title: Optimization of process parameters for foam-mat drying of papaya pulp.
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 significant 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.
authors.affiliation: Agricultural Engineering Section, Institute of Agriculture, Visva-Bharati Central University, Santiniketan, West Bengal 731 235 India.
authors.forename: Palani
authors.initials: P
authors.lastname: Kandasamy
authors.affiliation: Department of Food and Agricultural Process Engineering, Agricultural Engineering College & Research Institute, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu 641 003 India.
authors.forename: N
authors.initials: N
authors.lastname: Varadharaju
authors.affiliation: Department of Food and Agricultural Process Engineering, Agricultural Engineering College & Research Institute, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu 641 003 India.
authors.forename: S
authors.initials: S
authors.lastname: Kalemullah
authors.affiliation: Department of Food and Agricultural Process Engineering, Agricultural Engineering College & Research Institute, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu 641 003 India.
authors.forename: D
authors.initials: D
authors.lastname: Maladhi
keywords: Drying; Foam expansion; Foam thickness; Foaming agents; Moisture content; Papaya pulp