Study On Production Technology Of Germinated Brown Rice And Improvement Of Hot Air Drying Equipment

In order to solve the problems resulting in the shortage of production capacity and unstable quality of germinated brown rice(GBR)in China,the influences of germination conditions and drying conditions on the quality of GBR were investigated in current study.Moreover,the processing conditions of GBR and the design of hot-air dryer with mesh-belt type were also optimized,which aimed at promoting the industrial development of GBR.The main research contents were following:(1)The effects of germination conditions on the quality of GBR were investigated.The effects of germination temperature and duration on the yield of germination,y-aminobutyric acid content(GABA)and fissure rate for GBR were studied by single factor experiments.The range of optimal germination processing parameters was optimized according to the production capacity of germination device with box-type.The results showed that the germination device with box-type can effectively reduce the fissure rate of GBR,and improve production efficiency with low energy consumption,which can promote the industrial production of GBR.The germination rate increased with the germination time and temperature under the germination temperature of 21-30℃ and the germination time of 16～32 h.After germination for 32 h,the germination rate showed no significantly difference(p>0.05)at temperature higher than 30℃.In germination temperature range of 21～39℃ with germination time for 16～48 h,the fissure rate increased with the germination time and temperature.But the fissure rate of GBR was all lower than 7%,and it decreased 20%～70%as compared to traditional soaking germination.Germination duration had great influences on GABA content of GBR,and the appropriated germination temperature and time was propitious to the enrichment for the GABA content.In addition,the GABA content of GBR rapidly increased with the germination temperature lower than 30℃ under the germination time less than 36 h.However,the enrichment of GABA content was limited at germination time higher than 36 h and the germination temperature higher than 30℃.(2)The main structures of the existing hot-air dryer with mesh-belt type were improved.A circulating fan,a moisture exhaust device and a feeding device were installed on the dryer.After the completed improvement of equipment,the drying time was shortened from 80 min to 50 min,and the yelid of GBR increased from 200 kg/h to 350 kg/h than that of the un-improvement of equipment.Furthermore,the more uniform for material spreading on the conveyor belt,the better drying effect.(3)The production process of GBR was investigated.Using the improved hot-air dryer with mesh-belt type,the center-combination test method with three factors and five levels was used to study the effects of germination time,germination temperature and drying temperature on the fissure rate,cracking rate,GABA content and chroma of GBR.The influence of the interaction between each experimental factor on the evaluation indexes were analyzed.The germination duration had the most influence on the GABA content of GBR,followed by germination temperature,and the drying temperature was the least.The effect on chromaticity L*at from high to low order as germination temperature,drying temperature,germination time.In terms of chromaticity a*,the influence order was the germination temperature,germination time,and drying temperature.Furthermore,the influence order for the chromaticity b*was drying temperature,germination temperature and germination time.The drying temperature had the most influence on fissure rate,followed by germination temperature and germination time was the least.The influence order was the drying temperature,germination time and germination temperature with respect to the cracking rate.The optimized combination of process parameters was the germination temperature of 30℃,germination time of 31 h and drying temperature of 55℃.Moreover,the validated experiments were performed on the basis of the optimized parameter combination.The obtained test values were fissure rate of 29.4%,cracking rate of 4.76%,GABA content of 16.1 mg/100g,color the degree L*value of 57.2,the chromaticity a*value of 4.83,and the chromaticity b*value of 24.58,repectively.The production processing conditions of GBR were optimized by using the pilot test equipment in this study.The research results can be applied to the medium-scale industrial production of GBR,and provide a more reliable basis for large-scale production application.