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

What does regolith mean, What does regolith mean? Ans) This refers to ...

What does regolith mean? Ans) This refers to a layer of loose surface material covering bedrock.

Explain scurvy, Scurvy  Disease occurs due to vitamin C deficiency.

Scurvy  Disease occurs due to vitamin C deficiency.

Science fair , what kind of questions do they ask at a science fair

what kind of questions do they ask at a science fair

Explain primary processing of oilseeds and pulse products, Pulse products: ...

Pulse products: The important processed pulse products are puffed chickpea and pea,  besan, papads, pulse-based weaning foods, quick cooking dhals, and canned dry peas   Oils

Renaissance (1440-1540), Renaissance (1440-1540): The Renaissance was a...

Renaissance (1440-1540): The Renaissance was a revolutionary movement. It marked a definite and deliberate break with the past.  It swept away the medieval forms of economy, of

Mendilian genetics, what are the 7 characters of pea plants observed by men...

what are the 7 characters of pea plants observed by mendal?

Explain physiology of ageing, Explain Physiology of Ageing Ageing in si...

Explain Physiology of Ageing Ageing in simple terms refers to a physiological process that occurs in an organism as it gets older Ageing physiologically refers to the impaired

Psychology, Which theory focuses on how people are different than animals? ...

Which theory focuses on how people are different than animals? Functionalism Eclecticism Humanism Behaviorism

Define the factors that influence the facilitated diffusion, Define the Fac...

Define the Factors That Influence the Facilitated Diffusion Facilitated diffusion is influenced by the following factors: Minor differences in the molecular structure ma

Checking breathing and pulse for unconscious casualties, Checking Breathing...

Checking Breathing and Pulse : Before attempting to resuscitate a casualty, it is essential that you check his/her breathing rate and pulse. You can cause problems if you attempt

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