Food processing and preservation Quiz – 9

Q. Cold sterilization refers to the preservation of food by 

1. Refrigeration
2. Radiation
3. Dehydration
4. Lyophilisation

Answer: b)

Ionizing radiation is an excellent agent for sterilization/disinfection, it kills organisms without increasing the temperature; so aptly called cold sterilization.

Q. What is the purpose for blanching (immersing food in hot water) vegetables during canning

1. to soften products to fill better
2. to denature enzymes that change color, texture
3. to reduce microbial population
4. All of the above

Answer: d)

Blanching (scalding vegetables in boiling water or steam for a short time) is a must for almost all vegetables to be frozen. It stops enzyme actions which can cause loss of flavor, color and texture.

Blanching cleanses the surface of dirt and organisms, brightens the color and helps retard loss of vitamins. It also wilts or softens vegetables and makes them easier to pack.

Q. The method of preventing or reducing pathogens in food products by combining many methods like high temperature during processing, low temperature during storage, increasing the acidity etc is called

1. Mixed preservation approach
2. High pressure food preservation
3. Hurdle technology
4. Stumbling technology

Answer: c)

Highly advanced technologies like irradiation, high-pressure technology, and hurdle technology are used to preserve food items.

Q. Xerophilic fungi can grow at ______________ water activity

1. 0.65
2. 0.76
3. 0.85
4. 0.91

Answer: c)

Xerophiles are defined as microorganisms that grow at low water activity (a_w) levels. These were defined by Pitt as being below 0.85.

Q. The effectiveness of UV rays are influenced by 

1. Time
2. Intensity
3. Penetration
4. All of the above

Answer: d)