2.2. Ohmic cooking procedure
Ohmic cooking was applied as pre-treatment before final
cooking of meatballs. Experiments were conducted in specifically
designed custom-made continuous belt type ohmic cooking sys-
tem, which consisted of a power supply, an isolating-variable
transformer, a microprocessor board and a data recording system,
temperature measurement units, ohmic cooking unit and a rotating
belt system (Fig. 1). The cooking unit was designed specially, which
includes rotating (Polyester Monofilament) belt with motor for
controlling speed, two removable stainless steel electrodes
(5 cm 30 cm), electrically isolated Teflon mountings and electrical
connections to transformer unit. Temperature measurements were
conducted by using Teflon coated electronic temperature sensors
(Omega Eng. Inc., Stanford, CT). Teflon coated electronic tempera-
ture sensors had special design and isolation to electric current.
They could have been immersed into meatball. The occurrence of
the signal interference in the system was avoided by the usage of
Teflon as a coating material, and other possible signals were taken
into account by the control program of the microprocessor. The
time constants of temperature sensors were determined by cali-
brating them in standard calibration solutions (Omega Eng. Inc.,
Stanford, CT). The microprocessor board that was used to monitor
the temperatures, current (A) and voltage applied (V), and it
transmitted this information simultaneously to the microcomputer
at constant time intervals (1 s) (Fig. 1).