The shelf life of food is the duration of time that it is given before it is considered to be unsuitable for consumption. It is the amount of time that is recommended for food, beverages, medicines and other perishable goods to be stored and consumed before it becomes dangerous or harmful to the body.

Factors Affecting Shelf-life

Shelf life is affected by several factors such as exposure to light and heat, mechanical stresses, gas transmissions and contamination by microorganisms. Especially because bacterial contaminants are everywhere, foods that have been unused for a long period of time will accumulate bacterial colonies, leading to its unsuitability for consumption. Thus, food manufacturers have developed different ways to overcome these factors and extend the shelf life of their products. For instance, milk products undergo pasteurization to be free from bacteria. If a milk product has not been pasteurized and bacteria is already present before the product is opened, most likely that product will not be suitable for consumption even before its expiry date passes. To maintain its quality and shelf life, milk always has to be refrigerated.

Temperature is also a factor in the shelf life of a food product. Basically, temperature can either increase or decrease the chemical reactions in food. This is why temperature control is important in maintaining and sometimes extending the shelf life of a product. A form of temperature control is freezing or refrigerating.

Shelf Life and Expiration Date

It should be noted that shelf life is not the same as expiration date. The expiration date is related to the quality of a food, while shelf life is related to food safety. For instance, consuming a food item before its expiration date does not always mean that it is safe to eat. Also, a food item is not necessarily unsuitable for consumption even after its expiry date.

Other Terms Synonymous to Shelf life

Shelf life is synonymous with the term “use by.” “Use by” dates indicate when the product will no longer be safe for consumption. Basically, a product will no longer be safe to eat a day after the indicated “use by” date. Almost all food products that have “use by” dates are those that normally become spoiled quickly and thus have to be consumed before the indicated date.

Although somewhat similar, the term “best before” indicates that the product will no longer be at its optimum quality beyond the indicated date. However, it does not necessarily mean that a product is already dangerous once it goes beyond the indicated “best before” date.