Session: General Poster:

L-ascorbic acid, commonly known as vitamin C, is an antioxidant that the human body needs to protect itself from illnesses and diseases. It can be found in many different fruits and in a variety of vegetables. For convenient consumer consumption, many fruits and vegetables are processed into juices. Research has shown that the juice processing techniques these fruits and vegetables go through affect the degradation of L-ascorbic acid, decreasing the concentration of vitamin C present. However, many studies do not agree on the kinetic order of this degradation process. In this study, L-ascorbic acid solutions were prepared using two different solvents: deionized (DI) water and 9.78 x 10^-5 M acetic acid. Six L-ascorbic acid standard solutions (ranging from roughly 4.0 x 10^-4 M – 4.0 x 10^-6 M) were prepared using each of these solvents. UV-Vis spectroscopy was used to measure the absorbance values (l= 255 nm) for each standard solution. This data was used to generate two calibration curves. 3.80 x 10^-4 M and 4.13 x 10^-4 M L-ascorbic acid testing solutions were prepared in DI water and 9.78 x 10^-5 M acetic acid, respectively. Samples of both solutions were stored at 25.1 ^oC (benchtop) and 3.8 ^oC (refrigerator). Absorbance data was collected over a three-day period. Based on the four testing solutions, initial results indicate that L-ascorbic acid degradation likely follows either first-order or second-order kinetics. In order to explore these conflicting results, additional trials will be run, analyzing the degradation of each testing solution over a longer period of time.

Maria Garrett

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