Open AccessEffects of extrusion operating conditions and blend proportion on the physicochemical and sensory properties of teff-rice blend extruded products
Author(s) -
M. Minweyelet,
W.K. Solomon,
Geremew Bultosa
Publication year - 2021
Publication title -
food research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.218
H-Index - 7
ISSN - 2550-2166
DOI - 10.26656/fr.2017.5(2).467
Subject(s) - expansion ratio , extrusion , water content , bulk density , absorption of water , moisture , food science , materials science , barrel (horology) , flavor , composite material , chemistry , environmental science , soil science , geotechnical engineering , engineering , soil water
The effects of extrusion conditions, teff-to-rice blend ratio (25-100%), feed moisturecontent (21-25%) and barrel temperature (130- 150°C) on the physico-chemical propertiesand the sensory attributes of extruded product from teff-rice blend was investigated. Thephysico-chemical properties (specific length, bulk density, expansion, water absorptionindex (WAI), water solubility index (WSI) and hardness), and sensory acceptability(flavor, color, texture and overall acceptability) were significantly (p<0.05) influenced bythe extrusion conditions. Increasing barrel temperature resulted in higher expansion, lowerdensity, reduced hardness and higher WAI, and WSI. Increase in the proportion of teffresulted in increased density, hardness, and WSI whereas increase in teff proportionbrought about a decrease in expansion and WAI. Increasing feed moisture content resultedin higher density, lower expansion, higher WAI, lower WSI, higher hardness and lowercrispness. The sensory scores reduced with increase in the proportion teff. The numericaloptimization revealed that the optimal extrusion conditions for the best result wereextrusion temperature of 150°C, feed moisture content of 21.2% and blending ratio of40% teff with a desirability value of 0.901. The graphical optimization revealed that thebest results were found between 140 to 150°C, 21 to 22% feed moisture and 25 to 46% ofteff proportion.