Abstract:
Experiments were carried out to optimize the
process parameters for production of papaya powder using
foam-mat drying. Papaya pulp was foamed by incorporating
methyl cellulose (0.25, 0.5, 0.75 and 1 %, w/w), glycerol mono-stearate (1, 2, 3 and 4 %, w/w) and egg white (5, 10,
15 and 20 %, w/w) as foaming agents. The maximum stable
foam formation was 72, 90 and 125% at 0.75 % methyl
cellulose, 3 % glycerol-mono-stearate and 15 % egg white
respectively with 9°Brix pulp and whipping time of 20 min.
The foamed pulp was dried at air temperature of 60, 65 and
70 °C with foam thickness of 2, 4, 6, 8 and 10 mm in a batch
type cabinet dryer. The drying time required for foamed
papaya pulp was lower than non-foamed pulp at all selected
temperatures. Biochemical analysis results showed a signif icant reduction in ascorbic acid, β-carotene and total sugars
in the foamed papaya dried product at higher foam thickness
(6, 8 and 10 mm) and temperature (65 and 70 °C due to
destruction at higher drying temperature and increasing
time. There was no significant change in other biochemical
constituents such as pH and acidity. The organoleptic and
sensory evaluation of the quality attributes of papaya
powder obtained from the pulp of 9°Brix added with 3 %
glycerol-mono-stearate, whipped for 20 min and dried with
a foam thickness of 4 mm at a temperature of 60 °C was
found to be optimum to produce the foam-mat dried papaya
powder.
