Dehydration of potato

Drying behaviour of potato in a natural convection, solar dryer was investigated. In drying experiments conducted at low air velocity, as found in the solar dryer, it was shown that air flow conditions are of critical importance for drying behaviour. As a result of the presence of extensive, external mass transport resistances in deep bed drying, the air flow behaviour of the bed was more important than the drying behaviour of the single pieces. Thus, for deep bed solar drying, 10x10 mm french cut potatoes dried faster than 5 mm slices. (This result was opposite to that found for drying in thin layers). Drying time was noted to increase less rapidly than bed depth increased, so overall dryer productivity increased with increasing bed depth, within the constraint that drying be completable in 1 day.