When you put something fresh in a cupboard and leave it for a month, what happens? You expect it to go off, look mouldy, maybe smell quite strongly – in a bad way! So when a McDonald’s hamburger was stored for years, why didn’t it go off?
So let’s look at why food goes off. Each food is a unique ecosystem, which favours the growth of specific microbes. So different foods spoil in different ways depending on what they are made of.
So with meat and meat products, bacteria from the gut and skin of animals contaminate these meat products when the animal is slaughtered and processed.
Raw meat that’s put in the fridge is attacked by cold-loving phychrophilic bacteria. Once they’ve eaten the sugars in the meat, they go for the protein, making a slimy mess and a very strong odour.
Cured and fermented meats are dry and are often preserved with a lot of salt. They can get broken down by yeasts, which produce strange, nasty smells and slime, and salt or acid tolerant bacteria, which make the meat taste sour.
Fish and seafood go off very fast even if they’re stored on ice. There are no sugars in the flesh, so bacteria from the gut and gills get started breaking down the proteins in the fish flesh and produce a mix of chemicals that give off a unique smell. Shellfish should be kept alive as long as possible before they’re cooked and eaten to make sure you don’t get sick.
Cheese is a solidified mixture of milk protein and fats. Yeasts and moulds attack it, usually. Milk contains many different types of bacteria and goes sour quickly whether in the fridge or not! Yes, it does contain beneficial bacteria, so the key is to buy frozen or very fresh raw milk and drink it immediately where possible!
Yogurt is made using bacteria. They ferment the sugars in milk and make the yogurt acid. Yeasts and moulds can make it spoil, but when it’s fresh it’s great for your digestion.
So when a newspaper editor saved a hamburger and pie in his desk for some years, and the burger hadn’t even decayed, he was surprised to find that it had shrunked and was dry, but was otherwise fine. When Marshall V. King, the managing editor of an American newspaper performed this experiment. He says:
“The patty shrank. The bun dried. But neither got moldy. Five years later, it looks about the same as it did a few weeks after I bought it: like an air hockey puck with a dried out bun. With a faint smell of beef.”
Experts have joked that if a burger like this doesn’t go off, it must have special qualities – special bacteria and microorganism-fighting powers. And if it can defy all logical laws, what is it doing to your body? Will it preserve you too?
Preservatives are chemicals that inhibit the growth of different types of yeasts, moulds and bacteria. They work to keep food safe and palatable, but they mostly benefit the companies that use them, not the consumer. What do health experts tell us? Eat fresh fruit and vegetables. Natural foods. Avoid foods that are packaged and processed. These goods contain enzymes that keep us young and health, vitamins that are killed when commercial sterilization and other methods are used on them.
However, maybe they’re not all bad. Let’s look at antioxidants. They slow down the oxidation of fats and lipids that lead to rancidity when the products are exposed to air. Unsaturated fatty acids in oils and lipids are especially susceptible to oxidation and start to turn more quickly.
The rest, though, are well worth avoiding. We actually don’t know to what extent they are hurting us. This is why it’s a good idea to stick to clean, honest, fresh food. The good news is that food scientists are busily searching for more preservatives they can extract from natural products. This means that processed food might start getting a little healthier soon.