The Effect of Time on the Vitamin C Concentration of Green Bell Peppers
This research tests the vitamin C concentration in green bell peppers over time post-harvest. The goal was to discover if as the shelf life increases, the concentration of vitamin C (ascorbic acid) decreases. The ascorbic acid concentration was taken on the first, third, and fifth day after harvest. The process was repeated for two weeks to confirm a clear conclusion. It was hypothesized that the peak of vitamin C would be the first day after harvest due to oxidization of fresh produce over time. A titration method, with a black-blue endpoint, involving iodine solution (Appendix A) and soluble starch indicator (Appendix B) was utilized.
The volume of the iodine solution used during titration was utilized for data collection; It was then quantified to find the concentration of ascorbic acid (mol/L). The values from the first, third, and fifth day after harvest were compared to determine the peak of vitamin C within the five-day span after harvest. Descriptive analysis and an ANOVA statistical test were conducted to further determine if there was a significant difference between at least one of the population means.
After conducting both analyses, the researchers failed to reject the hypothesis that the first day after harvest will yield the highest vitamin C concentration. This confirms an inverse relationship between time and vitamin C concentration. As the shelf life of the peppers increased, the concentration of vitamin C decreased. An average of 42.12% of the vitamin C was lost in the five-day span. This research is meant to impact the nutrition and produce industry to determine what type of produce is more beneficial to consume: Fresh or Frozen. Overall, helping nutritionists that are attempting to aid vitamin C deficient patients on when to eat which type produce.
Research Conducted By:
Paige Redlin
Lake Shore High School
Merna Sana
Warren Mott High School
Warren Consolidated Schools