Sorbitol enhances the physicochemical stability of B12 vitamers

2020 ◽  
Vol 90 (5-6) ◽  
pp. 439-447 ◽  
Author(s):  
Andrew Hadinata Lie ◽  
Maria V Chandra-Hioe ◽  
Jayashree Arcot
Keyword(s):  
Ascorbic Acid ◽  
Uv Light ◽  
Heat Exposure ◽  
Water Soluble ◽  
Uv Exposure ◽  
Physicochemical Stability ◽  
Before And After ◽  
The Stability

Abstract. The stability of B12 vitamers is affected by interaction with other water-soluble vitamins, UV light, heat, and pH. This study compared the degradation losses in cyanocobalamin, hydroxocobalamin and methylcobalamin due to the physicochemical exposure before and after the addition of sorbitol. The degradation losses of cyanocobalamin in the presence of increasing concentrations of thiamin and niacin ranged between 6%-13% and added sorbitol significantly prevented the loss of cyanocobalamin (p<0.05). Hydroxocobalamin and methylcobalamin exhibited degradation losses ranging from 24%–26% and 48%–76%, respectively; added sorbitol significantly minimised the loss to 10% and 20%, respectively (p < 0.05). Methylcobalamin was the most susceptible to degradation when co-existing with ascorbic acid, followed by hydroxocobalamin and cyanocobalamin. The presence of ascorbic acid caused the greatest degradation loss in methylcobalamin (70%-76%), which was minimised to 16% with added sorbitol (p < 0.05). Heat exposure (100 °C, 60 minutes) caused a greater loss of cyanocobalamin (38%) than UV exposure (4%). However, degradation losses in hydroxocobalamin and methylcobalamin due to UV and heat exposures were comparable (>30%). At pH 3, methylcobalamin was the most unstable showing 79% degradation loss, which was down to 12% after sorbitol was added (p < 0.05). The losses of cyanocobalamin at pH 3 and pH 9 (~15%) were prevented by adding sorbitol. Addition of sorbitol to hydroxocobalamin at pH 3 and pH 9 reduced the loss by only 6%. The results showed that cyanocobalamin was the most stable, followed by hydroxocobalamin and methylcobalamin. Added sorbitol was sufficient to significantly enhance the stability of cobalamins against degradative agents and conditions.

USE OF THE PURIFIED APPLE PECTIN FOR STABILIZATION OF ASCORBIC ACID IN FRESH JUICES

2019 ◽  
Author(s):  
Н.Ш. КАЙШЕВА ◽  
А.Ш. КАЙШЕВ ◽  
Л.Б. ГУБАНОВА ◽  
А.Б. САМОРЯДОВА
Keyword(s):  
Ascorbic Acid ◽  
Fruits And Vegetables ◽  
Molar Mass ◽  
Mass Ratio ◽  
High Molar Mass ◽  
Before And After ◽  
The Stability ◽  
Characteristic Maximum ◽  
Differential Spectroscopy

