A SIMPLE APPROXIMATE METHOD FOR PREDICTING CENTER TEMPERATURE OF CHICKEN WINGS TREATED AT CRYOGENIC TEMPERATURE

摘要

A simple approximate method was proposed/or predicting the center temperature of chicken wing treated at three cryogenic temperatures (-80℃, -120℃, and -160℃) in a rapid simulated forced-air freezing process (air velocity = 1,0 m s{sup}(-1)). This method used three equations depending on the period of the freezing process: (1) an interpolation equation available for the prediction of relative heat extraction was adopted for predicting the center temperature during the pre-cooling period, (2) a semi-empirical equation was developed for the phase transition period by correlating freezing point depression with moving freezing front, and (3) a well-known heat conduction equation was used for the tempering period due to small Biot numbers. The calculated surface heat transfer coefficients ranged from 19.7 to 22.1 W m{sup}(-2) K{sup}(-1) for the three cryogenic conditions, and the center temperature profiles were well predicted. The predicted freezing times also agreed well with the experimentally recorded values with prediction errors of -5.81% to 10.31%.