Processing methods

Process description

Food Use Examples

Used at Home

Benefits

Drawbacks

Cooking/Heating

Increasing the temperature of a food and beverage product to destroy microorganisms, inactivate enzymes, preserve the food, and improve the edibility of some foods

Eggs, meat, vegetables, potatoes, cereal grains (rice, oats, wheat), and pasta

Yes

Food safety; shelf-life; impact flavor and texture of some food products

Potential loss of heat sensitive vitamin(s);

changes color; impacts taste in some food products

Pasteurization

Heating food and beverage products at a specific temperature for a particular length of time

Milk, juices, some egg products, jams, jellies, and some sauces

Yes

Food safety; shelf-life

Potential loss of heat-sensitive vitamin(s); modifies protein structures

Drying

Using heated air or light (infrared, solar) to substantially reduce water content

Meat, milk, cheese and, other dairy products, egg products, grains, and fruits and vegetables

Yes

Shelf-life

Potential loss of heat-sensitive vitamin(s); changes product texture and flavor; increases calorie content due to water loss

Direct Steam Injection

Heating a liquid food product by injecting steam under pressure to achieve a particular temperature (e.g., pasteurization)

Milk, processed cheese, and other dairy products, nutrition shakes, juices and other beverages, and soups

No

Food safety; shelf-life

Increases moisture content of the food product; potential loss of heat-sensitive vitamin(s); modifies protein and fiber structures from the original state; imparts burnt flavor

Ultra-High Heat Treatment (Indirect steam heating)

Rapid heating of a product above the boiling point of water for a very short time

Shelf-stable liquid dairy products (e.g., milk and nutrition shakes), juices, and other beverages, pastes, sauces, and purees

No

Food safety; shelf-life

Potential loss of heat-sensitive vitamin(s); modifies protein structures; imparts burnt flavor

Frying

Rapid heating or cooking of a food product in hot oil (300-500 F)

Fried meat, potatoes (e.g., French fries or potato chips), fried vegetables, and eggs

Yes

Food safety; shelf-life; changes texture and color and flavor

Adds fat to the food, thereby increasing calorie content of the food; potential loss of heat-sensitive vitamin(s); modifies protein structures; could impart burnt flavor; could generate components that are potentially carcinogenic (e.g., acrylamide)

Baking

Heating or cooking a food product using either a batch or continuous oven at a specified temperature and time to achieve a desired temperature within the food product

Meat, breads, cakes, potatoes, vegetables, mixed dishes (e.g., casserole), and fruits

Yes

Food safety; shelf-life; imparts brown color on the surface and flavor; modifies texture

Potential loss of heat-sensitive vitamin(s); modifies protein structures; increases calorie content due to water loss

Grilling

Cooking a food product over open flame (usually 350-600 F) for a specified time to achieve a desired temperature within the food product

Meat, potatoes, and vegetables

Yes

Food safety; shelf-life; imparts favorable taste, texture, and appearance

Potential loss of heat-sensitive vitamin(s); modifies protein structures; imparts burnt flavor; generates compounds that are potentially carcinogenic (e.g., acrylamide)

Smoking

A method used to preserve meat by using salts to dehydrate the meat and cooking the meat at a lower temperature ranging between 190-250 F in the presence of smoke, generated by burning organic material(s)

Various types of meat and some cheeses

Yes

Food safety; shelf-life; imparts unique flavor; modifies texture

Modifies protein structures in meat; could impart unacceptable flavor due to the variation in the absorption of smoky flavor

Radio Frequency Heating (Microwave, Pulsed Electric Field, Ohmic)

Heating food via radio waves (e.g., microwaves and pulsed energy) causing rapid molecular vibration of water or via electrical resistance (ohmic) to achieve pasteurization or sterilization

Meat, potatoes, grains, and vegetables

Yes

Food safety; shelf-life; causes less structural changes compared to other thermal processes

Potential loss of heat-sensitive vitamin(s); modifies food structure

Infrared Heating

Heating the surface of the food by absorption of infrared radio waves followed by heat conduction to achieve a desired internal temperature in the food

Meat, potatoes, grains, and vegetables

No

Food safety; used in food service to maintain the required temperature of cooked foods

Slow heating process makes it inefficient for high throughput production systems; leads to more moisture loss compared to other thermal processes and modifies texture

Canning & Pressure Cooking

Cooking food in a can or jar over 250 F for a set time period to potentially destroy microorganisms, including spores (e.g., Clostridium botulinum), to achieve food sterility

Meat, vegetables, potatoes, jams, jellies, and some dairy products

Yes

Food safety; shelf-life

Substantial loss of heat-sensitive vitamin(s). Container seal integrity is a critical factor in canning process to ensure correct treatment and that the package remains commercially sterile post processing

Extrusion Cooking

Blended food mixture is heated to a specific temperature and simultaneously driven by the extrusion screw towards the head of the press and forced through a die to potentially destroy microorganisms

Grain based pastas, ready-to-eat cereals, and proteins derived from plant sources

No

Food safety; makes the food convenient to use, for example pasta can be easily rehydrated and cooked

Potential loss of heat-sensitive vitamin(s); changes texture

Pressure Assisted Thermal Sterilization

Combining high pressure processing with heat to achieve sterilization temperature

RTE meals, vegetables, fruits, meats

No

Food safety; less nutrient, flavor, texture, and color loss than traditional pressure cooking

Limited scaling and availability; high cost associated with equipment and packaging