Abstract:

This study investigated the changes in physicochemical properties of ‘Baiyan No. 2’ oats after twin-screw
extrusion. It was shown that when the extrusion conditions were set as feed moisture content 22%, temperature 160 ℃,
and screw speed 42 Hz with a fixed feeding rate of 26 Hz, the expansion ratio of oat extrudate was 1.16. Maillard reaction
occurred during extrusion, resulting in changes in color and amino acid content. L*, a* and ΔE decreased, while b*
increased. Total amino acid content decreased by 5.44%. Compared to the original material, oat extrudate had a layered
rough surface. Water absorption index increased by 378.4%, water solubility index decreased by 1.08%, soluble betaglucan
content increased by 62.0%, apparent viscosity of the extract of in vitro digested oat extrudate increased, and both
polymerization and depolymerization reaction occurred during extrusion. Conclusively, twin-screw extrusion is a kind of
processing technique that has the potential to improve wholegrain oat quality.

Key words: ‘Baiyan No. 2&rsquo, oat, twin-screw extrusion, β-glucan, physicochemical properties