Research On Adhesion Properties Of Dough Sheet And Preparation Of Cooked Wheaten Food Anti-Adhesive Composite Film

In order to reduce the adhesion ability of the dough sheet on the contact surface,and increase the water addition of mechanical Cooked Wheaten Food(CWF).This paper focuses on the adhesive properties of the dough sheet and the preparation of CWF anti-adhesive composite coatings.A test machine for characterizing the adhesive ability of the dough sheet was designed and built,the adhesion characteristics of the dough sheet and the failure modes between the dough sheet and the contact surface were studied by the testing machine,key factors that influence the adhesion ability of the dough sheet were analyzed.According to adhesion failure modes of the dough sheet and analysis results of the physical properties of the dough sheet during the rolling process,a composite anti-adhesion layer was designed and prepared,anti-adhesion composite layer has micro texture and elemental doped carbon based film on the surface.The effect of texture parameters on the adhesion ability was studied.The excellent textured Cr-DLC(Chromium Doped Diamond-Like)anti-adhesion composite film was designed and prepared.The main research contents and conclusions of this article are as follows:A test machine for characterizing the adhesive ability of the dough sheet was designed and built,Adhesion performance of the dough sheet coupling with various process parameters under rolling condition was evaluated and realized by using the testing machine.The variation rules between water addition,rolling ratio,salt addition,linear velocity and adhesion ability were obtained.It is found that water addition,rolling ratio and peeling speed are the key factors to increase the adhesion ability of the dough sheet.With the increase of water addition(35%-75%),the failure mode of the dough sheet shifts from interface failure to cohesive failure mode.Under the same water addition(55%),the adhesion ability of the dough sheet increases linearly with the rolling ratio.The water distribution and migration in the dough sheet were studied in the process of making dough sheet.Low nuclear magnetic resonance(NMR)instrument was used to analyze the variation of water distribution in the dough sheet,in the "adding water" and"rolling" process.It was found that the water molecules in dough(or dough sheet)mainly existed in three forms:strong bound water,weak bound water and free water,the proportion of strong and weak combined water is more than 99%.With the increase of water addition(25%-55%),the transverse relaxation time of T22 and T23 moved to the right,and the additional water mainly existed in the form of weakly bound water,and the strongly bound water transferred to weakly bound water.Gluten Network Analysis(GNA)and NMR were used and found that increasing the rolling ratio.would destroy the continuity of gluten,and the relaxation time of T22 and T23 moved significantly to the right,and the weak free water moved to the direction of free water,the proportion of free water increased from 0.59%to 1.6%,which reduced the water holding capacity of the weak free water the dough sheet.A composite functional film was designed and prepared to resist the adhesion of the dough sheet on the contact surface.The micro textures were fabricated on the surface of 06Cr19Ni10 alloy by picosecond laser.It was found by the comparison of the adhesion tests that the micro texture can reduce the adhesion ability of the dough sheet,the large spacing and the large depth of the texture parameters can improve the adhesion resistance of the micro texture.Cr-DLC films were prepared by ion source assisted non-equilibrium magnetron sputtering on the surface of the micro texture.It was found that the micro texture and the Cr-DLC film had synergistic effect on reducing the adhesion ability of the dough sheet.It was found that the textured Cr-DLC film with diameter of 40?m,spacing of 85?m and depth of 5?m had the best adhesion resistance.Compared with micro texture,the adhesion ability of the dough sheet on the was reduced by 47.3%.Compared with the substrate,the adhesion ability of the dough sheet on the textured Cr-DLC film surface was reduced by 68.3%.The surface topography test showed that micro texture surface formed regular bow-type characteristics,and the bow-type morphology gradually changed to convex morphology when the spacing and depth parameters were reduced.The hydrophobic performance test showed that the water drop contact angle on the surface of the textured Cr-DLC film increased significantly after the film was prepared on the texture surface,reaching the maximum of 93.4°.The surface energy analysis shows that the adhesion ability of the dough sheet on the contact surface decreases linearly with the increase of the difference(??)between the surface energy dispersion component and the polarity component.M1+Cr-DLC film has the highest ?? value and the best adhesion resistance.The thickness of the prepared Cr-DLC film is about 5.76?m,there is no obvious effect on the thickness of the film with or without micro texture.The scratch test shows that the critical load of the textured Cr-DLC film is increased by about 60%,reaching 18.23N,compared with non-micro texture film.After Cr-DLC film was prepared on the surface,the tribological coefficient of M1(textured structure with diameter of 40?m,spacing of 85?m and depth of 5?m)decreases from 0.7092 to 0.2088,and with the decrease of the micro texture distance and depth parameters,the friction coefficient of the textured Cr-DLC film decreases gradually and remains below 0.2.