scholarly journals Stability of ‘mangaba’ pulp powder obtained by freeze drying

2017 ◽  
Vol 21 (9) ◽  
pp. 645-650
Author(s):  
Juliana Conegero ◽  
Luciana C. Ribeiro ◽  
José M. C. da Costa ◽  
Antonio R. G. Monteiro
Keyword(s):  
Ascorbic Acid ◽  
Water Activity ◽  
Acid Concentration ◽  
Freeze Drying ◽  
Room Temperature ◽  
Ascorbic Acid Concentration ◽  
Daily Consumption ◽  
Brazilian Legislation ◽  
The Stability ◽  
Plastic Containers

ABSTRACT This work examined the stability of lyophilized ‘mangaba’ pulp powder, rolled and packaged in plastic containers, with and without vacuum during 90 days of storage under room temperature, with evaluation of the parameters every 15 days. Analyses of ascorbic acid concentration, pH, color and water activity were carried out. It was found that ascorbic acid remained in accordance with the standards specified for daily consumption according to the Brazilian legislation in all analyzed packages, with preservation of stability in the laminated package with vacuum, which was also effective in maintaining water activity, which contributes to better stability of the product.

Factors affecting measurement of urinary oxalate.

1984 ◽  
Vol 30 (8) ◽  
pp. 1339-1343 ◽  
Author(s):  
B C Mazzachi ◽  
J K Teubner ◽  
R L Ryall
Keyword(s):  
Ascorbic Acid ◽  
Room Temperature ◽  
Alkaline Ph ◽  
Ascorbic Acid Concentration ◽  
Factors Affecting ◽  
The Stability ◽  
Gas Chromatographic Method ◽  
And Storage ◽  
Urine Specimens ◽  
Positive Interference

Abstract Using a gas-chromatographic method, we examined the effects of phosphate concentration, added calcium chloride, and pH on precipitation of oxalate from urine. All three factors are important, but the pH of precipitation is particularly so, especially in the presence of even normal concentrations of ascorbic acid. At pH 8, increases in measured oxalate ranged from 20% at an ascorbic acid concentration of 1 mmol/L to more than 300% at 15 mmol/L. Ascorbic acid is rapidly converted to oxalate at alkaline pH. We also investigated the stability of both untreated and acidified urine containing ascorbic acid during storage for up to one month at -70, -20, and 4 degrees C, and room temperature. After one month, untreated collections were stable at -70 degrees C and acidified collections at -20 and -70 degrees C. We recommend conditions for assay and storage of urine specimens that are to be assayed for oxalate under which positive interference by ascorbic acid is minimized.

scholarly journals Effect of cold and heat stress on rat adrenal, serum and liver ascorbic acid concentration

2006 ◽  
Vol 58 (3) ◽  
pp. 161-164 ◽  
Author(s):  
Jelena Djordjevic ◽  
S. Djurasevic ◽  
Tamara Vuckovic ◽  
N. Jasnic ◽  
Gordana Cvijic
Keyword(s):  
Ascorbic Acid ◽  
Heat Stress ◽  
Cold Stress ◽  
Acid Concentration ◽  
Wistar Rats ◽  
Room Temperature ◽  
Heat Exposure ◽  
Ascorbic Acid Concentration

Changes in ascorbic acid (AA) concentration were examined in the adrenals, serum and liver of Wistar rats exposed to cold (6 ?C) and heat stress (38 ?C) for 60 min. The exposure of animals to cold stress for 60 min did not change concentration of AA in the serum, adrenals and liver as compared to controls maintained at room temperature. After a 60 min heat exposure the concentration of AA in the adrenals decreased (***p<0.001), in the liver remained unchanged whereas it significantly increased in the serum (***p<0.001) in respect to control values. .

