Ascorbic acid and total vitamin C concentrations in plasma, gastric juice, and gastrointestinal mucosa in lymphocytic gastritis

1998 ◽  
Vol 114 ◽  
pp. A146 ◽  
Author(s):  
M. Hayat ◽  
S. Everett ◽  
K. White ◽  
I. Drake ◽  
S. O'Mahony
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Gastric Juice ◽  
Gastrointestinal Mucosa ◽  
Total Vitamin ◽  
Lymphocytic Gastritis

scholarly journals Ascorbic acid and total vitamin C concentrations in plasma, gastric juice, and gastrointestinal mucosa: effects of gastritis and oral supplementation.

Gut ◽  
1996 ◽  
Vol 38 (2) ◽  
pp. 171-176 ◽  
Author(s):  
A J Waring ◽  
I M Drake ◽  
C J Schorah ◽  
K L White ◽  
D A Lynch ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Gastric Juice ◽  
Gastrointestinal Mucosa ◽  
Total Vitamin ◽  
Oral Supplementation

scholarly journals Dietary antioxidants and DNA damage in patients on long-term acid-suppression therapy: a randomized controlled study

2002 ◽  
Vol 88 (3) ◽  
pp. 265-271 ◽  
Author(s):  
K. L. M. White ◽  
D. M. Chalmers ◽  
I. G. Martin ◽  
S. M. Everett ◽  
P. M. Neville ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Dna Damage ◽  
Ascorbic Acid ◽  
Vitamin E ◽  
Vitamin C ◽  
Gastric Juice ◽  
Proton Pump ◽  
Dietary Antioxidants ◽  
Total Vitamin

Free radicals and reactive species producedin vivocan trigger cell damage and DNA modifications resulting in carcinogenesis. Dietary antioxidants trap these species limiting their damage. The present study evaluated the role of vitamins C and E in the prevention of potentially premalignant modifications to DNA in the human stomach by supplementing patients who, because of hypochlorhydria and possible depletion of gastric antioxidants, could be at increased risk of gastric cancer. Patients undergoing surveillance for Barrett's oesophagus (n100), on long-term proton pump inhibitors were randomized into two groups: vitamin C (500 mg twice/d) and vitamin E (100 mg twice/d) for 12 weeks (the supplemented group) or placebo. Those attending for subsequent endoscopy had gastric juice, plasma and mucosal measurements of vitamin levels and markers of DNA damage. Seventy-two patients completed the study. Plasma ascorbic acid, total vitamin C and vitamin E were elevated in the supplemented group consistent with compliance. Gastric juice ascorbic acid and total vitamin C levels were raised significantly in the supplemented group (P=0·01) but supplementation had no effect on the mucosal level of this vitamin. However, gastric juice ascorbic acid and total vitamin C were within normal ranges in the unsupplemented group. Mucosal malondialdehyde, chemiluminescence and DNA damage levels in the comet assay were unaffected by vitamin supplementation. In conclusion, supplementation does not affect DNA damage in this group of patients. This is probably because long-term inhibition of the gastric proton pump alone does not affect gastric juice ascorbate and therefore does not increase the theoretical risk of gastric cancer because of antioxidant depletion.

Streamlined three step total vitamin C analysis by HILIC-UV for laboratory testing

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Michael Fitzpatrick ◽  
Paul Bonnitcha ◽  
Van Long Nguyen
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Laboratory Testing ◽  
Potassium Phosphate ◽  
Internal Standard ◽  
Good Precision ◽  
Hydrophilic Interaction ◽  
Reverse Phase Hplc ◽  
Reverse Phase ◽  
Total Vitamin

Abstract Objectives In the clinical setting, the analysis and quantification of vitamin C (ascorbic acid) poses several challenges including analyte instability and poor retention by reverse phase HPLC systems. In this article we describe a rapid hydrophilic interaction chromatography ultraviolet method for the measurement of total vitamin C in plasma which overcomes these issues. Methods Ascorbic acid and the internal standard were separated under isocratic conditions using a Waters BEH-Amide column and a mobile phase containing 0.005 M potassium phosphate in 80% acetonitrile. Results The proposed method was validated and showed good precision (coefficient of variation <5%), accuracy (>99%), and analyte stability after extraction (>24 h). Conclusions The simple sample preparation allows full automation and rapid analytical run times of the assay and is therefore suitable for a high-throughput clinical chromatography laboratory.

