The Development And Properties Of Germinated Lightly Milled Brown Rice

Rice as one of the staple food consumption of residents in our country,and its dietary nutrition is closely related to human health.Therefore it is of great significance to research and development of functional nutrition staple food,and promote its popularization.On the basis of germinated brown rice research,our study used lightly milled brown rice?LMR?as raw material,and has developed and prepared the germinated lightly milled brown rice?GLMR?.To improve the germination rate,we optimized the process parameters of LMR,and determined the optimal process condition of GLMR.Besides,the drying characteristics of GLMR under different drying temperature was investigated,and mathematical model also selected to simulate the water change of GLMR at drying process.In addition,compared with Brown rice?BR?,LMR and germinated brown rice?GBR?,the changes in some nutrients,pasting properties,texture properties and microstructure of GLMR were also analyzed.To provide a theoretical basis and reference for the improvement of GBR edible quality and the rice quality.Because the germ of LMR was partly damaged in the process of milling,resulting in a lower germination rate.To solve this problem,the study of degree of milling,soaking time and temperature,germination time and temperature and concentration of gibberellin?GA₃?single factor experiment were conducted,and the optimal values of each influencing factor were determined.respectively,the degree of milling was 1.0 percent,soaking time was 8 hours,soaking temperature 35 centigrade,germination time was 24 hours,germination temperature was 30 centigrade,concentration of GA₃ was 0.2 mg/L.On this basis,the soaking time,germination temperature and GA₃ concentration which had significant effect on the germination rate were selected to conduct response surface optimization,the optimal process parameters were as follows,the soaking time was 8.57 hours,the germination temperature was 28.97 centigrade,the GA₃ concentration was 0.28 mg/L,and the germination rate of LMR was 91.52 percent at this condition.The drying characteristics experiments show that under 30⁶0 centigrade hot air drying conditions,the moisture ratio of GLMR declined in the form of exponential function with the increase of the drying time.Simulation results show that the model of Henderson that“MR=Aexp?-k₁t?+Bexp?-k₂t?”had highest degree of fitting,through this equation the drying time of GLMR can be predicted to achieve a target moisture content.TheeffectivediffusioncoefficientsofGLMRwasbetween2.919×10^-91.017×10^-8m²/s,the activation energy was 33.78kJ/mol,which between rice and brown rice,but higher than GBR.Compared with BR,LMR,and GBR,the change of nutrition,pasting properties,texture properties and microstructure were analyzed.The results show that after germination,there was no significant change of starch and protein content of LMR,but the fat content had a significant reduction.The reducing sugar and GABA concent of GBR were respectively 5.48 times and 3.11 times of BR,and GLMR were respectively 2.72 times and 2.10 times of LMR.Compared with GLMR,changes in the nutrient composition of GBR were more significant,GBR has the highest reducing sugar content,while the protein content was the least,but phytic acid content of GLMR was the lowest.After germination,the value of peak viscosity,through viscosity,final viscosity,breakdown and setback were decline sharply,peak temperature increased slightly,but the changes GBR was greater than GLMR.Texture properties show that the hardness and chewiness of GLMR was lower than GBR,and stickiness was also higher.It indicated that GLMR has a softer texture.The SEM of rice flour show that starch particles conglutinated and form rough surface aggregates in BR flour,the aggregates also has a continuous dense structure.After germination,this continuous dense structure was destroyed and form some separated fragments.Besides,the surface of aggregates and separated starch particles was more smooth.The micro structure of GLMR was similar with GBR,but the stripping phenomenon which happened in GLMR was less obvious than GBR.