Food Preservation Techniques

Human beings have always found out ways to preserve food, right from their existence. In ancient times, the need was limited. It was easy for our ancestors to store food by drying it under the sun. But today, due to fast paced modern life, due to globalization and easy transport facilities, shelf life of various types of food is increased by employing various techniques. Introduction of new technology and discovery of new preservatives have completely changed the concept of marketing and food safety.

Ancient Methods of Food Preservation

Growth of bacteria, fungi and other micro-organisms can make food poisonous. Similarly, oxidation of fats results in rancidity. To maintain the nutritional value or edibility of food, our ancestors used to dry the food under the sun. Dehydration of food helps inhibit growth of microbes. Similarly salting or curing also helped to store food, especially, fish and meat. People knew that keeping the food deep into the earth helps maintain the food quality. In India, people used to preserve turmeric like this. In colder countries, people used to preserve food by keeping it under the ice. Methods of sugaring and pickling for food preservation were introduced in the 18th century. Cooking fruits in sugar syrup was the easiest way of storing fruits. Vinegar and certain oils were used for pickling. These methods helped enhance the aroma and flavor of the food. Olive oil, salt, sugar, vinegar and rosemary extract are some of the commonly used food preservatives. Such natural food preservatives are safe and good for making jams and pickles. Alcohol is also used for pickling.

Drying, freezing, smoking, salting and fermenting were some of the common ancient Japanese methods of food preservation. Fermentation techniques involve production of preservation agent by the food itself. Fermented food produces acid which does not allow microorganisms to grow. Canning the meat in hot fat also helps preserve meat. Adding lye (sodium hydroxide), jellying, potting, jugging were some other food preservation methods followed by our ancestors.

Modern Methods of Food Preservation

Everyone knows that high heat processing or pasteurization of milk helps destroy microorganisms. Thermization helps sterilize raw milk. Airtight preservation was introduced by Nicolas Appert and is known as appertization. This method is used to preserve soups, vegetables, juices, dairy products, jellies, jams and syrups. Requirement of preservatives, other acidic elements and boiling time, mainly depend upon how acidic the food is. Canning and bottling help retain the original taste and flavor of the food and hence are commonly followed methods of food preservation. Once you open the can or bottle, you should consume the entire quantity, otherwise the leftover food is likely to get spoiled. Quality control plays an important role in canning. These days, people enjoy eating pickled vegetables, peppers, beef cured in brine, pickled herrings and eggs. But you have to keep it in mind that water-soluble nutrients from the food can get lost into the liquid in can and dangers of unhealthy packaged foods also cannot be overlooked.

Vacuum packing has proved to be beneficial for sales and marketing. This technique is used to preserve potato chips, cereals, nuts, etc. Other modern methods of food preservation include preserving food with the help of ultra high water pressure (cold pasteurization), exposing the food to ionizing radiation, pulsed electric field (PEF) processing, etc. Carbon dioxide is used to store food in case of modified atmosphere packaging. Sodium hydroxide is used to make food too alkaline. This way, growth of microorganisms is controlled.

While thinking about 'how to preserve food against bacteria', you have to take into consideration safety of your health first. Studies show that some preservatives in food can prove to be harmful to health. They can affect the function of your brain or can trigger allergies like skin rashes and asthma. They can even destroy the nutritional value of the food. High salt and sugar content can affect your health seriously. Some food preservation techniques and some preservatives are believed to cause cancer. You should keep the list of 'preservatives in food to avoid' handy and you should always check the labels before buying processed or canned foods.