Grade Level: 7th - 9th; Type: Microbiology
In this experiment, we will discover the effectiveness of “FIT” Fruit/Veggie Wash vs. plain water. Should you pay more for cleaner fruits/vegetables?
- Do you wash your fruits/vegetables before consumption?
- Are you able to see any bacteria around you?
Although some kinds of bacteria called pro-bacteria are helpful and essential to the human body, many are not. There is more harmful varieties of bacteria than there are harmless ones. It is what causes many illnesses and diseases in people. That is why it is important to take appropriate measures of hygiene and sanitation to avoid running into problems with bacterial contamination. In this experiment, we'll compare ordinary water to store-bought veggie wash to see which does a better job of removing bacteria.
- FIT Fruit/Veggie Wash (You can get this online or via most local grocery stores)
- Fifteen apples
- A knife
- Sterile plastic baggies
- Separate the 15 apples into three groups of five. One of these groups will be washed with the veggie wash, another washed with plain water, and the remaining five will not be washed.
- Wash five of the apples with FIT and set it on a clean surface.
- Wash the other five of the apples with plain water for the same amount of time and set it on the clean surface.
- Dip the knife in alcohol.
- Use a knife and take a sample of the skin from each of the apples. Keep the samples at the same size. Put it in a sterile plastic baggie and label which group the skin came from.
- Prepare a slide of one of the apple skins and observe under a microscope for bacteria. They can be recognized as stringy and structures with no true nucleus.
- Observe all 15 apple skin samples.
- Conclude which sample group had the most bacteria present.
Amount of Bacteria Present in Each Apple Peel Sample
Washed w/ FIT
Washed w/ H2O
Terms/Concepts: bacteria; structure of a bacteria; strains of harmful bacteria
- Enchanted Learning: Bacterium
- Alcamo IE (2001).Fundamentals of microbiology. Boston: Jones and Bartlett.
- Atlas RM (1995).Principles of microbiology. St. Louis: Mosby.
- Holt JC, Bergey DH (1994).Bergey's manual of determinative bacteriology(9th ed.). Baltimore: Williams & Wilkins.