Исследована возможность применения очищенных пектинов для стабилизации аскорбиновой кислоты (АК) в фреш-соках с концентрацией 10–6–10–4г/мл. В работе использованы: АК, щавелевая кислота (ЩК), свекловичный (СП), цитрусовый (ЦП) и яблочный (ЯП) пектины с высокой молярной массой 61000–87500 г/моль и степенью этерификации 46,5–76,3%, предназначенные для фармацевтического применения. Фреш-соки получены посредством отжима ягод, плодов и овощей (18 видов). Установлено отсутствие мешающего влияния пектинов на определение АК методом дифференциальной спектроскопии в УФ-области – характеристический максимум поглощения АК 264 нм. По серии растворов АК (0,25–1,25) · 10–3% определен удельный показатель поглощения АК 727, в соответствии с которым оценено содержание АК в модельных растворах со вспомогательными веществами при хранении. Устойчивость АК составляет, сут: в присутствии ЩК 5, СП 4, ЦП 6, ЯП 10. Установлено оптимальное массовое соотношение АК : ЯП как 1 : 16, что использовано для купажирования фреш-соков, в которых предварительно определена концентрация АК 0,40–19,99 мг % методом титрования 2,6-дихлорфенолиндофенолятом натрия. Сравнительная оценка соков до и после купажирования ЯП при хранении (20°С, 10 сут) показала, что ЯП способствует смещению рН в оптимальную для АК область рН 4,5–8,0; увеличению вязкости соков на 5–148% и сроков хранения в 3,3–59 раз. Относительная погрешность различных определений (n = 5, P = 95%, t = 2,57) составила ± (0,7–5,6)%. Доказана возможность применения очищенного ЯП в качестве стабилизатора АК в фреш-соках с концентрацией АК 10–6–10–4 г/мл, что создает перспективы безопасного «продления жизни» соков. The possibility of using purified pectins to stabilize ascorbic acid (AA) in fresh juices with a concentration of 10–6–10–4g/ml was investigated. In the work were used: АA, oxalic acid (OA), beetroot, citrus and apple pectins (BP, CP and AP) with high molar mass (61000–87500 g/mol) and the degree of etherification (46,5–76,3%), intended for pharmaceutical use. Fresh juices were obtained by pressing berries, fruits and vegetables (18 kinds). Absence of interfering effect of pectins on the determination of AA by differential spectroscopy in the UV region (characteristic maximum absorption of AA – 264 nm) was established. According to the series of AA solutions (0,25–1,25) · 10–3%, the specific absorption rate of AA 727 was determined, according to which the content of AA in model solutions with auxiliary substances during storage was estimated. The stability of AA in the presence of OA is 5 days, BP – 4 days, CP – 6 days, AP – 10 days. The optimal mass ratio of AA : AP 1 : 16 was established, which was used for blending fresh juice, in which the concentration of AA (0,40–19,99 mg %) was previously determined by the method of titration with 2,6-dichlorphenolindophenol sodium. A comparative assessment of juices before and after blending during storage (20°C, 10 days) showed that AP contributes to the displacement of pH in the optimal for AA area of pH 4,5–8,0; increase in the viscosity of juices by 5–148% and shelf life of 3,3–59 times. The relative error of different definitions (n = 5, P = 95%, t = 2,57) was ± (0,7–5,6)%. Thus, the possibility of using purified AP as an AA stabilizer in fresh juices with the concentration of AA 10–6–10–4g/ml is proved, which creates prospects for safe prolonging the life of juices.

scholarly journals Co-Loading of Ascorbic Acid and Tocopherol in Eudragit-Nutriosomes to Counteract Intestinal Oxidative Stress

Pharmaceutics ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 13 ◽  
Author(s):  
Maryam Rezvani ◽  
Maria Letizia Manca ◽  
Carla Caddeo ◽  
Elvira Escribano-Ferrer ◽  
Claudia Carbone ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Ascorbic Acid ◽  
Protective Effect ◽  
Natural Antioxidants ◽  
Water Soluble ◽  
Proliferative Effect ◽  
The Stability ◽  
Stress Damage ◽  
Negative Zeta Potential

The present study aimed at developing a new vesicular formulation capable of promoting the protective effect of ascorbic acid and tocopherol against intestinal oxidative stress damage, and their efficacy in intestinal wound healing upon oral administration. A pH-dependent copolymer (Eudragit® L100), a water-soluble prebiotic fibre (Nutriose® FM06), a phospholipid mixture (Lipoid S75), and two natural antioxidants (ascorbic acid and tocopherol) were combined to fabricate eudragit-nutriosomes by a simple, solvent-free procedure. The vesicles were spherical and oligolamellar, with some multicompartment structures in Eudragit-nutriosomes, small in size (~100 nm), with highly negative zeta potential. The effect of Eudragit® and Nutriose® on the stability on storage and in simulated gastrointestinal fluids were confirmed by the Turbiscan® technology and in vitro studies, respectively. Eudragit-nutriosomes exhibited a protective effect against H2O2-induced oxidative stress, and a proliferative effect in Caco-2 cells, as they provided the closure of the scratched area after 96 h of incubation.

