The Effect of drying on microorganisms
The main purpose of drying foods is to lower their moisture content to a particular level that will exclude the growth of microorganisms (bacteria, mould and yeasts).
For any given moisture content, one food may support the growth of microorganisms will growth in a dried food depends on the water activity.
The lower the water activity of a food, the less probable that microorganisms will grow. Generally, mold at lower water activities than yeasts and yeasts will grow at lower water activities than bacteria. For this reason, mold are opt to grow in dried foods than are yeasts or bacteria.
In dried foods, the moisture content is lowered to the point which microorganisms will not grow and it is kept that way through packaging, which includes moisture.
Water activity also can be lowered by soluble components, such as sugar or salt.
Thus, certain syrup and salted, partially dried foods (e.g foods) are relatively stable as far as at the growth of microorganisms is concerned , although there may be conditions in which they become subject to the growth of yeasts or molds.
The Effect of drying on microorganisms
