Food is one of the most important elements needed for human survival. Unfortunately, most foods have a finite shelf life and cannot be used for long periods. Most food tends to spoil within a few days. Food preservatives offset the normal processes that cause food to age and spoil. Nowadays many manufacturers have started adding chemicals like benzoates and sorbates to increase product shelf life. These can be harmful when consumed in large quantities. Fortunately, there are many methods like refrigeration, freezing, canning, salting, pasteurizing, carbonation, fermentation, dehydration and irradiation that are safe and can be used to preserve food for longer periods.
Salt serves to be an excellent food preservative since ancient times, especially for meat and fish. These days, food preservation with salt is done with special salts that are mixtures of nitrite or sodium nitrate and cooking salt. The basic idea behind salt curing is that by dehydrating meat, or hanging the meat until the salt works into the skin and tissues, will prolong shelf life. Many commercial brands like Morton sell blends made specifically for salt-curing.
Preserve food items such as jams, murabbas, squashes and jellies with sugar. You can add sugar in pickles not only to enhance taste, but also to act as a natural preservative. The sugar gets dissolved in the water content of food, which means that less water is available to encourages the growth of micro-organisms. Thus, the food stays safe and unspoiled for longer periods of time. However, before adding sugar to food items, you should know the correct proportion to add, as too much sugar may also lead to quicker spoilage.
Vinegar is commonly used for preserving tomatoes for ketchup, and preserving onions and other vegetables. Vinegar is acidic, thus increasing the ratio of acid in foods. This prevents growth and activity of micro-organisms on the food. Other household kitchen acids that can be used as food preservatives include citric acid and lemon juice.
Prepared with distilled rosemary leaves, rosemary extract, or rosemary oleoresin, is a food preservative that is used for its distinct flavor and aroma. Due to the carnosic acid, rosmarinic acid, carnosol and phenolic diterpenes present in rosemary extract, oxidation of food is prevented too. This means flavor and color are preserved for longer.
Mustard powder is a spice that prevents growth of micro-organisms in pickles and other preserves. It has two advantages: First, it prevents contact of food with micro-organisms and second, it prevents the contact of food with air so that micro-organisms are not able to grow.