scholarly journals COMPARISON BETWEEN CUSTOMS PREPARATIONS AND WORKOUT PREPARATIONS FOR PESTICIDE PROFENOFOS FROM DIFFERENT SOURCES AND UNDER SPECIFIC ENVIRONMENTAL CONDITIONS

2021 ◽  
Vol 21 (No 1) ◽  
Author(s):  
Hala. M. Ibrahim
Keyword(s):  
Uv Light ◽  
Degradation Products ◽  
Light Exposure ◽  
Sunlight Exposure ◽  
Factors Affecting ◽  
Trade Name ◽  
Before And After ◽  
The Stability ◽  
And Storage ◽  
Different Sources

Four generic profenfos formulations under trade name Camkron and Tiliton 72% EC (customs, workout) for each of those, which currently applied in Egypt from different companies were studied for the effects of sunlight exposure, UV-light, PH and storage on the stability of profenofos, its respective impurity 4-bromo-2-chlorophenol content and water as a relevant impurity. Exposure to sunlight, UV-light at 16 hours and storage for 14 days at 54±2o C indicated various degradation effects on profenofos content and increase the formation of its impurity 4-bromo-2-chlorophenol and the change in PH in long period cause breakdown of the active substance instability of some component. The storage of profenofos at intervals of 3, 7 and 14 days at 54 ± 2o C from the results obtained showed serious effects on the rate of degradation of profenofos and the increase in the rate of formation of 4-bromo-2-chlorophenol, as well as on sunlight, UV-light exposure, for all of the profenofos formulations under study. It found that the Camkron (workout) is invalid for use it may be due to several factors affecting the consistency of the formulation of profenofos in the manufacturing process, the origins of technical materials, the use of various forms of adjuvants and the long storage time in poor conditions. Analysis before and after storage, sunlight exposure, UV-light using GC-MS identified four degradation products: 4-bromo-2-chlorophenol, O-(4-bromophenyl) O-ethyl S-propyl phosphorothioate, O-(2-chlorophenyl) O-ethyl S-propyl phosphorothioate and O-(4-bromo-2-chlorophenyl) S-propyl hydrogen phosphorothioate and also used IR spectra.

The stability of dislocation networks under various oxygen-doping conditions in superconducting Bi2Sr2CaCu2Oy single crystals and their influence on the flux pinning properties

1994 ◽  
Vol 52 ◽  
pp. 802-803
Author(s):  
Y. Feng ◽  
X. Y. Cai ◽  
R. J. Kelley ◽  
D. C. Larbalestier
Keyword(s):  
Single Crystals ◽  
Oxygen Content ◽  
Basal Plane ◽  
Flux Pinning ◽  
Pinning Centers ◽  
Before And After ◽  
Anomalous Peak ◽  
Basal Plane Dislocation ◽  
The Stability ◽  
Further Development

The issue of strong flux pinning is crucial to the further development of high critical current density Bi-Sr-Ca-Cu-O (BSCCO) superconductors in conductor-like applications, yet the pinning mechanisms are still much debated. Anomalous peaks in the M-H (magnetization vs. magnetic field) loops are commonly observed in Bi2Sr2CaCu2Oy (Bi-2212) single crystals. Oxygen vacancies may be effective flux pinning centers in BSCCO, as has been found in YBCO. However, it has also been proposed that basal-plane dislocation networks also act as effective pinning centers. Yang et al. proposed that the characteristic scale of the basal-plane dislocation networksmay strongly depend on oxygen content and the anomalous peak in the M-H loop at ˜20-30K may be due tothe flux pinning of decoupled two-dimensional pancake vortices by the dislocation networks. In light of this, we have performed an insitu observation on the dislocation networks precisely at the same region before and after annealing in air, vacuumand oxygen, in order to verify whether the dislocation networks change with varying oxygen content Inall cases, we have not found any noticeable changes in dislocation structure, regardless of the drastic changes in Tc and the anomalous magnetization. Therefore, it does not appear that the anomalous peak in the M-H loops is controlled by the basal-plane dislocation networks.

