The vitamin content of a food is, in general, reduced by drying. This is
especially true for those vitamins (e.g. vitamin A and ascorbic acid)
that are easily destroyed by heat in the presence of air, through
oxidation.
The drying temperature has been shown to have no influence on vitamins
B1, B2, B6 and niacin, whereas vitamin A losses increase with increasing
drying temperatures. β-carotene which may be applied as the source of
the vitamin A is shown to be far more stable than the straight vitamin.
Drying methods affect vitamin C content as well. It can be stated that
the higher the drying temperature and air velocity, the greater the
degradation of vitamin C durign drying.
However the application of a drying process with low temperatures for a
short period of time can result in relatively high ascorbic acid
retention, avoiding its sensitivity to heating processes. The sulfuring
of fruit previous to drying also aids in reducing the amount of ascorbic
acid destroyed during drying.
Drying process affects vitamin in food
