This work discusses results of experimental investigations of the specific heat, C, of apple in a wide
interval of moisture contents (W = 0 − 0.9) and temperatures (T = 283 − 363 K). The obtained
data reveal the important role of the bound water in determination of C(W, T ) behaviour. The
additive model for description of C(W) dependence in the moisture range of 0.1 < W < 1.0 was
applied, where the apple was considered as a mixture of water and hydrated apple material (water
plasticised apple) with specific heat Ch. The difference between Ch and specific heat of dry apple,
∆Cb = Ch−Cd, was proposed as a measure of the excess contribution of bound water to the specific
heat. The estimated amounts of bound water Wb were comparable with the monolayer moisture
content in apple. The analytical equation was proposed for approximation of C(W, T ) dependencies
in the studied intervals of moisture content and temperature.