Investigating carotenoid loss after drying and storage of

84
3. Preliminary study
m) placed 30 cm above the ground, were loaded with a 2 mm layer of crimped sliced or
chipped sweet potato placed on terylene tissue (Figure 3-3). Two temperature probes
and one temperature/humidity probe were placed between the trays to measure
temperature and outlet air humidity. The temperature/humidity within the solar dryer
ranged from 27 to 50 ° C /14 to 52% compared to the external ambient range of 24 to
36 ° C/24 to 52% (Figure 3-4).
Figure 3-3: Greenhouse solar dryer. Views from the front (left) and the side that
includes sun dryer (right).
Polythene
cover
Sun radiation
751 W.m-2
(421-1005 W.m-2)
INLET
0.04m.s-1
Ambient air
32°C (24-36°C)/
31% (24-52%)
Sample
Greenhouse air
38°C (27-50°C)/
28% (14-52%)
OUTLET
Figure 3-4: SCec-Serre®!greenhouse solar dryer (front view). Temperature/
humidity: mean (min-max).