C 9 Plant oils and their uses Flashcards
(15 cards)
What are plant oils commonly extracted from?
Seeds, nuts, and fruits of plants.
How are oils extracted from seeds and nuts?
By pressing and crushing, followed by removing water and impurities.
What is the method used to extract oils from fruits like olives?
Pressing or crushing the fruit.
What are two common uses of plant oils?
As food (cooking oils) and as fuels (biodiesel).
Why are plant oils useful in cooking?
They have high energy content, transfer heat well, and change the texture and flavor of food.
What is an emulsifier?
A substance that helps mix oil and water to form an emulsion.
What is an emulsion?
A mixture of two immiscible liquids (like oil and water) that do not separate easily.
Give an example of a food that is an emulsion.
Mayonnaise.
What are unsaturated fats?
Oils that contain double carbon-carbon bonds (C=C) in their fatty acid chains.
How can you test for unsaturation in oils?
Add bromine water – it will decolorise if the oil is unsaturated.
What is hydrogenation?
The process of reacting unsaturated oils with hydrogen at 60°C using a nickel catalyst to make them saturated.
What is a use of hydrogenated oils?
Making margarine or other solid fats.
What is biodiesel?
A renewable fuel made by chemically reacting vegetable oils with alcohol (usually methanol).
Why is biodiesel considered more environmentally friendly than fossil fuels?
It is renewable and produces less net carbon dioxide.
Name two advantages of using plant oils as fuels.
Renewable source and lower carbon emissions.
