Exploring Banana Ripeness Conditions
Olivia Onderdonk, Ari Mabry, John Yang, Maximo Clark
Background
Background
As bananas ripen, they gradually go from green to yellow in color, and start to develop brown spots. The starches present in the fruit are broken down into sugars that cause it to become sweeter. There are many myths that claim to speed up or slow down this process. Some of these include placing a banana in the fridge, in a paper bag, in a warm place, in the dark, or in a bunch. Many of these myths involve the hormone ethylene, which causes bananas to ripen. The idea is, if you trap this hormone in a confined space, or increase how much is being produced, the banana will ripen faster.
Question
Question
How do different environments affect the amount of time it takes a banana to ripen?
Hypothesis
Hypothesis
If a bunch of bananas is placed in a paper bag, they will ripen quicker than a single banana sitting out in the open, because multiple bananas will produce more ethylene, and the paper bag will not allow the ethylene to escape as easily.
If a single banana is placed in the fridge, it will ripen slower than a single banana sitting out in the open, because it is not as exposed to light, and the cold temperature will slow down the breakdown of starch.
Materials
Materials
-Bananas, lots of them!
-2 paper bags
-A dark place
-A fridge
-Pipettes
-4 Centrifuge capsules
-Iodine solution
Procedure
To begin the experiment, place one banana in the paper bag and put it in a safe place. Next, take a bunch of bananas and put them in another bag. Make sure to put the bags in relatively the same place.
Next take two more bananas and put one in a dark place and one in the fridge.
After each 24 hours, check each banana's ripeness, record results.
At the end of the experiment (8 days), take a sample of each banana and put it in the capsule with 1 drop of iodine and 1 ml of water. Next, mix gently and count the plastids under a microscope. Record each banana's ripeness/ plastid count.
Procedure
Safety
When handling the iodine solution, wear goggles and gloves if available. Be careful to avoid spills and don't breath in the fumes.
Be careful of radiation emitted by the bananas! They could cause irreparable damage!
Safety
Dark Refrigerator Single Bunch
PICTURES DAY 1
Dark Refrigerator Single Bunch
PICTURES DAY 3
Dark Refrigerator Single Bunch
PICTURES DAY 7
Dark Refrigerator Single Bunch
PICTURES DAY 8
Lab Results Summary
Discussion (Summary)
- In comparison to the control banana, the banana in the fridge was less ripe than the control banana. However, it had less plastids than our bananas in the bag despite retaining a green color.
- The banana in the dark was approximately as ripe as the control banana, with the least amount of plastids.
- The banana in the paper bag by itself was less ripe than the control banana, the banana in the dark, and the banana in the fridge.
- The banana bunch in the paper bag was more ripe than the single banana in the paper bag, but was about as ripe if not less ripe than the control, "dark" banana, and "fridge" banana.
Discussion Hypothesis Comparison
Discussion
Hypothesis Comparison
- Our hypothesis was that:
- The dark banana would ripen less,
- The banana in the fridge would ripen much less,
- The single banana in the paper bag would ripen more.
- The bunch of bananas in the paper bag would ripen even more than the single bag banana and control..
- In comparison our results show:
- The dark banana ripened about the same as the control,
- The banana in the fridge actually ripened more than our other conditions, but retained its green.
- The single banana in the paper bag ripened less than the control.
- The bunch of bananas in the paper bag ripened more than the single banana in the paper bag, but ripened less than the control.
Lab Extension (Errors, Suggestions)
- Some possible errors for why our results are unexpected (especially with the paper bag) could be because the paper bags were near the window and the bananas became really cold, putting a temperature variable into that data.
- Another error could be the fact that we opened our bananas early, which could affect the ripening development.
- One final error could be that ethylene trapping could be more prominent in brown paper bags. In addition, on our first day, our bananas were not completely wrapped by the bags.
Lab Discussion Extension
- Possible suggestions for improving the lab are to do direct comparisons under the same conditions, such as having bananas be under the same lighting but have different temperatures measured by a thermometer. There could be incremental comparisons of banana bunches of different sizes. We could also compare different paper bags and the ripening of bananas wrapped by them,
Further Research Avenues
Further Research
- Given that our data may be skewed by the type of different paper bags, it may be interesting to find the amounts of ethylene trapped in bags.
- In fact, it is not really the type of paper bag, Ethylene gas released by the food causes the ripening and any bag traps this, However, paper bags are porous so they allow for air to come in and out, helpful for plant growth, unlike plastic bags, making paper bags much better.
- It is interesting to understand the optimal temperature of bananas.
- The optimum temperature and humidity conditions for ripening are 62 to 68 degrees Fahrenheit and 90 to 95 percent relative humidity. Storage temperatures should be 53 to 56 degrees Fahrenheit.
- We could research about the specific amount of light that is good for a banana, and even the optimal bunch amount for a banana for ripening.
Citation
Cited Sources
- How to Grow and Flower Indestructible Hoyas, www.logees.com/growingandfruitingbananas.
- “BANANA.” PAPAYA Fruit Facts, www.crfg.org/pubs/ff/banana.html.
- RAY, C. CLAIBORNE. “Q & A.” The New York Times, The New York Times, 10 Feb. 1998, www.nytimes.com/1998/02/10/science/q-a-490229.html.
- “Why Does a Brown Paper Bag Speed Ripening?” Seasoned Advice, cooking.stackexchange.com/questions/109/why-does-a-brown-paper-bag-speed-ripening.