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

The only way for growers to salvage frozen citrus is to process them quickly into juice concentrate before they rot when warmer weather returns.

  1. to process them quickly into juice concentrate before they rot when warmer weather returns.

  2. If they are quickly processed into juice concentrate before warmer weather returns to root them.

  3. for them to be processed quickly into juice concentrate before the fruit rots when warmer weather returns

  4. to have it quickly processed into juice concentrate before warmer weather returns and rots the fruit

  5. to have them quickly processed into juice concentrate before the warmer weather returns and rots the fruit
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

(D) Option (B) is incorrect as it used 'root' instead or rot, so it can be directly eliminated. 'Citrus' is a collective noun for all kinds of citrus fruits hence, it should be followed by a singular verb, 'them' is used for a group of people hence 'it' should be used, so option (D) is correct.

Multiple choice

Microbes can be preserved for long periods of time by deep-freezing called

  1. sublimation

  2. lyophilization (freeze-drying)

  3. methylene blue

  4. yeast Infusion Broth

  5. mannitol
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Microbes can be preserved for long periods of time by deep-freezing or lyophilization (freeze-drying). Deep freezing is done quickly, from -50° down to -95°C. Lyophilization is a quick freeze in which a vacuum pump removes water in a process called sublimation.

Multiple choice

Which of the following is used most commonly as a food preservative?

  1. Benzoic

  2. Acetic acid

  3. Tartaric acid

  4. Sodium carbonate
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Benzoic acid and its sodium salt (sodium benzoate) are commonly used as food preservatives because they effectively inhibit the growth of bacteria, yeast, and molds in acidic foods. Acetic acid (vinegar) is used but less commonly as a preservative.

Multiple choice

Microbes can be preserved for long periods of time by deep-freezing. What is this called as?

  1. Sublimation

  2. Lyophilisation

  3. Methylene blue

  4. Yeast Infusion Broth

  5. Mannitol
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Microbes can be preserved for long periods of time by deep-freezing or lyophilisation (freeze-drying). Deep freezing is done quickly, from -50° down to -95°C. Lyophilisation is a quick freeze in which a vacuum pump removes water in a process called sublimation.

Multiple choice

Milk is pasteurized in order to _____.

  1. destroy microorganisms

  2. enhance taste and flavour

  3. make it concentrated

  4. none of these

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Milk is pasteurized to destroy the microorganisms. Pasteurization is a process of heating a food, usually a liquid, to a specific temperature for a definite length of time and then cooling it immediately. This process slows spoilage due to microbial growth in the food. Unlike sterilization, pasteurization is not intended to kill all micro-organisms in the food. Instead, it aims to reduce the number of viable pathogens so they are unlikely to cause disease (assuming the pasteurized product is stored as indicated and is consumed before its expiration date). Commercial-scale sterilization of food is not common because it adversely affects the taste and quality of the product. Certain foods, such as dairy products, may be superheated to ensure pathogenic microbes are destroyed.

Multiple choice

An autoclave is designed to sterilize with:

  1. Dessication

  2. Boiling water

  3. Steam and pressure

  4. Dry heat and methane gas
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

An autoclave uses high-pressure saturated steam to achieve temperatures above the boiling point of water, which is highly effective at killing bacteria, viruses, and spores.

Multiple choice

Which of the following is/are the precautions to be observed while reading laboratory thermometer?

  1. The thermometer should be kept upright either by freely suspending it or by fixing it in cork, etc.

  2. The bulb of the thermometer should be completely surrounded by the liquid.

  3. The bulb of the thermometer should not touch the sides or the base of the container.

  4. The reading should be taken only when the level of the mercury is steady for 30 seconds or more.

  5. All of the above
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

This is the correct option, as all of the above are the correct precautions to be taken while taking the reading of the laboratory thermometer.

Multiple choice

An autoclave is designed to sterilize with

  1. dessication

  2. boiling water

  3. steam and pressure

  4. dry heat and methane gas
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

An autoclave uses pressurized steam to achieve temperatures above the boiling point of water, which is highly effective at killing microorganisms and spores.