Ionizing Radiation in Food Processing

Ionizing Radiation in Food Processing

• Radioactive atoms release energy in the form of ionizing radiation, which can knock tightly bound electrons from an atom's orbit, causing it to become a charged ion.
• Ionizing radiation produces free radicals, which are highly chemically reactive and account for most of the biological damage caused by radiation.
• Gamma rays, electron beams, and x-rays are the most commonly used forms of ionizing energy in food processing.
• Gamma rays penetrate foods deeply, while electron beams can only penetrate up to three centimeters, and x-rays are suitable for thick food materials.
• Irradiation damages the DNA structure of microorganisms, which helps to reduce their population.
• Irradiation is used to reduce pathogenic microorganisms, control insects, eliminate parasites, decrease sprouting, and extend shelf life of perishable foods.
• Irradiation is known as a cold process since it only raises the temperature of the food by 1-2°C during the process.
• Irradiation is a physical process, leaving no chemical residue, and is suitable for use with packaged foods.
• Irradiation is not suitable for fat-containing foods or those high in protein, as it can cause undesirable flavor and aroma formation.
• The efficacy of irradiation is related to the dose of radiation received, which is divided into low, medium, and high dose applications.
• Irradiation has been approved for use in many countries, including the United States, where it is used to eliminate insects from wheat, potatoes, flour, spices, tea, fruits, and vegetables.
• All irradiated products must carry the international symbol called a radura, which resembles a stylized flower, and has been required since 1986.