Safe Food Processing

Reviewed by Wendy Marcason, RDN
food processing


The United States' food supply is affordable, plentiful and one of the safest in the world – but it is not completely risk-free. From farm to fork, food safety is a top priority and many traditional food processing methods help minimize food safety risks, including canning, freezing, drying, irradiation and pasteurization. These methods preserve food and destroy bacteria that cause food poisoning, helping to keep food safe. Let's take a closer looks at these methods.


In your cupboard, you may find canned tuna, canned vegetables or even foods you canned yourself. The canning process has been a safe way to preserve food for 200 years. The food quality and nutrient content of canned goods remain relatively stable as long as the container and seal are intact, allowing for a long shelf life. Another safety advantage of canned foods is that they are tamper-resistant — any opening is clearly evident.

Canning is simply cooking food at high temperatures in a sealed and sterile can or jar, which destroys organisms that would cause spoilage – no need for preservatives. In addition, canning removes nearly all pesticide residues during the washing and peeling steps of the commercial canning process. Some nutrients can be lost during the heating process, but canned foods are as nutritious as fresh and frozen foods, and can even be more nutritious than fresh or frozen foods when handled improperly. Canned products are convenient, portable and quick to prepare. Just reheat since they are already cooked during the canning process.

Note: Salt or added sugars are only used to enhance the flavor in canned foods, not as a preservative, so look for cans with no added salt.


Freezing is an excellent way to preserve foods such as vegetables, meat or fish for a very long time. You can freeze almost any food, with the exception of canned food and eggs in the shell. Freezing keeps food safe almost indefinitely, so the recommended storage times are for quality alone. So what does freezing actually do?

Freezing is a food processing method that prevents the growth of bacteria, yeasts and molds that cause food spoilage and food poisoning. This method keeps food safe by storing perishable food well below the temperature at which harmful microorganisms thrive and keeps foods out of the danger zone, between 40°F and 140°F. Freezing also helps retain the nutrition and quality of foods for a longer period of time.


Among the oldest methods of preserving food, the drying process removes moisture making perishable foods safe without refrigeration. Common dried foods include fruit, vegetables, beans and nuts, or even fish, meat and poultry.

Drying removes the moisture from foods, leaving bacteria without a key ingredient to grow - water. Dried foods can remain safe in dry, covered conditions at room or cool temperatures. A preservative is generally used to keep dried protein-rich foods like meat, seafood and poultry safe.


Pasteurization is the process of heating foods such as raw milk, raw eggs and fresh juice to a temperature high enough to destroy bacteria and inactivate most enzymes that cause spoilage. Milk, eggs, soft cheeses and juice are commonly pasteurized to kill harmful bacteria. Unpasteurized products can be harmful to everyone, but those at high risk of food poisoning (pregnant women, older adults, young children and those with weakened immune systems) should especially avoid any unpasteurized products.


Irradiation is used on wheat, flour, fruits, vegetables, spices, seafood, beans, shelled eggs, raw poultry and red meats to control spoilage and eliminate foodborne pathogens.

Irradiation destroys bacteria, mold, fungi and insects by passing a field of radiant energy through food, similar to how sunlight passes through a window. Often referred to as cold pasteurization, irradiation uses no heat to destroy disease-causing bacteria and other organisms. Irradiation extends the freshness of food and helps retain quality and safety longer. Like other processing methods, irradiation is regulated and approved by the U.S. Food and Drug Administration. Whole foods that have been irradiated must be labeled.

While these food processing methods play a key role in keeping our food safe, these methods cannot replace safe food handling practices in the home. Always remember the four easy steps – wash, separate, cook and refrigerate and be sure to store, prepare and cook food in a safe manner.

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