This set of Fruits Processing Multiple Choice Questions & Answers (MCQs) focuses on “Sterilization of Juices”.
1. Which of the following process is high-hydrostatic-pressure processing?
a) Dehydration
b) Non-thermal food preservation method
c) Thermal food preservation method
d) Irradiation method
View Answer
Explanation: Pressure treatment can be used to process both liquid and high-moisture-content solid foods. Although lethal to microorganisms, pressure treatment does not break covalent bonds and has a minimal effect on food chemistry. Thus, it provides a means for retaining food quality.
2. Which of the following process is also called as Joule heating?
a) Ohmic heating
b) High pressure processing
c) Pulsed electric field processing
d) Irradiation
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Explanation: Ohmic heating is also called as Joule heating, electrical resistance heating, or electro conductive heating. It is an alternative heating technology. It ensures uniform, rapid heating, compact design, and minimal heating of the product surroundings.
3. Which of the following products can use ohmic heating for preservation?
a) Viscous liquid
b) Solids
c) Gaseous products
d) Liquid, solids, gases
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Explanation: Ohmic heating is particularly suitable for the processing of viscous, liquid foods and foods containing particles. It enhances the shelf life of the product. It inactivates the vegetative spores in the food.
4. Which of the following method has been recommended as an alternative fast-heating method for fruit juices?
a) Ohmic heating
b) Pasteurization
c) Sterilization
d) Irradiation
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Explanation: Ohmic heating has been recommended as an alternative fast-heating method for fruit juices. Ohmic heating technique was utilized for several food processing applications such as blanching, sterilization, dehydration and extraction. It is a quick process.
5. What is the process involved in ohmic heating?
a) Internal energy generation process
b) External energy generation process
c) No energy generation process
d) Very high energy generation process
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Explanation: Ohmic heating is an internal energy generation process. Ohmic heating is used for heating food by transferring an electric current through it. It reduces potential thermal exploitation of treated product where gentle heat penetration happens.
6. What are the operating conditions of the ohmic heating?
a) Low voltage and low current
b) High voltage and high current
c) High voltage and low current
d) Low voltage and high current
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Explanation: Ohmic heating works at low current and high voltage. The heat flows through the heating field and its electrical conductivity changes over the length which heats the products are heated. The material at top end has high field strengths whereas the bottom locations has lower field strengths.
7. What are advantages of ohmic heating?
a) Rapid heating
b) No surface fouling
c) Low cost
d) Rapid heating, no surface fouling, low cost
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Explanation: The advantages of ohmic heating are there is no boundary of the depth of penetration like microwave heating and conventional heating. There is no hot surface, surface fouling and heat damage. In addition, this type of heating does not generate waste.
8. Total protein content and amino acids were not affected by ohmic heating.
a) True
b) False
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Explanation: The total protein content and amino acids were not affected by ohmic heating. Only the arginine has been reported to be declined. In addition, it maintains a similar content of essential and non-essential amino acids.
9. The voltage gradient affects the heating rate, pH, and electrical conductivity in ohmic heating.
a) True
b) False
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Explanation: The voltage gradient affects the heating rate, pH, and electrical conductivity in ohmic heating. Increase in voltage gradient resulted with a decrease in system performance, time, and pH. An increase in voltage gradient results in reduction of total evaporation time.
10. What is the effect of ohmic heating on juices?
a) Inactivates enzymes
b) Retains color
c) Retains chemical properties of juice
d) Retains texture
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Explanation: The ohmic heating is used for inactivating the enzymes without affecting the flavor of the fruit juices. It also destroys the microbes. The technology is useful for the treatment of proteinaceous foods, which tend to denature and coagulate when thermally processed.
11. How is ohmic heating process environmental friendly?
a) No harmful emission
b) Reduces the usage of lye in fruit peeling
c) Low wastage
d) No harmful emission, reduces the usage of lye, low wastage
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Explanation: Ohmic heating is environmentally friendly as it uses ordinary electricity therefore no emissions are produced at the point of use. One emerging application of ohmic heating is fruit peeling, which may greatly reduce the use of lye. Lye is a corrosive alkaline substance.
12. What is the basic principle behind ohmic heating?
a) Joules effect of heating
b) Ohms’s law of heating
c) Joules effect of cooling
d) Ohms’s law of cooling
View Answer
Explanation: It is based on joules effect of heating. Heating rate is directly proportional to electrical conductivity and squire of applied electric field. It is the process by which the passage of an electric current through a conductor produces heat.
Sanfoundry Global Education & Learning Series – Fruits Processing.
To practice all areas of Fruits Processing, here is complete set of 1000+ Multiple Choice Questions and Answers.
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