In an air blast freezing operation, a flat tray of 1.0 m×1.0 m×0.02 m dimensions is used to freeze filled depodded peas. Bulk density and moisture content of peas are 550 kg m³ and 85% (w.b.), respectively. Latent heat of freezing from water to ice at -1 °C is 335 kJ kg⁻¹ and heat transfer occurs identically from the top and the bottom surfaces of the tray. Convective film heat transfer coefficient on the heat transfer surfaces of the tray is 30 W m² K⁻¹ and the thermal conductivity of frozen peas is 0.54 W m⁻¹ K⁻¹. Assuming the tray to be a semi-infinite slab, the freezing time (in minutes) to completely freeze the product (rounded off to one decimal place) is