Conclusions
Roasting is one of the most important steps of the nut
processing. Drying is one of the important changes occurring
during roasting of nuts. In this study, drying
during thin layer roasting of hazelnuts was characterised.
Hazelnut drying during roasting occurred in the
falling rate period. Temperature dependence of the diffusivity
coecients was described by Arrhenius-type
relationship. The activation energy for moisture diusion
was found to be 1891.6 kJ/kg. Thin layer drying
characteristics of hazelnut roasting were satisfactorily
described by empirical Thompson model with the linear
temperature dependence. Further research about eect
of initial moisture content, air velocity, air relative humidity
and layer thickness on drying characteristics and
quality of hazelnuts is necessary for optimisation of
hazelnut roasting and development of hazelnut roasters.