The Effect of Stress and Warfarin on the Adrenal Gland in Relation to Spontaneous Hemorrhage, as Judged by Measurement of Adrenal Ascorbic Acid and Serum Corticosterone

1971 ◽  
Vol 26 (02) ◽  
pp. 275-288 ◽  
Author(s):  
S Chattopadhyay ◽  
D. D Johnson ◽  
G. J Millar ◽  
L. B Jaques
Keyword(s):  
Ascorbic Acid ◽  
Acid Concentration ◽  
Ascorbic Acid Concentration ◽  
Corticosterone Concentration ◽  
Serum Corticosterone ◽  
Spontaneous Hemorrhage ◽  
Combined Action ◽  
Series Of Experiments ◽  
Pituitary Adrenal Axis

SummaryRats were subjected to the following procedures: No treatment, Stressor (10% NaCl i.p.), Warfarin for 7 days, Stressor followed by Warfarin; and groups were sacrificed at intervals for assessment of spontaneous hemorrhage and of adrenal ascorbic acid concentration. There was no hemorrhage in the no treatment and stressor groups; some hemorrhage in the warfarin group; profound hemorrhage with Warfarin + Stressor. The adrenal ascorbic acid concentration was found to be lower, 8 h and again 5 days after stress, and remained lower in the warfarin + stress animals. Warfarin had no effect on adrenal ascorbic acid level.In another series of experiments in which the stress consisted of an electric current to the cage floor for 6 sec over 15 min, rats were sacrificed daily for determination of serum corticosterone concentration and occurrence of spontaneous hemorrhage. There was a statistically significant increase of serum corticosterone concentration with stress, warfarin and combined warfarin and stress treatments (P< 0.001 for all three variables). There was a significant correlation (r = 0.96 and 0.89, P< 0.01) for serum corticosterone concentration with hemorrhage score and incidence of hemorrhage in stressed rats receiving warfarin, but not in those receiving only warfarin. The results indicate an activation, rather than an exhaustion, of the pituitary-adrenal axis during the combined action of anticoagulant and stress, which results in the development of spontaneous hemorrhage.

Impact of high temperature stress on ascorbic acid concentration in tomato

2018 ◽  
pp. 985-990
Author(s):  
V. Hernández ◽  
P. Hellín ◽  
J. Fenoll ◽  
M.V. Molina ◽  
I. Garrido ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
High Temperature ◽  
Temperature Stress ◽  
Acid Concentration ◽  
High Temperature Stress ◽  
Ascorbic Acid Concentration

scholarly journals Interference of ascorbic acid with chemical analytes

2005 ◽  
Vol 42 (6) ◽  
pp. 475-477 ◽  
Author(s):  
Qing H Meng ◽  
William C Irwin ◽  
Jennifer Fesser ◽  
K Lorne Massey
Keyword(s):  
Ascorbic Acid ◽  
Creatine Kinase ◽  
Uric Acid ◽  
Total Cholesterol ◽  
Acid Concentration ◽  
Total Bilirubin ◽  
Binding Capacity ◽  
Ascorbic Acid Concentration ◽  
Sodium Potassium ◽  
Creatine Kinase Mb

Background: Ascorbic acid can interfere with methodologies involving redox reactions, while comprehensive studies on main chemistry analysers have not been reported. We therefore attempted to determine the interference of ascorbic acid with analytes on the Beckman Synchron LX20®. Methods: Various concentrations of ascorbic acid were added to serum, and the serum analytes were measured on the LX20. Results: With a serum ascorbic acid concentration of 12.0 mmol/L, the values for sodium, potassium, calcium and creatinine increased by 43%, 58%, 103% and 26%, respectively ( P<0.01). With a serum ascorbic acid concentration of 12.0 mmol/L, the values for chloride, total bilirubin and uric acid decreased by 33%, 62% and 83%, respectively ( P<0.01), and were undetectable for total cholesterol, triglyceride, ammonia and lactate. There was no definite influence of ascorbic acid on analytical values for total CO2, urea, glucose, phosphate, total protein, albumin, amylase, creatine kinase, creatine kinase-MB, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total iron, unbound iron-binding capacity or magnesium. Conclusions: Ascorbic acid causes a false increase in sodium, potassium, calcium and creatinine results and a false decrease in chloride, total bilirubin, uric acid, total cholesterol, triglyceride, ammonia and lactate results.

