Cereal Chem 65:267-270   |  VIEW ARTICLE

Optimization of Initial Moisture, pH, and Extrusion Temperature of an Acetone-Extracted Maize Gluten Meal and Soy Extrudate for Use in Pet Foods.

P. L. Harris, S. L. Cuppett, J. H. Rupnow, C. E. Walker, R. F. Mumm, and M. A. Hanna. Copyright 1988 by the American Association of Cereal Chemists, Inc. 

This study was conducted to optimize the textural properties of acetone-extracted maize gluten meal (AEMGM) and defatted soy flour (DSF) extrudates to achieve an extruded product for use as a canned pet food ingredient. Optimal blend moisture, pH, and extruder exit temperature were determined using a three- variable response-surface statistical design and analysis. Acidifying the blend, increasing the moisture level, and increasing the extrusion temperature improved structural integrities of the resultant extrudates. Upon retorting, all extrudates remained intact with no evidence of disintegration. As extruder exit temperature increased, the amount of trypsin inhibitor activity in the resultant AEMGM-DSF extrudates decreased. The blend ratio, moisture, and pH level did not affect trypsin inhibitor activity. Optimum textural properties of AEMGM-DSF blends occurred using a 50:50 AEMGM-DSF ratio with moisture level of 32%, a pH of 6.25, and an extruder exit temperature of 153 C. Optimum extruded products were characterized by a low water-holding capacity and inactivation of trypsin inhibitor activity.