and bubble end point
(final stage of frying when the process is extended to longer times).
With start of surface boiling, water starts vaporizing, and bubbling
increases to a maximum value (Costa et al., 1999) after initial heating.
The second stage is characterized by increase in heat transfer
coefficient and sudden loss of free moisture from surface with crust
formation (Farkas et al., 1996). In this stage, surface conditions
change from free convection to boiling with a further increase in
surface renewal (Farkas et al., 1996). In the last stage, heat transfer
rate is expected to decrease due to increased thickness of lower
thermal conductivity crust and reduced mass transfer from the
product