Which Fruit Has a Greater Rate of Dehydration?
Researched by Rochel B.
2002-03
PURPOSE
HYPOTHESIS
EXPERIMENT DESIGN
MATERIALS
PROCEDURES
RESULTS
CONCLUSION
RESEARCH REPORT
BIBLIOGRAPHY
ACKNOWLEDGEMENTS
ABOUT THE JUNIOR SCIENTIST
Purpose
The 1st purpose of this experiment was to determine which fruit had a greater rate of dehydration.
The 2nd purpose of this experiment was to determine the percentage of weight loss for each fruit.
I became interested in this idea when my mother had sliced a variety of fruits and left them on the counter. The next day I went to eat them and they were dried entirely.
The information gained from this experiment would benefit fruit producers and fruit growers because they would know which fruits dehydrate the fastest and they might be able to prevent it.
Hypothesis
My 1st hypothesis was that the apple would have the greatest rate of dehydration.
My 2nd hypothesis was that the apple would have the greatest percentage of weight loss.
I base my 1st and 2nd hypothesis on Fredrick J. Francis, a food industry scientist, who stated, "The apple has a rather large amount of moisture." Therefore, I think that the apple will dehydrate the fastest along with losing the most weight due to having a large amount of moisture.
Experiment Design
The constants in this study were:
Humidity
Air temperature in testing environment
Approximate mass of the fruit in test tray
Thickness of the slices
Amount of heat
Amount of light
Heat level in dehydrator
Fan speed in dehydrator
The manipulated variable was the kind of fruit that was being dehydrated.
The 1st responding variable was the rate of dehydration and the 2nd responding variable was the percentage of weight loss.
To measure the 1st responding variable I determined the amount of time each tray of fruit took until the mass no longer decreased.
To measure the 2nd responding variable I subtracted the original mass of the fruit from the ending mass of the fruit, and then I would divide the difference by the original beginning mass of each fruit.
Materials
Quantity Item Definition
1 Dehydrator
2 Clean dehydration tray’s
1 Triple-Beam-Balance
1 Kitchen Knife
1 Timer
1 Calculator
4 Fresh flavored fruits
1 Garbage can
1 Clipboard with paper
Procedures
1. Label 2 test tray’s A and B
2. Measure the mass of both tray’s A and B
3. Slice each fruit (0.5 millimeters thick)
4. Arrange on each fruit tray a single layer of fruit
5. Record initial mass of each tray of fruit, (including tray)
6. Dehydrate
a. Set temperature
b. Start timer
c. Check every 60 minutes and record mass
d. Rotate the fruit tray in a clockwise manner, each 60 minutes
e. Repeat step C until mass no longer decreases more than 1.0% of the original fruit mass
f. Record time
7. (Optional) Repeat steps 2-5 with same fruit for following trials
8. Repeat 2-6 for next type of fruit
Results
The 1st original purpose of this experiment was to determine which fruit had a greatest rate of dehydration.
The 2nd original purpose of this experiment was to determine the percentage of weight loss for each fruit.
The results of the experiment indicated that the banana had the fastest dehydration rate of the tested fruits. The fruit with the slowest dehydration rate was the grapefruit. The banana took 6 hours, followed by the apple at 7 hours, orange at 10.6 hours and the grapefruit at 11.3 hours.
However, the apple had the greatest percentage of weight loss, and the banana had the lowest. The apple had 88% of its mass evaporated, the orange had 86%, grapefruit with 85%, and the banana at 69% of its moisture evaporated.
View my table and graph.
Conclusion
My 1st original hypothesis was that the apple, due to lots of moisture, would dehydrate fastest.
The results indicate that the 1st hypothesis should be rejected because the banana dehydrated faster than any other fruit.
My 2nd original hypothesis was that the apple would have the greatest weight loss.
The results indicate that the 2nd hypothesis should be accepted because the apple did lose a large percentage of weight.
Because of the results of this experiment, I wonder if I dehydrated more fruits would the banana still perform as it did and if I had used the a different method of dehydrating would the outcome change.
If I were to conduct this project again I would dehydrate more types of fruit, and I would also conduct more trials for each type of fruit.