Abstract:
The present study was conducted to assess the effect of various pretreatments and drying
methods on the qualities of dried mango slices. Four drying methods (solar, tray, freeze and
fluidized bed drying) and four pretreatments (lemon juice, salt solution dips, hot water
blanching and control) were considered and arranged in factorial experimental design. The
proximate composition, physicochemical properties, antioxidants, rehydration ratio, microbial
loads and sensorial acceptance were evaluated. The result showed that the pretreatments and
drying methods showed significant effects on the proximate composition, physicochemical
properties, colour, antioxidants, rehydration ratio, microbial load and sensory acceptance of
the dried mango slices. The nutrient analysis showed that mango slices had respective ranges
for moisture, protein, fat, fibre, ash and carbohydrate contents (5.63-9.91%, 2.49-2.71%, 2.89-
3.16%, 6.51-6.56%, 2.66-2.73% and 75.51-79.35%). The pH, TSS, TA and hardness of the dried
mango slices, respectively were 3.17-3.68, 69.36-86.29ºBrix, 2.20-2.54 g/100g and 7.27-
15.63N. Regarding the colour of dried mango slices, the values ranged from 55.28-57.00, 11.85-
12.84, 32.99-48.58 and 5.15-20.02 for L*, a*, b* and ΔE colour values, respectively and were
significantly affected by the treatments. The ascorbic acid and phenol contents were affected by
drying methods and had respective values of 33.18-41.24 mg/100 g and 131.13-251.12 mg/100
g. As far as the rehydration ratio is concerned, better rehydration performance was observed
for the samples dried by the freeze and fluidized bed driers after subjected to the four different
pretreatments. It could be inferred that the total plate count of dried mango slices ranged from
1.4*102
-9.6*103 CFU/g while yeast and mould were 4.2*101
-8.2*101 CFU/g. Generally, the
overall acceptance of dried mango slice was good during three months of storage periods.
Mango peels were good sources of nutrition and phenolic content (564.54 mg/100g), and no
microbial loads have been detected during the storage period of three months.
