Food preservation is known “as the science which deals with the process of prevention of decay or spoilage of food thus allowing it to be stored in a fit condition for future use”.
Preservation ensures that the quality, edibility and the nutritive value of the food remains intact. Preservation involves preventing the growth of bacteria, fungi and other microorganisms as well as retarding oxidation of fats to reduce rancidity.
The process also ensures that there is no discolouration or aging. Preservation also involves sealing to prevent re-entry of microbes.
You can preserve foods inexpensively by using canning, freezing, or drying techniques. Modern-day food preservation methods, such as water-bath canning, help you can and preserve with ease. After you understand the basic procedures for a food preservation method, you’ll just need to concentrate on preparing your recipe.
Here are different ways to preserve food that can help stabilize our food supply:
1. Chilling and/or Freezing
Yeast and bacteria have favorite temperatures for them to start multiplying. It is typically between 40 and 140 F, so by lowering the temperature (below 40F), their actions are stalled. Note though that chilling food will not kill bacteria or yeast, but spoilage process is definitely slower.
This is a very popular method of preserving food in which oxygen is removed, so that microorganisms stop multiplying. Canning is typically with another factor to stop microbial growth, such as salt or acid.
3. Salting and Pickling:
Salting also known as curing removes moisture from foods like meat.
Pickling means preserving food in brine (salt solution) or marinating in vinegar (acetic acid) and in Asia, oil is used to preserve foods. Salt kills and inhibits growth of microorganisms at 20% of concentration. There are various methods of pickling like chemical pickling and fermentation pickling. In commercial pickles sodium benzoate or EDTA is added to increase shelf life.
An ancient method, fermenting is quite popular even today mainly because it brings unique flavor to the food. In truth, fermentation is actually a form of spoilage, but the microorganisms are strictly controlled. This therefore results to desirable effects and even provides safety against harmful organisms. Yeast or bacteria in the fermentation process generate a byproduct in the form of acid to prevent other harmful bacteria from growing. Sauerkraut and kimchi are great examples of fermentation used to preserve cabbage.
Many microorganisms need moisture, so dehydrating food is an effective way to stop spoilage. The key here is to finish the process fast, while evaporation is quickened using moderate heat or even natural sunlight. Modern dehydration methods utilize heated circulating air for fast dehydration without the need to “cook” food. This preservation technique is often used in dried fruit, herbs, and meat jerky.
An electric dehydrator is the best and most efficient unit for drying, or dehydrating, food.
Today’s units include a thermostat and fan to help regulate temperatures much better. You can also dry food in your oven or by using the heat of the sun, but the process will take longer and produce inferior results to food dried in a dehydrator.