Preserving foods, Biology

Assignment Help:

One of man's oldest methods of preserving foods is drying or desiccation. The preservation of foods by drying is a direct result of removal of moisture. Microorganisms need water for growth. The exact amount of water needed for growth of microorganisms varies. This water requirement of microorganisms is best expressed in terms of available water or water activity aw, the vapour pressure of the solution (of solutes in water in most foods) divided by the vapour pressure of the solvent (usually water). Thus aw, for pure water would be 1.00. The water activity depends on the number of molecules and ions present in solution, rather than their size. Thus a compound like sodium chloride, which dissociates into two ions in solution, is more effective at reducing the water activity than a compound like sucrose on mole-to-mole basis.


Related Discussions:- Preserving foods

Concerning their permeability how are membranes classified, Q. Concerning t...

Q. Concerning their permeability how are membranes classified? Membranes can be classified as permeable, impermeable, selectively permeable or semipermeable. An impermeable

Father, who is the father of science

who is the father of science

Define the management of obesity, Define the Management of Obesity? Man...

Define the Management of Obesity? Management of obesity should be taken up with a clear understanding of the harsh realities of the problem and its outcome. It may be a frustra

Explain about picaridin, Picaridin Laboratory and field studies docume...

Picaridin Laboratory and field studies documenting the efficacy of picaridin. No published data are available on the efficacy of the 7% solution now available in the US. Insec

Define the magnesium requirements in body, Define the Magnesium Requirement...

Define the Magnesium Requirements in body? Let us learn about the magnesium requirements. Since plant foods are particularly high in magnesium, on a vegetarian diet with plenty

Protoplasmic - level of body organization, Protoplasmic - Level of body org...

Protoplasmic - Level of body organization Organisms which are made of just one cell are the simplest and the most primitive creatures called unicellular organisms. Their level

Explain food borne toxic infections, Q. Explain Food borne toxic infections...

Q. Explain Food borne toxic infections? Ans. The food borne toxic infections, you may recall reading earlier, are caused by the ingestion of a large numbers of ent

Effect of respiratory frequency, Q. How does the pulmonary ventilation affe...

Q. How does the pulmonary ventilation affect the carbon dioxide concentration in blood? What happens to the carbon dioxide concentration and to the blood pH when the respiratory fr

The physical environment - stress of hospitalization, The Physical Environm...

The Physical Environment   The actual hospital environment is another factor that may be stressful for the child and family. There are many unfamiliar sights, sounds and smells

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