scholarly journals Routine Analysis of Ascorbic Acid in Citrus Juice Using Capillary Electrophoresis

2001 ◽  
Vol 84 (3) ◽  
pp. 987-992 ◽  
Author(s):  
Paul F Cancalon
Keyword(s):  
Ascorbic Acid ◽  
Capillary Electrophoresis ◽  
Vitamin C ◽  
High Speed ◽  
Ethylenediaminetetraacetic Acid ◽  
Internal Standard ◽  
Dehydroascorbic Acid ◽  
Sodium Borate ◽  
Internal Standard Method ◽  
Citrus Juice

Abstract A procedure to monitor citrus juice samples was established to quantitate vitamin C by capillary electrophoresis using a previously developed method. Dilution and filtration were the only preparation requirements and separation was achieved with an uncoated capillary using a 35mM sodium borate buffer (pH 9.3) containing 5% (v/v) acetonitrile at 21 kV and 23°C. Detection was performed by high speed scanning between 200 and 360 nm. From the multiwave length scan, the electropherogram at 270 nm was extracted and used to quantitate ascorbic acid. The ascorbic acid concentration was calculated with an internal standard method, with ferulic acid as internal standard. The level of ascorbic acid during analysis was stabilized with ethylenediaminetetraacetic acid and dithiothreitol was used to reduce dehydroascorbic acid to ascorbic acid to estimate the total vitamin C level. Results were similar to those obtained by liquid chromatography and the method is now used to determine routinely the level of ascorbic acid in citrus juices.

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.

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.

Effect of Dietary Ascorbate on the Concentration of Tissue Ascorbic Acid, Dehydroascorbic Acid, Ascorbic Sulfate, and Activity of Ascorbic Sulfate Sulfohydrolase in Rainbow Trout (Oncorhynchus mykiss)

1990 ◽  
Vol 47 (8) ◽  
pp. 1518-1525 ◽  
Author(s):  
Konrad Dabrowski ◽  
Reinhard Lackner ◽  
Cristine Doblander
Keyword(s):  
Ascorbic Acid ◽  
Rainbow Trout ◽  
Vitamin C ◽  
Oncorhynchus Mykiss ◽  
Dehydroascorbic Acid ◽  
Control Group ◽  
High Demand ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Dietary Treatments ◽  
Kidney Liver

The concentrations of ascorbic acid in several tissues of rainbow trout (Oncorhynchus mykiss) are significantly influenced by various dietary treatments. Ascorbic acid was taken up readily by erythrocytes, kidney, liver, intestine, spleen, and brain in fish fed an ascorbate supplemented diet (AA group), the concentration being from 1.5 to 14.8-fold higher than in fish fed a diet lacking ascorbate (control group). In fish fed a diet supplemented with an equimolar amount of ascorbic acid in the form of ascorbic sulfate (AS group) the ascorbic acid concentrations in kidney, intestine, and erythrocytes were significantly elevated above those of the control group. Ascorbic sulfate was found in kidney, liver, and intestine of the AS group, but not in other groups. In fish fed a diet devoid of vitamin C the ascorbic acid concentrations in kidney, liver, intestine, and spleen were signficantly lower than in fasting fish over the same period of time (28 d), suggesting a high demand for vitamin C in an actively feeding animal. Salmonid fish are therefore probably unable to utilize ascorbic sulfate sufficiently to prevent the appearance of vitamin C deficiency, and thus resemble scurvy-prone mammals in this respect.

scholarly journals Vitamin C and the Role of Citrus Juices as Functional Food

2009 ◽  
Vol 4 (5) ◽  
pp. 1934578X0900400 ◽  
Author(s):  
Nuria Martí ◽  
Pedro Mena ◽  
Jose Antonio Cánovas ◽  
Vicente Micol ◽  
Domingo Saura
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Dehydroascorbic Acid ◽  
Antioxidant Response ◽  
Intestinal Wall ◽  
Processing Temperature ◽  
High Concentration ◽  
Citrus Juices ◽  
Citrus Extract

