
Antibacterial Power of Common Spices
Medium
Do everyday cooking spices actually kill bacteria? People in tropical regions have used spices for thousands of generations. One theory suggests these spices help keep food safe from spoilage.
You streak E. coli bacteria across agar dishes. Then you place a quarter teaspoon of one spice on the lid of each inverted dish. You test seven spices:
- Cinnamon
- Garlic
- Mustard
- Black pepper
- Coriander
- Lemon juice
- Chili powder
You incubate the dishes at 27 degrees Celsius for four days with three replicates. Coriander inhibited 100 percent of bacterial growth. Mustard stopped 83 percent. Cinnamon and lemon juice each blocked 67 percent. Black pepper and garlic showed only 17 percent. Chili powder had no effect.
Hypothesis
The hypothesis is that spices have the ability to kill food-spoilage microorganisms.
Method & Materials
You will set up an experiment to test the volatile emission from the spices. You will streak E. coli on agar dishes, turn them upside down, and apply 1/4 tsp. of spice on the lid. You will leave the dish at 27 degrees Celsius for 4 days.
You will need agar dishes, E. coli, sterile swabs, and the following spices: cinnamon, garlic, mustard, black pepper, coriander, lemon juice, and chilli powder.
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See what’s includedResults
The results of the experiment show that not all of the spices used were effective. Coriander had complete inhibition, while mustard, cinnamon, and lemon juice had partial inhibition. Black pepper and garlic had 17% inhibition, and chilli powder had no inhibition.
Why do this project?
This science project is interesting because it tests the health benefits of spices that have been used in cooking for thousands of years.
Also Consider
Experiment variations to consider include testing different temperatures and different amounts of spices.
Full project details
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