YEAST AND BANANAS

Objective of the experiment

We want to observe the effect of the yeast on the decomposition of the banana.

Instructions

  • Prepare two banana pieces and put them in a bag
  • Strew a slice with dehydrated yeast of beer
  • Close the two bags watertight
  • Observe what happens for some day.

Observations

  Banana with yeast Banana without yeast
1th day There are some dark, brown spots The banana is a little darker where the seeds are
2nd day The brown spots have became largest. In some zones of the surface there are brown spots.
3rd day The banana is tenderer and smells oddly. The banana has became dark brown where it was cut
4th day By now it is difficult to distinguish the shape of the banana; its colour is brown Most of the surface has became brown, but the banana has kept its shape
5th day The banana has became a brown pulp No changes

 

Conclusions

The banana putrified more quickly with yeast that without. The decomposition is caused by the fermentation of the yeast that uses the banana starch to reproduce itself , decomposing it and changing its colour and consistency.

School site Aristotle Redi Spallanzani Metamorphosis Microorganisms "The tiny animals"