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Food doesn’t last. In days, sometimes hours, bread goes moldy, apple slices turn brown, and bacteria multiply in mayonnaise. But we can find all these foods on a shelf of a grocery store, hopefully unspoiled. Thanks to preservatives.

But what are preservatives?  How do they keep food edible? Are they safe?

Preservatives are substances that are added to food, cosmetics, or medicines to prevent them from spoiling.  They can be natural or synthetic. In food, they are also used as a gelling agent, a thickener, a shortener, or an emulsifier, a sweetener… the list is endless.

Looking at food, there are two major factors that make food bad. Microbes and Oxidation.

Food provides ample conditions for microbes (bacteria, fungus) to grow that feed off its nutrients. Some of them may even cause discomfort and diseases, such as food poisoning, listeria, botulism, etc, while some may turn food into moldy, slimy, and smelly mess.

Oxidation, whereas is a chemical change that happens in the food molecules caused by enzymes or free radicals which turns fat rancid and brown produce like potatoes and apples.

Preservatives can prevent both types of deterioration, although they make food quality a little compromised.

Before artificial refrigeration, microbes could run rampant in food and make it bad. People then found out different ways to make the food environment inhospitable to microbes. For example, making food acidic, as acid unravels the enzyme that microbes need to survive Sometimes. bacteria can actually help. In olden times; people used bacteria to save food that produces lactic acid.  Lactic acid preserves perishable vegetables and milk for a longer time; like that in curd, yogurt, or cheese. These cultured foods also colonize your gut with beneficial bacteria. Some chemical preservatives are also acids, like benzoic acid in salad dressing, sorbic acid in cheese, and propionic acid in baked goods.

Are they safe?

Sustained and excessive amounts of preservative consumption can weaken heart tissue.

Some studies suggest that benzoates, related to benzoic acid cause hyperactive behavior and asthma. But the results aren’t conclusive. Otherwise, these acids seem to be perfectly safe.

Another antimicrobial strategy is to add a lot of sugar, like in jams and syrups or salt, like in salted meats. Sugar and salt bind to food moisture, which is otherwise free and required by microbes to survive and multiply. They also suck out water from any microbial cell that may have been present already. Of course, too much sugar or salt may increase the risk of heart disease, diabetes, and high blood pressure. So these preservatives are best in moderation.

Antimicrobial nitrates and nitrites, often found in cured meat, ward off bacteria that cause botulism, but may cause other health problems. Some studies have linked cured meats to cancer, which have suggested that these preservatives may be the culprit.

Antioxidant preservatives prevent chemical change that can give food an off-flavor or color. Like smoke has got some antioxidant vapors that preserve food. To avoid smoky flavor in food, salt is used with other compounds such as BHT (Butylated hydroxytoluene) and Vitamin E (Tocopherol), which sop up free radicals as they are antioxidant in nature and stave off rancid flavors that can develop in foods like oil, cheese, and cereals. Other antioxidants, such as citric acid and ascorbic acid help cut food retain their color, by thwarting the enzyme that causes browning.

Some compounds like sulfites can multitask. They are both antimicrobials and antioxidants. Sulfites may cause allergy symptoms in some people. People suffering from asthma may have serious difficulty in breathing, tightness in the chest, etc. But most antioxidant preservatives are generally considered safe.

So, should you be worried? How are additives and food preservatives approved for use in foods?

Today, food and color additives, including preservatives, are more strictly studied, regulated, and monitored than at any other time in history, and the FDA has the primary legal responsibility for determining their safe use. To add a new food preservative to the market, or before using a substance already approved for one use in another application, the manufacturer or other sponsor must obtain approval from the U.S. Food and Drug Administration (FDA) and provide scientific data demonstrating that the substance is safe for its intended use.

Preservatives are used in fewer amounts as recommended by the FDA to be considered safe. Also, many companies are already finding alternatives such as packaging tricks, like reducing the oxygen around the food can help. But without any chemical assistance, there are very few foods that have stable shelf-life for long.

However, the use of food preservatives varies greatly depending on the country. Many developing countries that do not have strong governments to regulate food additives face either harmful levels of preservatives in foods or complete avoidance of foods that are considered unnatural or foreign. These countries have also proven useful in case studies surrounding chemical preservatives, as they have been only recently introduced. In urban slums of highly populated countries, the knowledge about the contents of food tends to be extremely low, despite the consumption of these imported foods.

As it is all about quantity consumed, it’s important to look at your dietary quality. It’s about striking a balance between the consumption of fresh produce and processed products. You can have your apple as well as apple cake.


M. Sc. Gold Medalist

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