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In relation to lipids, explain each of the following terms: Oxidative rancidity________________________________________________ Hydrolytic rancidity________________________________________________ - Leaving Cert Home Economics - Question 2 - 2013
Question 2
In relation to lipids, explain each of the following terms: Oxidative rancidity________________________________________________ Hydrolytic rancidity_______________... show full transcript
Worked Solution & Example Answer:In relation to lipids, explain each of the following terms: Oxidative rancidity________________________________________________ Hydrolytic rancidity________________________________________________ - Leaving Cert Home Economics - Question 2 - 2013
Step 1
Oxidative rancidity
Answer
Oxidative rancidity refers to the process that occurs when unsaturated fatty acids react with oxygen from the air. This interaction leads to the oxidation of the fats, causing undesirable changes in flavor and aroma. Particularly, the double bonds in unsaturated fatty acids are particularly vulnerable to this reaction, where oxygen can combine with carbon atoms, ultimately forming byproducts such as aldehydes and ketones. These compounds are often responsible for the unpleasant rancid smell associated with spoiling fats.
Step 2
Hydrolytic rancidity
Answer
Hydrolytic rancidity occurs when fats are broken down by the action of enzymes known as lipases. These enzymes hydrolyze the fats into free fatty acids and glycerol. This process can be catalyzed by micro-organisms present in spoiled fat foods, which may produce additional enzymes that further degrade the fats. The result of hydrolytic rancidity is not only the production of free fatty acids, which can contribute to off-flavors and odors but can also occur in environments such as freezers where enzymes are not adequately inactivated.