Effects Of Grinding Methods On Properties Of Brown Rice And Quality Of Rice Noodle

Brown rice(BR)is rich in a variety of active substances,nutritional value is higher than white rice,but BR products palatability was poor,processing technology is not yet mature,and overall utilization is low.Processing BR into rice noodle is an effective way to improve utilization rate and added value of rice.Milling process is one of the important factors that influences the quality of BR products,this thesis mainly analyzes the physical and chemical properties of BR flour and the quality of rice noodles by dry,half dry and wet grinding method,to provide reference basic for making rice noodle for raw material.In this paper the main research content is as follows:Early indica-grain as raw material to dry superfine grinding,crushing strength from 0 to 40;Half dry grinding,embellish of rice moisture content 20% to 35% for BR quality;Wet grinding,liquid ratio from 1:1 to 1:4.Three types of the milling process of BR powder damage starch content is between 3.66% and 14.58%,particle size was 15 microns to 190 microns,whiteness of 81.18 to 81.18.The results show that decline of BR flour particle size is often associated with damage starch content increased.Adding the right amount of moisture can effectively reduce the damage starch content in BR flour before grinding.Hydration characteristics results show that the particle size decreased will greatly improve BR flour absorbent and expansion potential,hydration characteristics significantly increased after pasting.The water absorption index and water soluble,expansion potential was higher in dry grinding method.RVA analysis results show that with the decline of BR flour particle size,pasting viscosity,breakdown value,setback are risen,the initial pasting temperature drop.Half dry method and wet method than the dry method has higher viscosity and pasting temperature,damage starch pasting properties have great influence.Rheological analyzer results show that the dry powder in BR starch granules is damaged seriously,gelatinization starch paste gel texture is formed in the process of evacuation poor,show the lower modulus of elasticity.And starch granular molecular chain rupture,macromolecule is decomposed into more small molecules,weaker after gelatinization viscosity resistance,viscous modulus was also significantly lower than half dry method and wet method,the consistent with RVA measured results.DSC analysis results show that BR flour particle size is smaller,the enthalpy value and initial pasting temperature is lower.It proves that the smaller of particle size of starch granules is more easily from multiple crystalline into amorphous.Microstructure results showed that the more dry grinding intensity,the more damaged of BR flour particles structure..Half-dry and wet methods can effectively reduce the damage of BR flour received,original starch granule morphology preservation is well,the surface damage mechanical force is lesser,shows that damage starch content is mainly due to the results of the starch granules by mechanical force.Correlation analysis showed that the damaged starch content,grain fineness,pasting properties,hydration properties and rheological properties have significant correlation in BR flour.BR noodles quality analysis results show that with the BR flour particle size is decline,the BR noodles rehydration time and vitro digestion rate were lower,the broken rate and resistant starch content were higher.Half dry method and wet method process preparation of BR noodles hardness,tip resistance,flexibility is higher than dry method.The overall sensory score of BR noodles of half-dry method was highest.About 15 microns,whiteness90.57,damaged starch content 13.59 of BR flour is suitable for processing into a BR noodle.Correlation analysis showed that the damaged starch content,particle size,rehydration time,broken rate,hardness were significantly correlation.