Determination of Total Vitamin C by Ion Exclusion Chromatography with Electrochemical Detection

1989 ◽  
Vol 72 (4) ◽  
pp. 681-686
Author(s):  
Hie-Joon Kim
Keyword(s):  
Ascorbic Acid ◽  
Sulfuric Acid ◽  
Vitamin C ◽  
Retention Time ◽  
Acid Content ◽  
High Speed ◽  
Reference Electrode ◽  
Dehydroascorbic Acid ◽  
Total Vitamin

Abstract A rapid and sensitive liquid chromatographic method for determination of total vitamin C in foods and beverages is described. Ascorbic acid and dehydroascorbic acid are extracted with sulfuric acid solution, and the dehydroascorbic acid in the extract is reduced to ascorbic acid by dithiothreitol at pH 7. The reduction is complete in 2 min at room temperature. The resulting total ascorbic acid is separated on an anion exclusion/high speed column with 20mM sulfuric acid as eluant and detected amperometrically with a platinum electrode operating at +0.6-0.8 V vs Ag/AgCl reference electrode. Dithiothreitol (retention time, 3.2 min) does not interfere with the separation and detection of ascorbic acid (retention time, 1.3 min). The dehydroascorbic acid content can be estimated as the difference in ascorbic acid content measured with and without reduction by dithiothreitol. The completeness of the reduction was demonstrated by purposely allowing the oxidation of ascorbic acid in the food extract and determining the total vitamin C after reduction. The determinations of vitamin C content in selected foods and beverages were in good agreement with the expected values. Total analysis time for vitamin C is 10 min and the detection limit is 0.1 ng. The method is specific for vitamin C, and interference by other food constituents is minimal.

Automated Fluorometric Method for the Determination of Total Vitamin C in Food Products

1976 ◽  
Vol 59 (6) ◽  
pp. 1244-1250 ◽  
Author(s):  
Ram B Roy ◽  
Aldo Conetta ◽  
Jerry Salpeter
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Dehydroascorbic Acid ◽  
Food Products ◽  
Total Vitamin ◽  
Automated Method ◽  
Highly Sensitive ◽  
Aoac Method ◽  
Analytical System

Abstract A specific microfluorometric method for the determination of ascorbic acid, dehydroascorbic acid, and total vitamin C in food products has been automated. The procedure developed is an adaptation of the official AOAC method (secs. 43.056–43.062), except that N-bromosuccinimide is used instead of Norit to oxidize vitamin C. Ascorbic acid is selectively oxidized by N-bromosuccinimide before other interfering substances that may be present, so this method is a highly sensitive and specific technique with extensive applicability. The proposed automated method is simple, rapid, reliable, and sufficiently sensitive to analyze as little as 2 × 10−3 to 0.1 mg ascorbic acid/ml. Analytical results obtained for ascorbic acid, dehydroascorbic acid, and total vitamin C in a wide variety of food products are reported. The analytical system developed has the capability of analyzing 50 samples/hr.

scholarly journals Functional Quality and Colour Attributes of Two High-Lycopene Tomato Breeding Lines Grown under Greenhouse Conditions

2016 ◽  
Vol 4 (5) ◽  
pp. 365 ◽  
Author(s):  
Ilahy Riadh ◽  
Siddiqui Mohammed Wasim ◽  
Tlili Imen ◽  
Piro Gabriela ◽  
Lenucci Marcello Salvatore ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Antioxidant Activities ◽  
Rio Grande ◽  
Total Vitamin ◽  
Total Carotenoids ◽  
Breeding Lines ◽  
Functional Quality ◽  
Fresh Cut ◽  
Β Carotene

This study investigates the antioxidant components (total carotenoids, lycopene, β-carotene, total phenols, flavonoids, ascorbic acid and total vitamin C) as well as the hydrophilic and lipophilic antioxidant activities (HAA and LAA) of tomato genotypes consisting of one ordinary cultivar Rio Grande and the two high-lycopene breeding lines HLT-F71 and HLT-F72. The correlation of nutritional value to L∗, a∗, b∗ colour indexes and a∗/b∗ ratio was also investigated in whole and fresh cut tomato fruits. Except for β-carotene content, significant differences were found among cultivars for antioxidants. The berries of both HLT-lines recorded higher antioxidant contents, HAA and LAA (TEAC and FRAP assays) than Rio Grande. Under controlled conditions, HLT-F72 reached the highest levels of total carotenoids (165.5 mg β-ca Eq per kg fw), lycopene (150.1 mg per kg fw) and total phenolics (549.7 mg GAE per kg fw). However, HLT-F72 exhibited the highest levels of ascorbic acid (193.3 mg per kg fw), total vitamin C (271.6 mg per kg fw) and flavonoids (450.5 mg RE per kg fw). Line HLT-F71 showed the highest HAA (148.0 µM Trolox per 100 g fw and 4.2 mM FRAP per g fw) and LAA values (258.5 µM Trolox per 100 g fw and 3.2 mM FRAP per g fw respectively). Colour readings in red ripe fresh cut tomato berries particularly a∗, b∗ and the ratio a∗/b∗ could represent an indicator not only for lycopene but also for other phytochemicals and resulting antioxidant activities. HLT-Lines may serve as a starting point for the development of semi-determinate growth habit tomato cultivars with higher functional quality.

