Enzyme Excitement in Garlic Experiment
Overview of Experiment: You are going to prepare three samples of garlic butter, each made with one garlic clove treated as follows:
· The first sample of garlic is crushed, but not cooked.
· The second garlic sample is cooked before being crushed
· The third sample is cooked after being crushed.
Your taste panel will describe the odor and taste and rate the intensities of odor and taste at several times during the preparation of the samples. Check off each step as you complete it.
Steps for the Experiment:
1. Wash your hands with soap.2. Select three paper plates. They will be labeled as follows:
o “1. Crushed Only”
o “2. Cooked, Then Crushed. “
o “3. Crushed, Then Cooked”
3. Label the top of each plate “1”, “2” or “3” on the upper edge where it can be seen.
4. Choose 3 cloves of garlic that are about the same size. Peel off the dry “skins,” without scratching the underlying cloves, and put one on each plate. Move the plates away from each other so the smell of one won’t affect the smell of another.
5. Each group member will need to have their own Individual Recording Sheet to complete this step - Testing in the assigned order (you decide the order), you and the rest of your taste panel should sniff the garlic samples and describe their odors on the first row of the Individual Recording Sheet. Also give each sample an odor strength rating from 0 to 10 with 0 being no odor and 10 being the strongest odor of garlic you could imagine. Each person should decide on his or her rating without knowing the ratings of the others. You will get more reliable results the more subjects you have.
6. Smash the first clove with a garlic press or the side of a butcher knife. Put the crushed garlic back on the plate.
7. Wash the garlic press or knife, cutting board and your hands.
8. Put the second clove into the microwave for 30 seconds. Then crush it with garlic press or the side of the butcher knife and put the garlic back on the plate. Wash the press or knife, cutting board and your hands.
9. Crush the third clove of garlic in the garlic press. Put the crushed garlic back on the plate and microwave it for 30 seconds. Wash the press/knife, cutting board and your hands.
10. Set the samples apart, then use the 2nd row of the Individual Recording Sheet to rate the odors of each sample.
11. Mix 1/3 of the stick of butter (2 2/3 T.) into each of the garlic samples on the labeled plates. Be sure that the garlic is mixed well with the butter. Butter some bread with each sample and put the pieces on the plate.
12. Return the samples to their separate locations again. Have each subject continue to test the samples in the assigned orders. Do odor and taste descriptions and strength ratings for each sample and record on the third and fourth rows of the Individual Recording Sheet.
13. Transfer the information from each Individual Recording Sheet to the main record sheet. Find the average odor and flavor rating at each point by adding the ratings and dividing by the number of subjects.
14. Consider any sources of error in your subject, anything big or little that made the test unfair. Were the sizes of the cloves identical? Did you wash the garlic press between each sample? Could the members of your pan have been influenced by each other?
15. Make 2 bar graphs to show your results.
· In one graph, use three bars to show the average garlic butter flavor ratings for each of the three garlic treatments.
· In another, use bars to compare the average odor ratings before and after treating each clove of garlic. This will give you six bars.
16. Complete the conclusions page. Now you should be able to solve the mystery of the strong two-clove of garlic chicken vs. the mild 40-clove of garlic chicken dish. What is your solution? Write it on the record sheet.