Effects of feed moisture and extruder screw speed and temperature on physical characteristics and antioxidant activity of extruded proso millet (<i><scp>P</scp>anicum miliaceum</i>) flour
Paridhi Gulati, Steven A. Weier, Dipak K. Santra, Jeyamkondan Subbiah, Devin J. Rose
International Journal of Food Science & Technology
Abstract
Summary The objective of this work was to determine the impact of extrusion variables [moisture (17–25%), screw speed (170–250 r.p.m.) and temperature (90–150 °C)] on the physical properties and antioxidant activity of proso millet extrudates. Extrusion variables were adjusted using an inscribed central composite rotatable design. Response variables were bulk density ( BD ), radial expansion ratio, water absorption index, water solubility index, hardness, colour ( L *, a *, b *) and antioxidant activity. Moisture and screw speed were the most influential variables affecting millet extrusion: their linear, quadratic and interaction terms accounted for more than 50% of the variability in all responses except for b *. Expansion was greatest at severe conditions of low moisture and high screw speed. These conditions were also consistent with the highest antioxidant activity. This study demonstrated that high expansion and antioxidant activity can be obtained by extruding proso millet under low moisture and high screw speed conditions.
Extracted Claims
9 claims extracted from this paper into the knowledge graph
extrusion affects hardness
“Response variables were bulk density (BD), radial expansion ratio, water absorption index, water solubility index, hardness, colour (L*, a*, b*) and antioxidant activity”
extrusion increases expansion
“Expansion was greatest at severe conditions of low moisture and high screw speed”
extrusion affects water absorption index
“Response variables were bulk density (BD), radial expansion ratio, water absorption index, water solubility index, hardness, colour (L*, a*, b*) and antioxidant activity”