1. Ascorbic acid content variation with fruit volume: A study of relative vitamin C content in different sized oranges Andrew Hudson EDTEP 586, AU 2002

2. Background of ascorbic acid A necessary cofactor to the body’s synthesis of collagen, a cementing protein in bones, dentin (teeth), connective tissue, and scars; antioxidant minimizing occurrence of free radicals throughout the body Deficiency state: a breakdown of the protein collagen; blood capillary walls deteriorate, free radical propagation increase, resulting in higher risk of tissue damage, lowered immune response, also cancer Water soluble, found in dark green, leafy vegetables, citrus fruits, & berries… most Americans obtain by consuming citrus or supplements

3. My initial model Oranges produce ascorbic acid as a function of total volume; ascorbic acid content increases along with fruit size. Orange size Ascorbic acid content Nutrients available Maturation (increasing)

4. My question Does a 500 ml dilution of increasingly larger oranges contain a progressively higher concentration of ascorbic acid? ? 500 ml

5. Method Obtain a size range of oranges; I used satsumas, available in golf, racquet-, and tennis ball sizes Determine each volume by immersion in water Blenderize each orange, pulp & peel Dilute each orange into a total volume of 500ml Mix each solution, then…

6. Set up two equal-volume vials with indicator and water Titration of Indophenol Blue: OJ dilution WaterIndicator

7. Transfer OJ dilution into pipet, then… Titration of Indophenol Blue OJ dilution WaterIndicator

8. into indicator and water at the same rate… Titration of Indophenol Blue OJ dilution WaterIndicator

9. …drop… Titration of Indophenol Blue OJ dilution WaterIndicator

10. …by… Titration of Indophenol Blue OJ dilution WaterIndicator

11. …drop… Titration of Indophenol Blue OJ dilution WaterIndicator

12. …until the colors… Titration of Indophenol Blue OJ dilution WaterIndicator

13. …of the indicator and water is the same. Titration of Indophenol Blue OJ dilution WaterIndicator

14. Drops to Titrate vs. Orange Volume Evidence

15. A 500ml dilution of increasingly larger oranges does contain a progressively higher concentration of ascorbic acid. > 500 ml My answer

16. Oranges produce ascorbic acid as a function of total volume; ascorbic acid content increases along with fruit size. The bigger oranges contain more ascorbic acid than the smaller ones. Orange size Ascorbic acid content Nutrients available Maturation (increasing) My final model

17. Assumptions Ascorbic acid was the single contributing cause to the indicator color change Ascorbic acid dissolved to the same extent in all trials Any fragments of peel or pulp contained a relatively insignificant % of ascorbic acid.