However, different insect species and stages, physical and
thermal properties of products, and product size have different
susceptibilities to heat treatment and furthermore, mortality
is not related only to grain temperature; the rate at
which the grain is heated is also important, and an increasing
rate of heating by a higher medium temperature will create
thermal shock and achieve significantly higher mortality
[15,19,22]. Above tests for investigating conditions to meet
insect mortality, therefore, are very labor-intensive and
costly, and the results are only valid for the product tested
under the specified conditions investigated. Furthermore,
there is difficulty in measuring temperature distribution