稻穀水分含量分佈之研究

Studies on the Moisture Distribution of Rice Grain

洪梅珠(Mei-Chu Hong)

《臺中區農業改良場研究彙報》 54期 (1997/03) Pp. 15-24

https://doi.org/10.6956/BTDAIS.199703.0015

摘要

本試驗以越光及台稉號為供試驗材料，探討測定水分含量之最適樣品大小，進而據此調查稻穀在不同收穫期及收穫後不同階段的水分含量分佈情形，期作為適期收穫與改善乾燥及貯存措施之參考。試驗結果顯示，利用單粒水分計與130℃恒溫乾燥法測得水分含量，其二者間之相關係數達0.99。溼穀狀態水分含量之變異係數大於乾穀，當容忍誤差為0.5%時，測定溼穀水分含量合理之樣品大小約271～298粒，乾穀約25～27粒，當容忍誤差為1%時，溼穀之合理樣品大小約68～75粒，乾穀則為6～7粒。本試驗也發現同一單穗內各穀粒的水分含量仍有不同，且單穗溼穀的水分含量分佈幅度比乾穀大。不同成熟度收穫之稻穀，其水分含量分佈亦不同，提早收穫者，其分佈偏向高水分含量的方向，延遲收穫者，分佈則偏向低水分含量的方向。溼穀在存放過程，雖然平均水分含量變化不大，其單粒水分含量分佈之幅度及標準偏差，隨貯放時間之延長而變小。乾燥過程，平均水分含量隨著乾燥時間之延長而降低，標準偏差則有變小的趨勢，水分含量降到18%以後，標準偏差的變化漸趨於緩和。

關鍵字

水稻 ； 水分含量分佈

並列摘要

In these studies ,the reasonable sample size of moisture content of rice grain was established and the variation of moisture distribution in different harvest time and in post-harvest processing were identified. The correlation of moisture content between measured with single grain moisture meter and measured with 130℃oven were also studied.The moisture content measured with single grain moisture meter was positively correlated with which measured with 130℃ oven (r=0.99). The resulting data indicates that when tolerable error(ε) is 0.5%, the necessary sample size needed 271-298 grains for wet rice, 25-27 grains for dry rice, but when tolerable error is 1%, the necessary sample size needed 68-75 grains for wet rice, 6-7 grains for dry rice.It shows a wide moisture distribution within panicle, and variation of wet rice is larger than that of dry rice.It also shows different moisture distribution in different harvest time, the peak of moisture distribution of rice grain harvested earlier is moved to the way of high moisture content, and that of rice grain harvested latter is moved to the way of low moisture content.The moisture content of wet rice has no significant change during storage,but the standard deviation of moisture content decreased in parralled with the length of storage time. The moisture content and its standard deviation decreased during dry processing, but after the moisture content is under 18%, the rate of change becomes slowly.

並列關鍵字

rice ； moisture distribution