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Determination of Ascorbic Acid Content of Wine & Soft Drinks By Central JSM Chemistry Bringing Excellence in Open Access Research Article *Corresponding author Assmamaw Taye, Department of chemistry, College of Science, Bahir Dar University, Ethiopia Determination of Ascorbic Acid Submitted: 04 January 2019 Accepted: 19 January 2019 Content of Wine & Soft Drinks by Published: 21 January 2019 ISSN: 2333-6633 Copyright Voltammetric Techniques at Glassy © 2019 Taye et al. Carbon Electrode OPEN ACCESS Keywords Asmamaw Taye* and Assefa Sergawie • Ascorbic acid Department of chemistry, Bahir Dar University, Ethiopia • Cyclic voltammetry • Square wave voltammetry • Glassy carbon electrode Abstract • Wine Ascorbic acid is a white crystalline powder with a molecular formula of C6H8O6 and a • Soft drinks formula weight of 176.12 g/mol. It is a water-soluble, antioxidant vitamin, important in forming collagen, cartilages, muscles, and blood vessels. Therefore, this research aims to develop method for quantitative determination of ascorbic acid in different wine and soft drinks by using cyclic and square wave voltammetey. The oxidation peak for Ascorbic acid occurs at about 596 mV (versus Ag/AgCl) on a glassy carbon working electrode by using cyclic voltammetry and about 450 mV by using square wave voltammetry. For square wave voltammetry method, the influence of pulse amplitude, step potential, frequency, PH dependence and concentration dependence was investigated. For cyclic voltammetry method, the influence of scan rate, concentration and PH was also investigated. The obtained calibration graph shows a linear dependence between the peak height and Ascorbic acid concentration within the range 1.0 mM - 8.0 mM with a glassy carbon working electrode for both cyclic and square wave voltammetry methods. The Ascorbic acid content determined ranged between 2.76 mg/100 mL for sprite and 14.71mg/100 mL for kemila white wine by using cyclic voltammetry and 4.13 mg/100 mL for sprite and 16.34 mg/100 mL for kemila white wine by using square wave voltammetry method. Different Ascorbic acid concentrations (from standard solution) were added to analyzed samples. The degree of recovery being comprised between 97.45 and 100.72 %. INTRODUCTION may contain fruit Wine juice and salts. Their flavor may derive from vegetable Non-alcoholic extracts orsoft other drink aromatic beverage substances can be divided [4]. into fruit The term wine describes an alcoholic beverage that contains products of fermentation of the Juice from the grapes, pears, drinks and soft drinks. The top soft drink brands are coca-cola and Pepsi. The other popular soft drink brands include Fanta, apples, berries, and even flowers such as dandelions [1]. Wine Miranda,Soft drinks 7Up, Sprite available etc. in glass bottles, aluminum cans, PET naturally contains about 85−89% water, 10−14% alcohol, bottles or disposable containers can be divided into carbonated less than 1% fruit acids, and hundreds of aroma and flavor and smell, is derived from many factors including the grapes carbonated drinks and fruit juices and squashes are non- itcomponents is made from, in very where small they amounts. were grown, Wine andcharacter, the production its taste and non-carbonated drinks. Cola, lemon and oranges are carbonated drinks. The major ingredient of soft drinks is water techniques applied by the wine maker [2]. Wines are consumed and it accounts for 86%-90% of the soft drink composition. in all over the world. Wine is also widely produced and consumed Aromatic substances are added to soft drinks to give a pleasant in Ethiopia. Awash Winery is the first commercial winery in tasteThe and most better common stability acids to the used taste. in soft drinks are citric acid, Ethiopia, established in 1943 E.C. The winery produces a range phosphoric acid of well made wines, including Gouder Red, Dukem Red, Awash drink is to balance the sweetness, make the drink fresh and and malic acid. The function of acidity in the CrystalSoft drinks White, Axumite Red and Kemila White [3]. , potassiumthirst-quenching. Color is added to soft are drinks added to increasemake them the that are optionally sweetened, acidulated, carbonated and which presentable and appetizing. Preservatives like natrium benzoate Soft drinks are non-alcoholic water-based flavored drinks sorbate and sulphur dioxide life of the product. Cite this article: Taye A, Sergawie A (2019) Determination of Ascorbic Acid Content of Wine & Soft Drinks by Voltammetric Techniques at Glassy Carbon Electrode. JSM Chem 7(1): 1054. Taye et al. (2019) Central Bringing Excellence in Open Access a selective and sensitive method for ascorbic acid assessment in Antioxidants are substances, which prevent reactions that destroy aromatic substances in soft drinks. The most common