Explain the process of freezing, Science

Assignment Help:

Explain the process of Freezing

Freezing, as a method, is the easiest, most  convenient and least time-consuming way of preserving foods. Freezing does not sterilize foods or destroy the organisms that cause spoilage. How then does it preserve foods? Well, the  extreme cold simply slows the growth of microorganisms and the chemical changes that affect quality or cause spoilage. You already know that all microbial and biochemical activities are temperature dependant and slow down as the temperature is reduced. As a rule of thumb, for every 10°C temperature change, the rate of reaction changes by a factor of 2 to 3. 
 
Further, freezing helps to preserve food by its action on enzymes. Enzymes, as you already know are complex proteins, present in all living tissue, that help organisms ripen and mature. During freezing, enzyme action is slowed but not stopped. If not inactivated, these enzymes can cause color and flavor changes and loss of nutrients during freezer storage. 
 
We are all familiar with chilling and refrigerated storage. At home or at the industry level, refrigerated storage of food is generally practiced. In the unit operation of chilling, the temperature of a food is reduced generally to between -1°C and 7 °C and thus subsequent storage at refrigerated temperature extends the shelf life of both the fresh and processed foods. It is also used as an adjunct process to extend the storage life of mildly processed (e.g. pasteurized, fermented and irradiated) and low-acid foods. In the United States, refrigerated storage of food is mandated by regulations at temperatures at or below 7.2°C.  Such foods are also marketed under refrigeration and labeled as 'needing refrigeration'. Commercially sterilized and processed foods that may become contaminated after opening should also be labeled for refrigerated storage.
 
Chilling and refrigerated storage prevents the growth of bacteria, particularly the thermophiles (organisms that grow at high temperature) and mesophiles (organisms that grow at medium temperature). Psychrophiles (organisms that grow at low temperatures), however, can and do cause food spoilage during low temperatures  storage, but there are some psychrophillic pathogens.

611_freezing.png


Related Discussions:- Explain the process of freezing

Integumentary system , _____ are often responsible for clogging pores and c...

_____ are often responsible for clogging pores and causing pimpiles

Explain the duodenum - small intestine, Explain the Duodenum The first ...

Explain the Duodenum The first part of the small intestine is called the diodenum. It is about 10 inches in length. At the mid-point of the duodenum, there is a common opening

Explain the kidney as an endocrine gland, Explain the Kidney as an Endocrin...

Explain the Kidney as an Endocrine Gland The kidney produces substances that can be described as hormones. Hormones are the chemicals produced by glands in the body and circula

Biotechnology in agriculture, Biotechnology in agriculture: Production ...

Biotechnology in agriculture: Production of enough food to meet the demands of an ever-increasing population in the world is a major task and a challenge to agricultural scient

The movement of a glacier, Which is primarily involved in the movement of a...

Which is primarily involved in the movement of a glacier: gravity

What are vitamins, What are Vitamins Vitamins are generally synthesi...

What are Vitamins Vitamins are generally synthesized  by plants and found  in animals as a result of food intake and  also because of synthesis of some of the vitamins by gu

How does the atmosphere act as a blanket, Q.How does the atmosphere act as ...

Q.How does the atmosphere act as a blanket? The atmosphere acts as a blanket by performing the following functions: (a) It keeps the average temperature of the Earth fairly c

CONDUCTION, EXPLAIN THE PARTICLE THEORY EXPLANATION OF WHY BLACK OBJECTS GE...

EXPLAIN THE PARTICLE THEORY EXPLANATION OF WHY BLACK OBJECTS GETS OBSORBED QUICKER OR BETTER THAN WHITE OBJECTS?

Explain adventitia or outer covering, Explain Adventitia or Outer Covering ...

Explain Adventitia or Outer Covering In the thorax, the outer covering is made up of loose fibrous tissue and in the abdomen, the organs are covered through a serous membrane k

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd