Is There Seaweed/Algae in Your Food?*

Science - Grade (middle school)

Teacher: Teachers can predetermine a food item list with algae and nonalgae containing products. By having the students bring in what they have at home, they are given the opportunity to decide if their products contain algae derivatives. A bonus of this method is that no two groups will have the same set of food items or outcome of algae contents.

Objective: Students will understand that seaweed/algae is a small part of the resources the oceans provide. By investigating common household products, students will discover that human senses are not enough to detect the presence of seaweed/algae in food.

Materials:

Teacher Background:

Although fish and other seafood products make delicious and healthy meals for people around the world, many American children would not object if they never had to eat another tuna casserole again. But they would object if suddenly there were no more cheese, chocolate milk, peanut butter, pudding, frozen desserts or fruit drinks. What could so many different types of food products have in common? These are just a few food products that contain plants which grow in the sea, seaweed.

Many kinds of seaweed are eaten by people because they are full of vitamins and iodine. Asian cultures use seaweed like green beans and carrots are used in the United States. But because American people have not developed a taste for seaweed, manufacturers use derivatives from seaweed instead. These alginates, carrageenan, and beta carotene, act as stabilizers, thickeners, and colorants in the foods Americans eat today.

Seaweeds are really not a weed but large marine algae that grow in the coastal waters of many countries. They include thousands of species from microscopic plants called phytoplankton to huge floating/anchored plants commonly seen washed up on shore. The three main groups of seaweed are brown, red, and green algae and each one provides important ingredients for manufacturing foods. For example, carrageenan is a generic term for compounds extracted from species of red algae used in stabilizing and gelling foods, cosmetics, pharmaceuticals and industrial products. Alginates are extracted from brown algae and are used to make water-based products thicker, creamier, and more stable over extreme temperatures and time, making the product last longer. From green algae a natural pigment, beta carotene, is removed and used as a yellow-orange food coloring in food products and is currently believed to help prevent certain forms of cancer.

These seaweed derivatives are only a portion of the many products derived from ocean plants, animals, minerals and sea water. Together they provide many good reasons to protect Earth's oceans.

Activities:

  1. The teacher can decide to make this a one-to-several day lesson activity.
  2. Divide students into groups and ask them to bring items from the food list. Review the Teacher Background information about algae products.
  3. Ask students if they would ever eat seaweed/algae. With the food items in hand, let the student hypothesize on their lab sheet which ones they think contain algae products.
  4. Explain that each product may or may not contain algae. Students are to follow the lab sheet, discovering if their food product contains algae products.
  5. After completion of the lab sheet, ask students if they would eat the whole seaweed plant, knowing now that they already eat algae extracts in many foods. Display the various types of seaweed (nori, kombu, kelp, dulse) to the class. Smell and taste if possible.
  6. Explain that algae contains a large nutritional value, used in many cultures to wrap vegetables, rice, or raw fish (sushi). What seems as an unlikely food to Americans is very common in other countries because of the differences in cultures.

Answer Key:

Product Name Carrageenan Alginate Beta Carotene
Brownie mix X
Cheese X
Chocolate milk X
Coffee creamer X X
Cottage cheese X
Egg substitute X
Evaporated milk X
Frozen foods/desserts X X
Frozen yogurt X
Ice cream X X
Infant formula X
Margarine X
Mayonnaise X
Multiple vitamins X
Pudding (cooked) X
Relishes X X
Salad dressing X X
Sauces and gravies X X
Sour cream X
Toothpaste X
Whipped topping X X
Whipping cream X
Yogurt X

Worksheet: Problems for student use.

Group Names ______________________________________ Subject _________________
Date _____________ Class ______________

Is There Algae in Your Food?

Materials:

Activities:

  1. Divide into groups. Decide who will bring what items from the food list.
  2. Review the background information about algae products.
  3. Would you ever eat seaweed/algae? With the food items in hand, hypothesize on the lab sheet which products you think contain algae products.
  4. Each product may or may not contain algae. Look for the following ingredients that come from seaweed: carrageenan, alginates, and beta carotene. Follow the lab sheet, placing an X in the appropriate column if the food product contains these algae derivatives.
  5. Examine the various types of seaweed (nori, kombu, kelp, dulse) to the class. Smell and taste if possible.

Background:

Although fish and other seafood products make delicious and healthy meals for people around the world, many American children would not object if they never had to eat another tuna casserole again. But they would object if suddenly there were no more cheese, chocolate milk, peanut butter, pudding, frozen desserts or fruit drinks. What could so many different types of food products have in common? These are just a few food products that contain plants which grow in the sea, seaweed.

Many kinds of seaweed are eaten by people because they are full of vitamins and iodine. Asian cultures use seaweed like green beans and carrots are used in the United States. But because American people have not developed a taste for seaweed, manufacturers use derivatives from seaweed instead. These alginates, carrageenan, and beta carotene, act as stabilizers, thickeners and colorants in the foods Americans eat today.

Seaweeds are really not a weed but large marine algae that grow in the coastal waters of many countries. They include thousands of species from microscopic plants called phytoplankton to huge floating/anchored plants commonly seen washed up on shore. The three main groups of seaweed are brown, red, and green algae and each one provides important ingredients for manufacturing foods. For example, carrageenan is a generic term for compounds extracted from species of red algae used in stabilizing and gelling foods, cosmetics, pharmaceuticals, and industrial products. Alginates are extracted from brown algae and are used to make water-based products thicker, creamier and more stable over extreme temperatures and time, making the product last longer. From green algae a natural pigment, beta carotene, is removed and used as a yellow-orange food coloring in food products and is currently believed to help prevent certain forms of cancer.

These seaweed derivatives are only a portion of the many products derived from ocean plants, animals, minerals and sea water. Together they provide many good reasons to protect Earth's oceans.

Data Chart:

Hypothesis:

Product Name Algae Carrageenan Alginates Beta Carotene
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.

Questions:

  1. Would you ever eat seaweed? Why?
  2. Which of the products do you think contain seaweed derivatives? How can you tell?
  3. How are seaweed derivatives used in American foods?
  4. Which products actually contained seaweed derivatives?
  5. Look at your answer for question 2. How close were your guesses?
  6. Why do you think other countries eat seaweed more than Amerians do?
* From the Naval Meteorology and Oceanography Command Homepage