This set of Food Processing Unit Operations Multiple Choice Questions & Answers (MCQs) focuses on “Heat Transfer Applications – Sterilization”.
1. Where should a sterilization indicator placed in an autoclave?
a) At the center
b) Close to lid of the autoclave
c) Sides of the autoclave
d) Anywhere inside the autoclave
View Answer
Explanation: The best place to keep the biological indicator in the autoclave is at center of the load. Autoclave tape is used in autoclaving to indicate whether a specific temperature has been reached.
2. Which of the following is target microbe in commercial sterilization?
a) Pseudomonas aeruginosa
b) Bacillus anthracis
c) Salmonella typhi
d) Clostridium botulinum
View Answer
Explanation: Commercial Sterilization is defined as the thermal process intended to ensure safety of a shelf stable food product. In most cases, the process is applied to a food after the product is packed in a container. Clostridium botulinum is target microbe in commercial sterilization.
3. ____________ is used for sterilizing inoculating loops.
a) Flaming
b) Incineration
c) Hot air oven
d) Steam
View Answer
Explanation: Flaming is used for sterilizing metallic devices like needles, scissors. Incineration is used particularly for inoculating loops used in microbe cultures. The hot air oven is appropriate for dry material like glass ware, powders and metal devices.
4. Are these statements about the sterilization true?
Statement 1: Sterilization process consists of 3 phases.
Statement 2:Phase 2 in sterilization process is known as holding phase.
a) True, False
b) True, True
c) False, True
d) False, False
View Answer
Explanation: Sterilization process consists of 3 phases. They are i) Heating Phase where the product temperature is increased from ambient to the required sterilization temperature. ii) Holding phase where the temperature is maintained for a defined time. iii) Cooling phase where the temperature in the can is decreased by using cold water.
5. Who developed steam sterilizer?
a) Louis Pasteur
b) Charles Chamberland
c) Nicolas Appert
d) Clarence Birdseye
View Answer
Explanation: The pasteurization process was developed by Louis Pasteur. Charles Chamberland developed the first pressure steam sterilizer. Nicolas Appert is the father of food technology. Clarence Birdseye developed processes for freezing fish based on quick freezing.
6. Which of the following statements about sterilization are correct?
Statement 1: Sterilization is achieved by a heat and chemicals alone.
Statement 2: Ultraviolet radiation cannot be used for sterilization.
a) True, False
b) True, True
c) False, True
d) False, False
View Answer
Explanation: Sterilization can be achieved by using irradiation, high pressure, chemicals, chlorine dioxide gas, heat, filtration, ultraviolet radiation. The UV rays, X-rays, gamma rays are exposed on the packed materials for sterilization. The UV radiation has low penetration power. It is less effective but is safe compared to other rays.
7. _______ is the quickest way to sterilize solutions without heating.
a) Filtration
b) Chemical method of sterilization
c) Steam Sterilization
d) Chlorine dioxide gas
View Answer
Explanation: Filtration is the fastest way to sterilize solutions without heating. In this method the filters with a pore diameter of 0.2 um are used for the removal of bacteria. But they cannot be used to remove fungi and virus as they are in smaller size compared to bacteria.
8. _______ is used for sterilizing metallic devices like needles, scalpels.
a) Flaming
b) Incineration
c) Hot air oven
d) Steam
View Answer
Explanation: Flaming is used for sterilizing metallic devices like needles, scissors. Incineration is used particularly for inoculating loops used in microbe cultures. The hot air oven is appropriate for dry material like glass ware, powders and metal devices.
9. The sterilization of ________ is generally carried out by retorts.
a) low carbohydrate foods
b) low acid foods
c) high acid foods
d) medium acid foods
View Answer
Explanation: The sterilization of low-acid foods is done by using retorts. Initially they are heated at temperatures ranging from 116 to 129 °C. Then at the end of the heating cycle, the cans are cooled to approximately 38 °C under water sprays or in water baths and finally dried to prevent any rusting on the surface.
10. Does sterilization kill viruses?
a) True
b) False
View Answer
Explanation: Sterilization is defined as the process that eliminates or deactivates all forms of life like microorganisms (bacteria, spores, fungi, viruses) at high temperature.
Sanfoundry Global Education & Learning Series – Food Processing Unit Operations.
To practice all areas of Food Processing Unit Operations, here is complete set of 1000+ Multiple Choice Questions and Answers.
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