Teach:
Ask students, "Why might it be useful to find out which fruits dehydrate the slowest?" Some responses should indicate that the slower a fruit dehydrates, the longer it stays fresh for us to eat. You may also get a response that some people like to eat dried fruit and they would need to know how long to dry their fruit before they can eat it. You can find dried fruit in the grocery store and may want to bring some in to sample with the students on the day of the experiment. Tell the students that they will be conducting a science experiment, similar to what nutritionists do to analyze food. Have students observe the different kinds of fruit you are using in the experiment.
Materials:
- Banana
- Apple
- Pear
- Orange
- Scale that measures in grams
- Cutting Knife
- Notebooks
- Pencils
Procedure:
- Cut the fruits open and make sure they weigh the same on your gram scale. You cannot compare how much water the fruit is dehydrated without starting at the same weight. Discuss with students the size of each fruit piece? Why must the sizes vary at the same weight? You may want to bring more than one of each variety on the first day, in case they aren't cut equally on the first try.
- Set each piece of fruit on its own paper towel or paper plate.
- Have the students record the type and weight of each fruit in their notebooks. Then have the students draw a hypothesis as to which fruits they think will dehydrate the fastest.
- Every two days have the students weigh each piece of fruit on the scale. Students should record the data in their notebooks. You can show them how to make a chart to record their data on the black board.
- After a week or two, finish the project. All the fruit should be dried by that time.
Review:
Ask students to tell you which of the fruits dehydrated the fastest? Ask the students which one stayed the freshest? Have students tell you why their hypothesis was correct or incorrect. Finally, have them record the conclusion to this experiment in their notebooks.