Analysis of Transient Heat and Mass Transfer during Deep-Fat Frying of Pantoa

Abstract

Pantoa is a traditional dairy product of the Indian subcontinent. Heat transfer in pantoa during deep-fat frying was evaluated using lumped thermal capacity model and one-dimensional transient heat conduction equation. Moisture and fat transfers were modeled using one-dimensional transient moisture diffusion equation and second order polynomial model, respectively. Lumped thermal capacity model was found to be unsuitable. As the frying temperature increased from 125C to 145C, the heat transfer coefficient obtained from one-dimensional transient heat conduction equation increased from 101.77 to 237.10 W/m2 K, while the moisture transfer coefficient increased from 7.79 × 10−6 to 9.05 × 10−6 m/s. The effective moisture diffusivity varied from 5.55 × 10−8 to 38.8 × 10−8m2/s for the temperature range studied. The moisture diffusivity was affected by frying temperature, and it was described by modified Arrhenius relationship. From the steady decline in Lewis number (2.18 to 0.35) with increase in frying temperature from 125C to 145C, it could be concluded that thermal diffusion was prominent at 125C, which was superseded by moisture diffusion at 145C. Practical Applications Pantoa is a traditional and popular dairy product of the Indian subcontinent. Deep-fat frying of pantoa involves simultaneous heat and mass transfer. In this study, the heat and mass transport during frying were analyzed and modeled. The effects of process temperature and time, on heat and mass transfer properties and diffusivities also were evaluated. The heat and mass transfer models will be useful to optimize the frying process and improve the quality of pantoa.