| In this study,mung beans were used as raw materials and treated under conditions of 15 min and 400 Mpa.The comparison between the sub-treated and untreated mung beans was used to explore the changes in the nutritional content of mung beans after ultra-high pressure.Exploring its swelling force and solubility,the physical and chemical properties of whole grain mung bean treated with ultrahigh pressure were investigated by Fourier and scanning electron microscopy.The gelatinization test,texture test,and differential scanning calorimeter were used to evaluate the processing characteristics of whole grain mung beans after ultrahigh pressure treatment.The whole grain mung bean after the overpressure treatment is added to wheat flour in a certain proportion to make a dough,and the bread is made by fermentation.Through tensile test,texture test and rheological test,explore the influence of it on making dough.The effect of mung bean bread was investigated through fermentation test and texture test.After analysis,the following conclusions were reached:(1)Compared with the control group,the content of water and crude protein in mung bean flour is increased.Hydration.The content of starch,fat and crude fiber is reduced because the ultra-high pressure treatment will form a fat-starch complex.The expansion force and solubility measured at low temperature increase with the increase of pressure level and holding time.Ultrahigh pressure treatment will break the starch crystal structure;the expansion force and solubility will decrease at higher temperature Under the dual effects of amylose and lipid,a starch-lipid complex was formed to inhibit the swelling of starch granules.(2)Fourier tests show that ultra-high pressure treatment can form starch-lipid,starchprotein complexes,and this combination becomes more pronounced as the pressure level increases and the holding time increases.Scanning electron microscopy showed that more protein molecules adhered to starch molecules after ultra-high pressure treatment,and wrinkles appeared on the surface of starch molecules with increasing pressure and holding time.These results show that the ultra-high pressure treatment effectively changed the physical and chemical properties and microstructure of mung bean flour.(3)Ultra-high pressure treatment increases the gelatinization temperature and thermal stability of whole grain mung bean flour,indicating that the association between starch-protein,starch-lipid complexes is enhanced after ultra-high pressure treatment,and the gelatinization viscosity of whole grain mung bean flour is reduced,which is attributed to the linear The effect of starch swollen granules,leaching of amylose and amylopectin branch chain length distribution.The increase in gel elasticity of mung bean flour with the increase of pressure level and dwell time is attributed to the increase in pressure level and dwell time to form starch-lipid and starch-protein complexes.The chewability decreases,and the transition temperature and enthalpy value decrease first and then increase as the pressure level increases,because at relatively low pressure and low holding time,the spirals can only dissociate side by side,but not the double spirals.The destruction of the interaction leads to a decrease in the transition temperature and the gelatinization enthalpy;although the starch structure is destroyed under ultra-high pressure and a long holding time,it provides more possibilities for the combination of starch-protein and starch-lipid With the increase of pressure,more complexes will be formed,and these compounds will be more firmly bonded with the increase of pressure,so the enthalpy and transition temperature will increase.(4)Compared with the dough with untreated mung bean flour,the dough formed by adding mung bean flour under 400 Mpa / 15 min pressure treatment has higher ductility and expandability.At low pressure levels and short holding time,mung beans The structure of the protein is changed,which increases the chance of binding to wheat starch.This starch-protein interaction is enhanced,which increases the ductility and expandability of the dough;mung bean protein is treated under high pressure and a long holding time The enhanced interaction with mung bean starch itself will increase the formation of mung bean starch-protein complexes,explaining the reasons for the decrease in ductility and scalability.In the texture analysis of the dough,the adhesion increases with the increase of the pressure level holding time,while the viscosity,cohesion and elasticity increase first and then decrease.At low pressure levels and short holding time,The protein that changes the structure is more bound to wheat starch,and the role of the wheat starch-protein complex is enhanced;high pressure and longer dwell time allow the damaged starch to form more reaction sites,which can generate molecular forces To change the structural characteristics of gluten.Compared with the control,the storage modulus,loss modulus,and loss factor of the dough formed by the addition of ultra-high pressure mung bean flour were increased.The structure-modified mung bean protein and wheat protein had more opportunities to combine to form a more With multiple gluten networks,mung bean protein and starch will be more tightly combined under high pressure and long holding time,which affects the formation of dough gluten structure;the dough fermentation performance test was performed at a pressure of 400 Mpa / 15 min The dough has the lowest(Hm-h)/ Hm value.Under low pressure and short holding time,more mung bean protein and wheat protein combine to form a strong gluten structure.The gluten structure of the dough inhibits the free expansion of the dough;high pressure and long holding time dietary fiber will interfere with gluten Network formation.Due to the formation of a gluten network that requires a large amount of water,the damaged starch tends to compete with gluten for water due to competing with protein for water absorption.The texture test showed that the bread baked with mung bean flour treated with 400 Mpa / 15 min pressure had better hardness and chewiness. |
