DYNAMIC ANALYSIS OF ONLINE PRODUCT QUALITY ATTRIBUTES OF A FOOD EXTRUDER

The dynamics of a twin screw food extrusion process, including product quality attributes (PQA), to change in feed rate, water rate, screw s peed, and barrel temperature at zone 5 were defined. Two PQA variables clearly dominated, colour-b and collet moisture content, which were h ighly correlated to bulk density. Product temperature at the die also showed high steady-state correlation with bulk density. Moisture in th e barrel was the primary driver for the colour-b and collet moisture c ontent responses. Barrel temperature-5 was important in the response o f product temperature, but excessive delay times made it less importan t as a control variable. The gains indicated a non-linear system over the response range explored.