Oil and Vinegar Do Mix…When You Have an Emulsifier

Abstract

In this cooking and food science fair project, you will explore the role of proteins as emulsifying agents. Emulsifying agents are substances that are soluble in both fat and water and enable fat to be uniformly dispersed in water as an emulsion. Foods that consist of such emulsions include butter, margarine, salad dressings, mayonnaise, and ice cream. Emulsifying agents are also used in baking to aid the smooth incorporation of fat into the dough and to keep the baked goods tender. Natural emulsifying agents used in foods include agar, albumin (egg whites), alginates, casein, egg yolk, gums, Irish moss, and lecithin. Here is a procedure to test albumin, which is a protein found in egg whites, as an emulsifier.

Collect three glass jars with tops. Add 1/2 cup of vegetable oil (or olive oil), 1/2 cup of white vinegar, and one drop of food dye to each jar. The dye stays in the vinegar and makes it easier to see the boundary between the oil and vinegar. (A chemist would explain this step as the dye partitions into the aqueous phase).

Number the jars 1 to 3. Separate the white and yolk of an egg (keep both parts). In jar #1, add 1 tablespoon of egg white and 1 tablespoon of water; in jar #2, add 2 tablespoons of egg white; in jar #3, add 2 tablespoons of water. Shake the jars to mix the oil and vinegar. Measure how long it takes for a clear boundary to form between the oil (top layer) and the vinegar (bottom layer). A good emulsifying agent will keep the oil and vinegar mixed together, delaying the appearance of a clear boundary. Try variations with more egg white, or with other emulsifiers, such as egg yolk, balsamic vinegar instead of white vinegar, etc.

Cite This Page

General citation information is provided here. Be sure to check the formatting, including capitalization, for the method you are using and update your citation, as needed.

MLA Style

APA Style

Last edit date: 2017-07-28

Experimental Procedure

For this science project you will need to develop your own experimental procedure. Use the information in the summary tab as a starting place. If you would like to discuss your ideas or need help troubleshooting, use the Ask An Expert forum. Our Experts won't do the work for you, but they will make suggestions and offer guidance if you come to them with specific questions.

If you want a Project Idea with full instructions, please pick one without an asterisk (*) at the end of the title.

Ask an Expert

The Ask an Expert Forum is intended to be a place where students can go to find answers to science questions that they have been unable to find using other resources. If you have specific questions about your science fair project or science fair, our team of volunteer scientists can help. Our Experts won't do the work for you, but they will make suggestions, offer guidance, and help you troubleshoot.

Ask an Expert

Related Links

• Science Fair Project Guide
• Other Ideas Like This
• Cooking & Food Science Project Ideas
• My Favorites

If you like this project, you might enjoy exploring these related careers:

Looking for more science fun?

Try one of our science activities for quick, anytime science explorations. The perfect thing to liven up a rainy day, school vacation, or moment of boredom.

Find an Activity