The Role of Steam in the Food Processing Industry

Steam plays a pivotal role in the food processing industry, combining efficiency with versatility to meet the demands of modern food production. Its applications span cooking, sterilization, pasteurization, and dehydration, ensuring that food products are safe, nutritious, and of high quality.

One of the most significant uses of steam is in cooking. Steam cooking offers even heat distribution, which helps retain the texture, flavor, and nutritional value of food. Unlike frying or baking, which can degrade nutrients, steaming is particularly beneficial for preparing vegetables, seafood, and grains, providing a healthier alternative. Advances in steam cooking technology, such as pressurized steam systems, have further improved cooking efficiency and consistency in industrial settings.

Steam is equally essential in sterilization and pasteurization processes, both critical for food safety. Sterilization involves using high-temperature steam to eliminate harmful microorganisms from food, equipment, and packaging materials. This ensures a safe production environment and extends the shelf life of food products. For pasteurization, steam heats food to precise temperatures for controlled periods to destroy pathogens while preserving sensory and nutritional properties. This technique is widely used for dairy products, beverages, and ready-to-eat meals, meeting regulatory standards and consumer expectations.

In dehydration, steam plays a supporting role in removing moisture from food to prevent spoilage and reduce bulk for storage and transportation. Techniques like steam-assisted freeze-drying are employed for high-value foods, such as fruits and spices, to maintain flavor and color while achieving extended shelf life.

The food industry is also leveraging innovations in steam technology to reduce energy consumption and enhance sustainability. For example, steam recycling systems recover and reuse waste steam, cutting operational costs and lowering environmental impact. These advancements align with global efforts to promote eco-friendly manufacturing practices.

In conclusion, steam's unparalleled efficiency and adaptability make it indispensable in the food processing industry. From preserving nutritional integrity to ensuring safety and sustainability, steam is a cornerstone of modern food production, meeting the growing demand for high-quality and safe food products worldwide.
The Role of Steam in the Food Processing Industry

Animal fat processing: steam rendering

Nearly all animal fats, tallow or beef fat and lard, are obtained bv rendering. The two predominant rendering processes are wet and dry rendering. Wet rendering produces the better quality oil while dry rendering produces the best quality protein.

Most of the edible animal fat produced in the United States is rendered by the steam process. In the steam rendering of high fat stock, 99.5% or more of the fat in the raw material is ordinary recovered.

The apparatus used is a vertical cylindrical steel autoclave or digester with a cone bottom, designed for a steam pressure of 40 to 60 pounds per square inch and a correspondingly high temperature. The comminuted fatty tissues are first heated to 50 °C – 60 °C and then quickly to 80 °C - 90 °C with direct steam.

Animal fat

The vessel is filled with the fatty material plus a small amount of water and steam is admitted to boil the water and displace the air.

The vessel is then closed except for a small vent, and the injection of steam is continued until the operating temperature and pressure are attained; then digestion is continued for a variable time depending upon the temperature and also the nature of the charge.

The usual digestion time is 4 to 6 hours. The process dissolves the tissue releasing the fat from proteinaceous material. The liquid fat floats on the top water, which can be separated thereby producing edible fat products where color, flavor and keeping quality are of great importance.
Animal fat processing: steam rendering  

Beets Processing

Beets Processing
Beets require 50 – 70 days from planting to harvesting. They are harvesting by machine and brought to the processing plant in hoppers or trucks. Generally they are not cooled prior to processing. Beets are canned but are not frozen. At the canning plant, the tops are cut off by machine, after which the roots are held for several days to allow the skin to wilt, thereby loosening it.

The beets are then graded for size by machine. After sizing, the beets are washed with sprays of water or in a soaking tank, and are then peeled. Beets are peeled by steaming at 220 degree F for about 20 min. after which the skin is removed. The peeled beets are then trimmed. Small beets are canned whole while the larger beets are sliced prior to filling into cans. The cans, to which beets have added to a point about 3/8 in. from the tops, are then filled with a weak salt solution. The cans are then sealed and heat processed.

Beets sold in the fresh state are washed, but usually not topped. They should be cooled to 32 – 35 degree F and held in this manner until sold to the consumer. In this edition, they have storage life of 10 – 14 days. When topped and cooled to 32 degree F they may be held for 3 – 5 months.
Beets Processing