Demostration - Exploration of the Importance of Marine Algae (Mike Wagner)

Title: Exploration of Algins: Alginate, Carrageenan, and Agar from Seaweeds in our daily lives and the importance of Marine Algae.

Principle(s) Investigated: List all principles that apply to this activity - Observations of local marine algae species ("Seaweeds"), and an example of Sodium Alginate, a polysccharide from brown algae cell walls used in many industries. Discussion of economic importance of marine algae. Observation, motor skills (sketching, writing), smell, taste, touch, interaction and discussion.

Standards : Past in the appropriate California content standards.

Can be used for All Life Science and all ages, depending on complexity: Environmental Science, Chemistry, General Science. Complexity from basic observations to advanced application of knowledge of Organic Chemsitry and taxonomic classification.

1.c - Students know the difference between Prokaryotic and Eukaryotic Cells. Students understand photosynthesis.

1.h - Students know most macromolecules (polysaccharides, nucleic acids, proteins, lipids) in cells and organisms are synthesized from a small collection of simple precursors.

6.a - Students know about biodiversity and how it can be affected through an altered environment.6.b - Students know how to analyze changes in an ecosystem due to climate, invasive species, population size and human activity.

6.e - Students know that a vital part of the ecosystem is the stability of its producers.

6.f - Students know about food webs.

Materials: Include a list of materials and sources from which they may be obtained.

1) Samples of local "Seaweeds" ex - (Macrocystis), (Phaeophyta) growing as kelp forests and in tidal zones along the Southern California coast. Red algae examples, (Rhodophyta), coralline with calcification, hold fasts, gas bladders (pneumocysts), etc.

2) Dried Sodium Alginate / Alginic Acid extract (from cell walls) used in food chemistry, by master chefs and in industry (Microbiology, dentistry, pharmacy, printing) and as a food additive as a gelling agent.

3) Small clear plastic cups + stir sticks.

4) Products containing algal extracts (specific - carrageenan from Chondrus sp) used as thickening agents, gelling agents, binders, emulsifiers and stabilizers as it absorbs water quickly.

5) Potable water.

6) Culinary samples (Seaweed Chips) for tasting.

Procedure: Data Table Give a detailed explanation of the procedure and include diagrams if possible.

1) Observe various examples of local seaweed samples collected from Point Dume State Beach (has a large kelp forest off shore and a rich reef offering tide pool explorations at low tide). Sketch, color and describe each sample.

2) Observe samples of a packaged, for consumption seaweed food, usually sold dehydrated as a snack chip. Observe them and record your observations: Color, texture, taste (yes, the are edible). Ex - Crunchy, brtittle, rubbery, smooth, rough, pale green, black, salty, bitter. Next, soak a few samples in fresh water and note any changes in color, taste and texture. Record your results. Create a simple chart in your lab book and label it as follows: Record texture, color, taste (only edible varieties), smell or any other observation that comes to mind. Let one sit in your mouth and feel it absorb moisture from your mouth and note the changes that occur.

3) Observe dry Sodium Alginate powder and record your observations - does it feel silky, smooth, or grainy? Does it have an odor or taste? Next, dissolve ~ 1/4 tsp of powdered Sodium Alginate into ~ 1 TBLS of water in a clear plastic cup. Stir with stir stick until the powder is completely dissolved. Record observations. Observe it in the cup. Swirl the cup around. Describe the mixture. Is it thick? Smell it, taste it, touch it. Think about what the powder and water are doing together to obtain the changes you see, feel and taste. Feel it on your fingers.....Why do you think it's used as a thickening or moisturizing/hydrating agent?

4) Observe processed products and scan the ingredients list looking for (mostly) Carregeenan - an algal extract from the Red Algae, Chondrus crispus. The molecular structure of the hydrocolloid is shown above. Quick thought question - Would this molecule be attracted to water? Why might this be a good additive to powdered products wanting to create a rich, smooth texture? Write down the products name in your lab book. When you get home, look at foods you have in your kitchen and write the names down if they contain Carrageenan in the ingredients list in your lab notebook. Flucoxanthin, chlorophyll c (found in kelps) shows various medical uses. Other ingredients = agar (Ogonori), algal oil.

Student prior knowledge: What prior concepts do students need to understand this activity?

Students would have been instructed to read the lab activity before coming to class as well as have had their parents sign a connection letter / consent form - if their child was free from food allergies and was able to taste, smell and touch the edible product used in this activity. Students would have been introduced to the Kingdom Protista, photosynthesis and the importance of algae as important producers. Understanding of basic taxonomy would be understood. Students would understand basic Organic Chemistry - monomers and polymers of carbohydrates, lipids, amino and nucleic acids.

Students would also be familiar with or have been introduced to the ecosystems seaweeds would be found in, the animals dependent on them in the littoral zones, their role in the food chain, atmospheric oxygen production, etc. In California, specifically the kelp forests off the coast would be a focus for a class here.

