What happens if you leave a piece of bread out in the open? Or bananas untouched on your table? Or forget to put your milk in the fridge?
They all spoil of course, turning mouldy and rotten and rancid. Yet, grocery stores seem to be full of these food items and they are mostly in a pristine state of freshness.
What’s keeping them safe to consume?
Preservatives have changed the landscape of food storage, as they allow food to last longer than their natural lifespan.
But how do preservatives work? And are they hazardous to your health? First things first, you must understand why food goes bad at all.
Food rots because of microorganisms and oxidation. If left to their own devices, fungi and bacteria, some of which are dangerous, will feast on your food, leaving behind a foul and mouldy mess.
Oxidation occurs when the chemicals in your food are exposed to oxygen and begin to change in terms of composition. This chemical change affects the taste and colour of food, and renders it inedible.
Through the use of preservatives, both these processes can be delayed or averted altogether. Refrigerators and the low temperatures slow the activity of bacteria.
Pickling a food item makes it more acidic, which tends to kill microorganisms. And for centuries, people have used this very method to prevent food from spoiling due to the action of microorganisms.
Examples of this can be found in German sauerkraut, Korean kimchi and Middle Eastern yoghurt.
In addition to being quite tasty, they are healthy too as they introduce good bacteria into your digestive system.
Modern science has also introduced manufactured preservatives into food production. Look at the ingredients label of your food products.
You will find benzoic acid in salad dressing, sorbic acid in cheese and propionic acid in pastry. But with all these big names, one must ask if these acids are safe for human consumption.
The answer, like most things in life, is complicated.
Some studies suggest that benzoates, found in benzoic acid, may contribute to hyperactivity. However, for the most part, it seems these acids are perfectly edible.
Another common way to preserve food is to through the addition of sugar or salt.
Sugar and salt help to dry out food, preventing bacteria from thriving in a moist environment.
Common sense dictates that eating too much salt or sugar is bad for health, hence the need to avoid eating these types of preserved foods too often.
Cured meats are meats that are smoked, canned, salted or dried to lengthen their shelf life.
Often, they are treated with nitrates and nitrites, which have antimicrobial properties, but they have their own issues as well. However, some scientists suggest that these preservatives may be carcinogenic.
Antioxidants also help in keeping food edible, as can be seen through the process of smoking.
Smoking works by infusing food with antioxidants from wood smoke. Often, these smoked foods are then salted to preserve them even further.
BHT and tocopherol, also known as vitamin E, are antioxidants used to preserve foods like cheese and cereal without giving it a smoky flavour.
Antioxidants like citric acid and ascorbic acid are used to keep food looking good, preventing them from turning brown.
So, ultimately, are preservatives worth avoiding?
They are actually used in very small amounts, and there are indeed safety standards in place to prevent excessive usage.
Alternatives are being sought by both companies and consumers, and vacuum-packing seems promising enough.
It should be noted that without the use of chemicals, a lot of food will not be able to last long on shelves and in pantries.