Title: Algae is Um, Um Good!
(Health & Nutrition)
Grade(s): 6
Introduction: Many kinds of seaweed are edible and rich in vitamins and iodine. They are as common
in many Asian Countries as green beans and carrots are in the United States. But until more people here
develop a taste for sea vegetables, it is alginates, carrageenan, and beta carotene—seaweed derivatives that
act as stabilizers, thickeners, and colorants—that end up on our dining room tables. Seaweeds are not really
weeds but large forms of marine algae that grow in the coastal ocean waters of many countries. They
include thousands of species ranging from microscopic plants called phytoplankton to giant floating or
anchored plants.
The three main groups of seaweed are brown, red, and green algae, each providing important ingredients for the manufacture of food and other products. Carrageenan is a generic term for compounds extracted from species of red algae. Carrageenans are used in stabilizing and gelling foods, cosmetics, pharmaceuticals, and industrial products. From brown algae come alginates. They make water-based products
thicker, creamier, and more stable over extreme differences in temperature, ph, and time. For example,
alginates prevent ice crystals from forming in ice cream. Beta Carotene, a natural pigment derived from
green algae and numerous other land plants, is used as a yellow-orange food coloring and may help prevent
certain types of cancers.
These seaweed derivatives represent only a small part of the many living and nonliving products we
derive from ocean plants, animals, minerals, and sea water. Together, they provide an important reason to
protect the oceans.
Learner Objectives:
•
The student will be able to demonstrate that, although we sometimes can neither smell or taste
them, many ingredients in our foods and household products come from the sea.
•
The student will be able to investigate the foods that you eat to determine what algae derivatives
they contain.
Florida Sunshine Standard(s): Science: SC.G.2.3.2
Math: MA.E.1.3.1
Competency Based Curriculum: Math: M/J-I-V-1-A/M/J-3-VI-1-A; Science: M/J-I-VII-4-A
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Materials:
Collection of food items containing algae derivatives
Copies of Home Algae Products survey
Samples of brown, red, and green algae
Activity Procedures:
1. Look through your own kitchen and find a few food products that contain algae derivatives.
Show these items to your class, without mentioning that they come at least partially from the sea.
Ask students to guess what the foods have in common.
2. Explain that each product contains algae in the form of seaweed, which is now used in many
everyday foods and household items. Hold up one of the products that you brought in and show
the students where they can find the nutrition label on the packaging. Show students pictures or
samples of brown, red, and green algae, from which ingredients in the foods on display are
derived. To find these different types of seaweed, check an Asian supermarket or specialty food
store.
3. Distribute copies of survey, Home Algae Products, and tell them to complete the survey at home.
Remind them that not all brands of the product contain seaweed derivatives.
4. The following day, divide the class into groups of three and give each group a few minutes to
compare the results of its members’ survey.
5. Ask if any of the groups found information on all of the foods listed on the survey. Ask them if
any of the foods contained two or more of the algae ingredients.
6. Allow students to consider whether they would eat the whole seaweed plant, knowing now that
they already eat algae extracts in many foods. Offer samples of dried, edible seaweed (nori,
kombu, dulse, kelp), if available, for students to smell and taste. Explain that algae are rich in
vitamins and iodine and, in Asian cultures especially, are used in wrapping to hold together rice,
meat, and vegetables (for example in sushi). Ask students what food they use to hold these
ingredients together and what makes bread so much more readily available in the United States
than in Japan and other Asian countries.
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Student Assessment:
Allow students to answer critical thinking questions assigned by the teacher during the class activity.
a. Scientists use marine organisms for research. For example, sea urchins are used in embryology, and sharks are studied in immunology. Explain your feelings regarding this issue.
b. Classify consumer goods that come from the ocean into groups and identify their source.
Students will be assessed on their group participation when comparing the results of their respective
surveys.
Activity Extension(s):
1. Provide the opportunity for students to investigate how one change in a freshwater environment
can affect everything that lives in that environment by discovering how the amount of fertilizer
affects algae growth (Environmental Science).
2. Allow students to discuss why many seafood products and seaweed derivative foods are healthy
meals for people all over the world (Health/Nutrition).
Home Learning Activity:
Home Algae Products survey
Look for the following ingredients which come from seaweed, in the foods that you have in your home:
carrageenan, alginates, beta carotene. Place a check mark in the appropriate box to indicate which of these
ingredients are listed in each food’s label. There may be more than one per food.
Teacher Key:
! carrageenan
@ alginate
# beta carotene
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Products Containing Algae:
Brownie mix!@
Cheese (yellow and orange)#
Chocolate milk!
Coffee creamer!#
Cottage cheese!
Egg substitute#
Evaporated milk!
Frozen foods and desserts@#
Frozen yogurt!
Ice cream!#
Infant formula!
Margarine#
Mayonnaise#
Multiple vitamins#
Pet food!
Pudding (cooked)!
Relishes!@
Salad dressing@#
Sauces and gravies!@
Sour cream!
Toothpaste!
Whipped topping!#
Whipping cream!
Yogurt
Vocabulary:
alginates, carrageenan, beta carotene
References/Related Links:
www.aquariumteacher.com
http://seawifs.gsfc.nasa.gov/ocean_planet.html
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Algae is Um, Um Good!
Reading Passage
The ocean is the source of many materials, from ores mined from its depths to relaxing mineral salts for
a bath. Exquisite mother-of-pearl inlay, decorative shells, and pearl jewelry are found in gift shops worldwide. And whether your tastes run to the exotic, like yellowfin tuna sushi, or the mundane of fast food
milkshakes, products from the sea are probably in your diet. Many species of vertebrate and invertebrate
marine animals as well as marine algae are important sources of food worldwide.
Examine the foods in your own kitchen and you may find the terms “alginate” and “carrageenan” on
the food labels. Carragenans are compounds extracted from red algae that are used to stabilize and jell foods
and pharmaceuticals. Brown algae contain alginates that make foods thicker and creamier and add to shelf
life. They are used to prevent ice crystals from forming in ice cream. Alginates and carragenans are often
used in puddings, milkshakes, and ice cream. The commonly used color additive beta-carotene often comes
from green algae as well as many vegetables, including carrots.
On the grocer’s shelf and in the pharmacy, in industry and in the arts, the ocean is a resource without
equal. However, exploitation of these natural resources carries with it the responsibility to use them wisely
and preserve them globally. Algae represent only a small part of the many living and nonliving products we
derive from ocean plants, animals, minerals, and sea water. Together, they provide an important reason to
protect the ocean.
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Algae is Um, Um Good!
FCAT Questions
Directions: Read the passage, then answer all the questions below. Answer multiple-choice questions
by circling the letter of the answer that you select. Write your answer to the “Read, Think, and Explain”
question on the lines provided.
1. Which of the following is not a source of food?
A.
B.
C.
D.
Vertebrate marine organisms
Invertebrate marine organisms
Mineral salts
Marine algae
Answer:
C
2. Which of the following compounds are extracted from red algae?
A.
B.
C.
D.
Carrageenans
Alginates
Beta carotene
Seaweed
Answer:
A
3. Beta carotene is derived from which of the following algae?
A.
B.
C.
D.
Red algae
Green algae
Brown algae
Blue algae
Answer:
B
4. Explain why the ocean is such a rich natural resource.
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