Journal article
Waxy flour degradation – Impact of screw geometry and specific mechanical energy in a co-rotating twin screw extruder
Food chemistry, Vol.239, pp.688-696
01/15/2018
Handle:
https://hdl.handle.net/2376/105724
PMID: 28873623
Abstract
•Extruder screw profiles were found to have a large impact on flour degradation.•Specific mechanical energy was found to relate directly to the amount of degradation.•Size exclusion chromatography identified starch splitting and protein destruction.•The extruder die was found to have no impact on the flour degradation.
Dextrinization of starch using extrusion processing is crucial to the quality of direct expanded products. To determine the extent of dextrinization, flour samples were extracted from a twin-screw extruder that had been brought to a sudden stop and molecular weights were determined by intrinsic viscosity. The screw profile and moisture feed content had the most significant impact on molecular weight reduction, reducing intrinsic viscosity from 1.75 to 0.70dL/g at the most. The breakdown, as shown by a reduction in intrinsic viscosity, had a strong negative correlation (r=−0.96) with specific mechanical energy. However, the extruder die did not have a measurable impact on the molecular weight reduction of waxy flour. Size exclusion chromatography confirmed intrinsic viscosity measurements were associated with reduction of the size of amylopectin molecules to approximately 1/10 the original molecular weight while native gliadin was nearly eliminated from the waxy flour following the extrusion treatments.
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Details
- Title
- Waxy flour degradation – Impact of screw geometry and specific mechanical energy in a co-rotating twin screw extruder
- Creators
- Ryan J Kowalski - School of Food Science, Washington State University, Pullman, WA 99164, USAJacob P Hause - School of Food Science, University of Idaho, Moscow, ID 83844, USAHelen Joyner (Melito) - School of Food Science, University of Idaho, Moscow, ID 83844, USAGirish M Ganjyal - School of Food Science, Washington State University, Pullman, WA 99164, USA
- Publication Details
- Food chemistry, Vol.239, pp.688-696
- Academic Unit
- Food Science, School of
- Publisher
- Elsevier Ltd
- Identifiers
- 99900546707501842
- Language
- English
- Resource Type
- Journal article