The word canned is derived from the Greek word canned meaning to protect. Therefore, it can be said that the purpose of the word canning in the food industry is to create conditions under which the desired product can be stored for a long time. As a result, from a general point of view, all preservation methods such as using heat, cold, additives, radiation, etc. are in fact a kind of canning method.
Canning purposes
The general goals of canning technology can be summarized as follows:
1. Food storage using heat and prevention of microbial, enzymatic, chemical and physical spoilage of food and food protection with proper packaging
۲. Simplify the steps of storage, transportation and consumption of food
3. Possibility to use some seasonal products in other seasons of the year
Another advantage of this goal is the economic aspect, which to a large extent prevents the increase of the product price in its many seasons.
v Collection of canning operations
It can be said that the following steps are used in the production of most canned foods:
1. Selection and preparation of appropriate raw materials:
Includes harvesting and receiving the product by the factory.
۲. Preparation of raw materials:
At this stage, different operations are performed depending on the type of raw material, including:
– Cleaning and washing
It is a single operation that is performed to isolate and remove various contaminants in raw materials. The result is an improvement in the overall quality of the product and an effective and efficient process.
The most important raw food contaminants are shown in the table below:
The most important goals in the different cleaning process:
Consumability: Elimination of most harmful contaminants in health and maintaining the desired purity of food
– Product uniformity: to increase marketability
– Reduce microbial load and prevent the spread of corruption
– Help to carry out an effective process: in order to prevent damage to equipment by removing foreign materials such as rocks, particles and… as well as help sterilization by reducing microbial load
– Elimination of chemical agents
– Reaching the level of product quality standards
3. Enzyme depletion or inactivation of enzymes:
Enzymatic blanching is a relatively gentle heat process to inactivate enzymes in vegetables and some fruits. Although a small number of vegetables such as onions and green peppers do not need to inactivate enzymes during storage, most of them will be significantly spoiled if the blanching operation is eliminated or defective.
In canning, this process is used only to avoid undesirable changes in the color and texture of vegetables in the distance between slicing and sterilization.
Most fruits are canned without enzymatic action, but in the case of peaches, this process is often used to prevent browning after peeling.