Kit Library / Food Science and Technology / Food Preservation Technology
⚡ Topic Learning KitShared by a Veda learner · Generated with Veda AI
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💡 Key Idea
Dose decides the destiny.
Food irradiation is classified into three processes based on the radiation dose applied. Radappertization (30-40 kGy) destroys microorganisms for sterility. Radicidation (2.5-10 kGy) reduces non-spore-forming pathogens. Radurization (0.75-2.5 kGy) reduces spoilage organisms to extend shelf life.
↳ Higher dose means stronger microbial kill; each process targets a different goal.
📖 Definition
Electrons smash metal, X-rays emerge.
X-rays are ionizing radiations produced by bombarding a suitable metal target with high-velocity electrons. In their behaviour, they are similar to Gamma rays.
↳ X-rays are ionizing radiations generated by electron bombardment of a metal target.
➗ Formula
83 ergs per gram.
↳ 1 REP equals absorption of 83 ergs per gram of matter.
➗ Formula
100 ergs per gram.
↳ 1 RAD equals 100 ergs per gram; 1 krad = 1000 rads.
➗ Formula
Newer unit, 100 rads.
↳ 1 Gray = 100 rads = 1 joule per kg; 1 kGy = 10^5 rads.
📖 Definition
Destroy microbes, achieve sterility.
Radappertization is a radiation process that destroys microorganisms, equivalent to commercial sterility of heat-processed foods. Also called radiation sterilization, it uses a dose of 30-40 kGy and ensures a sterile product with prolonged shelf life.
↳ Radappertization uses 30-40 kGy to achieve sterility and long shelf life.
📖 Definition
Target non-spore-forming pathogens.
Radicidation reduces the number of viable non-spore-forming pathogens that are undetectable by standard methods. It is equivalent to pasteurization and uses a radiation level of 2.5-10 kGy.
↳ Radicidation uses 2.5-10 kGy to reduce non-spore-forming pathogens, like pasteurization.
📖 Definition
Minimize spoilage organisms.
Radurization minimizes the load of spoilage organisms to extend shelf life. It is considered equivalent to pasteurization and causes substantial reduction in viable specific spoilage microorganisms. Suitable for fresh meat, seafood, fruits, and vegetables. Dose used: 0.75-2.5 kGy.
↳ Radurization uses 0.75-2.5 kGy to reduce spoilage organisms and extend shelf life.
⭐ Important Fact
Free radicals cause quality loss.
Irradiation can bring undesirable changes directly or indirectly. Free radicals produced during radiation cause oxidative changes: discoloration, tissue softening (due to pectin and cellulose degradation), and rancidity in high-fat products (from carbonyl and peroxide radicals). These can be reduced…
↳ Free radicals from irradiation cause discoloration, softening, and rancidity; low temperature and no oxygen reduce these.
🛠️ Application
Many foods, many purposes.
↳ Irradiation is permitted for sprout inhibition, decontamination, parasite destruction, pathogen inactivation, and shelf-life extension.
⭐ Important Fact
Direct hit and free radicals.
The microbicidal effect of irradiation is due to direct interaction of radiation with key molecules within the microbial cell, as well as the inhibitory effect of free radicals (H⁺, OH⁻ ions) produced by the radiolysis of water.
↳ Irradiation kills microbes by direct damage and by free radicals from water radiolysis.
⚖️ Comparison
Gram-negative most sensitive.
Many spoilage bacteria of seafood are Gram-negative, hence least resistant to irradiation. E. coli is highly sensitive and not useful as an indicator.
↳ Gram-negative bacteria are most sensitive; spores are most resistant. Seafood spoilage bacteria are Gram-negative.
🎯 Exam Tip
Radappertization > Radicidation > Radurization.
For exams, memorize the dose ranges: Radappertization (30-40 kGy), Radicidation (2.5-10 kGy), Radurization (0.75-2.5 kGy). Also remember the unit conversions: 1 Gray = 100 rads, 1 kGy = 10^5 rads.
↳ Dose ranges and unit conversions are high-yield exam facts.
Food irradiation uses ionizing radiation to preserve food through three processes: radappertization (sterilization), radicidation (pathogen reduction), and radurization (shelf-life extension). Radiation dose is measured…
Full explanation, worked examples & memory tricks in the app
All 55 questions, laddered from warm-up to topper-level, each with its answer and the reasoning behind it.
Q1. X-rays used in food irradiation are produced by bombarding a suitable metal target with:
BeginnerAnswers and explanations are in the Veda app.
Q2. 1 Gray (Gy) is equal to how many rads?
BeginnerAnswers and explanations are in the Veda app.
Q3. Irradiation is permitted for inhibition of sprouting in which of the following?
BeginnerAnswers and explanations are in the Veda app.
Q4. 1 Krad is equal to 1000 rads.
BeginnerAnswers and explanations are in the Veda app.
Q5. What is the primary purpose of food irradiation?
BeginnerAnswers and explanations are in the Veda app.
Q6. Which radiation process is used to achieve commercial sterility in food?
BeginnerAnswers and explanations are in the Veda app.
Q7. What unit is equivalent to 83 ergs per gram of matter?
BeginnerAnswers and explanations are in the Veda app.
Q8. Which of the following is a permitted use of food irradiation?
BeginnerAnswers and explanations are in the Veda app.
Q9. What is the radiation dose range for Radicidation?
BeginnerAnswers and explanations are in the Veda app.
Q10. What effect can free radicals produced during irradiation have on food?
BeginnerAnswers and explanations are in the Veda app.
Q11. What is the equivalent of 1 Gray (Gy) in rads?
