1 / 23

Effect of ph on antioxidant capacity

Effect of ph on antioxidant capacity. Group Members: Ng Aik Yang (2A1) Siah Zhi Xuan (2A1) Darryl Hwang (2A2) Timothy Loe (2A3). Hypothesis. Hypothesis : The higher the pH, the faster the reaction between antioxidants and free radicals. Null Hypothesis:

gaetan
Download Presentation

Effect of ph on antioxidant capacity

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Effect of ph on antioxidant capacity Group Members: Ng Aik Yang (2A1)SiahZhiXuan (2A1) Darryl Hwang (2A2) Timothy Loe (2A3)

  2. Hypothesis Hypothesis : The higher the pH, the faster the reaction between antioxidants and free radicals. Null Hypothesis: pH does not affect antioxidant capacity.

  3. Rationale To investigate if Alkaline water really helps antioxidants function better to counter the free radicals in our body

  4. Methodology Chemicals used: • Different kinds of antioxidants (aqueous). E.g. red tea, ginger tea, vitamin C solution • 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) • Hydrochloric acid (HCl) • Sodium Hydroxide (NaOH) • Salt Solution (NaCl)

  5. Methodology Chemicals needed: • ABTS Molecular Formula: C18H18N4O6S4. NH3 • Frequently used by the food industry and agricultural researchers to measure the antioxidant capacities of foods • Blue solution, but converted to a colorless solution after reactions with antioxidants

  6. Methodology Test for light absorbance level by putting the cuvette into the UV-Vis Spectrometer, and record the results Put 3ml of ABTS into a cuvette 1 min Record the light absorbance level Add 25µl of antioxidants of varying pH level into the cuvette of ABTS

  7. What happens • Antioxidants from the solution will react with the free radicals in the ABTS • The ABTS would turn from blue to colorless gradually as the antioxidants react with the ABTS. • The higher the colour intensity of the solution, the more light will be absorbed. • Thus, by measuring the light absorbance, we can see how much of the ABTS has reacted.

  8. variables

  9. *Light absorbance = (light absorbance of ABTS with chemicals - original light absorbance of ABTS) divided by original light absorbance of ABTS × 100% Experiment procedures • 4 beakers of the various antioxidants with varying pH values (adjusted with the chemicals, NaOH and HCl) • pH meter used to measure pH • 3 beakers with NaCl solution (control) • One unchanged solution • Add in 3 ml of ABTS into cuvettes and test the absorbance • Put the 25µl of antioxidant in, and start timing • And after shaking, put it in the UV-Vis Spectrometer and wait for 1min • Observe and recorded results obtained

  10. Ginger

  11. Has a trend that a high pH leads to a higher light absorbance, showing that it has a higher antioxidant capacity • Light absorbance relatively low Ginger

  12. Red tea

  13. Shows a similar trend with Ginger • Error bars can show that range of results defy trend • Subjective conclusion Red tea

  14. Chrysanthemum tea

  15. Tie guan Yin

  16. Chrysanthemum tea • Both showed two similar dips in terms of graphs. • Error bars show that results between the 5 tests we took were rather consistent • In this case, pH does not affect antioxidant capacity Tie guan Yin

  17. GINGER (EXTENDED)

  18. General trend shows that antioxidant capacity decrease then increases slowly throughout, with a drastic increase between pH 9.7 – pH 10.5 GINGER (EXTENDED)

  19. Conclusion • pH does not affect antioxidant capacity for antioxidant bodies like tea • Different antioxidant bodies might react differently to the ABTS • Alkaline water does not really help antioxidants function better to counter free radicals in our body • Acid-base homeostasis, part of human homeostasis concerning the proper balance of pH, already adjusts the body for anti-oxidant capacity to work at its peak. • Our results fulfill the null hypothesis which would be that pH does not affect antioxidant capacity.

  20. challenges we faced • Adjustments of the pH for antioxidant bodies such as fruits • Varying the pH by the number of drops instead

  21. General reflections

  22. Works Cited • ABTS. In Wikipedia. Retrieved from http://en.wikipedia.org/wiki/ABTS • Wikipedia. [Image ABTS molecule structure]. Retrieved from http://en.wikipedia.org/wiki/File:ABTS.png • Fairy-water watertec Co. Ltd. [Image alkaline water machine]. Retrieved from http://www.ro-filter.com/images/products/ALKALINE_WATER_IONIZER_MANUFACTURER.jpg

  23. Thank you for your kind attention!

More Related