We have often seen that oily food if not used within a limited time gives bad taste, smell and becomes unfit for consumption

We have often seen that oily food if not used within a limited time gives bad taste, smell and becomes unfit for consumption. This is due to oxidation of oils and fats present in the food.
Now, answer the following questions:
(i) On marriages or other celebrations, a lot of food goes waste. What methods do you suggest to prevent this wastage?
(ii) Often preservatives are added to certain foodstuff, so that they can stay consumable for a longer time but these preservatives are chemicals which may be harmful. What alternatives do you suggest?
(iii) What method of preservation of food items should be followed at home?

(i) The person giving the party should give an undertaking to the fact that the left out food would be served to the poor people or beggars. And there should be some restrictions on the number of items to be served to avoid wastage.
(ii) Instead of chemical preservatives, some food items can be preserved by vacuum or by replacing air around the food item by nitrogen.
(iii) At home, the best method to preserve food items is by keeping them in the refrigerator. When the food is stored in a refrigerator, the oxidation of fats and oils in it is slowed down due to low temperature. Food can also be stored in airtight containers,then there is little exposure to oxygen of air.