| 
  • If you are citizen of an European Union member nation, you may not use this service unless you are at least 16 years old.

  • Stop wasting time looking for files and revisions. Connect your Gmail, DriveDropbox, and Slack accounts and in less than 2 minutes, Dokkio will automatically organize all your file attachments. Learn more and claim your free account.

View
 

Ethanol from Various Starch Sources

Page history last edited by jbfriesen 11 years, 3 months ago

This experiment as been done at various levels with different starch sources. In order to increase the skill level for this experiment, I introduced an analysis of glucose and/or reducting sugars this year.

 

Summary of procedure:

A suitable source of starch is boiled, cooled, and digested with amylase enzymes.

The starch source is fermented with yeast for a week.

The ethanol is distilled from the fermentation mixture and analyzed for ethanol content with refractive index.

 

 

Positive:

+It is a very accessible experiment that has some practical value.

+Measuring the alcohol content by carbon dioxide loss and direct distillation of ethanol gives an interesting comparison.

+The analytical value of the experiment can be increased by measuring the glucose and/or reducing sugar content before the starch source is fermented and by measuring the ethanol content of the fermented mixture by various methods.

 

Neutral:

±It has to take two weeks.

Negative:

- It is not a very advanced experiment.

 

Inquiry & Extension Ideas:

●Various starch sources can be investigated. I was suprised to discover that pre-soaked minute rice yields much more alcohol than the "traditional" frozen sweet corn.

●Different modes of preparation could be compared. What is the contribution of boiling, adding buffer, amylase, and amyloglucosidase to the process?

 

Student handout week 1

Student handout week 2

Photo Gallery 2009

Student Comments 2009

 

 

Comments (0)

You don't have permission to comment on this page.