Preservatives are added to food to prevent food spoilage caused by bacteria, moulds, fungus, and yeast. Preservatives can keep food fresher for longer periods of time, extending its shelf life.
Food preservatives also are used to slow or prevent changes in colour, flavour or texture and delay rancidity. They are also often used in used in convenience and snack foods.
Preservatives can be made of “natural” chemicals such as salt or alcohol. They can also be man-made, or synthetic chemicals. “Natural” or “organic” chemicals are not necessarily healthier than synthetic or man-made chemicals.
Artificial preservatives such as sodium nitrate, sodium benzoate and propionate have been used in food preparation for a long time because they are effective in small amounts.
Today, food and colour additives, including preservatives, are more strictly studied, regulated and monitored for side effects.
Regardless of whether one likes it or not, without added preservatives and food preservation processes, many of the foods we love today would never make it to the dinner table. Here are some of the more popular foods that rely on preservatives to keep them safe:
Most wines contain sulfite. It occurs naturally in certain wines during fermentation and is also sometimes added during the fermentation process to prevent acidification (and preserve flavour), enhance colour, and remove fermentation by-products such as acetaldehyde. Potassium sulphate is also used in wine. Sulfites are also found in some ciders, dried fruits, and dried potatoes.
Even organic peanut butter brands contain a touch of natural preservatives, like sugar or salt.
Curing red meats also includes adding sodium nitrate and potassium nitrite to the meat to preserve its colour, prevent fats from becoming rancid, and killing harmful bacteria. These ingredients keep you safe from illnesses—such as botulism poisoning. Sodium diacetate is also used to preserve meats, fish and poultry.
Fruits such as apples, pears, peaches and apricots are prone to go brown rather quickly once oxygen breaches the skin due to a reaction that occurs between oxygen and enzymes present in the flesh of the fruit. Antioxidants are often added to store bought pre-sliced fruits to remove oxygen and prevent browning. These and other fruits may be treated with ascorbic acid, otherwise known as Vitamin C, which has natural antioxidant characteristics. Citric acid is also used to preserve and enhance the flavour of canned fruits and vegetables.
BERRIES AND JAMS
Benzoic acid, often in the form of sodium benzoate in food. It is an antifungal and is used to prevent mould, yeast, and bacteria in some jams, jellies, and condiments. Benzoic acid in food is perfectly safe to eat and occurs naturally in many types of berries (especially cranberries), mushrooms, cinnamon, and cloves. Many manufacturers also use potassium sorbate / sorbic acid in the preparation of jams, jellies, concentrates, preserves, relishes, pastes, pulps, salad dressing, spreads, and cheese spreads.
Fried noodles are kept fresh thanks to alpha-tocopherol, the active form of natural vitamin E. Many types of noodles also use a synthetic antioxidant, tertiary butylhydroquinone (TBHQ), to preserve freshness. TBHQ is a common food additive used to protect the longevity of food products and help maintain taste, colour and smell.
STORE-BOUGHT BAKED GOODS
TBHQ, as well as other synthetic antioxidants, may be used in packaged cookies, cakes, and crackers. It helps prevent the breakdown of fats and oils preventing “off” tastes and odours. Sodium diacetate and sodium metabisulphate is also used in breads and other prepared foods.
Butylated hydroxytoluene, or BHT, is a synthetic preservative designed to protect the flavour of packaged foods. It helps preserve product freshness for the duration of its shelf life.
CHEESE AND OTHER SAUCES
Sodium citrate is the natural salt of citric acid is widely used as a melting salt for smooth cheese sauces.
For more information on preservatives used in the food industry contact Chemgrit Food.
[Sources: www.chemicalsafetyfacts.org; www.mentalfloss.com]