Science General · Chemistry

Food Processing and Storage

2,379 Questions

Food processing and storage principles focus on preservation techniques, packaging methods, and preventing microbial contamination. These topics are essential for general science sections in various competitive examinations. Questions explore pasteurization, canning, chemical preservation, and safe food handling practices.

Food preservation methodsPasteurization techniquesFood packaging materialsMicrobial contamination preventionCryopreservation concepts

Food Processing and Storage Questions

Multiple choice

What term describes the limited shelf life of a product?

  1. Obsolescence

  2. Perishability

  3. Stock-take

  4. Product update
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Perishability refers to products that have a limited shelf life, such as fresh food or flowers, which must be sold or used within a certain timeframe.

Multiple choice

A great way to sterilize a culture broth would be

  1. heavy metals

  2. autoclaving

  3. dry heat

  4. pasteurization
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Autoclaving uses pressurized steam to achieve temperatures above boiling, which effectively kills all microorganisms, including endospores, making it the standard for sterilizing culture media.

Multiple choice

what are preventive and control measures used before storage of grains?

  1. proper drying of the product first in sunlight and then in shade

  2. strict cleaning of product before storage

  3. fumigation using chemicals that can kill pests

  4. all of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Proper drying, cleaning, and chemical treatment (fumigation) are all standard practices used to protect stored grains from moisture, pests, and microorganisms.

Multiple choice

Retrogradation is undesirable _______.

  1. in any food mixture

  2. when a mixture thickens as it cools

  3. when it causes syneresis

  4. with foods that will be frozen
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Retrogradation is the realignment of starch molecules. While sometimes useful, it is undesirable when it leads to syneresis, which is the weeping or leaking of water from the food matrix.

Multiple choice physics option b: engineering physics conversion of heat into work: heat engine and it's efficiency engines and cycles refrigerators and heat pumps

Refrigerators and freezers works by:

  1. Converting hot air to cold air

  2. Keeping hot air out with cold air pressure

  3. Removing heat from inside themselves

  4. Blowing cold inside them

  5. Producing cold air
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A gas refrigerant or sometimes air is key to refrigeration in freezers.
The gas refrigerant goes into the compressor and the process of compression makes the gas hot. That hot gas moves through the system getting colder and colder. By the time it reaches the valve – and is pushed through the very small opening – it has turned into a cold mist. 

As the mist goes through the coils under the freezer compartment, it starts to evaporate and turn back into a gas. This evaporation process takes the heat from the freezer compartment with it and as the refrigerant starts to warm up, it is sent back to the compressor to start the process all over again. Eventually the process is completed and there is no heat left in the freezer meaning that all objects in the freezer are frozen.

Multiple choice physics option b: engineering physics conversion of heat into work: heat engine and it's efficiency engines and cycles refrigerators and heat pumps

What is the function of the evaporator in a refrigerator?

  1. The evaporator supplies the heat to the substance, which is to be cooled.

  2. The evaporator absorbs the heat from the atmosphere.

  3. The evaporator absorbs the heat from the substance, which is to be cooled.

  4. Both a and b
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Evaporator is an important component together with other major components in a refrigeration system such as compressor, condenser and expansion device. The reason for refrigeration is to remove heat from air, water or other substance.

It is here that the liquid refrigerant is expanded and evaporated. It acts as a heat exchanger that transfers heat from the substance being cooled to a boiling temperature.
Multiple choice physics option b: engineering physics conversion of heat into work: heat engine and it's efficiency engines and cycles refrigerators and heat pumps

The freezer in a refrigerator is located at the top section so that;

  1. The entire chamber of the refrigerator is cooled quickly due to convection

  2. The motor is not heated

  3. The heat gained from the environment is high

  4. The heat gained from the environment is low
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The freezer in a refrigerator is located at the top section so that the entire chamber of the refrigerator is cooled quickly due to convection.  
The correct option is A.

Multiple choice

Time/temperature control, safety foods include:

  1. Milk and dairy products

  2. Cut melons

  3. Raw seed sprouts and soy products

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

TCS (Time/Temperature Control for Safety) foods include dairy, cut melons, sprouts, and soy products because they support rapid bacterial growth.

Multiple choice

When receiving food, which of the following is not a reason for rejecting food:

  1. Frozen food is thawed or partly thawed

  2. There is visible mold or slime

  3. Receiving TCS Food at 5 Celcius or 41 Fo

  4. Packaging is damaged or dirty
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When receiving TCS foods at 5°C (41°F) or below is CORRECT and acceptable. Foods should be rejected if: thawed/partially thawed frozen foods, visible mold/slime, damaged/dirty packaging, or temperatures above safety thresholds. Receiving at proper temperature is good.

Multiple choice

Which of the following is not a safe method to thaw food:

  1. At ambient temperature ( ordinary room temperature)

  2. In a refrigerator unit at 5 celcius ( 41 Fo ) or cooler

  3. Submerged under running potable (drinking quality) water at 21 celcius, (70

  4. As part of the cooking process
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Thawing food at room temperature is unsafe because it allows the outer layers of the food to enter the temperature danger zone while the inside remains frozen, promoting bacterial growth.