Food Preservation

Food preservation is the application of techniques to prevent or minimize undesirable changes in food.

Factors Affecting Food Spoilage1. Microbiological factors include yeasts, molds, and bacterial activity.2. Macrobiological factors includes insects, rodents, and other animals.3. Chemical factors are those catalyzed by enzymes of the tissues4. Physical factors are such changes caused by freezing, burning, drying, and

pressure.

Advantages of Preserving Foods 1. Improves the general health of the family by supplying more varied and balanced

diet2. Enables one to eat certain foods even when they are out of season3. Saves time, money, and energy4. Prevents the waste of perishable foods5. Helps mother build up healthier members of the family6. Gives profitable work to idle hands 7. Enables people to save the surplus products of one locality to sell to other

localities8. Stimulates agricultural development by encouraging more food to be produced9. Stabilizes prices by balancing supply and lessening the amount of imported food10.Enables families to have food in stock in cases of emergency

Methods of Food Preservation

The common method of food preservation are:1. Removal of microorganism as in washing and trimming2. Use of low temperature as in refrigeration and freezing3. Drying as in sun drying and dehydration4. Us of high temperatures as in the pasteurization of juices and acetic acid

preserves, boiling, or blanching5. Use of chemical preservation either developed by microorganism s as in

fermentation in a salty medium or added chemical additives. 6. Asepsis or keeping out microorganisms, as in packaging 7. Maintenance of anaerobic conditions in sealed, empty container, or by

replacement of the air with carbon dioxide8. A combination of two or more methods, the best example of which is canning

Principles underlying methods of preservation 1. Prevention or delay of microbial decomposition by keeping out microorganisms

(asepsis) By the removal of microorganisms By hindering the growth and activity of microorganisms By killing the microorganisms

2. Prevention or delay of self-decomposition of foods By destruction or inactivation of food enzymes By prevention or delay of purely chemical reactions

3. Prevention of damage caused by external factors such as insects, rodents, dust, fumes, odor, desiccation, and mechanical factors, such as fire, heat, or water damage.

Drying, salting, pickling 1. Drying. The primary and one of the oldest methods of preserving food. This

method keeps the food’s moisture content below the level in which microorganisms can grow and reproduce. This can be done through the following ways:a. Slicing the food thinly and drying it under the sunb. Using artificial heat from the ovenc. Using electricity, alcohol, or gas

2. Salting. It is the cheapest and easiest way of preserving food. Salt removes water from the food as it penetrates the tissues. With this method, the food becomes harder, thus preventing spoilage. Two ways of salting are:a. Adding salt to food and drying it afterwards as in making tuyob. Soaking in salt solution as in ham making

3. Pickling. Usually done to food with flat taste. Vinegar and other preservatives are added to improve the food’s flavor. Two ways of pickling are:a. Simple pickling wherein the food is salted and sugar is added.

An example of this is the pickled papaya.b. Fermental pickling is done by means of adding ingredient to food and using

the process of lactic acid fermentation within one week.

Reference: Technology and Livelihood Education III (Edita Tampico Rafael) pp. 120 - 122