Effects Of Drying On Physical Properties And Eating Quality Of Rice

Using Japonia rice and Indica rice of different initial moisture content as material, theeffects of quality on rice by hot-air drying, vacuum drying and microwave drying werestudied. and the evaluation models of drying quality were erected in this paper. the researchresults showed as following:The higher the drying temperature or power, the shorter drying time to safe waterrequired, and the maximum average drying rate increased. At the same drying temperature,the average drying rate of vacuum drying was larger than that of hot-air drying; the higher theinitial moisture content, the longer drying time to safe water required, and the average dryingrate increased. Microwave drying with initial water content changes differently, thechronological order of microwave drying with the initial water content is22%>26%>18%.The laws of drying rice properties quality changes by the drying conditions were roughlythe same on Japonia rice and Indica rice, with the drying temperature and power increaseing,the L*value, head rice yield, brokeing force decreased, and the ratio of rice kernel cracking,husked rice yield increased. With the initial moisture content decreasing, the L*value, huskedrice yield, head rice yield, brokeing force increased, the ratio of rice kernel cracking decreased,i.e. drying temperature or power and the initial moisture content were lower, the propertiesquailty of rice were better after drying. the more indexes of properties quailty of rice werecorrelated with drying conditions by three kinds of drying.With the drying temperature or power increasing, iodine blue value, taste ratingdecreased; the amylose content, water absorption, solids of rice soup, hardness increased thegel consistence,With the initial moisture content increasing, the gel consistence, iodine bluevalue, hardness taste ratingdecreased; the amylose content, water absorption, solids of ricesoup increased. The effects on the pH, flexibility and mastication produce by dryingconditions, but the variation is not obvious. The cooking, texture and taste quailty of rice werecorrelated with drying temperature or power, initial moisture content by three kinds of drying,which the correlation with drying temperature or power was greater than that with initialmoisture content. And most indicators of rice cooking, texture and taste quality werecorrelated with the ratio of rice kernel cracking.The prediction and evaluation model were established through to the dried rice material and cooking and eating quality of17indexes such as principal component analysis after theindica rice and japonica rice drying quality. The comprehensive evaluation model ofF=λ₁*Z₁+λ₂*Z₂+λ₃*Z₃basically reflects the drying of rice quality, this method uses multiplequality index to reflect the comprehensive quality of dry rice, can more accurately reflect thechanges of quality of dry rice. The results show that: the research method and sensory qualityevaluation method the evaluation results with higher consistency.