“What’s for dinner?” is a timeless question around the world. Around this time of year, Thanksgiving causes us to be more curious about “what’s for dinner?” because we get the opportunity to eat foods that are meaningful or exciting to us. Foods we enjoy during the holiday includes personal and family favorites, traditional dishes, and everything from sweet to savory.
As we think about Thanksgiving food, additional questions might come to mind for educators. What is the chemistry of Thanksgiving food, and what activities can teachers plan to help students connect with chemistry and Thanksgiving food?
Turkey and Osmosis
Turkey is a highly favored, traditional Thanksgiving meat that can be really juicy, tasty, or dry. With the proper preparation and a chemical change, the turkey will be most flavorful and juicy. The chef can place the turkey in saltwater for better results. The salt and water move from areas of high concentration, outside the turkey, to regions of lower concentration, inside the turkey, through osmosis. The movement of salt and water causes the turkey to be more flavorful and juicy rather than dry and bland.
Educators can use activities to demonstrate osmosis which may be differentiated based on students’ ability and learning levels. Younger children can create a paper turkey and then draw each stage of osmosis around the paper turkey. Older students with access to a lab or kitchen can place a turkey in saltwater and another in an empty pan. The students can then watch for and document any changes they observe before cooking the turkeys. Finally, if possible, teachers can assist students in cooking the turkeys to note the differences in flavor and tenderness.
Baked Goods and CO2
Baked goods play a big role in Thanksgiving dinners. Cakes, cookies, danishes, rolls, buns, and other types of bread require ingredients to interact and chemical changes to occur. Without the proper chemical reactions in the baking process, the goods become tasteless or even flat rather than fluffy. Ingredients in the baked goods react with each other. For example, baking soda and milk react to release carbon dioxide bubbles that expand under heat, causing baked goods to rise. Yeast, a living organism and often used in breads, also creates a similar reaction to cause dough to rise.
For Thanksgiving and chemistry connections, educators may engage students with various activities related to baked goods. One activity is to have students mix a given set of ingredients in a no-bake recipe, then observe and document the look, feel, reaction, and taste after mixing ingredients. Students with a lab or access to a kitchen area can mix and bake ingredients and document each stage in the baking process. Older chemistry students can engage in a writing activity to explain the chemical reactions that had to occur during the baking process.
Casseroles and the Maillard Reaction
When I think about casseroles, I immediately think about the crispy onions, breadcrumbs, or cracker crumbs that are toasty on the top. Can you believe that chemistry causes the pieces to be toasty and brown? The chemical reaction called the Maillard reaction is why casseroles have a toasty, brown hue on the top. In the Maillard reaction, sugars and proteins react under high heat and in the absence of water. The molecular mixture that forms gives the food a brown, toasty color.
For educators wanting students to show their understanding of the Maillard reaction, activities using Thanksgiving casseroles can be used. Young students can watch videos that show the browning of casseroles, marshmallows, toast, and more. Then students can create thinking maps that include descriptive words describing various states of the foods before and after experiencing heat. Older students with access to the proper equipment can cook casseroles, brown marshmallows, or toast bread in the oven then write reports on the process, the chemical reactions, and the visual changes in the foods.
The word “gravy” can be music to many people’s ears due to the flavor it adds to many types of meat, vegetables, and bread. Have you had gravy that was too runny or gravy that was too thick? There is a science behind the thickening of gravy. Chemical reactions occur to thicken gravy after adding proper starch to the mix. When placed in heated liquid, starch granules absorb the liquid and swell, which causes thickening.
For purposes of connections and demonstration, educators can try it out with students. Teachers can add cornstarch to heated water and allow students to observe and document the reaction through illustrations or writing. Mixing ingredients and applying heat are two initiators of chemistry, including chemical changes and chemical reactions.
This year when you eat your Thanksgiving feast, remember that chemistry is one reason your tasty favorites, traditional foods, new flavors, and scrumptious bites fill your mouth. Who knew chemistry could taste so good?