Effects Of Extrusion Cooking On Composition And Solvent Retention Capacity Of Tartary Buckwheat Flour

[Objective] The study aims to study the effects of extrusion temperature,material moisture,screw speed on the composition and the solvent retention capacity of tartary buckwheat flour.The results can provide some theoretical guidances for tartary buckwheat processing.[Methods] Tartary buckwheat flour was used as raw material.The extrusion temperature was set as40℃,60℃,80℃,100℃,130℃;40℃,60℃,80℃,100℃,150℃;and 40℃,60℃,80℃,100℃,170℃.,The moisture content of the material was 18%,24%,30%,and the screw speed was 200 rpm,230 rpm,and260 rpm,respectively.The content of protein,fat,starch,dietary fiber,flavone,and water solvent retention capacity(WSRC),sucrose solvent retention capacity(SSRC),sodium carbonate solvent retention capacity(SCSRC),lactate solvent retention capacity(LASRC),oil holding capacity(OHC)were all measured.[Results](1)Compared with untreated tartary buckwheat flour,the protein content,fat content,starch content and flavone content of tartary buckwheat flour decreased significantly(P<0.05),and the dietary fiber content increased significantly(P<0.05).The starch content of tartary buckwheat flour decreased with the increase of extrusion temperature when the conditions of material moisture and screw speed were not changed;when the conditions of extrusion temperature and screw speed were not changed,the starch content decreased with the increase of material moisture;when the extrusion temperature and the material moisture condition were not changed,the starch content does not change with the screw speed condition.There were no obvious change trends in the content of protein fat,dietary fiber,flavonoids with the changes of extrusion temperature,material moisture,screw speed condition.(2)Compared with untreated tartary buckwheat flour,extrusion cooking significantly increased WSRC,LASRC,SCSRC and SSRC of tartary buckwheat flour(P<0.05),and there was no significant change in OHC.After the tartary buckwheat flour was treated with different extrusion cooking conditions,when the material moisture and screw speed conditions were unchanged,the LASRC,SCSRC gradually increased with the increase of extrusion temperature;WSRC,SSRC and OHC value had no obvious change trends with the change of extrusion temperature.WSRC,LASRC and SCSRC increased gradually with the increase of material moisture when the extrusion temperature and screw speed were constant;SSRC and OHC did not show obvious changes.WSRC,LASRC,SCSRC,SSRC and OHC did not show obvious changes with the change of screw speed.[Conclusion] After extrusion cooking,the content of protein,fat,starch and flavone in tartary buckwheat powder were all reduced,and dietary fiber content was increased.Extrusion cooking made the WSRC value,LASRC value,SCSRC value and SSRC value increased.The OHC value had no significant changes after extrusion cooking.