| The use of a CCD spectrometer system consists of an extruder/monitor interface, a fiber-optic-assisted charged-coupled device spectrometer and customized analysis software. It was shown that the CCD spectrometer was an attractive option for real time inline color monitoring. Neural networks provided excellent (r=0.99) correlation between in-line and offline color. Effect of color change with extruder parameters of corn feed, water feed and die temperature in presence and absence of a food colorant was also found to be well correlated. The usefulness of a microphone located near an extruder to monitor the extrusion cooling of corn meal was also examined. Acoustic monitoring has not been previously attempted in published literature. Using neural network methods, it was found that the frequency shift in the sound spectrum caused by the superheated water flashing off the extruder water could be well correlated with the die temperature, corn feed rate and the water feed rate. |
