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L Yo Phil Ization

Lyophilization, also known as freeze drying, is a process used to preserve perishable foods. It involves freezing the food, reducing the surrounding pressure so that the frozen water sublimates from solid to gas, leaving the food highly dehydrated. This removes nearly all moisture, allowing the food to be stored at room temperature for long periods without spoiling. Freeze drying is used to produce instant coffee and some pharmaceuticals. It also helps preserve the flavor, smell, and structure of foods better than conventional dehydration.

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83 views2 pages

L Yo Phil Ization

Lyophilization, also known as freeze drying, is a process used to preserve perishable foods. It involves freezing the food, reducing the surrounding pressure so that the frozen water sublimates from solid to gas, leaving the food highly dehydrated. This removes nearly all moisture, allowing the food to be stored at room temperature for long periods without spoiling. Freeze drying is used to produce instant coffee and some pharmaceuticals. It also helps preserve the flavor, smell, and structure of foods better than conventional dehydration.

Uploaded by

visha
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
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Name Nonfiction Reading Comprehension

Lyophilization
Lyophilization is the scientific name for what you have When you preserve a food by basic dehydration, you
probably heard of before as freeze drying. Freeze simply put it somewhere hot and arid (like setting it out
drying is useful for preserving perishable foods, as well in the sun, or using a dehydrator, which circulates hot
as for making them lighter, and thus easier to air around the food) and the water in the food
transport. The idea of freeze drying was popularized by evaporates―but not all of the water. Conven onal
the creation of freeze dried ice cream, sold at the Air dehydration only removes about 90 to 90% of the
and Space Museum to tourists as an example of moisture, which can slow down spoilage, but will not
astronaut food. But freeze drying is not just a novelty. entirely prevent it. Freeze drying, on the other hand, is
Hikers often carry freeze dried food because of its light a multi‐part process. First the material is frozen. Then
weight, and reconstitute it using available water the surrounding pressure is reduced so that the frozen
sources. Freeze drying is also used to manufacture water in the material can transform directly from its
instant coffee and some pharmaceuticals. solid phase into a gas. This process is called
sublimation, and it is the same process that gradually
The idea behind freeze drying is to remove every bit of causes unused ice cubes to shrink in the freezer, and
water from a substance. Because the water content in which accounts for the disappearance of snow in the
freeze dried items is so greatly reduced, it is less likely winter even though temperatures have not risen
to spoil due to microorganisms and enzymes, and if enough for it to melt. A cold condenser chamber or
properly sealed, freeze dried foods can remain condenser plates are used as a surface on which the
unspoiled at room temperature for many years. Freeze vapor can become a solid again, but this only works if
drying also preserves the material being dried, unlike these surfaces are colder than the material being dried.
typical dehydrating methods which can cause food to Freeze drying can take days, because rushing the
shrink and become leathery (think of dried apple drying process by overheating the food can
slices). Freeze drying also allows food to retain its flavor
and smell.

CCSS.RI.7.10 |© www.EnglishWorksheetsLand.com
Name Nonfiction Reading Comprehension

change its structure and composition, and one of the intact.


objectives of freeze drying is to leave these things

1. Which two words are synonyms?

A. freeze drying and dehydration


3. Name three products that are created using
B. freeze drying and Lyophilization
Lyophilization:
C. Lyophilization and dehydration

2. What are the objectives behind freeze drying?


Select all that apply.

A. reducing moisture content


B. extending shelf life
C. preserving flavor 4. Explain the difference between Lyophilization and
D. preserving smell conventional dehydration.
E. making food weigh less

3. Describe the steps involved in Lyophilization.

CCSS.RI.7.10 |© www.EnglishWorksheetsLand.com

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