic acid (vitamin C) has an essential role in the human body mainly due to its antioxidant function. In this work, metallic silver nanoparticle (AgNP) colloids were used in SERS experiments to detect ascorbic acid in aqueous solution. The AgNPs were synthesized by a green method using potato starch as reducing and stabilizing agent, and water as the solvent. The optical properties of the yellowish as-synthesized silver colloids were characterized by UV–vis spectroscopy, in which besides a typical band at 410 nm related to the localized surface plasmon resonance of the silver nanoparticles, a shoulder band around 500 nm, due to silver nanoparticle cluster formation, is presented when relatively higher concentrations of starch are used in the synthesis. These starch-capped silver nanoparticles show an intrinsic Raman peak at 1386 cm−1 assigned to deformation modes of the starch structure. The increase of the intensity of the SERS peak at 1386 cm−1 with an increase in the concentration of the ascorbic acid is related to a decrease of the gap between dimers and trimers of the silver nanoparticle clusters produced by the presence of ascorbic acid in the colloid. The limit of detection of this technique for ascorbic acid is 0.02 mM with a measurement concentration range of 0.02–10 mM, which is relevant for the application of this method for detecting ascorbic acid in biological specimen.

Molybdenum oxide nanosheets meet ascorbic acid: Tunable surface plasmon resonance and visual colorimetric detection at room temperature

Here we report a simple, rapid, and environmentally friendly method for the preparation of non-stoichiometric MoO3 (MoO3-x) nanosheets using ascorbic acid (AA) as a reducing agent under an acidic environment at room temperature. The resultant MoO3-x nanosheets show an intense blue color and strong localized surface plasmon resonance (LSPR) in the visible and near-infrared region, which can be tuned by changing the pH values of the preparation solution. The hydrogen ions intercalate into the lattice of MoO3 and bond to oxygen atoms to generate water molecules, and the electron of the AA is transferred to Mo cations, which results in the reduction of Mo6+ and formation of oxygen vacancies, giving rise to the LSPR. Additionally, a visual colorimetric assay has been developed for the detection of AA in aqueous solutions and serum samples. The absorbance at 820 nm is linearly related to the logarithm of the AA concentration in the range of 1 mM–100 mM with a limit of detection of 0.09 mM at a signal-to-noise ratio of 3.

Hydrothermal Transformations of Ascorbic Acid

Hydrothermal treatment of aqueous solution of ascorbic acid has resulted in the formation of soluble and insoluble products. The soluble product (carbon quantum dots) has exhibited pronounced fluorescent properties. The insoluble product consists of densely aggregated 1–2 μm particles. The increase in the hydrothermal treatment duration has resulted in continuous transformation of carbon quantum dots into the microparticles.