1. Review information found in the Background Agricultural Connections section of the lesson, lesson Procedures, and the attached Essential Files.
2. Prepare materials for each group.
   • For Part B, assign each student group a treatment (sugar, acid, fat, or salt).
   • Prepare materials for treatment assignments. You are encouraged to allow students to measure out their own treatments; but if time is a concern, pre-measuring treatments is recommended.
     • Egg White: 6 clear cups containing 1/8 cup of egg white
     • Treatment A: 2 clear cups containing 1 teaspoon sugar
     • Treatment B: 2 clear cups containing ¼ tablespoon (1/2 tsp. + 1/4 tsp.) acid (cream of tartar or lemon juice)
     • Treatment C: 2 clear cups containing ¼ teaspoon fat (oil – any type)
     • Treatment D: 2 clear cups containing ¼ teaspoon salt
3. Separate the egg yolk and white ahead of time if you do not want students to participate in this portion of the lab. For Part B, you may also choose to use a carton of egg whites versus separating raw eggs.
4. Frequent hand washing is an important emphasis in egg lab activities. Students should be discouraged from tasting raw egg (including foams). When practicing appropriate food safety procedures, eggs can be safely handled in the classroom.
   • Timesaver: If feasible, students should use an electric mixer versus a whisk, particularly if time is a concern.
   • Important Note: If you choose to separate the egg yolk and white to obtain the egg white needed for Part B, make sure the egg yolk does not contaminate the egg whites. Additionally, make sure no oils contaminate the bowl or beater. These factors can negatively impact the formation of egg whites during the investigation.

Lab: Foam Formulations

1. Before beginning the lab investigation:
   • Require students to wash their hands.
   • For food safety reasons, DO NOT allow students to taste any egg products. When practicing appropriate food safety procedures, eggs can be safely handled in the classroom.
   • Emphasize the importance of practicing good food safety behaviors by not consuming substances used as part of the lab investigation.
2. Give each student one copy of Foaming Bonds and ask them to read the handout and complete the focus questions for this lab investigation.
3. Distribute lab materials. It is recommended that materials are organized into stations for easier distribution. Students should be arranged in small groups of 4-5. Each group should receive the lab supplies outlined in the Materials section as well as 1 copy of the Foam Formulations lab sheet.
4. Launch Part A of the lab by asking students to make a prediction about actions that can be taken to increase the stability (firmness) of egg white foams.
5. Show students the Egg Cracking Demonstration Video. The video will demonstrate how to properly crack an egg and separate the white from the yolk.
6. Next, show students the Foam Formulations Part A Video which will illustrate the four stages of peak formation in egg whites. The photographs found beginning on page 9 of the Student Demonstration Slideshow for illustration.
7. Throughout Part A of this lab investigation, students will observe the parts of an egg and the different stages of foam formation in egg whites. This part of the lab will provide a foundation for Part B, when students observe how various substances impact foam formation.
8. Allow students to work in small groups on the Foam Formulations lab sheet to complete Part A. After completing initial observations and conclusions, students should be prepared to begin Part B.
9. Launch Part B of the lab by distributing the lab supplies outlined in the Materials section of the lesson. It is recommended that materials are organized into stations for easier distribution. Students should still be arranged in small groups of 4-5.
10. Provide students with their assigned treatments. Students will predict what will happen to their egg white’s stability when their assigned treatment is added. Photographs demonstrating each treatment (before and after) are included in the Student Demonstration Slideshow.
    • Sugar: When sugar is added to an egg white at the foamy stage it will create a smooth, stable foam. However, the addition of the sugar will delay denaturation of the egg proteins, increasing the beating time required to reach peak foam stage. Sugar is best added to egg whites in the beginning stages of foam formation.
    • Acid: An egg white’s natural pH is basic (7.6 to 7.9). When an acid is added, it will decrease the pH of the egg white. Proteins are less stable and more prone to denaturation at lower pH levels. The denaturation of the egg proteins will improve foam formation; however, adding too much acid (pH less than 4.6) will result in delayed foam formation and decreased stability.
    • Fat: Fat will cause a decrease in the stability of egg white foam. Even a small amount will interfere with formation of a foam. For this reason, the egg yolk cannot mix with egg white when making foams. The fat in the egg yolk will prevent the formation of foam
    • Salt: Salt is often added to egg foams because it adds flavor. The addition of salt will decrease the stability of egg white foams if eggs are only beaten for a short time. If eggs are beaten for an extended amount of time, salt will not have an effect of the stability of the foam.
11. Demonstrate how to measure the foam height or show students the Lab III: Foam Formulations Part B Video.
12. Allow students to work in small groups to finish the Foam Formulations lab sheet.
13. Follow-up with a class discussion about the impact of various substances on proteins.

Investigating Your Health Activity: Extraordinary Eggs

1. Instruct students to research eggs and their health and/or nutritional benefits prior to beginning the activity.
2. Using the information provided in the Background Agricultural Connections section of the lesson or information learned from researching eggs, students should examine the nutrition profile for brown and white eggs and egg whites and egg yolks.
3. Students can find the nutrition profile of eggs by accessing the USDA’s FoodData Central, or by using the label information in the graphic below.
4. If you choose to use the provided egg nutrition information, see the attached teacher key for answers to the Investigating Your Health lab questions. Answers to questions should be similar despite the food label source used.
5. If completed in-class, allow students to work in small groups on the handout to further explore the topic and respond to questions.
6. Follow-up with a class discussion about student findings related to the health benefits of eggs.