TITLE:To determine thepercentages of vitamins C in various type of BRANDS OF ORANGE JUICES Abstracts • The title of this project is to determine the percentages of vitamins C in various brands orange juices. This is not just to ensure consumers are able to have a healthier and safer lifestyle, but also allowing them to have a better understanding about orange juices on the market • we have used the 2,6-dichlorophenolindophenol, ( DCPIP, also DPIP ) titration method. This method requires us to measure amount of volume of various brands of vitamin C needed to decolorize the DCPIP solution Introduction and Background Objectives • Importance of Vitamin C • Amount of vitamin C in different brands of orange juice Vitamin C • Most important nutrient • may not be the cure for common cold • protection against immune system deficiencies, cardiovascular disease, prenatal health problem, eye disease and even skin wrinkling. • 500 miligrams daily to achieve health Amount of vitamin C in different brands • Process of preparation of ready-make orange juice • Sunkist,Tesco Choice, Minute’s Maid, Tropicana Twister. Methodology 1. 2. 3. 4. 5. 6. 7. Hypothesis Method Variables Apparatus Materials Procedure Results DEFINITION: A system of methods used in a particular area of study. “In This Case, study about how – topic – results” Hypothesis & Method • Sunkist, brand of orange juice contains the highest amount of vitamin C percentage. • Quantitative Analysis. Student during titration with a burette Variables • Constant Variables: Amount of 0.1% DCPIP solution used. • Manipulated Variables: Brands of orange juices. • Reponding Variables: Percentage of vitamin C among brands of orange juices. 0.1% DCPIP Solution Vitamin C % Black Guy With An Oranges Facts Brands of orange juices Apparatus & Materials Syringes x 6 Test Tubes x5 Beakers x2 0.1% ascorbic acid (vitamin C) solution (standard solution) – 50ml 0.1% freshly prepared DCPIP solution (0.1 g DCPIP in 100ml distilled water) – 100ml Minute Maid Tropicana Twister Sunkist Peel Fresh Tesco Choice ProcedureS • • • • • • • • • • • • Use 1 ml-syringe to add 1.0 ml of 0.1% DCPIP in test tube. Draw up 5.0 ml of 0.1% ascorbic acid solution into a 5 ml-syringe, and expel any air bubbles. Place the needle end of the 5 ml syringe in the 0.1% DCPIP and add one drop of the 0.1% ascorbic acid solution to the DCPIP in the test tube. Shake the test tube gently to mix it. Repeat step 3 until the mixture in the tube has decolorized Record the volume of ascorbic acid used to decolourised the DCPIP. Repeat steps (1) – (5) for two times. Then calculate the average volume used. Repeat steps (1) – (4) on a range of different brand of fruit juices using 1ml of DCPIP each time. The percentage of vitamin C in each juice sample is calculated as follows: One molecule of ascorbic acid reacts with one molecule of DCPIP, changing its colour from blue to colourless. Let the volume of 0.1% ascorbic acid solution that decolourise 1 ml of 0.1% DCPIP solution = X ml Let the volume of brand of fruit juice extract that decolourise 1ml of 0.1% DCPIP solution = Y ml. Therefore the quantity of ascorbic acid present in the Y ml of juice extract equals the quantity of ascorbic acid present in the X ml of the 0.1% ascorbic acid solution. Therefore, the concentration of ascorbic acid in juice extract = ( ) x 0.1% • Result: Results Observations 1 2 3 4 5 FINAL Discussion [Problems & Solution] • • 1) Mixing the flask is important to ensure that the solutions have completely reacted with each other. When adding the iodine solution, you may see a temporary color change that goes away when you swirl the flask. The color change that is important for this experiment is the one that is not temporary and does not go away after mixing the solutions. 2) There are a number of reasons your titration may not work. Three of the most common problems that can lead to a solution not changing colors in a titration are: • Using the wrong substances. Make sure that you use Lugol's DCPIP solution or another • • iodine solution sold as a DCPIP indicator (not a pure potassium iodine solution) and a true, soluble DCPIP. (If you purchased the Science Buddies kit, this problem would not apply. The materials in the kit are correct for this Project Idea.) Comparing DCPIP Solution Using incorrect concentrations. If your vitamin C standard solution is too concentrated or your DCPIP titration solution is too dilute, or your DCPIP indicator solution is not between 0.5 to 1.0%, it may require much more than 50 mL of DCPIP solution to titrate the standard solution and/or orange juice. The most common problem here is an overly dilute DCPIP solution; sometimes, the Lugol's DCPIP solution sold in stores is already dilute, and you don't need to dilute it more. Using too much orange juice. If there is a large amount of vitamin C in the orange juice that is being tested, it may require more than 50 mL of DCPIP titration solution for it to change color. You could try using a smaller volume of orange juice. Conclusion • Different brands of orange juices have different amount of vitamin C content or percentages. Sunkist, brand of orange juice contains the highest amount of vitamin C percentage among other brands of orange juices.