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 various methods for preventing or retarding rancidity of food.
Hint: Oxidation is defined as the loss of electrons or we can say that increase in the oxidation state of an atom, ion or molecule while reduction can be defined as the gain of electrons or decreases in the oxidation state of any given atom, ion or molecule. Step by step explanation: Rancidity is generally based on the concept of oxidation. a) Rancidity can be explained as the condition produced by aerial oxidation of fats and oils in foods that can be judged by the unpleasant smell and taste of food. In a simple manner we can say that spoiling food is known as rancidity. Rancidity spoils the food materials prepared in fats and oils which have been kept for a considerable time and make it unfit for eating. b) Oxidation reactions are responsible for causing rancidity. c) There are a number of methods for preventing or retarding rancidity of food some of them can be explained as follows: 1. It can be prevented by adding antioxidants to foods which contain fats and oils. 2. It can be prevented by packaging fat and oil-containing foods in nitrogen gas. 3. By storing the food in the refrigerator. 4. By storing food in an air-tight container. 5. Storing food away from light.
Note: The increase in oxidation state of an atom, through a chemical reaction, is known as an oxidation; a decrease in oxidation state is known as a reduction. Such reactions involve the formal transfer of electrons: a net gain in electrons being a reduction, and a net loss of electrons being an oxidation. For pure elements, the oxidation state is zero.