Preparation of Plant and Animal Products
Generally, human food consists of resources of either plant or animal origin, which cannot be kept long after harvest or slaughter and starts deteriorating rapidly. Thus, it becomes imperative to find various ways of extending the shelf life of these materials/resources. The nature and characteristics of the material, like environment of the food and the interactions between the food and its environment, should be well understood. Traditional methods of food preservation include cold storage, fermentation, salting, drying, curing and smoking.
However, the features of these traditional methods are largely centered on non-controllable processes that rely solely on 'chance effects'. Modern food preservation techniques include dehydration, refrigeration, freezing, industrial fermentation, freeze drying, irradiation, evaporation, concentration, thermal processing, use of chemical preservatives, high-pressure technology, plant-derived food preservation technology, modified atmosphere packaging, use of bacteriolytic enzymes and a combination of two or more preservative methods (the hurdle concept), which lend themselves to controllable processes and allow for predictable final product quality attributes to be attainable. Traditional and modern food preservation techniques applicable to some of the common food raw materials.
Food preservation refers to methods used for keeping food from getting spoilt. Food spoilage . . . is any adverse change that makes food unfit for human consumption and this process can be due to chemical and physical changes; for example, browning and bruising, growth of unwanted pathogenic microorganisms and infestation by insects or other pests. Thus food preservation is important in increasing/enhancing the shelf life of food and ensuring food safety. Extending the shelf life of foods is based on controlling enzymes or chemically active molecules in food, controlling microbial deteriorative processes and avoiding faulty postharvest handling practices.