Analysis of the differences of percentage of vitamin C (ascorbic acid ) between the fresh orange juice and artificial orange juice (Sunkist). Problem statement : Does have different types of fruit juice contain similar amount of vitamin c ? Objevtive: To analyse the concentration and percentage of different food sample by using titration method and state whether the percentage and concentration of vitamin C. Methodology: Theory : DCPIP can also be used as an indicator for Vitamin C.
If vitamin C, which is a good reducing agent, is present, the blue dye, which turns pink in acid conditions, is reduced to a colorless compound by ascorbic acid. DCPIP (blue) + H+ ——> DCPIPH (pink) DCPIPH (pink) + VitC ——> DCPIPH2 (colorless) C6H8O6 + C12H7NCl2O2 ——> C6H6O6 + C12H9NCl2O2 In this titration, when all the ascorbic acid in the solution has been used up, there will not be any electrons available to reduce the DCPIPH and the solution will remain pink due to the DCPIPH. The end point is a pink color that persists for 10 seconds or more.
Pharmacological experiments suggest that DCPIP may serve as a pro-oxidantchemotherapeutic targeting human cancer cells in an animal model of human melanoma; DCPIP-induced cancer cell death occurs by depletion of intracellular glutathione and upregulation of oxidative stress. Literature review : When most people think of Vitamin C in foods, their minds go immediately to citrus fruits, especially oranges. While citrus fruits are a good source of Vitamin C, some other fruits have even more of this health-promoting vitamin.
Juices, rather than the whole fruit, are a quick way to get Vitamin C, but the vitamin content degrades over time after juicing. Vitamin C is a term for the chemical ascorbic acid. In processed citrus products, additional Vitamin C may be added, labeled as ascorbic acid.
Citrus fruits include oranges and related fruits such as tangerines and satsumas, limes, lemons, grapefruit, kumquats and many others not commonly available in Western markets (http://www. livestrong.com/article/127884-concentration-vitamin-c-citrus-fruits/) May 20, 2010 You know you need to eat fruits because they contain nutrients that help keep you healthy.
But if you don’t eat your fruit soon after it’s been picked, you may be losing out on some of the goodness. Vitamins, such as vitamin C, are susceptible to light and heat. While you may be eating that kiwi to help meet 100 percent of your daily value for vitamin C needs, if the kiwi has been sitting around for a few weeks, you may not be getting as much as you think. Vitamin C is an essential water-soluble vitamin.
As a water-soluble vitamin, any excess vitamin C you consume is excreted in your urine. This also means that vitamin C is not stored in your body and must be consumed regularly to meet your needs. Vitamin C is needed for the synthesis of collagen, a protein that helps with wound healing. Vitamin C also supports immune health and normal growth and development. It is also an important antioxidant, protecting your cells against oxidation, and decreasing your risk of chronic diseases such as cancer and heart disease. Your daily vitamin C needs vary depending on your age and gender.
Adult men need 90 mg of vitamin C a day, and adult women need 75 mg a day, according to the Office of Dietary Supplements. Libby Swope Wiersema, Does the Amount of Vitamin C Change When a Fruit Gets Older? (http://www. livestrong. com/article/517371-does-the-amount-of-vitamin-c-change-when-a-fruit-gets-older/) Aug 18, 2011 Technique : Measure and determine the volume of standard vitamin c solution / fruit juices needed to decolourise of 1ml of DCPIP . Calculate the vitamin c content of juice by comparing it with the standard vitamin c solution.
Percentage of ascorbic acid in fruit juice = Volume of 0. 1 % ascorbic acid ? 0. 1 Volume of fruit juice Concentration of ascorbic acid in fruit juice = volume of 0. 1% ascorbic acid ? 1. 0mg/cm? volume of fruit juice Material : 1. 0% dichlorophenolindophenol (DCPIP) solution, 0. 1% ascorbic acid solution, freshly prepared orange juice and artificial orange juice (Sunkist) Apparatus : Specimen tubes, syringe (1ml), syringe (5ml), beakers (50ml) Procedure : 1. 1 ml of DCPIP solution is filled in a specimen tube by using 1 ml syringe 2. 5 ml syringe is filled with 0. 1% ascorbic acid solution 3.
