| A study originally directed at simply adapting an in-line colour monitoring system of synthetic polymer extrusion to extrusion cooking, of necessity, resulted in the development of a new "in-line" calibration procedure that greatly improved the quality of the results. This significant outcome was one of many from a broadly based colour monitoring study of extrusion cooking. All five objectives of the work were accomplished. A precise and accurate in-line colour monitoring system based upon a charge-coupled-device (CCD) visible spectrophotometer was implemented. Accurate and precise colour changes during extrusion of corn flour were obtained in real-time by the new in-line calibration system. A semi-empirical model for correlating CIELAB in-line and off-line colour data was performed and assessed. A suitable method to SEC fractionate corn meal and extrudates was developed. And finally, using methanol-extraction UV-vis spectrophotometry, the progress of the Maillard reaction as a function of the extrusion conditions was detected off-line. |
