Expanded extrudates from corn starch lamb blends: process optimization using response surface methodology

A central composite second-order design was used to study the effects of fe ed (raw material blend) moisture, process temperature, and screw speed on e xpansion ratio (ER) and shear-force (SF) of extrudates from blends of corn starch and lean lamb. Quadratic polynomial equations were obtained by multi ple regression analysis using response surface methodology. The predicted m odels were adequate when tested by the lack of fit and coefficient of deter mination. The validity of the models was also confirmed by experimental dat a. Regression analysis predicted an optimal (minimal) SF to be attained wit h 26.5% feed moisture, 148 degrees C process temperature, and 134 rpm screw speed. This process condition was used in a companion study to produce and compare extrudates from blends of corn starch and lamb or mutton with simi lar extrudates produced with other meats. (C) 1999 Elsevier Science Ltd. Al l rights reserved.