米粒物化特性與米穀粉粒徑分佈之關係   全文下載

Relationships between Grain Physicochemical Characteristics and Flour Particle Size Distribution for Taiwan Rice Cultivars

本實驗係採用1996年第一期作之14種梗米、秈米及精米為試驗材料，觀察米粒物化特性與米穀粉粒徑分佈之相關性。實驗結果顯示，粒徑大小指標（PSI）與Stenvert Hardness Test之硬度值（RT）與磨粉溫度、破損澱粉含量及大於60 mesh粒徑百分比（> 60 mesh %）之間均呈現顯著負相關（p < 0.05），但與60 - 100 mesh粒徑百分比（60 - 100 mesh %）呈現顯著正相關（p < 0.05）。主成份分析結果，第一與第二主成份分別佔總變異之56.14%及21.44%。第一主成份為兩極化成份，其與RT、> 60 mesh %、磨粉溫度、破損澱粉含量呈高度正相關性，與Brahender Micro-hardness Test硬度值（BMHT）、60 - 100 mesh %及PSI呈高度負相關性。因此，第一主成份主要與米粒之機械行為及米粒胚乳質地有關，而第二主成份與灰份、粗油脂含量呈正相關性，而與穀粒千粒重（TKW）及穀粒形狀呈負相關性，顯示第二主成份主要與米粒之理化特性有關。蛋白質含量與第一及第二主成份無顯著之相關性（p < 0.05）。結果顯示，米粒胚乳之物理性質為主要影響因子，而化學性質之影響較小。

Fourteen cultivars of rice, 5 indica, 6 japonica and 3 waxy types were used to investigate the relationship between grain physicochemical characteristics and particle size distributions of rice flour. The data showed that particle size index (PSI) negatively correlated with the resistance time (RT) and milling temperature of Stenvert hardness test, damaged starch of rice flour, and percentage retained on 60 mesh (> 60 mesh %) (p < 0.05), but positively correlated with percentage that passed through 60 mesh and retained on 100 mesh (60-100 mesh %) (p < 0.05). From principal component analysis (PCA), the first and the second principal components, describing 56.14 and 21.44% of the variance of rice samples, respectively. The first principal component highly correlated with variables including RT, > 60 mesh %, milling temperature of Stenvert hardness test and damaged starch of rice flour, but negatively correlated with hardness index of Brabender micro-hardness test (BMHT), 60-100 mesh % and PSI. The second principal component positively correlated with ash and fat contents, but negatively correlated with shape and thousand-kernel weight (TKW) of rice grains. The effect of protein content was intermediate between the first and second principal component. Based on the results of PCA, the rice grain physical characteristics (i.e., RT and BMHT) are major factors, followed by chemical compositions, affecting the rice flour particle size distributions. 本實驗係採用1996年第一期作之14種梗米、秈米及精米為試驗材料，觀察米粒物化特性與米穀粉粒徑分佈之相關性。實驗結果顯示，粒徑大小指標（PSI）與Stenvert Hardness Test之硬度值（RT）與磨粉溫度、破損澱粉含量及大於60 mesh粒徑百分比（> 60 mesh %）之間均呈現顯著負相關（p < 0.05），但與60 - 100 mesh粒徑百分比（60 - 100 mesh %）呈現顯著正相關（p < 0.05）。主成份分析結果，第一與第二主成份分別佔總變異之56.14%及21.44%。第一主成份為兩極化成份，其與RT、> 60 mesh %、磨粉溫度、破損澱粉含量呈高度正相關性，與Brahender Micro-hardness Test硬度值（BMHT）、60 - 100 mesh %及PSI呈高度負相關性。因此，第一主成份主要與米粒之機械行為及米粒胚乳質地有關，而第二主成份與灰份、粗油脂含量呈正相關性，而與穀粒千粒重（TKW）及穀粒形狀呈負相關性，顯示第二主成份主要與米粒之理化特性有關。蛋白質含量與第一及第二主成份無顯著之相關性（p < 0.05）。結果顯示，米粒胚乳之物理性質為主要影響因子，而化學性質之影響較小。