Thursday, April 1, 2010

How does packaging affect the rate of fruits staying fresh

Walking around the supermarket, I noticed that different types of fruit have different packaging. For e.g., strawberries were in little boxes that had holes and pears had plastic netting. I wondered if other fruits such as bananas and apples needed packaging to stay fresh longer, because sometimes they have packaging, sometimes they don't. So I decided to test this curiosity.

Aim:
To determine what type packaging allows fruits to stay fresh the longest.

Equipment:
  • 4 Brown paper bags
  • 2 plastic bags
  • 4 green bananas
  • 4 apples
Method:
  1. Cut/Hole Punch some holes in 2 of the 4 brown paper bags.
  2. Ensure that the holes are around the same size and the bags have the same number of holes.
  3. Place the 3 of the 4 bananas in the different packaging, 1 in the brown paper bag, 1 in the now brown paper bag with holes and the last in the plastic bag.
  4. Seal the opening of the packagings.
  5. Place the last banana next to the 3 other bananas without placing it in a packaging.
  6. Repeat steps 3 -5 but instead of bananas, use apples.
  7. Put the 8 fruits into the same place, where there is not a direct threat of sunlight.
  8. Observe any changes (listed below) every day for a few weeks.
  9. Tabulate your results.
Observed Changes:
  • Smell
  • Colour
  • Hardness of the fruit.
  • Other (such as wrinkles, spots etc.)
By the end of the experiment, I should be able to answer the following questions:
  • Which type of packaging experimented allowed the fruit to stay longer?
  • Did holes make a difference in any way?
  • Does different fruits prefer different packagings?

I also did a little research and I learnt that as fruits ripens, it develops a gas called the 'Ethylene gas' and this gas can over ripen fruits which leads to spoilage. Also, there is actually a branch of science called 'Packaging Science'. I actually wasn't aware of the fact that there are scientists who are still experimenting with the type of packaging for a certain fruit. I never knew that packaging would be such a hard process.

All information/method/inspiration was from this site:
"How Does Packaging Affect the Ripening of Fruit?" - Science Buddies
http://www.sciencebuddies.org/mentoring/project_ideas/MatlSci_p022.shtml
[last updated 24th August 2007]