BeginnerAnswers and explanations are in the Veda app.
Q12. Which group of microorganisms is most sensitive to radiation?
BeginnerAnswers and explanations are in the Veda app.
Q13. What is the purpose of irradiating food at low temperatures?
BeginnerAnswers and explanations are in the Veda app.
Q14. What is the primary purpose of food irradiation?
BeginnerAnswers and explanations are in the Veda app.
Q15. Which radiation process is used to achieve commercial sterility?
BeginnerAnswers and explanations are in the Veda app.
Q16. What is the dose range for Radicidation?
BeginnerAnswers and explanations are in the Veda app.
Q17. What unit is equivalent to 1 Gray (Gy)?
BeginnerAnswers and explanations are in the Veda app.
Q18. Which of the following is a permitted use of food irradiation?
BeginnerAnswers and explanations are in the Veda app.
Q19. What is the equivalent of 1 REP in ergs per gram of matter?
BeginnerAnswers and explanations are in the Veda app.
Q20. Which group of microorganisms is most sensitive to radiation?
BeginnerAnswers and explanations are in the Veda app.
Q21. What undesirable change can free radicals cause in food during irradiation?
BeginnerAnswers and explanations are in the Veda app.
Q22. What is the purpose of Radurization?
BeginnerAnswers and explanations are in the Veda app.
Q23. Which unit represents the absorption of 83 ergs per gram of matter?
IntermediateAnswers and explanations are in the Veda app.
Q24. Which radiation process is equivalent to commercial sterility of heat processed foods?
IntermediateAnswers and explanations are in the Veda app.
Q25. The radiation dose used in Radappertization is:
IntermediateAnswers and explanations are in the Veda app.
Q26. Radicidation is used for the reduction of:
IntermediateAnswers and explanations are in the Veda app.
Q27. Which process is given to minimize the load of spoilage organisms and extend shelf life of fresh meat, seafood, fruits and vegetables?
IntermediateAnswers and explanations are in the Veda app.
Q28. The radiation dose used in Radurization is:
IntermediateAnswers and explanations are in the Veda app.
Q29. Tissue softening in irradiated fruits is caused by degradation of:
IntermediateAnswers and explanations are in the Veda app.
Q30. Inactivation of Salmonella by irradiation is permitted in:
IntermediateAnswers and explanations are in the Veda app.
Q31. Radurization uses a higher radiation dose than Radappertization.
IntermediateAnswers and explanations are in the Veda app.
Q32. Which radiation process is specifically designed to achieve commercial sterility in food?
IntermediateAnswers and explanations are in the Veda app.
Q33. How does the radiation dose in Radicidation compare to that in Radurization?
IntermediateAnswers and explanations are in the Veda app.
Q34. What is the primary reason for irradiating food at low temperatures?
IntermediateAnswers and explanations are in the Veda app.
Q35. Which of the following microorganisms is least resistant to irradiation?
IntermediateAnswers and explanations are in the Veda app.
Q36. Which radiation process is equivalent to pasteurization?
IntermediateAnswers and explanations are in the Veda app.
Q37. What effect do free radicals have on high-fat products during irradiation?
IntermediateAnswers and explanations are in the Veda app.
Q38. What is the equivalent of 1 kGy in rads?
IntermediateAnswers and explanations are in the Veda app.
Q39. Which of the following is a permitted use of food irradiation?
IntermediateAnswers and explanations are in the Veda app.
Q40. What is the main mechanism by which irradiation kills microorganisms?
IntermediateAnswers and explanations are in the Veda app.
Q41. Which of the following statements about Radappertization is true?
IntermediateAnswers and explanations are in the Veda app.
Q42. Free radicals produced during radiation can cause rancidity in high fat products mainly due to the production of:
AdvancedAnswers and explanations are in the Veda app.
Q43. Product discoloration and rancidity during irradiation can be reduced by:
AdvancedAnswers and explanations are in the Veda app.
Q44. Among microorganisms, which group is most sensitive to radiation?
AdvancedAnswers and explanations are in the Veda app.
Q45. The microbicidal effect of irradiation is due to:
AdvancedAnswers and explanations are in the Veda app.
Q46. If a food product undergoes Radappertization, what is the expected range of radiation dose applied, and what is its primary purpose?
AdvancedAnswers and explanations are in the Veda app.
Q47. Which of the following statements accurately describes the relationship between Radicidation and its equivalent process?
AdvancedAnswers and explanations are in the Veda app.
Q48. A food product is irradiated at a dose of 1 kGy. How many rads does this correspond to?
AdvancedAnswers and explanations are in the Veda app.
Q49. During which irradiation process is the primary goal to extend the shelf life of food while minimizing the load of spoilage organisms?
AdvancedAnswers and explanations are in the Veda app.
Q50. What undesirable effect can be minimized in irradiated high-fat products by irradiating in the absence of oxygen?
AdvancedAnswers and explanations are in the Veda app.
Q51. If a food product is treated with a radiation dose of 5 kGy, which of the following best describes the expected effects on microorganisms?
AdvancedAnswers and explanations are in the Veda app.
Q52. Which of the following statements regarding the resistance of microorganisms to irradiation is true?
AdvancedAnswers and explanations are in the Veda app.
Q53. What is the effect of free radicals produced during irradiation on food quality, particularly in high-fat products?
AdvancedAnswers and explanations are in the Veda app.
Q54. In terms of radiation dose, how does Radurization compare to Radicidation?
AdvancedAnswers and explanations are in the Veda app.
Q55. Which of the following uses of food irradiation is primarily aimed at delaying the maturation of fruits?
AdvancedAnswers and explanations are in the Veda app.
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