Methods of food preservation

10. Modern methods of food preservation

Irradiation

During this process foods are exposed to β-particles or γ-rays radiation to kill bacteria, molds, pests, and others. Although WHO and FAOn approved this process it must be noted, that the regulations for food irradiation vary greatly from country to country. In many countries of the European Union only dried herbs, spices, and seasonings can be processed with irradiation.

Chemical preservatives

Antimicrobial chemical agents are added for the long-term preservation of foods. These chemical agents are added in small quantities, as larger amounts can be toxic. Acids and benzoates are used to preserve acidic foods, such as jams, salad dressings, juices, pickles, carbonated drinks, and soy sauce. Sorbic acids and sorbates and sulphites are used to preserve cheese, and juices. Nitrates and nitrites are used to preserve meat products. For wine and dried fruits sulfur dioxide and sulfites are used, whereas propionic acid and propionates are used for baked goods.

Pascalization

In this process, foods like juices and meats are exposed to very high pressure ( ~5000kg/cm²) to destroy microbes. This process helps to retain the food’s original flavor, texture, and nutrients.

Hurdle technology

In hurdle technology, more than one approach is used to inactive the microbes. These combined preservation approaches act as multiple hurdles for microorganisms in order to prevent spoilage. Some of the hurdle approaches are high temperature, in combination with pressure, acidity, and adding biopreservatives. The selection of hurdles depends on the food’s nature and potential pathogens.

Nonthermal plasma

In this process, the food surface is exposed to a flame of ionized gas molecules, such as nitrogen or helium to kill the microbes on the food’s surface.

Modified atmosphere

In this process, the oxygen inside an airtight and sealed packaging or storage environment is reduced to 1% or 2%, and carbon dioxide (CO₂) and/or nitrogen gas (N₂) is increased to prevent the growth of bacteria, insects, molds, and to prevent oxidation reactions.