The literature on the content and stability of vitamin C (ascorbic acid, AA) in citrus juices in relation to industrial practices is reviewed. The role of vitamin C from citrus juices in human diet is also reviewed. Citrus fruits and juices are rich in several types of bioactive compounds. Their antioxidant activity and related benefits derive not only from vitamin C but also from other phytochemicals, mainly flavonoids. During juice processing, temperature and oxygen are the main factors responsible for vitamin C losses. Nonthermal processed juices retain higher levels of vitamin C, but economic factors apparently delay the use of such methods in the citrus industry. Regarding packing material, vitamin C in fruit juice is quite stable when stored in metal or glass containers, whereas juice stored in plastic bottles has a much shorter shelf-life. The limiting step for vitamin C absorption in humans is transcellular active transport across the intestinal wall where AA may be oxidized to dehydroascorbic acid (DHAA), which is easily transported across the cell membrane and immediately reduced back to AA by two major pathways. AA bioavailability in the presence of flavonoids has yielded controversial results. Whereas flavonoids seem to inhibit intestinal absorption of AA, some studies have shown that AA in citrus extract was more available than synthetic ascorbic acid alone. DHAA is reported to possess equivalent biological activity to AA, so recent studies often consider the vitamin C activity in the diet as the sum of AA plus DHAA. However, this claimed equivalence should be carefully reexamined. Humans are one of the few species lacking the enzyme (L-gulonolactone oxidase, GLO) to convert glucose to vitamin C. It has been suggested that this is due to a mutation that provided a survival advantage to early primates, since GLO produces toxic H2O2. Furthermore, the high concentration of AA (and DHAA) in neural tissues could have been the key factor that caused primates (vertebrates with relative big brain) to lose the capacity to synthesize vitamin C. Oxidative damage has many pathological implications in human health, and AA may play a central role in maintaining the metabolic antioxidant response. The abundance of citrus juices in the Mediterranean diet may provide the main dietary source for natural vitamin C.

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.

Liquid Chromatography, Microfluorometry, and Dye-Titration Determination of Vitamin C in Fresh Fruit and Vegetables

1983 ◽  
Vol 66 (6) ◽  
pp. 1377-1379
Author(s):  
Ron B H Wills ◽  
Pushparany Wimalasirl ◽  
Heather Greenfield
Keyword(s):  
Ascorbic Acid ◽  
Liquid Chromatography ◽  
Vitamin C ◽  
Dehydroascorbic Acid ◽  
Fresh Fruit ◽  
Fruit And Vegetables ◽  
End Point ◽  
Liquid Chromatographic ◽  
Good Agreement

Abstract The vitamin C content of several fresh fruit and vegetables was determined by a liquid chromatographic (LC) method which gave simultaneous separate values for ascorbic acid and dehydroascorbic acid (DHA) and by the official AOAC methods of microfluorometry and dye-titration. The levels of ascorbic acid obtained by LC and dye-titration were in good agreement, except for a few colored products where it was difficult to determine the end point of the titration. The combined values for ascorbic acid and DHA obtained by LC and microfluorometry were in agreement for most produce, but for about one-third of the samples, the values obtained by microfluorometry were significantly higher.

scholarly journals Dehydroascorbic acid uptake in a human keratinocyte cell line (HaCaT) is glutathione-independent

2000 ◽  
Vol 345 (3) ◽  
pp. 665-672 ◽  
Author(s):  
Isabella SAVINI ◽  
Sylvie DUFLOT ◽  
Luciana AVIGLIANO
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Reductase Activity ◽  
Thioredoxin Reductase ◽  
Dehydroascorbic Acid ◽  
Reduction Process ◽  
Enzymic Activity ◽  
Glutathione Depletion ◽  
Acid Uptake ◽  
Hacat Cells

Vitamin C plays an important role in neutralizing toxic free radicals formed during oxidative metabolism or UV exposure of human skin. This study was performed to investigate the mechanisms that regulate the homoeostasis of vitamin C in HaCaT cells by identifying the events involved in the transport and in the reduction of dehydroascorbic acid. Dehydroascorbic acid accumulated to a greater extent and faster compared with ascorbic acid; its transport appeared to be mediated by hexose transporters and was entirely distinct from ascorbic acid transport. Dehydroascorbate reductase activity was unaffected by glutathione depletion, although it was sensitive to thiol protein reagents. These observations, as well as the subcellular distribution of this enzymic activity and the cofactor specificity, indicate that thioredoxin reductase and lipoamide dehydrogenase play an important role in this reduction process. HaCaT cells were able to enhance their dehydroascorbic acid reductase activity in response to oxidative stress.

scholarly journals The effect of Commercial Practices on Ascorbic Acid and Dehydroascorbic Acid (Vitamin C) in Milk

1940 ◽  
Vol 23 (11) ◽  
pp. 1131-1141 ◽  
Author(s):  
Warren W. Woessner ◽  
K.G. Weckel ◽  
Henry A. Schuette
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Dehydroascorbic Acid
Sign in / Sign up

Export Citation Format

Share Document