The Impact Of Different Drying Methods On Rice Quality And Storage Performance

The quality and the storage performance of the rice samples which wereprocessed of different drying methods at different temperatures were studied in thispaper. To the rice drying allow heating temperature (50℃) for reference, To naturaldrying as control, using temperature-controlled MCR-3microwave chemical reactorand electric blast oven to decrease the moisture of2011harvest japonicasamples(initial moisture content of16.1%) to safe moisture (14.5%) by hightemperature thermostat drying(65℃) and low temperature thermostat drying(45℃).By measuring the germination rate of rice, selected to better maintain the qualityof rice after the thermostatic microwave and hot air drying at low temperature (45℃)and natural drying in artificial climate chamber at15℃,20℃,25℃,30℃to simulatestorage180d. Various physical and chemical indicators, texture, pasting properties,chromatic aberration were detected every30d, by multiple-factor test analysis we canget the following conclusions:(1) Change of the germination rate and the determine of the drying process:With low temperature microwave and hot air drying, the rice germination rate wasless affected. The low temperature microwave and hot air drying and high temperaturehot air drying make smaller impact on rice germination rate, and high temperaturemicrowave drying seriously affected the germination rate of rice. Therefore, select alow temperature microwave, hot air drying and natural drying rice samples to beartificially simulated stored. The time of the experimental samples japonica moisturedecreased from16.1%to14.5%: the low-temperature microwave drying needs70min,low temperature hot air drying needs3h.The rice with different drying methods storedunder different temperature conditions, their germination rate is reduced with timeextend, the higher the storage temperature, the faster it decrease.(2) Changes in physical and chemical indicators: the rice samples with differentdrying methods stored under different temperature conditions, moisture content,water-soluble protein content, iodine blue value, soluble amylose content decreasedwith time extend; All amylose content and insoluble amylose content increased withtime extend. Low temperature microwave drying compared to natural drying and lowtemperature hot air drying makes slow changes in iodine blue value, soluble amylosecontent and insoluble amylose content. (3)Textural quality change: the rice after different drying methods stored underdifferent temperature conditions, its rice hardness increased with the storage timeextend; while spring and adhesive decreased with the storage time extend.Lowtemperature microwave drying compared to natural drying and low temperature hotair drying makes slow changes in texture quality.(4)The gelatinization characteristics changes: the rice after different dryingmethods stored under different temperature conditions, gelatinization eigenvaluesincreased with storage time extend. Low temperature microwave drying compared tothe natural and low temperature hot air drying makes slowly changes in pastingproperties.(5)Changes in the color values: the rice samples after different drying methodsstored under different temperature conditions, the lightness L value of the ricedecreased with time extend; the chroma a, b values and color difference ΔE valueincreased with time extend [rice surface color (white) from shallow to deep (black),the color changes from red, yellow to green, blue]. the storage temperature,dryingmethods and storage time on ΔE values was extremely significant.Summary: Comprehensive comparison of time and the impact of qualityindicators with different drying temperature different drying methods processing rice,as well as the change of quality indicators of rice processing by different dryingmethods indifferent storage temperatures during storage, compared to nature dryingand hot air drying, hypothermia thermostatic microwave increased drying efficiency,and it slowed the the deterioration part of the physical and chemical quality, thetexture quality and pasting properties of rice during storage.