Why are foods processed? Extending shelf life


Foods processed to extend shelf life.

Food scientists are obsessed with extending the shelf life of foods. Next to protecting the safety of foods, food scientists want to prevent fresh foods from rotting. Although some writers appear to praise fresh foods that rot, not everyone thinks that rotting is such a good idea. Throughout history rotting has claimed crops and claimed lives. In an era of calls for sustainability, slowing rotting through cooking or processing should be considered a good thing. Delayed rotting reduces food waste. Food scientists prefer to use the word spoilage as it is more encompassing than rotting, but I will use the latter term as it is considered a major distinction of fresh and processed by those who encourage us to avoid processed food. There are four types of microbes in foods: pathogens, spoilage (rotting), beneficial (includes fermenters and probiotics), and free riders (they just happen to be there, but they don’t affect the food or the humans who eat the food).

Rotting is a natural process. Nature can be cruel, but natural processes can be stopped. Food scientists seek to stop nature’s destructive activities by processing raw materials. Rotting can result from activity of microbes, enzymes, or natural chemicals on or in the food. Physical damage to the food can trigger rotting. Traditional processing preserves food through canning, freezing, drying and fermenting. Canning works by using heat to kill harmful microbes. Freezing and drying make water in the food unavailable to spoilage and pathogenic microbes. Fermenting uses beneficial microbes to produce chemicals in food that prevent growth of objectionable microbes. Such preservation processes can occur in a huge corporate plant, a small family-run operation, in the back of a restaurant, or at home in the kitchen. Minimal processes such as refrigeration, adding chemicals such as acids like vinegar or lime juice, and vacuum sealing merely slow rotting. Such operations do not stop the rotting process.

Preserving foods is one of the most environmentally responsible acts each one of us can do to prevent food waste. The most widely used food process in the home is cooking. Heating is an excellent method of developing flavors in addition to killing the pathogens and rotting microbes. We also depend on the refrigerator and freezer to slow or prevent growth of those organisms we don’t want messing up our food. Home preservers of foods also include the diligent ones who use fermentation to produce their own beer, bread, cheese, kimchi, sauerkraut, wine or other cultured products. Restaurant chefs have become adept at adapting processing techniques to produce interesting color, flavor and texture sensations in their dishes. Molecular gastronomy is the field most effective at blending food science with culinary expertise.

Processing and extended shelf life provide convenience. Most of us are on the run with busy lives. Home cooking remains the gold standard, but preparing a fully cooked meal more than two or three evenings a week is difficult for anyone but a stay-at-home cook. Since I retired, I have enjoyed preparing home-cooked meals two-to-three times a week, but I rely on restaurant meals for at least two meals a week, processed cereals for most of my breakfasts and leftovers for the rest. At the food pantry, I observe that most of the food we provide is processed as it needs to last for two weeks when the clients can visit us again. Two very interesting books that provide a window for the middle class to view the life of the working poor are Nickel and Dimed and The American Way of Eating. It appears that the modern version of Rachel Laudan’s humble cuisine consists of fast food and packaged snacks, particularly when a working person is without access to a refrigerator or stove.

There are many other benefits of foods with extended shelf life. Prepared formula and other types of infant foods are important for babes in arms, particularly if the mother can’t nurse her child or is severely malnourished. Distribution of nutrient dense meals and bottled water are critical for relief of victims of natural disasters as well as for military personnel in the field. Other foods are formulated to meet specific nutritional needs. The more we learn about rare genetic diseases, the better we can tailor diets that allow people with these diseases to live meaningful lives. For example, phenylketonurics need to avoid more than diet drinks containing NutraSweet. They are generally placed on a protein-restricted diet for life to avoid meats, cheese, eggs, nuts, soybeans and even potatoes. On a gluten-restricted diet processed items are difficult to design meet specifications and taste good too.

Many processed foods, particularly formulated foods, pose a danger to the general population in terms of obesity and chronic diseases. Yes, Americans eat too many calories and too much sugar and salt, but the idea of placing all the blame on the food or the victim oversimplifies the problem. In the first chapter of In Defense of Processed Food, I make the case for the complexity of America’s and the world’s growing weight problem. All processed foods are not obesogenic. All whole foods are not healthy. Many whole foods are also processed foods. The dialogue about food in the United States around the world has been reduced to symbolism and advocacy. The main message I have been trying to convey on this blogsite and in the book is that we need to be rational about the food we choose to eat and that mindfulness about our diet and not dogma should prevail.

Next week: Why are foods processed? Protecting nutrients

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16 thoughts on “Why are foods processed? Extending shelf life

    1. Thank you for your comment! I really liked your article on the safety of processed food. I particularly liked your perspective on nuance as it relates to children. The same principle also relates to adults.

      I disagree on some other points. The Bible for human addiction, Diagnostic and Statistical Manual of Mental Disorders (DSM-5), considers video games to be addictive but not foods. That may change with the release of DSM-6 which will be published in the next few years. I think we need to be very careful to distinguish substances and activities that are considered to be clinically addictive from those that are highly appealing.

      I also believe that it is excess calories and lack of exercise that are the major cause of childhood obesity. Excess sugar leads to excess calorie consumption. My posts this month (October, 2020) contest the notion that highly or ultra processed foods are as unsafe as claimed. Highly processed foods include candy. cake and soda. They also include high-fiber, low-sugar breakfast cereals; plant-based meats and milks; and most gluten-free and lactose-free products.

      I am so glad that you commented on my blog, and I wish you the best on your blog.


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