PROCESS OPTIMIZATION WITH RESPECT TO THE EXPANSION RATIOS OF MILLET- AND LEGUME (PIGEON PEA)-BASED EXTRUDED SNACKS

摘要

Extruded snacks were made from five blends of millet and legume atnvarying moisture content (12, 15, 18, 21 and 24%, wet basis [wb]). Thenpercent of legume in the blends were, 12, 16, 20, 24 and 28. Designednexperiments were conducted based on central composite rotatable designnto determine the optimum processing condition with respect to the expansionnratios of the extrudates. A single-screw laboratory Brabender DA47055n(Duisburg, Germany) extruder was operated at different die head temperaturesn(160–200C), barrel temperatures (100–140C) and screw speedsn(100–140 rpm). The optimum processing conditions obtained using responsensurface methodology were: moisture content – 19%, wb; blend ratio – 15.7%nlegume; die head temperature – 190C; barrel temperature – 136.5C and screwnspeed – 140 rpm. The corresponding expansion ratios viz. specific length,n5 Corresponding author. TEL: +91-941-5060125; FAX: +91-510-2320761; EMAIL: subir8275@nyahoo.co.innJournal of Food Process Engineering 34 (2011) 777–791. All Rights Reserved.n© 2009 Wiley Periodicals, Inc.nDOI: 10.1111/j.1745-4530.2009.00433.xn777nsectional expansion index, longitudinal expansion index and volumetricnexpansion index were 64.3, 5.5, 0.6 and 3.3, respectively.