Page 7 - curriculum

INTRODUCTION

Dear Trainee

Since the early ages human has tried various methods in order to consume food independent

from the season or to preserve food in hot or cold conditions. Drying is one of the most
widespread method.

This method has provided consumption of various food in various seasons and has also

prevented them to become inconsumable due to factors such as harmful micro-organism growth
and decay. Therefore, shelf life can be prolonged to 12 months by hot air application which

provides removal of essential water for micro-organism growth and prevents decay and
enzymatical spoiling. We are aware that any fruit is inconsumable in 3-10 days after it is

removed from the branches. It is obvious that consumption date is much longer when same fruit
is preserved by drying.

Drying is a temperature and mass transfer by carrying the water inside-out and evaporation

from the surface. Dehydration is removing moisture from food products. Dehydration provides
longer endurance for food. This method has been recognized since the primitive human.

However, it has been industrialized in eighteenth century.
The major advantage of drying food is to overcome decay during storage. Moisture is removed

by drying and microbial development with other reactions is prevented. Quality figures such as
scent, nutrition value are also preserved by decreasing moisture amount in products. Product

volume is decreased by drying; thus, transportation and storage stages are facilitated.

Food is subjected to some preliminary procedures. These procedures can be described as
sorting, washing, chopping and salinization. Some products are also submersed into alkali

solution or many food products are vulcanized.

The moisture within products are naturally removed which provides loss of weight. Dry food
weight ratio is a major criteria in terms of keeping taste, and texture.

Dry food weight ratio studies are performed in authorized laboratories within the scope of
physical analyses. Domestic and foreign standards are applied during these tests. Generally

accepted test methods and test criteria are complied in order to obtain reliable and neutral
results.

This module provides information on how to dry food with geothermal energy utilized system

which is a sustainable energy source and related research has provided the data for the module.
Dried food has become essential beyond a method due to advancing technology, increasing

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