ALBUQUERQUE, N.M. — Working in nutrition, I must say that I am in favor of food processing. I can see that preservation of foods offers us a safe, year-round supply of nutritious choices.
When working with clients to achieve their nutrition needs, however, I have found that people have differing viewpoints in their acceptance of food processing. In part, I have learned that clients vary in their working definitions of the term “processed.”
According to the 2010 USDA Dietary Guidelines Committee, a processed food is “any food other than a raw agricultural commodity …” Processed foods include any that have undergone one or more mechanical or chemical operations to change or preserve them. Just think of the wide spectrum of alterations that could be done to a given food product!
The nonprofit International Food Information Council (IFIC) has developed a set of definitions for processed foods, outlining a continuum of operations. The categories and some examples are:
Minimally processed foods: Washed, packaged fruits and vegetables
Foods processed for preservation: Canned, frozen fruits and vegetables
Mixtures of combined ingredients: Foods that combine ingredients and preservatives to improve safety and taste and/or add visual appeal, such as cake mixes or salad dressings
Ready-to-eat foods: Foods that need minimal or no preparation, such as breakfast cereals, peanut butter or jarred tomato sauce
Convenience foods: Foods packaged to stay fresh and save time, such as frozen pizzas or prepared deli items
I generally recommend people work toward including as many minimally processed foods as possible based on their circumstances. However, all processed foods have some benefits:
Food processing keeps our food safe to eat: Methods such as cleaning, washing, pasteurizing, irradiating, heating and boiling remove dirt and kill microorganisms. We count on food manufacturers to utilize processing techniques to keep our food safe. Foods that are not sanitarily processed can, and have, made us sick. Food recalls in recent years of cantaloupes and spinach are good examples.
Food processing stops food from spoiling: Canning, drying, freezing and salt-curing are examples of processing methods that are used. In canning, heat deactivates plant enzymes and kills harmful microbes. Drying works to remove water needed for microbes to survive.
Salting the surface of foods while drying, keeps microbes and molds from growing on the surface. The vinegar in pickles raises the acidity and inhibits the growth of microbes. Blanching vegetables in boiling water and chilling to below the freezing point prevents spoilage by reducing the enzymatic activity of the plant cells for many months.
This kind of processing can result in some nutrient losses. But, current research reports that steaming is one of the best ways to process vegetables in order to retain more of the water-soluble vitamins, such as vitamin C and the B vitamins, along with cancer-fighting phytochemicals, such as myrosinase. To steam a food, place it in a steamer basket above, not sitting in, a pan of boiling water. Seasoning the cooking water or sprinkling the foods with herbs and spices can add flavor.
Food processing makes foods more affordable and convenient: Even in the middle of winter I can still buy green beans economically, either frozen or canned, that have a similar nutrient profile to fresh green beans. The “processed” beans I buy were likely preserved the same day they were picked and close to the processing plant, contrary to the fresh green beans that have to be transported to the market. True, there is some nutrient loss in processing, but much of the vitamins have been retained.
Also, there will be less waste and preparation time with these processed vegetables. When this is factored in, canned foods, especially, are often a lower cost. This savings can be as much as 20 percent, according to a recent report.
If you are concerned about the salt in canned vegetables, choose a no-added-salt product, or drain and rinse salted vegetables to reduce the sodium by up to 41 percent.
Food processing makes certain food components more absorbable: Important chemicals can be bound up in plant foods by structural parts, such as the cell walls. When bound, nutrients or other beneficial chemicals cannot be absorbed into the body. A good example is the carotenoid lycopene believed to be protective against certain cancers. Lycopene is a phytochemical found in many red or orange fruits and vegetables, such as tomatoes or carrots.
By exposing these foods to heat the bioavailability of lycopene is improved. Crushing the tomatoes further breaks the fruit down, making processed tomato products some of the best sources of lycopene.
Food processing brings us together and nourishes the entire body: As long as we were hunter-gatherers, it was everyone for himself.
In today’s culture, food is eaten in communities and food processing has helped us achieve this. Gathering to grill foods on the barbecue, simmer stews on the stove, break bread at the table, or chop and toss salad ingredients keeps us connected. Many studies show that meals eaten together feed more than just our physical bodies.
It would be extremely difficult to consume a diet that only included “raw agricultural commodities.” On the other hand, a diet consisting of only convenience foods would likely be deficient in important nutrients. In your food choices, consider how food processing can help you achieve the most healthful diet, given your options.
Sara Perovich is a registered dietitian nutritionist working as a clinical dietitian and nutrition educator in the Albuquerque area. She is a member of the New Mexico Academy of Nutrition and Dietetics.