MATHEMATICAL MODELING OF THIN-LAYER DRYING OF JACKFRUIT LEATHER

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Abstract

ABSTRACT

Thin-layer drying experiments of jackfruit leather were conducted at four different temperatures, five relative humidities and five air velocity levels. The drying rate increases with the increase of temperature but decreases with the increase of relative humidity. Drying rate also increases with the increase of air velocity, but it becomes independent of air velocity when velocity is above 1.5 m/s. There was no change in color of the dried products for drying in the temperature range of 40–50C, but lightness decreased with the temperature for drying in the temperature range above 50–70C. Effective moisture diffusivity values were between 3.25 × 10−10 and 1.0062 × 10−9 m2/s, and activation energy value of water diffusion was 31.49 kJ/mol for 5-mm thickness. Nine thin-layer drying models were fitted to the experimental data of thin-layer drying, and the Modified Page's Model was found to be the best.

PRACTICAL APPLICATIONS

The amount of jackfruits spoiled during the harvesting season can be minimized by drying the jackfruit into jackfruit leather to increase its shelf life and to ensure year-round availability of jackfruits. In this study, thin-layer drying characteristics of jackfruit leather are presented under controlled conditions of drying air temperature, relative humidity and air velocity to search for optimum drying conditions in terms of efficient drying and product quality. Optimum drying temperature for production of quality dried jackfruit is recommended. Thin-layer drying models developed are also useful in the simulation and optimal design of both solar and mechanical dryers for drying of jackfruit leather.

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