Radiation Preservation: 36 MCQs with answers

The emission and propagation of energy through space or a material medium

Radiation is defined as the emission and propagation of energy through space or a material medium.

60Cobalt and 137Cesium

Gamma rays are emitted from the excited nucleus of radioactive elements such as 60Cobalt and 137Cesium.

Radiolysis

The three types of radiation process are radappertization, radicidation, and radurization. Radiolysis is not mentioned.

False

UV rays are non-ionizing radiations of < 450 nm wavelength. Ionizing radiations include beta rays, gamma rays, and X-rays.

True

Gamma rays are produced by the decay of radioactive isotopes and are the cheapest form of radiations for food preservation since source elements are available as by-products of atomic waste.

The emission and propagation of energy through space or a material medium

Radiation is defined as the emission and propagation of energy through space or a material medium, which is crucial for destroying microorganisms in food.

Ultraviolet rays

Ultraviolet rays are used for surface disinfection because they are powerful bactericidal agents, although they do not penetrate deeply.

2000 Å or less

Ionizing radiations have wavelengths of 2000 Å or less, which allows them to carry enough energy to ionize atoms or molecules.

They penetrate deeply into food

Gamma rays penetrate deeply into food, making them effective for food preservation, and are also the cheapest form of radiation.

Killing microorganisms without raising temperature

'Cold sterilization' refers to the process of killing microorganisms using ionizing radiation without raising the temperature of the food.

Radappertization

Radappertization is the radiation process that achieves sterilization equivalent to the commercial sterility of heat-processed foods.

260 nm

Ultraviolet rays are most effective as bactericidal agents at a wavelength of 260 nm.

0.1 mm

Ultraviolet rays penetrate only 0.1 mm into food, which limits their application to surfaces and packaging.

Gray (GY)

Gray (GY) is a unit used to express radiation dose, specifically in terms of energy absorbed per kilogram of matter.

Ultraviolet rays

Ultraviolet rays are non-ionizing radiations, unlike X-rays, gamma rays, and beta rays, which can ionize atoms.

2000 A° or less

Ionizing radiations of wavelength 2000 A° or less are important in food preservation and include beta rays, gamma rays, and X-rays.

Killing microorganisms using electromagnetic radiations without raising temperature

Cold sterilization refers to killing microorganisms in foods using electromagnetic radiations without raising temperature.

260 nm

UV rays are most effective at 260 nm (2600 A°), although they are bactericidal/virucidal between 200–290 nm.

They have poor penetration capacity (only 0.1 mm thickness)

UV rays have poor penetration capacity, penetrating only 0.1 mm thickness, which limits their application to disinfection of air and food surfaces.

They are a stream of high energy electrons

Beta rays are ionizing radiations that are a stream of high energy electrons emitted by radioactive substances or machine generated electrons.

30–40 K Gray

Radappertization uses a radiation dose of 30–40 K Gray and ensures sterility, equivalent to commercial sterility of heat processed foods.

RAD

1 RAD = absorption of 100 ergs/g of matter. REP is 83 ergs/g, and Gray is 100 rads.

20 cm

Gamma rays have excellent penetration power and can penetrate food up to a depth of 20 cm.

It causes rancidity

UV radiation can cause rancidity in high fat products, which is a limitation of its use.

1 Gray = 100 rads

1 Gray = 100 rads = 11 joules/kg. This is a newer and recently used unit of radiation.

They are produced by bombarding a suitable metal target with high velocity electrons

X-rays are ionizing radiations produced by bombarding a suitable metal target with high velocity electrons, and they behave like gamma rays.

They have a deep penetration capability and are cost-effective.

Gamma rays penetrate up to 20 cm into food, making them effective for killing microorganisms deep within fish, and they are also the cheapest form of radiation.

Gamma rays penetrate deeper than ultraviolet rays.

Gamma rays can penetrate up to 20 cm into food, while ultraviolet rays only penetrate about 0.1 mm, making gamma rays significantly more effective for deeper microbial control.

Radappertization destroys all microorganisms, while radicidation targets specific pathogens.

Radappertization is a stronger process that achieves complete sterilization, while radicidation specifically targets pathogens and spoilage organisms.

They cause rancidity in high-fat products.

Ultraviolet rays can cause rancidity in high-fat products due to their photochemical effects, limiting their use in preserving such foods.

Radappertization

Radappertization is specifically designed to achieve commercial sterility, making it the most suitable process for fish preservation.

It ionizes atoms and molecules, leading to cell death.

Ionizing radiation carries enough energy to ionize atoms and molecules, which disrupts cellular functions and leads to microbial death.

Both behave similarly, but X-rays are machine-generated.

X-rays behave similarly to gamma rays in their effects but are generated by machines rather than from radioactive decay.

It marks the boundary for effective ionizing radiation.

Wavelengths of 2000 Å or less are considered ionizing, which is crucial for the cold sterilization process that kills microorganisms without heat.

1 Gray = 100 rads; it measures energy absorbed per kg.

1 Gray is defined as 100 rads and represents the amount of radiation energy absorbed per kilogram of matter.

It effectively destroys microorganisms without heat.

Ionizing radiation is used in cold sterilization because it kills microorganisms effectively without raising the temperature of the food.