Food Processing Methods to Preserve, Protect and Nourish


Food processing is a series of steps used to transform fresh, raw products into food. There are multiple steps involved in this transformation, depending on the material and the desired final product. Once the food is in edible form, it may end up at the market or move into commercial production of pre-prepared convenience products, commonly referred to as processed foods. There are also multiple processing and preservation techniques designed to eliminate diseases, slow spoilage, and maintain nutritional value. Food processing may also include the addition of elements to extend shelf-life and increase nutritional value. The following examples are just a few of the processing methods in use today.


In 1864, Louis Pasteur developed the pasteurization process to lengthen the shelf-life of wine. The process was later used with dairy products to remove harmful organisms that had been causing illnesses in children. The milk pasteurization process includes heating the liquid to a specific temperature below boiling, holding it there for a specified amount of time and then cooling it. The heating process may take place inside large vats or by flowing the liquid through a series of heated plates. The cooled milk is then either distributed to the bottling station or transferred for use in other products, such as cheese and yogurt.


The canning process also involves heating the product, but then placing it in cans or jars while it is still hot. As the product cools, the container becomes vacuum sealed. This process kills microorganisms that cause food to spoil, and therefore extends the product’s shelf-life. Green beans, for example, go through a variety of processing steps before being placed in cans or jars. The raw beans are cleaned and trimmed, then make their way along vibratory conveyors or other conveying machines until they reach the canning station. These products will survive on pantry shelves for five years or more.


Freezing is another standard food processing method in use today. With fruits and vegetables, the time between harvest and freezer is brief, so maximum taste and nutrition are maintained. Blueberries, for example, are picked, cleaned using a winnowing machine to remove debris and irregular berries, then individually flash-frozen and packaged. This entire process generally takes only twenty-four hours. One could argue that the frozen berries may even be healthier than fresh ones in the grocery store that may have been sitting on the shelf for a week.

Grain Processing

From the field to the grocery store, grain processing involves many more steps than produce does. Grains, including wheat, oats, corn, rice and others, fall into two groups, which are whole grains and refined grains. Whole grains contain three edible parts, the bran, germ and endosperm. Refined grains are missing one or more of these elements as a result of the milling process. Besides smoothing its texture, milling the bran and germ away from the whole grain prevents it from spoiling, so it can be stored much longer. However, much of the protein and nutrients get lost in the refining process.


In addition to alcoholic beverages, many other food products use fermentation in their processing. Yogurt, apple cider vinegar and bread are just a few examples. This process involves using yeast and beneficial bacteria to convert carbohydrates into alcohol or organic acids. The resulting products are high in probiotics and have other health benefits as well, such as improved digestion and a more robust immune system, and even promote weight loss.

Between farm and table, foods go through a variety of processes before they become ingredients for cooking. Some are relatively simple, while others, like grain processing, can be more complex. There are also a variety of methods used to preserve the finished products, ensure their safety, and maintain or fortify their nutritional value. Before shipping them to the grocery store, some foods get cooked and frozen, so they are ready just to heat and serve.


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