Course: BFM 201 Ethanol Production

Unit 4 Lab

View these two presentations prior to coming to lab for an introduction to the topic of starch analysis.

By measuring starch levels we can determine how well our process is going. The first presentation is from the series of videos from Nebraska and discusses the cook process in the facility. The second presentation is from "Lets Learn Science" and will introduce you to the effect of three parameters on our starch test results:  increasing temperature, change in pH and change in enzyme activity.

"Can Corn Fuel the Future? Chapter 3" by Nebraska Corn Kernels, Standard YouTube License

If you cannot see the video above, click here to open it in a new window.
by Letslearnscience, Standard YouTube License

If you cannot see the video above, click here to open it in a new window.

In this unit, you will conduct a simple and inexpensive color test for starch.

1. Place a small dab of the liquefaction sample and slurry sample in separate test tubes.
2. Add filtered water to about ½ inch from the top of the tube.
a) Cover each tube with a finger and invert several times to mix.
3. Add one drop of iodine to each tube and mix again.
4. Check the color of each tube
a) Slurry samples test positive (purple) for starch.
b) Liquefaction samples test negative (yellow/brown) for starch.

Submit a report in class on the presence of starch in the liquefaction, indicating incomplete alpha amylase enzyme digestion.

What are the main causes of incomplete enzyme digestion?
Ethanol Training Simulator job numbers:

00100 Boiler Start-up

00150 Regenerative Thermal Oxidizer Start-up

00200 Dryer Start-up