Ascorbic Acid does not Improve Endothelium-Dependent Flow-mediated Dilatation of the Brachial Artery in Patients with Raynaud’s Phenomenon Secondary to Systemic Sclerosis

2003 ◽  
Vol 73 (1) ◽  
pp. 3-7 ◽  
Author(s):  
M. E. Mavrikakis ◽  
J. P. Lekakis ◽  
M. Papamichael ◽  
K. S. Stamatelopoulos ◽  
Ch. C. Kostopoulos ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Smooth Muscle ◽  
Systemic Sclerosis ◽  
Endothelial Dysfunction ◽  
Brachial Artery ◽  
Raynaud’S Phenomenon ◽  
Raynaud's Phenomenon ◽  
Water Soluble ◽  
Placebo Administration ◽  
Flow Mediated Dilatation

Previous studies have shown that patients with Raynaud’s phenomenon secondary to systemic sclerosis present abnormal endothelial function; the mechanisms responsible for the endothelial dysfunction are unknown but increased vascular oxidative stress could be a possible cause. The hypothesis that a potent water-soluble antioxidant can reverse endothelial dysfunction in these patients was tested in the present study. We examined 11 female patients with Raynaud’s phenomenon secondary to systemic sclerosis and ten healthy control women by ultrasound imaging of the brachial artery to assess flow-mediated (endothelium-dependent) and nitrate-induced (endothelium-independent) vasodilatation. Flow-mediated dilatation and nitrate-induced dilatation were significantly reduced in patients with Raynaud’s phenomenon, indicating abnormal endothelial and smooth muscle cell function. Patients with Raynaud’s phenomenon entered a double-blind, randomized, crossover placebo-controlled trial and received orally 2 g of ascorbic acid or placebo; vascular studies were repeated two hours after ascorbic acid or placebo administration. Flow-mediated dilatation did not improve after ascorbic acid (1.6 ± 2.2% to 2.2 ± 2.5%, ns) or placebo administration (1.2 ± 1,9% to 1.7 ± 1.4%, ns); also nitrate-induced dilatation was similar after ascorbic acid or placebo (16 ± 7.4% vs 17 ± 8%, ns), suggesting no effect of ascorbic acid on endothelial and vascular smooth muscle function. In conclusion, ascorbic acid does not reverse endothelial vasomotor dysfunction in the brachial circulation of patients with Raynaud’s phenomenon secondary to systemic sclerosis. The use of different antioxidants or different dosing of ascorbic acid may be required to show a beneficial effect on endothelial vasodilator function.

Assessment of Color Stability of Treated Leathers with Silicone Oil and Polyethylene Glycol

2014 ◽  
Vol 1 (1) ◽  
pp. 24-34
Author(s):  
Alireza K. ◽  
Hossein Ahmadi ◽  
Mohsen Mohammadi
Keyword(s):  
Ascorbic Acid ◽  
Polyethylene Glycol ◽  
Treatment Process ◽  
Color Change ◽  
Silicone Oil ◽  
Accelerated Aging ◽  
Color Stability ◽  
Antioxidant Additive ◽  
Before And After ◽  
Aesthetic Values

Lubricants and leather dressings are the most common treatments of dry and water logged historical leathers. Color change has a great importance during the time and treatment process, due to visual and aesthetic values of historic leather relics. Polyethylene glycol (PEG) and silicone oil (SiO) are frequently used leather dressings in the conservation procedures. Therefore, color stability of treated leathers with PEG and SiO were investigated before and after heat accelerated aging. Moreover, application of ascorbic acid was evaluated as an antioxidant additive for PEG (PEG+AA).Color change after treatment and aging were studied by colorimetry technique in the CIE *L*a*b system. Results indicated to severe color alteration in PEG treated and aged leathers with or without ascorbic acid. Whereas, SiO treated samples showed better stability and minimum color shift after aging. Silicone oil was characterized as the best dressing for historical leathers with compared to PEG and PEG+AA, due to its high stability and aesthetical properties.

