when energetic contributions used to remove moisture from foodstuffs were obtained
exclusively by burning LPG. Initial drying efficiency is high
(86%), as the moisture that evaporates from the foodstuff is
free water and is more easily removed as a result of being
closer to the surface. As free water levels drop, linked water
migrates from the interior of the foodstuff to its surface.
This causes the drying process to proceed more slowly, as
mechanisms more complex than simple evaporation intervene.
This results in a progressive decrease in efficiency,
ultimately reaching a minimum level (7%). It can be
observed that drying efficiency has a sustained rate of
change resulting from the continuous and sufficient energetic
contribution provided by burning LPG. Drying time
in this mode of operation was 15 h, with an energetic contribution
of 11.24 kW h.