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This article has been cited by other articles in PMC. Abstract A method was developed for assessing ascorbic acid concentration in commercial fruit juice by cyclic voltammetry.
Experiment 1: Determination of Vitamin C (Ascorbic Acid) Concentration in Fruit Juice. Introduction. Vitamin C (L-Ascorbic acid) Vitamin C is a highly water-soluble compound that has both acidic and strong reducing properties. It naturally occurs in many plants and animals except in humans. The natural vitamin exists in L-ascorbic acid form. You May Also Find These Documents Helpful. Analysis of commercial vitamin C tablets Objective To determine the vitamin C content in commercial vitamin C tablets by titration between vitamin C (ascorbic acid) & iodine solution. Hence, compare this data with the manufacturer's specification. Principle In this analysis. Vitamin C (ascorbic acid) can comprise up to 32 percent of the fruits’ weight. Lemon juice contains percent vitamin C. Citric acid makes up 5 percent to 6 percent of the fruits’ content. Lemons contain approximately 3 percent pantothenic acid. Fresh lime juice contains percent vitamin C and 1 percent pantothenic acid.
The anodic oxidation peak for ascorbic acid occurs at about mV on a Pt disc working electrode versus SCE. The influence of the potential sweep speed on the peak height was studied.
The obtained calibration graph shows a linear dependence between peak height and ascorbic acid concentration in the domain 0. The developed method was applied to ascorbic acid assessment in fruit juice. The ascorbic acid content determined ranged from 0.
Different ascorbic acid concentrations from standard solutions were added to the analysed samples, the degree of recovery being comprised between Ascorbic acid determination results obtained by cyclic voltammetry were compared with those obtained by the volumetric method with dichlorophenol indophenol.
The results obtained by the two methods were in good agreement. Ascorbic acid plays an important role in collagen biosynthesis, iron absorption, and immune response activation and is involved in wound healing and osteogenesis. It also acts as a powerful antioxidant which fights against free-radical induced diseases [ 1 — 5 ].
Nevertheless, an ascorbic acid excess can lead to gastric irritation, and the metabolic product of vitamin C oxalic acid can cause renal problems [ 6 ].
Ascorbic acid is a labile substance, as it is easily degraded by enzymes and atmospheric oxygen. Its oxidation can be accelerated by excessive heat, light, and heavy metal cations [ 1 ]. That is why ascorbic acid content of foodstuffs and beverages represents a relevant indicator of quality which has to be carefully monitored, regarding its variation during manufacturing and storage.
Many analytical methods can be used for ascorbic acid determination. Classic conventional techniques are represented by volumetric methods—titration with an oxidant solution such as dichlorophenol indophenol DCPIP [ 89 ], potassium iodate [ 10 ], or bromate [ 11 ].
Volumetric techniques can suffer from lack of specificity [ 12 ] which limits their use to samples not containing other reducing agents. Other optical methods for vitamin C estimation include spectrophotometrical determination of iodine reacted with ascorbic acid [ 14 ] and chemiluminescence [ 15 ].
Liquid chromatography is a successful method for vitamin C determination when selectivity and specificity are concerned [ 16 — 18 ]. HPLC with electrochemical detection has turned out to be a selective and sensitive method for ascorbic acid assessment in foodstuffs and biological fluids [ 19 — 21 ].
A potentiometric biosensor [ 22 ] for ascorbic acid was made by ascorbate oxidase immobilization in a polymeric matrix, fixed on a graphite-epoxy composite electrode. Amperometric biosensors were obtained by ascorbate oxidase immobilization on a nylon net [ 23 ] or on a collagen membrane, using a Clark oxygen electrode as transducer [ 24 ].
Vitamin C analysis was also performed by using a glassy carbon working electrode as transducer incorporated in a flow system [ 25 ]. Ascorbic and uric acids were determined by coupling an amperometric technique with flow analysis [ 26 ].
Voltammetric and amperometric measurements were performed in a flow cell, using gold microelectrodes on which Pd was electrochemically deposited. This sensor was constructed by aniline electropolymerization on a glassy carbon or a screen-printed working electrode.
Kumar and Narayanan [ 27 ] investigated a method for vitamin C assessment based on an amperometric sensor obtained by graphite electrode modification by cobalt ferrocyanide.
Vitamin C determination was also performed in an FIA system with biamperometric detection, based on ascorbic acid reaction with iodine [ 30 ]. Voltammetry is an increasingly popular method applied to the determination of ascorbic acid in real samples [ 7 ], because it offers low detection limits, even when compared to more expensive techniques.
It requires little or no sample preparation. This technique provides us with the advantage of a fast analysis as well as with the easiness and rapidity of the standard addition method application.
Because of the low cost of the required equipment as well as simplicity of the employed procedures necessary to determine vitamin C, voltammetry appears to offer an attractive alternative to the titrimetric or instrumental methods mentioned earlier, in particular in food quality control.
It does not require complicated, expensive equipment and well-qualified personnel nor is it laborious or time consuming like the previously mentioned instrumental techniques [ 7 ].
Simultanoeus determination of vitamin C and glucose has also been performed using a voltammetric biosensor integrated in an automated SIA system [ 31 ]. Recently, the use of various voltammetric techniques has been combined with modified ascorbic acid sensors; square-wave voltammetry was used to determine ascorbic acid based on its oxidation at a zeolite modified carbon paste electrode [ 32 ], and the method was applied to ascorbic acid determination in citrus juice.
The results reported in literature regarding the determination of ascorbic acid by cyclic voltammetry are not numerous.sweet orange and lemon having almost twice the level of ascorbic acid than lime.
Patients with diabetes, stroke, heart diseases and cancer etc could take more of sweet orange and lemon, which have higher levels of ascorbic.
Vitamin C (ascorbic acid) is an antioxidant that is essential for human nutrition. Vitamin C deficiency can lead to a disease called scurvy, which is characterized by abnormalities in the bones and teeth. Keywords: Ascorbic acid, Lemon, Lime, Sweet Orange.
I. Introduction Ascorbic acid also known as vitamin C is the most important vitamin for human nutrition that is. Experiment 1: Determination of Vitamin C (Ascorbic Acid) Concentration in Fruit Juice. Introduction. Vitamin C (L-Ascorbic acid) Vitamin C is a highly water-soluble compound that has both acidic and strong reducing properties.
It naturally occurs in many plants and animals except in humans. The natural vitamin exists in L-ascorbic acid form. Materials and Methods: The citric acid content of 21 commercially-available juices and juice concentrates and the juice of three types of fruits was analyzed using ion chromatography.
Results: Lemon juice and lime juice are rich sources of citric acid, containing and g/oz, respectively. Lemon and lime juice concentrates contain and g/oz, respectively. For example, a food ranked #1 for being highest in the first amino acid and #10 for being lowest in the second would have a composite score of A food ranked #5 for being highest in the first amino acid and #5 for being lowest in the second would have a composite score of