Effects of drying temperatures on physico-chemical properties of dried and rehydrated chestnuts (Castanea sativa)

This work evaluated the effects of two drying temperatures (40 and 60 °C) on some physical and chemical properties of chestnuts, both dried and after their rehydration using steam at 100 °C. The morphological characteristics of fresh starch granules were characterized by a round or oval shape, with diameter length ranging from 3.0 to 15.0 μm. After drying and rehydration, the granules appeared more shapeless and the surfaces were quite rough. The changes also caused more of the open pore volume fraction in samples dried at 60 °C, than in those dried at 40 °C and, much more, than the fresh samples. Also, calorimetric behaviour, starch and simple sugar changes after chestnut drying and rehydration, were studied.