사출구 구조에 따른 옥수수가루 압출성형물의 팽화특성

구본재¹, 류기형¹^,^*

Effect of Die Geometry on Expansion of Corn Flour Extrudate

Bon-Jae Gu¹, Gi-Hyung Ryu¹^,^*

¹공주대학교 식품공학과

¹Department of Food Science and Technology, Kongju National University

^*Corresponding author: Gi-Hyung Ryu, Department of Food Science and Technology, Kongju National University, Yesan, Choongnam 340-800, Repulic of Korea, Tel: +82-41-330-1484; Fax: +82-41-335-5944, E-mail: ghryu@kongju.ac.kr

ⓒ Copyright 2011 Korean Society for Food Engineering. This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Received: Nov 30, 2010; Revised: Apr 25, 2011; Accepted: Apr 27, 2011

Published Online: May 31, 2011

Abatract

The objective of this study was to determine the effect of die geometry on expansion index of extruded corn flour. Water solubility index, water absorption index and specific mechanical energy (SME) input were analyzed to observe the relationship with die geometry. The feed moisture content was 20 and 25%. Die dimensions were tapered angle (57, 95°) and length/diameter (L/D) ratio of die land (0.67, 1.67 and 2.67). The SME input was the highest at 20% moisture content and 2.23E-10 m³ die constant. The sectional and volumetric expansion indices at 20% moisture were increased with increase in die constant. However, die constant did not influence sectional expansion index of corn flour extrudate at 25% moisture content. The extruded corn flour at 25% moisture content had higher longitudinal expansion index than those of extruded corn flour at 20% moisture content. Sectional expansion and longitudinal expansion index were negatively correlated. The water absorption index and water solubility index were not affected with the die constant.

Keywords: extruded corn flour; die constant; die geometry; expansion index