3.3.2.3. Weight reduction. Fig. 3 shows the evolution of weight
reduction of the coated and uncoated papaya samples during dehydration
process. All treatments, independently of the ripening degree,
showed a similar behavior for weight reduction, observing,
of general way, that coated papaya samples presented higher values
for this parameter than uncoated fruits, which it could due
to that the fruits treated with coatings lost more water (Fig. 1)
and won less solids than fruits without coatings (Fig. 2). It is agree
with the results obtained by Díaz (2003) and Argaiz, Leyva, and
Jiménez (2003).
3.3.2.4. Process efficiency index. The values of the process efficiency
index (Pr =WL/SG) are used for evaluation of efficiency of osmotic
dehydration process (Fig. 4), due to their easy interpretation, because
if Pr increases it could mean one of this three possibilities:
(i) the process is favoring the water loss and solids gain, but mostly
the water loss; (ii) the process limits the solids gain; and (iii) the
process favors the water loss.
It was observed, in general, that the treatments with coatings
presented higher values of Pr during the osmotic dehydration process,
what could be due to that in these treatments the water loss
was favored, while the soluble solids gain was limited. At the
beginning of the process, the changes in the Pr value can be attributable
mainly to the water loss, and when the process time increases,
the solids gain has more influence on the Pr value. This
indicates that upon designing an osmotic dehydration process for
this fruit, the time of contact will be defined in function of the pursued
objective.
Fig. 2. Variation of solid gain of papaya samples during osmotic dehydration in
sucrose solution 40Brix (n = 4). (a) Green papaya and (b) ripped papaya.
Fig. 3. Variation of weight reduction of papaya samples during osmotic dehydration
in sucrose solution 40Brix (n = 4). (a) Green papaya and (b) ripped papaya