Plant Oils

Question 1

What are the benefits to cooking with vegetable oils?

Answer 1

1. Higher boiling points than water/higher temperature/faster speed.
2. Oil carries the flavour making it more intense
3. Increases the energy we get from food

Question 2

Bromine water + unsaturated oil =

Why?

Answer 2

decolorised, because the bromine opens up the double bond between the carbon atoms.

Question 3

Explain the conditions needed for hydrogenation of unsaturated vegetable oils to make them harder and what happens.

Answer 3

They are hardened by reacting them with hydrogen in the presence of a nickel catalyst at about 60’c. The hydrogen reacts with the double-bonded carbons and opens them.

Question 4

Pros/cons of hydrogenated oils:

Answer 4

• Solid at room temp/useful as spreads and baking cakes.
• Margarine has a spreadable consistency because it is partially hydrogenated.
• Partially hydrogenated veg oils are used instead of butter in processed foods-This makes them cheaper and last longer.

-Partial hydrogenation of veg oils ends up with trans fats that are bad for you.

Question 5

How do veg oils in foods affect health?

Answer 5

• Partially hydrogenated oil increases amount of cholesterol in the blood because of trans fats.
• Cooking food in oil makes it more fattening.