Yr 11 Chemistry Eei - Orange Juice Vitamin C Content Essay

INTRODUCTION AIM: The aim of this investigation is to determine and analyse the effects of temperature and light exposure on Vitamin C concentration of a sample orange juice solution by means of volumetric analysis in conducting colorimetric titration testing. HYPOTHESIS: It is predicted that exposure of juice solutions to elevated temperatures and concentrated ultra-violet light rays, will result in increased levels of degradation of Vitamin-C due to oxidation and thus decreased concentrations of Vitamin-C in comparison to control orange juice solutions unaffected by these independent variables. BACKGROUND INFORMATION: Vitamin C, scientifically identified as L-ascorbic acid (information on the enantiomers of ascorbic acid is provided in Appendix ___),is an essential nutrient for normal growth and development of the human body and many animals. It works as a co factor for enzymes essential for synthesis of collagen proteins and also assists the body in the process of healing wound, the maintenance of bones and teeth, and important processes involving ligaments, cartilage, tendons and blood vessels. Vitamin-C is unable to be stored (due to its water solubility) or synthesized by the human body and therefore must be acquired from dietary sources; primarily citrus fruits and vegetables. Vitamin-C is a mild-reducing agent, a beneficial chemical property allowing it to play the important role of an antioxidant (additional information on Vitamin-C’s role as an antioxidant in the body is provided in Appendix ___)in the human body. Redox or oxidation-reduction reactions generally involve the transfer of electrons between two chemical species. Within an oxidation-reduction reaction, the compound that loses an electron is said to be reduced while reversibly the compound that gains this electron is said to be oxidised. A reducing agent is therefore known as the chemical species in