Non-thermal Processing Technologies Questions and Answers

Answer: D

It is called radicidation.

Food irradiation treatments are named by purpose and dose. Radicidation uses about 2.5 to 10 kGy to reduce viable non-spore-forming pathogens such as Salmonella, a radiation counterpart of pasteurisation.

Radurization uses lower doses, roughly 0.75 to 2.5 kGy, to reduce spoilage organisms and extend shelf life. Radappertization uses high doses, about 25 to 45 kGy, to sterilise food, killing spores as well. Thermoradiation is the combination of heat with irradiation, not a dose band.

Answer: B

The correct pair is Electromagnetic waves- γ rays and X- rays.

Food may be irradiated with three kinds of ionizing radiation: gamma rays from cobalt-60 or caesium-137, X-rays from machine sources, and electron beams from accelerators. Gamma rays and X-rays are both high-energy electromagnetic waves, so they belong together under that heading.

Electron beams are streams of particles, not waves, so they cannot be paired with X-rays or gamma rays as in options A and C. Cathode rays are electron beams, and beta rays are electrons from radioactive decay, so neither is an electromagnetic wave as option D says.

Answer: C

The correct sources are a and c only: isotope sources and electron accelerators.

Radiation for food processing comes from radioactive isotopes, mainly cobalt-60 and sometimes caesium-137, which emit gamma rays, and from machines: electron accelerators, which produce electron beams and, by converting them, X-rays.

'Heavy metal sources' and 'inert gas sources' are not used to irradiate food, so any option including b or d is wrong.