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

Rejection of heliocentrism, Rejection of Heliocentrism: This happened...

Rejection of Heliocentrism: This happened  in the year  1918 when the astronomer Harlow Shapley (1885-1972) first surveyed the size and shape of  the Milky Way Galaxy. He  sh

Observe the surface of the moon, Observe the surface of the moon :- Use ...

Observe the surface of the moon :- Use the small telescope or a pair of field glasses. Examine the surface of the moon and see if you can see any of its craters and mountains.

Food chain, a food chain that does not start with plants??

a food chain that does not start with plants??

Big bang boom, if we drink liquid nitrogen then what happen

if we drink liquid nitrogen then what happen

Transport of bulk chemicals, Transport of Bulk Chemicals : Ideally only su...

Transport of Bulk Chemicals : Ideally only sufficient concentrated acids, flammable solvents and other hazardous chemicals should be kept in the laboratory for immediate requireme

Nursing process, Purpose To develop beginning skills in planning care f...

Purpose To develop beginning skills in planning care for clients using the nursing process. General Instructions 1. This assignment should be presented type written, 8

#sociology., ? Select one of the sociological perspectives, the functionali...

? Select one of the sociological perspectives, the functionalist, conflict, or symbolic interactionist, and analyze the problems facing K-12 education in the United States.

Explain the process of filtration - formation of urine, Explain the Process...

Explain the Process of Filtration - Formation of Urine The kidneys form urine in three phases: simple filtration, selective re-absorption and secretion. Let us begin with the p

Emroyology, what is tetrology of fallut? write down the emroyological basis...

what is tetrology of fallut? write down the emroyological basis of this condition?

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