Food processing
Food processing is the transformation of agricultural products into food, or of one form of food into other forms. Food processing takes many forms, from grinding grain into raw flour, home cooking, and complex industrial methods used in the making of convenience foods. Some food processing methods play important roles in reducing food waste and improving food preservation, thus reducing the total environmental impact of agriculture and improving food security.
Not to be confused with Food processor.
The Nova classification groups food according to different food processing techniques.
Primary food processing is necessary to make most foods edible while secondary food processing turns ingredients into familiar foods, such as bread. Tertiary food processing results in ultra-processed foods and has been widely criticized for promoting overnutrition and obesity, containing too much sugar and salt, too little fiber, and otherwise being unhealthful in respect to dietary needs of humans and farm animals.
Added sodium[edit]
One of the main sources for sodium in the diet is processed foods. Sodium, mostly in the form of sodium chloride, i.e. salt, is added to prevent spoilage, add flavor and enhance the texture of these foods. Americans consume an average of 3436 milligrams of sodium per day, which is higher than the recommended limit of 2300 milligrams per day for healthy people, and more than twice the limit of 1500 milligrams per day for those at increased risk for heart disease.
Added sugars[edit]
While it is not necessary to limit the sugars found naturally in whole, unprocessed foods like fresh fruit, eating too much added sugar found in many processed foods increases the risk of heart disease, obesity, cavities and Type 2 diabetes. The American Heart Association recommends women limit added sugars to no more than 420 kilojoules (100 kilocalories), or 25 grams, and men limit added sugars to no more than 650 kJ (155 kcal), or about 38.75 grams, per day. Currently, Americans consume an average of 1,490 kJ (355 kcal) from added sugars each day.
Nutrient losses[edit]
Processing foods often involves nutrient losses, which can make it harder to meet the body's needs if these nutrients are not added back through fortification or enrichment. For example, using high heat during processing can cause vitamin C losses. Another example is refined grains, which have less fiber, vitamins and minerals than whole grains. Eating refined grains, such as those found in many processed foods, instead of whole grains may increase the risk for high cholesterol, diabetes and obesity, according to a study published in "The American Journal of Clinical Nutrition" in December 2007.
Trans fats[edit]
Foods that have undergone processing, including some commercial baked goods, desserts, margarine, frozen pizza, microwave popcorn and coffee creamers, sometimes contain trans fats. This is the most unhealthy type of fat, and may increase risk for high cholesterol, heart disease and stroke. The 2010 Dietary Guidelines for Americans recommends keeping trans fat intake as low as possible.
Other potential disadvantages[edit]
Processed foods may actually take less energy to digest than whole foods, according to a study published in "Food & Nutrition Research" in 2010, meaning more of their food energy content is retained within the body. Processed foods also tend to be more allergenic than whole foods, according to a June 2004 "Current Opinion in Allergy and Clinical Immunology" article. Although the preservatives and other food additives used in many processed foods are generally recognized as safe, a few may cause problems for some individuals, including sulfites, artificial sweeteners, artificial colors and flavors, sodium nitrate, BHA and BHT, olestra, caffeine and monosodium glutamate — a flavor enhancer.[14]
When designing processes for the food industry the following performance parameters may be taken into account:
