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

Syngamy - patterns of sexual reproduction, Syngamy - Patterns of Sexual Rep...

Syngamy - Patterns of Sexual Reproduction Sperm fuses with the egg. This results in both the union of the paternal nucleus with the maternal one (karyogamy), as well as the fu

Define the classification of carbohydrates, Define the Classification of Ca...

Define the Classification of Carbohydrates? If you go back and read up your theory, you will recall that there are four main classes of carbohydrates based on the number of mon

The cell, how autophagy help in converting a tadpole larva into adult amphi...

how autophagy help in converting a tadpole larva into adult amphibian

What is the host factors of implants, What is the Host Factors of implants ...

What is the Host Factors of implants These factors are very important and it is essential for the clinician to keep these in mind during the diagnosis and treatment planning st

Body composition assessment methods - underwater weighing, Define Body Comp...

Define Body Composition Assessment Methods - Underwater Weighing? Underwater weighing or hydrostatic weighing is one of the most common body composition methods used in laborat

Define about oxygen molecule, How many pairs of electrons do the two oxygen...

How many pairs of electrons do the two oxygen atoms in an oxygen molecule share with each  other? Explain your answer. The oxygen atoms share two pairs of electrons, sinc

Define the importance of zinc in humans, Define the Importance of Zinc in H...

Define the Importance of Zinc in Humans? Zinc deficiency in humans was reported by A.S. Prasad among people consuming mostly breads and very little animal protein in Middle Eas

What type of athlete, What type of athlete would have a above average react...

What type of athlete would have a above average reaction time please explain.

Nutritional requirements of fats and oils during pregnancy, Define Nutritio...

Define Nutritional Requirements of Fats and Oils during Pregnancy and Lactation? ICMR (1990) recommends that linoleic acid requirements should be raised to 4.5 en% during pregn

Concept of production - ecosystems, Concept of Production - Ecosystems ...

Concept of Production - Ecosystems The ecosystems are unable to function, unless there is a constant input of energy from an external source that is sun. Solar energy enters t

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