白米在貯藏期間理化性狀變化之研究

Changes in the Physicochemical Properties of Milled Rice Grain during Storage

許愛娜(Ai-Na Hsu)

《臺中區農業改良場研究彙報》 111期 (2011/06) Pp. 13-40

https://doi.org/10.6956/BTDAIS.201106.0013

摘要

以六個不同水稻品種的白米為試驗材料，利用室溫及15℃兩種溫度處理，探討兩年貯藏期間之米質理化性狀表現，發現不同期作、包裝形式、貯藏溫度、貯藏時期與品種皆顯著影響米質理化性狀，但其中以降低貯藏溫度最有效延緩劣變，且澱粉特質相近之品種其表現較為類似。理化性狀中差異較明顯之變化是pH值與凝膠展延性，其隨貯藏時期增加皆有下降趨勢，其迴歸方程式之表現亦會因期作或貯藏條件之不同而改變，故在進行白米樣品新鮮程度比較時，pH值在兩個期作皆可作為主要判別性狀，凝膠展延性可作為輔助判別性狀，但是在第二期作室溫貯藏的條件下，兩種性狀皆限於相同澱粉性質之品種內進行比較為宜。

關鍵字

白米 ； 貯藏 ； pH值 ； 凝膠展延性 ； 迴歸方程式

並列摘要

Milled rice grain of six varieties with different starch quality was stored at 15℃ vs. room temperature for 2 years to evaluate the physicochemical traits and quality. The results showed that there were significant differences among crop seasons, packaging methods, storage temperatures, storage periods and varieties. The lower storage temperature had more obvious effect to slow down the deterioration, and the varieties with the same starch quality varieties had the similar physicochemical properties. The more significant differences in physicochemical traits were the pH value and gel consistency, and both were declined with storage period. The regression relationship was also changed with crop season or storage conditions. Therefore, when we compare the freshness of milled rice sample, the pH value can be used as the main decisive characters for both crop seasons, while gel consistency could be considered as an assisting decisive characters but only under the condition of the second crop season stored at room temperature. In conclusion, both pH value and gel consistency could be used as indicators to determine the freshness of milled rice, but only valid in the same starch quality variety group.

並列關鍵字

milled rice ； storage ； pH value ； gel consistency ； regression equation