Non-Destructive Measurement of the Internal Quality of Citrus Fruits Using a Portable NIR Device

2020 ◽  
Author(s):  
Carla S P Santos ◽  
Rebeca Cruz ◽  
Diogo B Gonçalves ◽  
Rafael Queirós ◽  
Mark Bloore ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Dehydroascorbic Acid ◽  
Soluble Solids ◽  
Internal Quality ◽  
Total Acidity ◽  
Citrus Fruits ◽  
Citrus Industry ◽  
Total Vitamin ◽  
Non Destructive

Abstract The citrus industry has grown exponentially as a result of increasing demand on its consumption, giving it high standing among other fruit crops. Therefore, the citrus sector seeks rapid, easy, and non-destructive approaches to evaluate in real time and in situ the external and internal changes in physical and nutritional quality at any stage of fruit development or storage. In particular, vitamin C is among the most important micronutrients for consumers, but its measurement relies on laborious analytical methodologies. In this study, a portable near infrared spectroscopy (NIRS) sensor was used in combination with chemometrics to develop robust and accurate models to study the ripeness of several citrus fruits (oranges, lemons, clementines, tangerines, and Tahiti limes) and their vitamin C content. Ascorbic acid, dehydroascorbic acid, and total vitamin C were determined by HILIC-HPLC-UV, while soluble solids and total acidity were evaluated by standard analytical procedures. Partial least squares regression (PLSR) was used to build regression models which revealed suitable performance regarding the prediction of quality and ripeness parameters in all tested fruits. Models for ascorbic acid, dehydroascorbic acid, total vitamin C, soluble solids, total acidity, and juiciness showed Rcv2 = 0.77–0.87, Rcv2 = 0.29–0.79, Rcv2 = 0.77–0.86, Rcv2 = 0.75–0.97, Rcv2 = 0.24–0.92, and Rcv2 = 0.38–0.75, respectively. Prediction models of oranges and Tahiti limes showed good to excellent performance regarding all tested conditions. The resulting models confirmed that NIRS technology is a time- and cost-effective approach for predicting citrus fruit quality, which can easily be used by the various stakeholders from the citrus industry.

Note: Quantification of Ascorbic Acid and Dehydroascorbic Acid in Fresh Olives and in Commercial Presentations of Table Olives

2005 ◽  
Vol 11 (3) ◽  
pp. 199-204 ◽  
Author(s):  
A. López ◽  
A. Montaño ◽  
P. Garcia ◽  
A. Garrido
Keyword(s):  
Ascorbic Acid ◽  
High Performance Liquid Chromatography ◽  
Vitamin C ◽  
High Performance ◽  
Dehydroascorbic Acid ◽  
Maximum Level ◽  
Table Olives ◽  
Total Vitamin ◽  
Low Levels ◽  
To Come

Ascorbic acid (AA) and dehydroascorbic acid (DHAA) were determined by high performance liquid chromatography (HPLC) in fresh green olives as well as a diversity of commercial presentations of table olives (based on both Spanish-style green olives and directly brined olives). Fresh green olives (Manzanilla cv.) immediately after harvest contained about 9mg total ascorbic acid/100g f.w., with DHAA representing more than 90% of this amount. During the post-harvest period (till 2 weeks) the total vitamin C remained stable when olives were stored at 6°C, but significant degradation occurred at ambient temperature (~35% loss after 7 days). In commercial presentations of table olives, in general, the main contribution to the total vitamin C level appeared to come from AA added as an antioxidant, the maximum level being found in Manzanilla olives stuffed with anchovy streams (36.1mg/100g f.w.). However, in some samples (e.g. plain olives) that did declare any added AA, very low levels (0.1-0.6mg total AA/100g f.w.) were found. Our hypothesis is that, in those samples, AA would be degraded by lactic acid bacteria and/or yeast from olive fermentation, whereas pasteurisation in other presentations (e.g. stuffed olives) would stabilise added AA.

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