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

Which disorders is most likely to underlie, A healthy, primiparous (first-t...

A healthy, primiparous (first-time) mother delivered a healthy infant several hours ago, but the mother has experienced postpartum hemorrhage. Which of the following disorders is m

Zoology, Protozoa general characters and classification

Protozoa general characters and classification

Describe the various types of rna, Describe the various types of RNA? ...

Describe the various types of RNA? Types of RNA :  There are three different types of RNA, all formed by transcription from DNA: (1) Messenger RNA (mRNA) is a single unc

Acellular and cellular organisms, Acellular and Cellular Organisms you...

Acellular and Cellular Organisms you should be able to characterise living and non- living matter. However, the boundary-line between the two is not very precise. As you have

Evolution of man, EVOLUTION OF MAN - Mammals evolved from primitive...

EVOLUTION OF MAN - Mammals evolved from primitive reptiles (therapsida) in Triassic period, about 210 million years ago. Mammals existed as inconspicuous group of small

What is the meaning of chelicifore, What is the meaning of Chelicifore? ...

What is the meaning of Chelicifore? These feeding mouthparts are found on most, pycnogonads. Though the proboscis is the main feeding structure in these animals when chelicifor

Write short notes on urine, Write short notes on Urine? The concentrate...

Write short notes on Urine? The concentrated filtrate produced by the kidney is called urine, and is composed mainly of water, urea, toxins, and mineral salts. Urine from the c

Platelet, What happens if platelets aren''t present in blood?

What happens if platelets aren''t present in blood?

Assessment of ventricular septal defect, Assessment   On assessment a c...

Assessment   On assessment a child with ventricular septal defect will show clinical manifestations depending upon the size of  the defect. The small defects are usually asympt

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