Effect Of Microwave Pre-gelatintion On The Quality Of Extruded Whole Oat Noodles

Oat is rich in nutrition,but it does not contain gluten protein and is not easy to be processed.Therefore,it is difficult to process oat into noodles and other products.Even if oat flour was mixed with wheat flour,the gluten protein was diluted,resulting in large cooking loss of noodles and mixing of soup.Therefore,this study pre-gelatinized the rehydrated oat rice by microwave,and then made the obtained oat flour extruded into whole oat noodles.This study reported the effects of different microwave time,microwave power and rehydration rate of oat rice on the physical and chemical properties of oat.The results of the study showed that the gelatinization degree,water solubility index(WSI)and water absorption index(WAI)of microwave pre-gelatinized oat flour were significantly improved.For the thermodynamic properties,the Tp value and ΔH of the experimental group were significantly decreased compared to the control group’s 111.9°C and 222.6 J/g;the crystal type of oat flour gradually changed from A-type to V-type;there was no peak generation or shift in the infrared spectrum,and the changes of 1047/1022 and 1022/995 were all consistent with the XRD results.Correspondingly;SEM results showed that as the degree of gelatinization increased,oat flour particles gradually expanded,melted and agglomerated together.After microwave pre-gelatinization,the oat flour was extruded into extruded whole oat noodle.Moreover,as the degree of gelatinization increased,the L value of oat noodles gradually decreased,and a* and b* showed a gradually decline.At the same time,sensory indicators such as the color and performance state of the noodles also increased with the increasing of gelatinization degree.The cooking loss decreased with the increasing of gelatinization,and the texture quality of noodles also showed an increasing trend with the increase of gelatinization.To sum up,when the gelatinization degree raised to 88.50%,the cooking,texture,sensory and other quality indexes reached the best.After microwave pre-gelatinization,oat starch gradually agglomerated together.The infrared spectrum and TGA curve showed the consistency of chemical composition before and after the treatment,and the rheological properties showed that after microwave pre-gelatinization,the pasting temperature of oat starch decreased,G’,G’ and tanδ all increased significantly,indicating that oat starch formed a starch gel with higher viscoelasticity at a lower temperature after microwave pre-gelatinization.For the oat protein,the results of FTIR and TGA also showed an increase of molecular chain crosslinkin.The results showed that the degree of gelatinization affected the physical and chemical properties of oat flour,thereby improving its processing characteristics,so that the microwave pre-gelatinized oat flour can be extruded into whole oat noodles and obtained good qualities.These were mainly due to the fact that oat starch was in the change of rheological properties under microwave pre-gelatinization conditions made it easier to form starch gel instead of gluten.Therefore,microwave pre-gelatinization technology can be used as the production technology of staple food production of miscellaneous grains in the future.