Skip to main content

How to dehydrate


This book is available on the online bookstore, www.morebooks.de (https://www.morebooks.de/gb/search?utf8=%E2%9C%93&q=Ukponmwan+ifueko+oghogho+) or 
amazon.com/author/ifuekoukponmwan


Principles of dehydration

  • There should be sufficient heat to vapourise and remove the liquid water from food.
  • Foods should be dried rapidly but not so fast that the outside becomes hard before the moisture inside has a chance to evapourate
  • The required latent heat of vapourization is 540Kcal/kg water and must be supplied to the water molecules in the food to volatilise them.
  • Pre-treating some foods before drying preserves their colour and nutrients and prolong shelf life
  • Drying should not be interrupted, once drying is started, dont stop or allow the food to cool down in order to start drying again later. Moulds and other spoilage organisms can grow on partly dried foods
  • The foods should be uniformly dried by spreading thin layers of uniformly sized pieces of food on the drying racks.
  • Foods harvested must be prepared for dtying as soon as possible.
  • .....................................................


Excerpts from the book, Basic principles of food processing and preservation:Easy notes. By Ukponmwan, Ifueko Oghogho

Comments

Post a Comment

Popular posts from this blog

Physical classification of water

Hygroscopic water This is the water present in an air dry soil held tightly by soil solids at a suction pressure greater than 3.1 bar. This type of water cannot be removed by evapouration and roots of higher plants. Only microbial activities have been found to take place here.
Post a Comment
Read more

Aprilians

Strong resilient women are born in April, celebrate them!
Post a Comment
Read more

Drying oil in water emulsion

The drying curve varies according to the type of food and the kind of drier that is used, and also the way the food material also responds to temperature, humidity, air velocity and direction of air and thickness of food. Oil-in-water emulsion dries only quickly than water -in-oil emulsion. Case hardening is common with foods that contain dissolved sugars and other solutes in high temperature. As water leaves cells of the food, solutes are retained by cell membranes and air spaces in surface layers can act by capillary action whereby water caries solutes to the surface during drying and leaves them there. In some fruits, this can cause sticky sugary exudates on the surface, which shrinks and clogs pores leading to case hardening.................................................... Excerpts from the book, Basic principles of food  processing and preservation: Easy notes by Ukponmwan, Ifueko.  Get it from the online store www.morebooks.de  https://www.morebooks.de/g...
Post a Comment
Read more