Tyrosine-Selective Bioconjugation with Iminoxyl Radicals

2020 ◽  
Author(s):  
Katsuya Maruyama ◽  
Takashi Ishiyama ◽  
Yohei Seki ◽  
Kounosuke Oisaki ◽  
Motomu Kanai
Keyword(s):  
Reaction Time ◽  
Steric Hindrance ◽  
Room Temperature ◽  
Water Soluble ◽  
Light Irradiation ◽  
Sodium Ascorbate ◽  
Iminoxyl Radical ◽  
Short Reaction Time ◽  
Modified Peptides ◽  
The Stability

A novel Tyr-selective protein bioconjugation using the water-soluble persistent iminoxyl radical is described. The conjugation proceeded with high Tyr-selectivity and short reaction time under biocompatible conditions (room temperature in buffered media under air). The stability of the conjugates was tunable depending on the steric hindrance of iminoxyl. The presence of sodium ascorbate and/or light irradiation promoted traceless deconjugation, restoring the native Tyr structure. The method is applied to the synthesis of a protein-dye conjugate and further derivatization to azobenzene-modified peptides.

Molecularly Imprinted Sensor for Ascorbic Acid Based on Gold Nanoparticles and Multiwalled Carbon Nanotubes

2020 ◽  
Vol 16 (7) ◽  
pp. 905-913
Author(s):  
Youyuan Peng ◽  
Qingshan Miao
Keyword(s):  
Carbon Nanotubes ◽  
Gold Nanoparticles ◽  
Ascorbic Acid ◽  
Multiwalled Carbon Nanotubes ◽  
Ph Value ◽  
Biological Fluids ◽  
Water Soluble ◽  
Multiwalled Carbon ◽  
Experimental Conditions ◽  
Molecularly Imprinted

Background: L-Ascorbic acid (AA) is a kind of water soluble vitamin, which is mainly present in fruits, vegetables and biological fluids. As a low cost antioxidant and effective scavenger of free radicals, AA may help to prevent diseases such as cancer and Parkinson’s disease. Owing to its role in the biological metabolism, AA has also been utilized for the therapy of mental illness, common cold and for improving the immunity. Therefore, it is very necessary and urgent to develop a simple, rapid and selective strategy for the detection of AA in various samples. Methods: The molecularly imprinted poly(o-phenylenediamine) (PoPD) film was prepared for the analysis of L-ascorbic acid (AA) on gold nanoparticles (AuNPs) - multiwalled carbon nanotubes (MWCNTs) modified glass carbon electrode (GCE) by electropolymerization of o-phenylenediamine (oPD) and AA. Experimental parameters including pH value of running buffer and scan rates were optimized. Scanning electron microscope (SEM), fourier-transform infrared (FTIR) spectra, cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were utilized for the characterization of the imprinted polymer film. Results: Under the selected experimental conditions, the DPV peak currents of AA exhibit two distinct linear responses ranging from 0.01 to 2 μmol L-1 and 2 to 100 μmol L-1 towards the concentrations of AA, and the detection limit was 2 nmol L-1 (S/N=3). Conclusion: The proposed electrochemical sensor possesses excellent selectivity for AA, along with good reproducibility and stability. The results obtained from the analysis of AA in real samples demonstrated the applicability of the proposed sensor to practical analysis.