Explanation: Give a thorough explanation of the experiment or demonstration. Your explanation should be written to give your fellow teachers a solid understanding and include greater detail than what you might provide for your secondary students. Make certain to include equations whenever pertinent.

The purpose of the activity / observation is to allow students to experience organism(s) that are vital to marine ecosystems as well as to many economies around the world. Algal extracts are used in food production as thickeners, hydrants, stabilizers, emulsifiers and gelling agents commonly found in processed foods. They are also used in air freshener gels, beer, fire retardants, toothpastes, bio fuels, and pet foods.

Sodium Alginate comes from the cell walls of brown algae - example - Lamilaria. It is used in many products to thicken and emulsify a liquid - soy & almond milk, reduced fat sour cream, yogurt, ice cream, chocolate milk, pudding, etc. The seaweeds are also used in commercial fertilizers and animal feeds. You can stress the possible downside to harvesting as many marine species depend on algae and are affected in one way or another by the harvest. You can make arguments as many people are employed in this industry. Students could work together to brain storm possible ways to harvest in a managed way as to have less impact on an ecosystem while still offering employment for local workers (see photo below).

? & Answers: Give three thought-provoking questions and provide detailed answers.

1) Explain why food manufactures would use additives such as Sodium Alginate and Carrageenan in processed food products. Based on your observations of it (feel, texure) why would it be a desirable additon to certain food products (powdered cocoa mix for example)?

Sodium Alginate and or Carrageenan is often added to either keep water molecules bound, thus preventing dehydration of the product, which might sit for a long time on the shelf or to act as a water absorber in a dried food or drink product. Because it has a gooey, creamy feel and texture, it will often be used to replicate the "mouth feel" of fats that are removed in diet products. There is also a lot of buzz over omega-3 fatty acids in the diet. Some products add aglal oils (Horizon Organic Milk) as an Omega 3 supplement.

2) Briefly design and discuss how you would implement a conservation program off a small area of the coast line that can be harvested for economically important kelp, providing jobs yet maintain a balance so that the local ecosystem remains healthy.

Small harvests, at certain times of year, implementing "selective cutting", similar to healthier forest removal so that any large section of the kelp forest is not removed. Ongoing observations and research will be conducted to verify that there is no major disruption in the life cycles of the species that depend on the kelp forest.

3) Research online and list several countries where seaweeds are important as a food source and as an industrial product that is exported. Find specific genus/species names and list them and whether they would be grouped as brown, green or red algae and what they are specifically used for (eaten, or used for extraction of algins).

Taiwan, Singapore, Japan, Indonesia, Thailand, South Africa, Ireland, USA,Canada, etc. Seaweeds are used for food by many coastal people, especially Asia. An example is Chondras crispus, red algae giving carrageen. Seaweeds are farmed for their extracts (ex - Alginate) used in the food industry as a thickening agent in many foods and beverages...lists of...

Applications to Everyday Life: Explain (don't just list) three instances where this principle can be used to explain other phenomenon.

1) How can something dry, or fat-free end up to be so rich, thick and creamy? Students can see after this activity that by adding certain ingredients (agar, alginate), food chemists can create products that have characteristics of the real thing. For example, fat can be removed and algal extract added to moisten and thicken a product. Thickeners are also added to cut cost. For example, Trader Joe's Coconut Milk contains algal thickeners allowing them to add less actual coconut. Many times, the addition shows a sign of cost cutting and is used as a cheap filler. APPLICATION CHEMISTRY: Discuss the importance of chemistry in the food industry, the structure of Sodium Alginate, etc. Trace elements found in seaweeds important for human nutrition: Iodine, Magnesium, Copper, etc).

2) The importance of Kelp forest and other algae "forest" like Fucus, "rockweed" contributing to and supporting a vast array of species along a coast line important for environmental stability and industry (fishing, recreation). With the loss of the seaweeds, we could expect many other species to decline thus impacting the local environment and economy from fishing to tourism. APPLICATION PHYSICS: Macrocystis can grow very large - it's less dense than surrounding water, that exerts force, from all sides = Buoyancy. Less dense because of gas bladders that help support it in the water column.

3) Point out that the overall health of the oceans algae and phytoplankton, from the large (Macrocystis) to the small (Diatom) are a fundamental aspect to planetary stability (food web, oxygen production). Any loss or degradation of any ocean habitat should be of concern to humans and addressed accordingly to stop, reverse or manage the situation. Also of concern is that of invasive species. In this case, an invasive tropical algae crowding out native seaweeds and grasses in the Mediterranean as well as here in California. See link to view discussion. This could be used as a thought question in how to deal with this problem.

Photographs: Include a photograph of you or students performing the experiment/demonstration, and a close-up, easy to interpret photograph of the activity --these can be included later. Below - Sea Vegetable "Sea Witch" created by the author (that would be me) on a secluded small beach in Pacific Grove, CA. The nose is an inverted air bladder.