Blanching

Question 1

What is the importance of blanching in seafood processing?

Answer 1

1. Preservation
2. Texture Retention
3. Food Safety

Question 2

Benefits of blanching seafood products?

Answer 2

• Color Retention
• Microbial Growth
• FlavorLock
• Improved Texture

Question 3

Blanching Methods Used In Seafood Industry

Answer 3

1. Water Blanching
2. Steam Blanching
3. Microwave Blanching

Question 4

Factors to consider when blanching seafood products

Answer 4

• Blanching Duration
• Water Quality
• Tenperature Control

Question 5

Common Challenges & Solutions in Blanching Seafood

Answer 5

a) Overcooking
• C: Risk of texture & flavor degradation
• S: Proper timing & temperature control

b) Uneven Blanching
• C: Inconsistent texture & color
• S: Use of appropriate blanching equipment

c) Microbial Contamination
• C: Threat to food safety
• S: Strict adherence to hygiene & sanitation protocols

Question 6

What are the types of pasteurization of unpackaged food?

Answer 6

1. Low - Temperature - Long - Time (LTLT)
2. High - Temperature - Short - Time (HTST)

Question 7

What is LTLT?

Answer 7

• Typical batch method

Question 8

How does LTLT work?

Answer 8

1. A quantity of milk is placed in an open vessel
2. Then, they are heated to 63°C and held for 30 min

Question 9

How does HTST work?

Answer 9

• Involves heating to 72 - 75°C and being held for 15 - 20 s before it is cooled
• The shelf life depends on the quality of the raw milk and the degree of refrigeration

Question 10

Batch Pasteurization

Answer 10

• In the vessel, the food is heated and held throughout the holding period while being agitated
• The milk may be cooled in the vessel OR removed hot after the holding time is completed for every particle

Question 11

Continuous Pasteurization

Answer 11

• Time & energy saving compared to batch
• HTST pasteurizer is used (use a plate heat exchanger)

Question 12

What is UHT (Ultra High Temperature)

Answer 12

• Product is rapidly heated to temperatures ranging from 130°C - 150°C for a few seconds

Question 13

Define aseptic processing

Answer 13

• Product and the Package is STERILISED SEPARATELY, then the package is filled with the sterile product & sealed under sterile conditions

Question 14

Define retort processing

Answer 14

• Product is packed into a container
• The container is then sterilized
• A common retort temperature for sterilizing canned foods is 121 °C

Question 15

Factors affecting sterilization

Answer 15

1. Microorganism present
2. Properties of the food product
3. pH of the product
4. The products initial temperature

Question 16

Decimal Reduction Time (DT

Answer 16

: the time it takes to reduce a microbial population by 1 logarithm, or 90% of its initial value

Question 17

Thermal death time constant (thermal resistance constant), z

Answer 17

temperature required to make 90% reduction of DT

Question 18

Thermal death time, TDT (Fo) or process lethality

Answer 18

amount of time that is necessary to kill a specific number of microbes at a specific temperature.

Question 19

Heat processing using steam or water

Answer 19

Blanching
Pasteurisation
Heat sterilization

Question 20

Heat processing using hot air/oil

Answer 20

Dehydration
Baking and roasting
Frying

Question 21

Processing by the removal of heat

Answer 21

Chilling
Freezing
Freeze drying

Question 22

Mild Heat Treatment

Answer 22

• Aims:
Reduces bacterial load (Food is NOT sterile)
Inactivate enzymes

• Advantages:
Minimal damage to flavor, texture, and nutritional quality.

• Disadvantages:
Short shelf life
Another preservation method must be used, such as
refrigeration or freezing

• Examples:
Pasteurization
Blanching

Question 23

Severe Heat Treatment

Answer 23

• Aims:
Kills all bacteria
Food will be commercially sterile

• Advantages:
Long shelf life
No other preservation method is necessary

Disadvantages
Food is over-cooked
Major changes in texture, flavor, and quality

• Examples:
Sterilization/Canning

Question 24

Thermal processing

Answer 24

Heating packed/unpacked food for a specific time at a specific temperature to eliminate the microbial pathogens that endanger public health and microorganisms and enzymes that deteriorate food during storage.

Question 25

Blanching

Answer 25

Involving a brief exposure of the food to boiling water or steam followed by rapid cooling.

This method helps preserve the quality, texture, and
nutritional value of animal food products.

Question 26

Pumps

Answer 26

• Used to maintain the required product flow rate
• Usually, a positive displacement pump is used for this application.

Question 27

Flow diversion valve (FDV)

Answer 27

• Located downstream from the holding tube

-A temperature sensor located at the exit to the holding tube activates the FDV.

-The valve and sensor prevent products that have not received the established time-temperature treatment from reaching the product packaging system.

Question 28

Holding tube

Answer 28

-Correct heat treatment requires that the milk is held at a specified time at the pasteurization temperature.

-This is done by an external arrangement of plates or tubes, which has been dimensioned so that the residence time for the milk corresponds exactly to the required time.