UV Irradiation of Shell Eggs: Effect on Populations of Aerobes, Molds, and Inoculated Salmonella typhimurium

1997 ◽  
Vol 60 (6) ◽  
pp. 639-643 ◽  
Author(s):  
FUENG-LIN KUO ◽  
JOHN B. CAREY ◽  
STEVEN C. RICKE
Keyword(s):  
Salmonella Typhimurium ◽  
Uv Radiation ◽  
Uv Light ◽  
The Other ◽  
Uv Exposure ◽  
Microbial Populations ◽  
Aerobic Bacteria ◽  
Fluorescent Light ◽  
Uv Treatment ◽  
Shell Eggs

The effects were investigated of 254-nm UV radiation on populations of Salmonella typhimurium, aerobes, and molds on the shells of eggs. In the first experiment, the CFU of attached S. typhimurium cells on unwashed clean shell eggs were determined after 0, 1, 3, 5, and 7 min of UV treatment (620 μW/cm2) on both ends of the egg. All UV treatments significantly reduced S. typhimurium CFU (P &lt; .01). UVtreatment (620 μW/cm2) in 1-min alternating light and dark cycles for 5 min (three light and two dark) was compared to 0, 3, and 5 min of UV treatment. No significant differences in microbial populations were observed among light and dark cycles and the other UV treatments. In a subsequent experiment, the same UV treatments were utilized to evaluate photoreactivation. After UV exposure, eggs were exposed to 1 h of fluorescent light or I h of darkness or cultured immediately. S. typhimurium CFU were significantly (P &lt; .01) reduced by the UV treatments. However, no significant differences between microbial populations exposed to UV treatment and UV radiation plus photoreactivation were detected. For studies of aerobic bacteria and molds, different UV treatment times (0, 15, and 30 min) at the intensity of 620 μW/cm2 and different intensities (620, 1350, and 1720 μW/cm2) for 15 min were evaluated. Mold CFU per egg were either 0 or 1 for all UV treatments and a 99% reduction of CFU of aerobic bacteria per egg were observed for all UV treatments. It appears from these studies that UV light can significantly reduce populations of S. typhimurium, aerobes, and molds on shell eggs.

scholarly journals Stability and ocular biodistribution of topically administered PLGA nanoparticles

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sean Swetledge ◽  
Renee Carter ◽  
Rhett Stout ◽  
Carlos E. Astete ◽  
Jangwook P. Jung ◽  
...  
Keyword(s):  
Uv Light ◽  
Light Exposure ◽  
Polymeric Nanoparticles ◽  
Plga Nanoparticles ◽  
Eye Disease ◽  
Control Group ◽  
Eye Tissues ◽  
Nanoparticle Morphology ◽  
The Stability

AbstractPolymeric nanoparticles have been investigated as potential delivery systems for therapeutic compounds to address many ailments including eye disease. The stability and spatiotemporal distribution of polymeric nanoparticles in the eye are important regarding the practical applicability and efficacy of the delivery system in treating eye disease. We selected poly(lactic-co-glycolic acid) (PLGA) nanoparticles loaded with lutein, a carotenoid antioxidant associated with eye health, as our model ophthalmic nanodelivery system and evaluated its stability when suspended in various conditions involving temperature and light exposure. We also assessed the ocular biodistribution of the fluorescently labeled nanoparticle vehicle when administered topically. Lutein-loaded nanoparticles were stable in suspension when stored at 4 °C with only 26% lutein release and no significant lutein decay or changes in nanoparticle morphology. When stored at 25 °C and 37 °C, these NPs showed signs of bulk degradation, had significant lutein decay compared to 4 °C, and released over 40% lutein after 5 weeks in suspension. Lutein-loaded nanoparticles were also more resistant to photodegradation compared to free lutein when exposed to ultraviolet (UV) light, decaying approximately 5 times slower. When applied topically in vivo, Cy5-labled nanoparticles showed high uptake in exterior eye tissues including the cornea, episcleral tissue, and sclera. The choroid was the only inner eye tissue that was significantly higher than the control group. Decreased fluorescence in all exterior eye tissues and the choroid at 1 h compared to 30 min indicated rapid elimination of nanoparticles from the eye.

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