This Potato has a face!

Questions to Check Understanding

• What is a saturated compound?• What is an unsaturated compound?• Describe the differences between the

properties of unsaturated and saturated fats.

Saturated Unsaturated

Cooking with Vegatable Oils

1. Compare the boiling point of vegetable oil with water.2. At what temperature will corn oil condense from a gas into a liquid?3. Which oils will be liquid at 220 C?4. Predict the boiling point of butter. Can you justify your prediction?

What do you notice about the boiling points?

Water 100 C

Sunflower 266 C Soybean 257 C

Corn 246 C

Peanut 227 C

Sesame Seed 216 C

Olive 191 C

• Cooking with vegetable oils means the food cooks more quickly, changes colour and is crisper.

• Cooking with oil means the food will absorb the oil.

• Oils contain a lot of energy.

• So fried food contains more energy compared to boiled food.

Questions

• How does cooking with oil change potatoes?

Why is cooking with oil potentially unhealthy? Why could it be argued that it is healthy?

• We can increase the boiling points of oils by adding hydrogen to molecules.

• Doing this increases the melting point and they become solid at room temperature.

• This is how margarines are made.

• This process is called hydrogenation or hardening.

Hydrogenation (Higher Paper)

• Vegetable oils are hardened by reacting them with hydrogen gas at about 60ºC.

• A nickel catalyst is used to speed up the reaction.

• The double bonds are converted to single bonds by the hydrogenation.

Extension

1. What is hydrogenation/hardening? 2. What two conditions are needed for this

process?