foodstuffs and biological fluids. antioxidantVitamin C used(Ascorbic is ascorbic acid) acid. simple, selective and sensitive determination of low molecular A recently developed voltammetric methods allow rapid, 6H8O6 weight antioxidants and vitamins and drugs, without the Vitamin C is a white crystalline powder with a molecular necessitySquare-wave of time consumingvoltammetry separation was used [5]. to determine ascorbic formula of C and a formula weight of 176.12 g/mol. It damageis a water-soluble, & used in treatment antioxidant of certainvitamin, diseases important such in as forming scurvy, anemia,collagen, diabetes, cartilages, common muscles cold, and bloodhemorrhagic vessels. disorders,It prevents wound tissue usedacid, forbased electrocatalytic on its oxidation ascorbic at a acidzeolite determination, modified carbon at a carbon paste electrode [15]. Cyclic and differential pulse voltammetry were malaria, bacterial infections, plug poisoning, liver disease, allergic healing, cough, influenza, sores, gingivitis, skin diseases, diarrhea, appliedpaste electrode,to ascorbic modified acid content with estimation 2,7-bis (ferrocenylethynyl)in citrus juices and fluoren-9-one [16]. Cyclic voltammetry at a bare Pt electrode was reactions, arteriosclerosis as well as infertility in males. Vitamin C also aids in the absorption of iron, immune response activation soft drinks [17]. known for its reductive properties and it is used on a large scale simultaneously determined by differential pulse voltammetry, and helps maintain capillaries, bones, and teeth. Ascorbic acid is Ascorbic acid, uric acid and dopamine were as antioxidant in the pharmaceutical, chemical, cosmetic and performed on a glassy carbon electrode modified with food industry [5]. pulsea film voltammetry of poly was(3 used(5-chloro-2-hydroxyphenylazo)-4,5- for the assessment of ascorbic Adequate intake of vitamin C from foods and supplements is dihydroxynaphtalene-2,7-disulphonicacid [18]. Differential vital for normal functioning of the human body. Recommended Dietary Allowances of 75 mg/day and 90 mg/day have been pharmaceuticalsacid, at poly (3,4-ethylendioxythiophene) formulations was performed modified using differentialelectrodes established for adult women and men, respectively, and 45 mg/ [19]. Simultaneous determination of vitamins C and B6 in day for children 9–12 years old. For smokers, the recommended values are increased by an additional 35 mg [6]. pulseDopamine voltammetry was atdetermined a glassy carbon in the electrode presence [20]. of ascorbic and uric acids by differential pulse voltammetry at a bare glassy An ascorbic acid excess can lead to gastric irritation, and the inmetabolic the inhibition product of of naturalvitamin processesC and causes occurring renal problems in food and[7]. and uric acid was also possible with a ferrocenium-thioglycollate In some cases, excessive quantities of ascorbic acid may result carbon electrode [21]. Simultaneous determination of vitamin C -6 M, the achieved detection can contribute to taste deterioration [8]. Its oxidation can be modified electrode. Under the optimal-4 conditions-7 and within-7M, relevantaccelerated indicator by excessive of quality heat, which light, has andto be heavy carefully metal monitored, cations. the linear range of 1 × 10 M - 5 × 10 Ascorbic acid content of foodstuffs and beverages represents a limits for ascorbic acid and uric acid were 2 × 10 M & 1 × 10 respectively [22]. regarding its variation during manufacturing and storage [9]. A multi-walled carbon nanotube-tetradecyltrim Humans do not produce Vitamin C due to a mutation in the ethylammonium bromide film coated graphite electrode was gulonolactone oxidase gene, which results in the inability to used to study the electro oxidation of ascorbic acid in differential vegetables,synthesize tomatoes,the protein green [10]. and Thereforered peppers, humans grapes, dependsoft drinks, on pulse, cyclic and square-wave voltammetry [23]. winesexogenous or food sources supplements of the vitamin and which pharmaceutical include citrus preparations fruit, leafy The electro catalytic oxidation of ascorbic acid (cyclic and [11]. to implement method for measuring the amount of ascorbic There is a need to find an accurate, reliable, rapid and easy quantifying ascorbic acid due to its instabilities in aqueous acid in a sample. However there have been difficulties in to dehydroascorbic acid, which is a reversible reaction and solution. The instability of ascorbic acid is due to its oxidation subsequently to 2, 3-diketo-L-gulonic acid. The latter reaction is irreversible which is shown at scheme I [12], (Figure 1). The instable ascorbic acid oxidation to dehydroascorbic acid & subsequently to 2, 3- diketo L-gulonic acid [12]. The determination of vitamin C has
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