Quantitative Analysis of Vitamin C in Food Products Essay

at that place is growing evidence that Vitamin C serves as a squiffy antioxidant in vitro. There are many functions that Vitamin C has in the dust among which is the capacity to improve the immunity system such(prenominal) that a soulfulness is more than able to fight off colds and flus.Pre-Lab List five former(a) functions of Vitamin C in the human body.Vitamin C is an otherwise name for ascorbic acid. There is a marked similarity between the structure of glucose and Vitamin C. As a matter of fact, plants and most animals are able to synthesize Vitamin C from glucose. Unfortunately, human being are unable to do this and we must include Vitamin C in our diet or we risk a vitamin deficiency disease.We all get it on citrus takes as a valuable vitamin C source, but few of us realize that many freshly harvested vegetables contain considerably more of this vitamin than do oranges or lime. Unfortunately, storage and processing destroy most of the Vitamin C in vegetables before they reach the consumer. Consumer cooking manners further decrease the follow of vitamin C in vegetables. Vitamin C is water soluble and thus leaches disclose while cooking or steaming.One useful analytical method for measuring the Vitamin C inwardness of a vegetable or fruit involves an oxidation-reduction titration of ascorbic acid. In the titration, ascorbic acid is oxidized to form dehydroascorbic acid. You might destine it unusual to oxidize the acid rather than titrate it with a base. However, biological samples contain many substances that also act as acids (as was mentioned in investigate 3) and thus interfere in a titration of ascorbic acid with a base. In contrast, many fewer components of biological materials interfere with the oxidation of ascorbic acid by the oxidizing agent 2, 6-dichloroindophenol (DCP). Thus, an oxidation-reduction titration of ascorbic acid with DCP provides a more selective abstract than would an acid-base titration.Please note the equation for t he reaction belowC6H8O6 ( likenessless) + C12H7O2NCl2(red) (pH3) C6H6O6 (Colorless) + C12H9O2NCl2 (colorless)This titration is particularly favourable because DCP also serves as its own indicator. As we add DCP solution to a solution containing Vitamin C, the reaction mixture remains colorless until all of the Vitamin C has been converted to dehydroascorbic acid. The next drop of DCP solution added imparts a red color from excess DCP to the mixture, indicating both the equivalence point and the endpoint of the titration. (Expect solution to go from red to colorless then at the endpoint red again).Because DCP solutions endure a relatively short shelf life, we usually standardize such solutions immediately prior to using them. We can perform the standardization hands down by titrating aliquots of an ascorbic acid solution prepared from an accurately-weighed sample of reagent-grade ascorbic acid. The standardization titration reaction is the same as the analysis reaction above.In this experiment, you will depart by standardizing a DCP solution. Then you will determine the vitamin C content of liquid and solid food samples by titration with the standardized DCP solution.Prior to do the titrations, you will treat the food samples with metaphosphoric acid. Treatment with this acid serves to denature and pass proteins that would otherwise interfere with the analysis. Acidification of thesample also serves to stabilize the ascorbic acid, which will otherwise go bad and be undetectable.Acidification to pH less than 4 also minimizes reaction of DCP with other compounds which react with DCP only at pH levels greater than 4.