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

Define energy and protein requirement in geriatric nutrition, Define Energy...

Define Energy and Protein requirements in geriatric nutrition? Decreased physical activity and changes in body composition and decreased basal metabolic rate affects the ma

What is physical activity ratio, What is Physical activity ratio? Physi...

What is Physical activity ratio? Physical activity ratio (PAR): The energy cost of an activity per unit of time (usually a minute or an hour) expressed as a multiple of BMR. It

Explain the effect on serum proteins during pregnancy, Explain the Effect o...

Explain the Effect on serum Proteins during pregnancy? Total serum protein gradually decreases, along with a sharp decline in albumin. There is reduction in serum albumin along

Define blood pressure, Blood Pressure Blood pressure may be defined as ...

Blood Pressure Blood pressure may be defined as the force or pressure which the blood exerts on the walls of the artery. Blood pressure varies with the age of the individual. B

Classification levels of blood pressure, Table gives the current classifica...

Table gives the current classification of hypertension as recommended by JNC VII. The classification is based on the mean of two or more seated readings on two or more occasions.

Tools of lower paieolithic age, Tools of lower paieolithic age Pleistoc...

Tools of lower paieolithic age Pleistocene times there were huge herds of very large mammals. Bones of such large mammals were found associated with the human fossil finds and

The cardiac cycle during which the ventricles are filled, What is the stage...

What is the stage of the cardiac cycle during which the ventricles are filled? The filling of the ventricles with blood happens during diastole. The Circulatory System - Ima

Explain what is cyanosis and polycythemia, Explain what is Cyanosis and pol...

Explain what is Cyanosis and polycythemia? Cyanosis and Polycythemia: Central cyanosis involving the mucous membranes and trunk along with the lips and extremities in absence

Energy requirement during congestive cardiac failure, Q. Energy requirement...

Q. Energy requirement during congestive cardiac failure? Energy: Composition of the calorie requirements on the basis of body weight is usually not feasible due to the presence

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