Answer: 1. Preservation refers to the process of treating food in a way that helps to maintain its quality, nutritional value, and safety over a prolonged period. The primary objective of preservation is to extend the shelf life of food so that it can be stored and consumed at a later time. There are various methods of food preservation, such as drying, smoking, salting, canning, and freezing, that are used to prevent spoilage by bacteria, fungi, and other microorganisms.
2. Preserved food has a definite keeping time because the preservation process does not completely stop the chemical reactions that can lead to food spoilage. While preserving food can slow down the rate of spoilage, it does not completely stop it. As such, most preserved foods have a shelf life that is determined by the method of preservation used and the storage conditions. For instance, canned foods can typically be stored for several years, while dried foods and smoked meats have a shorter shelf life of a few months to a year. It is essential to follow the storage instructions provided for each type of preserved food to ensure that they are safe to eat and maintain their quality over time.