The tip of the syringe is placed into the DCPIP solution. 4. The ascorbic acid solution is added to the DCPIP drop by drop. The mixture is gently stirred with the tip of syringe. The ascorbic acid solution is continuously added until the DCPIP solution is decolourised. The volume of ascorbic acid solution used is recorded. 5. Steps 1 to 4 are repeated for another two times . 6. Step 1 to step 4 are repeated using freshly aqueezed orange juice and artificial orange juice (Sunkist). The volume of fruit juice is decolourised the DCPIP in each case is recorded in the table 7.
The results are tabulated. The percentage and the concentration of vitamin C in each of the fruit juices is calculated using the formulae. Result : Solution /orange juice| Volume of solution /orange juice needed to decolourise 1 ml of DCPIP solution ( ml )| Percentage of ascorbic acid (%)| Concentration of ascorbic acid ( mg/cm? )| | 1| 2| 3| Average| | | 0. 1 % ascorbic acid solution| 2. 0| 2. 0| 1. 8| 1. 93| 0. 10%| 1. 00| Fresh orange juice| 0. 8| 0. 7| 0. 7| 0. 73| 0. 26%| 2. 64| Artificial orange juice (Sunkist)| 1. 2| 1. 2| 1. 3| 1. 23| 0. 16%| 1. 57| Calculation:
Average of volume of 0. 1% ascorbic acid solution needed to decolourise 1 ml of DCPIP solution = (2. 0+2. 0+1. 8)ml? 3 = 1. 93 ml Average of volume of fresh orange juice needed to decolourise 1 ml of DCPIP solution= 0. 8+0. 7+0. 7ml? 3 = 0. 73 ml Average of volume of artificial orange juice (Sunkist) needed to decolourise 1 ml of DCPIP solution = (1. 2+1. 2+1. 3)ml? 3 = 1. 23ml Percentage of ascorbic acid in fresh juice = 1. 93 x 0. 1 0. 73 =0. 26% Percentage of ascorbic acid in artificial orange=1. 93 x 0. 1 juice(Sunkist) 1. 23 =0. 16% Concentration of ascorbic acid =1. 93×1.
0 in fresh juice 0. 73 =2. 64 mg/cm? Concentration of ascorbic acid =1. 93×1. 0 in artificial orange juice (Sunkist) 1. 23 =1. 57 mg/cm? Discussion: 1. Oxidation of vitamin C in juices causes the DCPIP solution to decolourise. / Vitamin C reduces blue DCPIP to become colourless. 2. The specimen tubes containing the DCPIP solution should not be shaken when the ascorbic acid solution and the fruit juices are being added. This is because oxygen from the atmosphere oxides the reduced DCPIP solution and turns it blue again more fruit juice is needed to reduce the DCPIP solution.
Hence, accuracy of theexperiment is affected since the actual vitamin C content cannot be determined. 3. Fruit juice contains the highest concentration of ascorbic acid/ vitamin C. In this experiment, less volume of fruit juice is needed to decolourise DCPIP if the vitamin C content is higher. 4. The vitamin C in the fruit juice is destroyed if the fruit juice is prepared a day earlier. 5. In order to maintain the vitamin C concentration in canned fruit juice, the can is sterilized under high pressure and high temperature.
Conclusion Based on the result obtain through the experiment, ascorbic acid is needed the most in volume with the average value of 1. 93ml so that the 1% DCPIP can be decolourised from blue to colourless. The percentage of the ascorbic acid obtain is the lowest compared to the fresh orange juice and the artificial orange juice (Sunkist) which is 0. 1%. For the fresh orange juice, it has the lowest value compared to ascorbic acid and artificial orange juice (Sunkist). The fresh orange juice has an average of 0.
73ml in order to decolourise the 1% DCPIP from blue to colourless with the percentage of the fresh orange juice being 0. 26%. On the other hand, the artificial orange juice (Sunkist) has the second highest reading compared to fresh orange juice and ascorbic acid. The average value to decolourise the 1% DCPIP from blue to colourless for the artificial orange juice(Sunkist) is of 1. 23ml. Besides that, the percentage of the artificial orange juice (Sunkist) is of 0. 16%. Thus, it can be concluded that fresh orange juice has more percentage of ascorbic acid compared to artificial orange juice (Sunkist).