Post on 16-Dec-2015
The Sensational Science Behind Antioxidants: Testing Facts vs. Myths of popular antioxidant products
Yesterday, you broke up into groups and selected a popular “antioxidant-rich” product
to endorse
Today you will chemically test the drinks to see if there’s truth to their marketing.
You are the Research & Development Team and the Marketing Team for your product.
Victims of Oxidation
Part I: The science behind antioxidants
Free radical with unpaired electron
Free radicals cause damage by oxidation
OO
Molecular OxygenO2
OO
OO
HH OO
O
H O
H
Add two H+
Add 3rd e-
Hydroxyl ion OH-
Add 1st e- Add 2nd e-
Superoxide radicalO2
-
Peroxide radicalO2
-2
Hydrogen peroxide
H2O2
Hydroxyl radicalOH
Add 4th e-O
H
Hydroxyl ion OH-
Add 2H+
O
H
H O
H
H
Water
Reactive Oxygen
Species
ROS
Oxidation occurs when one substance transfers one or more its electrons to another substance
CatecholColorless
+ ½O2
BenzoquinoneYellow-Brown
+ H2O
Electrons lost to
“Catechol is oxidized by O2 to become benzoquinone”“Catechol loses its electrons to O2 to become benzoquinone”
Free radicals cause damage by oxidation
CatecholColorless
+ ½O2
BenzoquinoneYellow-Brown
+ H2OPhenol Oxidase
Phenol Oxidase catalyzes the reaction that changes catechol, in the presence of O2, into benzoquinone
CatecholColorless
+ ½O2
BenzoquinoneYellow-Brown
+ H2OPhenol Oxidase
Phenol Oxidase catalyzes the reaction that changes catechol, in the presence of O2, into benzoquinone
+Antioxidant!
X
Browning reactions are due to oxidation
CatecholColorless
+ ½O2
BenzoquinoneYellow-Brown
+ H2OPhenol Oxidase
Phenol Oxidase catalyzes the reaction that changes catechol, in the presence of O2, into benzoquinone
Can any of these products inhibit the browning reaction in mushrooms?
BufferpH 7
100X Daily Dose of Vitamin C
x 10Controls:
1. Weigh mushroom2. Chop mushroom into
pieces and put into Ziploc bag
Multiply mass by 4 and add that amount of
buffer to the bag
3. Close bag tightly and mash gently with fingers
4. Wet the coffee filter with buffer and place over cup.
Use pipette to transfer mushroom extract to filter
Purifying mushroom oxidase
Perform the tests!
Spot test
1. Using the pipette, add two drops of mushroom oxidase to every square on your table.
2. Add the appropriate reactants to each square in the order they are listed
3. Once all the drops have been added to the 6 squares, start the timer.
4. Observe the reaction for 5 minutes, then answer the following questions.
Hint: Use a steady hand so that each drop is the same amount of liquid. Make sure the paper is level, so the drops do not move.
Time = 0 min
Time = 5 min
http://science-edu.larc.nasa.gov/EDDOCS/Wavelengths_for_Colors.html
Double bonds absorb light
Light absorption is like a fingerprint for compounds
AbsorbanceReadout
0.430
Light Prism to disperse light
Wavelength selector
How does a spectrophotometer work?
CatecholColorless
+ ½O2
BenzoquinoneYellow-Brown
+ H2O
0.5200.240
At Abs490 nm:
Spectrophotometer Test1. Label your test tubes #2, #4, #6 and buffer
blank
2. Add 4 ml of buffer to “buffer blank”. Place the tube into spectrophotometer holder and use the left knob to set the numbers in the absorbance window to 0.000.
3. Add the reactants for Tube #2—use correct pipettes for each reactant! Mix by tapping the test tube, and place tube into spectrophotometer. Start the timer and record absorbance at t=0 min.
4. Remove tube at t = 4:30 min and mix by tapping test tube. Record absorbance at t = 5 min.
5. Repeat steps 3-4 for each Tubes #4, #6.
There are many different ways to test for antioxidants
Our mushroom oxidase test may not be sensitive enough to pick up on antioxidant levels
CatecholColorless
+ ½O2
BenzoquinoneYellow-Brown
+ H2OPhenol Oxidase
+Antioxidant!
X
CatecholColorless
+ ½O2
BenzoquinoneYellow-Brown
+ H2OPhenol Oxidase
+Antioxidant!
X
Your drink has antioxidants, but it may be very low amounts compared to
100X Daily Value of Vitamin C
Part II: The marketing behind antioxidants
Present a 3 minute marketing campaign that showcases:
Your knowledge on the mechanism and health benefits of antioxidants defense against free radicals.
Your product’s antioxidant test results.
Your opinion why your classmates should buy your antioxidant drink.
Edited by Ms. Theresa
(Instructor note: show a video clip of antioxidants in the media. In my presentation, I edited together a video of 9 different commercials, interviews on the topic of antioxidants)
1. Do not make scientific claims that you cannot back with evidence
2. Find a different approach to market the product
Much research has to be performed before claims can be made
Much research has to be performed before claims can be made
“I recommend pizza since it is a vegetable and
therefore has *tons* of antioxidants.”
I’m actually a real doctor! Google me!
The best marketing campaign was for:
The best scientific argument was made by:
Write-in: Based on the overall campaign and facts, I would consider buying:
Sample BallotWhich product is the best antioxidant drink on the market?
☐ 7-Up Antioxidant
☐ Activate Antioxidants
☐ FUZE Triple Berry
☐ Lipton Green Tea
☐ POM Wonderful
☐ Vitamin Water XXX
☐ Other ___________
☐ 7-Up Antioxidant
☐ Activate Antioxidants
☐ FUZE Triple Berry
☐ Lipton Green Tea
☐ POM Wonderful
☐ Vitamin Water XXX
☐ Other ___________