The Influence Of Grain Heat Treatment On Oats Physical, Chemical And Extrusion Characteristics

The naked oat grain BaiYanErHao was selected in this study，and then heated the kernelby the far-infrared heat treatment equipment to study the variation of physicochemicalproperties and extrusion characteristics of oat grain, oat flour and oat flour extrudate withdifferent heat treatment time. The physical and chemical indicators includ moisture, surfacetemperature, color, bulk density, the starch pasting properties, fat content, protein content,dietary fiber content and volatile matter composition. This study also analyzed the effect ofthe heat treatment in the oats processing chain that from the oat grain to oat flour and then theoat extrudate.The Study hasd shown that the heat treatment had a significant effect on thephysicochemical properties and extrusion characteristics of oat grain, oat flour and oatextrudate. With the increase of heat treatment time, the water content of the oat grain showeda decreased trend,the grain surface temperature showed an increased trend,the grain brightdegree increased firstly and then decreased, the bulk density increased firstly and thendecreased, the protein and crude fat content did not change,the total fat content increasedfirstly and then decreased, the soluble dietary fiber content did not change, the content ofinsoluble dietary fiber and total dietary fiber increased firstly and then decreased. The pastingtemperature of starch decreased firstly and then increased, the viscosity increased firstly andthen decreased. The types and proportions of volatile substances also changed.With the increase of heat treatment time, the oat flour yield increased significant, and therate between the skin flour and heart flour showed a decreased trend in oat flour. With theincrease of heat treatment time, the color of oat flour decreased, the protein content did notchange, the dietary fiber content increased firstly and then decreased, the pasting temperatureincreased and the peak viscosity decreased, trough viscosity and final viscosity are increasedfirstly and then decreased.The heat treatment had an important effect on extrusion of oat flour. This study foundthat the untreated oat flour can not form the extrudate. Oat flour extrudate gradually takenshape after4min heat treatment, with the increase of heat treatment time, the extruder torquedid not change, the5zone pressure increased firstly and then decreased, the color of extrusion decreased, the radial expansion rate and the protein content did not change. The dietary fibercontent was decreased, the pasting temperature increased, the peak viscosity, trough viscosityand final viscosity are increased firstly and then decreased.Heat treatment had a very important role in the oat processing, heat treatment couldpromote the composition migrating between the different components of the oat grain.Fromthe oat grain to oat flour and then oat extrudate, the color increased firstly and then decreased,the initial pasting temperature decreased, the viscosity increased firstly and then decreased,theprotein content decreased firstly and then remain unchanged, the dietary fiber content showeda decreased trend.