以近紅外線分光光度計偵測稻米的含水率及蛋白質含量

The Detection of Rice Moisture and Protein Content with Near-Infrared Spectrophotometer

劉民卿(Min-Chin Liu) ； 蕭介宗(Jai-Tsung Shaw)

《農業機械學刊》 4卷3期 (1995/09) Pp. 1-14

https://doi.org/10.30062/JAM.199509.0001

摘要

本研究以本省稻米為試驗材料，針對臺農67號品種稻米內部之水分及蛋白質，利用近紅外線分析法和傳統的化學分析法，建立其校正關係，做為利用近紅外線偵測本省稻米品質之依據。
實驗結果顯示近紅外線光譜分析法可預測稻穀之含水率（13%~24%，濕基）及蛋白質含量(5.76%~6.54%)、白米之含水率（10%~18%，濕基）及蛋白質含量(5.76%~6.24%)。稻穀含水率之校正曲線所選定之波長為1900、2008、2188及2252nm，稻穀蛋白質含量之校正曲線所選定之波長則為1360、1848、1856、2192及2388nm，白米含水率之校正曲線所選定之波長為1904、2024及2192nm，而白米蛋白質選定之5個波長太接近，因此利用二次差分處理，可得較佳的校正曲線，所選定之波長則為1220、1964、2060及2176nm。
雖然已用美國農部規定之粉碎機，但樣本粉粒粒徑分佈仍不均勻。稻穀粒徑之平均值為296.02µm，其標準偏差為260.97µm。而白米粒徑之平均值為220.71µm，其標準偏差為179.64µm。雖然粒徑分佈不均勻，但建立校正曲線之相關係數均高，可能粒徑在小於推薦lmm對NIR測定的影響不大。

關鍵字

近紅外線 ； 稻米 ； 含水率 ； 蛋白質

並列摘要

Domestic rice are used as experimental materials in this study. The moisture and protein content of Tainung 67 were detected by the near-infrared reflection(NIR) method and traditional wet chemical analysis method. The calibration relationship was established for .testing the rice quality by NIR.
Experimental results showed that the moisture content from 13% to 24% (wet basis), and the protein content from 5.76% to 6.54% of rough rice, the moisture content from 10% to 18% (wet basis), and the protein content from 5.76% to 6.24% of milled rice could be measured by NIR. For detecting the moisture content of rough rice, four wavelengths 1900, 2008, 2188 and 2252nm were selected. For detecting the protein content of rough rice, five wavelengths 1360, 1848, 1856, 2192 and 2388nm were chosen. For detecting the moisture content of milled rice, three wavelengths 1904, 2024 and 2192nm were selected. For detecting the protein content of milled rice, the selected five wavelengths were too close. Therefore, by using the second difference method, it could find the better calibration curve with four selected wavelengths 1220, 1964, 2060 and 2176 nm.
Although the Udy cyclone miller adopted in this study was specified by the USDA for a standard sample crushing machine, the mean value of rough rice powder was 296.02 micrometer with standard deviation 260.97 micrometer. The mean value of milled rice powder was 220.71 micrometer with standard deviation 179.64 micrometer. Although the particle size is not uniform, the correlation coefficients of calibration curves are high. This result may be less effect on NIR measurement due to particle sizes smaller than recommended 1mm.

並列關鍵字

Near-infrared ； Rice ； Moisture content ； Protein