What type 1 Chemical reaction takes place in this case?
Question 12. (a) Explain the term "rancidity". What damage is caused by rancidity?
(b) What type of chemical reaction is responsible for causing rancidity?
(c) State and explain the various methods for preventing or retarding rancidity of food.
Answers
Answer:
Rancidity refers to unpleasant odours coming from spoilage of food. ... Oxidative rancidity: it occurs when the double bonds of an unsaturated fatty acid react chemically with oxygen
Rancidity means the oxidisation of fats and oils which changes their smell and taste. Usually substances which prevent oxidisation are added to foods containing fats and oils. They are called antioxidants
The type of chemical reaction is oxidation. Definition: Rancidity is the process of slow oxidation of oil and fat present in the food materials resulting in the production of foul odour and taste in them.
Rancidity can be prevented by adding antioxidants to foods containing fats and oils. ... Rancidity can be prevented by keeping food in a refrigerator because in a refrigerator when the food is kept the oxidation of fats and oils in it is slowed down due to low temperature and thus rancidity is retarded
hope it helps:
Rancidity: Rancidity can be defined as the chemical decomposition of fats and oils due to hydrolysis or auto-oxidation or microbial activity, producing aldehydes, hydroxyl acids, keta acids, and other compounds. This causes a considerable damage to the natural structure of fats and oils, producing undesirable odors, flavors and discoloration in the food containing them; making them unfit for consumption.
For Example: When butter is kept open for a long time, then its smell and taste gets changed (due to the presence of butyric acid (a four-carbon acid)).
Factors responsible for causing rancidity are light, oxygen, trace elements such as iron and zinc, salt, water, bacteria, and molds etc.
Types of chemical reactions responsible for causing rancidity:
(i) Oxidation Reaction: Oxidation is said to have occurred when a substance reacts with oxygen in the air forming oxides. It causes the formation of peroxide at the double bonds (C=C) of fat molecules with subsequent breakdown of these peroxides to form aldehydes, ketones and acids of lower molecular weight. This results in off-flavor, off-odour and sometimes change in colour.
(ii) Hydrolysis: Hydrolysis can be defined as the breaking down of a chemical compound into two or more simpler compounds by reacting with water. It decomposes a lipid into its component fatty acids and glycerol.
C-O-CO-R + H2O → C-O-H + HO-CO-R