Impacts of pulsed electric field and heat treatment on quality and sensory properties and microbial inactivation of pomegranate juice

2017 ◽  
Vol 23 (8) ◽  
pp. 668-680 ◽  
Author(s):  
Gulsun A Evrendilek
Keyword(s):  
Ascorbic Acid ◽  
Acid Concentration ◽  
Titratable Acidity ◽  
Sensory Properties ◽  
Pomegranate Juice ◽  
Total Phenolic ◽  
Anthocyanin Content ◽  
Linear Regression Models ◽  
Ascorbic Acid Concentration ◽  
Total Antioxidant

Synergistic effects of pulsed electric field+mild heat on quality properties of pomegranate juice were modeled using the best-fit multiple (non-) linear regression models with inactivation kinetics parameters of Escherichia coli O157:H7 and Staphylococcus aureus. No significant difference was detected between the control and the treated samples in terms of pH; °Brix; total antioxidant capacity; total monomeric anthocyanin content; total ascorbic acid concentration; and the sensory properties of flavor, taste, aftertaste, and overall acceptance ( p > 0.05). An exposure of 65.3 J and 40 ℃ caused an increase on conductivity; titratable acidity; L*, a*, and b* values; and a decrease of browning index, total phenolic content, total antioxidant capacity, total monomeric anthocyanin content, total ascorbic acid concentration, and in the sensory properties of color and sourness in pomegranate juice. The goodness-of-fit for the best-fit multiple (non-) linear regression models in descending order belonged to E. coli O157:H7 (92.98%), S. aureus (84.06%), color a* (83.9%), titratable acidity (81.3%), color L* (78.5%), color b* (78.3%), conductivity (74.8%), total phenolic content (74.1%), and total ascorbic acid concentration (64.74%), respectively. De and ze values for E. coli O157:H7 and S. aureus ranged from 105.64 to 1093.25 and from 79.18 to 1057.73 µs with 27.39 and 30.80 J, consequently.

O3-induced inflammation in prepregnant, pregnant, and lactating rats correlates with O3 dose estimated by18O

1999 ◽  
Vol 276 (2) ◽  
pp. L332-L340 ◽  
Author(s):  
Albert F. Gunnison ◽  
Gary E. Hatch
Keyword(s):  
Ascorbic Acid ◽  
Acid Concentration ◽  
Inflammatory Responses ◽  
Virgin Female ◽  
Chemical Species ◽  
Female Rats ◽  
Acute Exposure ◽  
Physiological Status ◽  
Ascorbic Acid Concentration ◽  
Lower Lung

Previous studies have shown that rats late in pregnancy and throughout lactation are more susceptible to ozone (O3)-induced pulmonary inflammation than are prepregnant (virgin) or postlactating rats. The major aim of the present study was to determine whether these differences in response intensity could be accounted for by the O3 dose to the lower region of the lung. The relative O3 dose to the lower lung of groups of pregnant, lactating, and virgin female rats was estimated by measuring the incorporation of the18O isotope into low-speed (cells) and high-speed (surfactant) pellets of bronchoalveolar lavage fluid immediately after acute exposure to 0.5–1.1 parts/million18O3. The polymorphonuclear leukocyte (PMN) and protein inflammatory responses were established 20 h after acute exposure of identical physiological groups to 0.5–1.1 parts/million16O3(common isotope). A single regression of PMN inflammation data against surfactant 18O concentration for all physiological groups gave a linear relationship, indicating direct proportionality of PMN inflammation with this estimate of relative dose to the lower lung regardless of physiological status. This implies that the chemical species that react with surfactant molecules, i.e., O3 or its metabolites, are the same as or proportional to those chemical species responsible for initiating PMN inflammation. Additional experiments showed that lung tissue ascorbic acid concentration was significantly lower in pregnant and lactating rats than in virgin female rats. Although a causative relationship cannot be assumed, the deficit in tissue ascorbic acid concentration in pregnant and lactating rats compared with virgin female rats is consistent with their greater responsiveness and higher relative surfactant O3 dose.

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