Properties of Lipids - Rancidity Flashcards Preview

Home Economics: 01.5 - Lipids > Properties of Lipids - Rancidity > Flashcards

Flashcards in Properties of Lipids - Rancidity Deck (15)
Loading flashcards...
1

What is rancidity?

It is the term used to describe lipids when they 'go off' which results in an unpleasant odour and taste

2

How many types of rancidity is there?

There are two types

3

What are the two different types of rancidity?

Oxidative rancidity
Hydrolytic rancidity

4

How do you prevent rancidity in fats?

Store fats in the fridge

5

How do you prevent hydrolytic rancidity in oils?

Store oils in a cool dark place

6

How do manufacturers prevent rancidity?

They use an anti-oxidant to prevent fatty acids from going rancid

7

Where are antioxidants naturally found?

In vitamins A, C and E

8

Where are antioxidants artificially found

In BHA and BHT

9

Antioxidants are added into what types of foods to prevent rancidity?
(5)

Biscuits
Cooking fats
Dairy spreads
Stock cubes
Oil

10

What is oxidative rancidity?

This is a form of rancidity that occurs when oxygen (O2) is forced through the double bond of an unsaturated fatty acid

11

Give an example of where oxidative rancidity

Oil solidifying on a pan

12

What is hydrolytic rancidity?

A form of rancidity which occurs when enzymes and bacteria react with the lipid

13

What effect does hydrolytic rancidity have on a lipid?

It results in the breakdown of the triglyceride with the glycerol separating from the fatty acids which results in an altered flavour

14

Hydrolytic rancidity occurs in what types of fatty acids/

Saturated and unsaturated fatty acids

15

Give an example of where hydrolytic rancidity occurs?

Occurs most commonly in freezers as enzymes are not destroyed