The three pre-drying treatments had significant ( P ≤ 0.05)
effect on the time of drying (Table 3 ). Salted pumpkin fruit
slices that was dried in the oven had significantly ( P ≤ 0.05)
shorter time of drying (23.8 h) and was followed by
blanched pumpkin fruit slices (24.2 h) while untreated control pumpkin fruit slices took longer time of drying (25.1 h).
This result was found to be in positive agreement with the
findings of Mayor et al. ( 2006 ) that clearly showed that salt
solution dipping reduces the time of drying. The data presented in this study confirmed that the main advantage of
pre-drying treatment is shortening the time of drying and
then resulting in lower energy requirements for drying
(Tsots as and Mujumdar 2012 ). Blanching reduces the time
of drying through reducing the firmness of fruit tissue and
facilitates moisture diffusion from sample fruit slices and
thereby reducing the required time of drying ( Brennand
19 94 ). Blanching is one of the most widely used pre-drying treatments in the dehydration procedures of most
fruits and vegetables (McB ean et al. 1964 ). Research reports
clearly showed that using appropriate drying condition sand
pre-drying treatment significantly reduces the drying time of
other fruit and vegetables (Park et al. 2002 ; Simal et al.
1997 ).
The two- way interaction between drying method sand
pre-drying pretreatment significantly ( P ≤ 0.05) affected the
drying time of pumpkin accession ( Tables 1 and 2 and
Fig. 2 ). Salted pumpkin fruit accession that were subjected
to oven drying required short drying time (18 h) which was
followed by blanched oven dried sample (20 h) to attain
10 % moisture content. Sun dried pumpkin fruit took relatively longer drying time (32 h) to attain 10 % moisture
content (Table 3 ).