Wednesday 11/20 - MM 3.4: Investigating Emulsifiers - Elorde Tuliao | Library

Warm Up - Introducing Emulsifiers

Welcome back salad dressing scientists! We already conducted Flavor Ingredients Tests and figured out which ingredients don’t leave sediments. Today, we will investigate how to create a salad dressing that doesn’t separate into layers.

You have shown through your observations, investigations, and models that you understand why oil and vinegar—or water—don’t mix. Now you need to consider how to make oil and vinegar (water) mix.

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Based on the picture above, when a salad dressing stays mixed, we refer to it as a ___________ mixture.

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Based on the picture above, when a salad dressing separates, we refer to it as a ___________ mixture.

Oil and Water Mixture

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Oil and Water (Vinegar) Model:

DIRECTIONS: In the Mode1, draw what the oil and water look like on the nanoscale when they are in the same container. Use the shapes in the key to draw your model.

Stability Test Procedure
Three group members go to one of the Materials Stations. Measure one level scoop of one of the texture ingredients into your vial of oil and water.
Snap on the cap tightly. Return to your seat.
Shake your vial for 30 seconds.
Wait for three minutes. Record your starting observations in the table on the next page.
Be sure to draw any layers you see.
Record notes about what the mixture looks like, the number of layers you see, if you see any sediments, and anything else you observe.
Shake your vial for 2 minutes.
Record your final observations. Be sure to draw any layers you see.
Record notes about what the mixture looks like, the number of layers you see, if you see any sediments, and anything else you observe.

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PREDICT: Which ingredient (cornstarch, flour, or lecithin) do you think will create the most stable salad dressing? Why?

Cornstarch

1

Do you see layers or sediment?

1

Did this ingredient make oil and vinegar (water) completely mix?

1

Is this a stable or unstable mixture?

Flour

1

Do you see layers or sediment?

1

Did this ingredient make oil and vinegar (water) completely mix?

1

Is this a stable or unstable mixture?

Lecithin

1

Do you see layers or sediment?

1

Did this ingredient make oil and vinegar (water) completely mix?

1

Is this a stable or unstable mixture?

1

Which ingredient created the most stable mixture? What is your evidence?

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Wednesday 11/20 - MM 3.4: Investigating Emulsifiers

Based on the picture above, when a salad dressing stays mixed, we refer to it as a ___________ mixture.

Based on the picture above, when a salad dressing separates, we refer to it as a ___________ mixture.

Oil and Water (Vinegar) Model:DIRECTIONS: In the Mode1, draw what the oil and water look like on the nanoscale when they are in the same container. Use the shapes in the key to draw your model.

PREDICT: Which ingredient (cornstarch, flour, or lecithin) do you think will create the most stable salad dressing? Why?

Cornstarch

Do you see layers or sediment?

Did this ingredient make oil and vinegar (water) completely mix?

Is this a stable or unstable mixture?

Flour

Do you see layers or sediment?

Did this ingredient make oil and vinegar (water) completely mix?

Is this a stable or unstable mixture?

Lecithin

Do you see layers or sediment?

Did this ingredient make oil and vinegar (water) completely mix?

Is this a stable or unstable mixture?

Which ingredient created the most stable mixture? What is your evidence?

Which ingredients created unstable mixtures? What is your evidence?

Oil and Water (Vinegar) Model:

DIRECTIONS: In the Mode1, draw what the oil and water look like on the nanoscale when they are in the same container. Use the shapes in the key to draw your model.