• 농업과학연구
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• 제39권3호
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• pp.413-420
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• 2012

Spectroscopic measurement method based on visible and near-infrared wavelengths was prominent technology for rapid and non-destructive evaluation of internal quality of fruits. Reflectance measurement was performed to evaluate firmness, soluble solid content, and acid content of truss tomatoes by hyperspectral reflectance imaging system. The Vis/NIR reflectance spectra was acquired from truss tomatoes sorted by 6 ripening stages. The multivariable analysis based on partial least square (PLS) was used to develop regression models with several preporcessing methods, such as smoothing, normalization, multiplicative scatter correction (MSC), and standard normal variate (SNV). The best model was selected in terms of coefficient of determination of calibration ($R_c^2$) and full cross validation ($R_{cv}^2$), and root mean standard error of calibration (RMSEC) and full cross validation (RMSECV). The results of selected models were 0.8976 ($R_p^2$), 6.0207 kgf (RMSEP) with gaussian filter of smoothing, 0.8379 ($R_p^2$), $0.2674^{\circ}Bx$ (RMSEP) with the mean of normalization, and 0.7779 ($R_p^2$), 0.1033% (RMSEP) with median filter of smoothing for firmness, soluble solid content (SSC), and acid content, respectively. Results show that Vis / NIR hyperspectral reflectance imaging technique has good potential for the measurement of internal quality of truss tomato.

• 한국식품과학회지
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• 제34권3호
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• pp.356-360
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• 2002

다양한 품질특성을 가지는 230점의 벌꿀시료를 선발하여 품질평가 요소에 대한 각각의 검량식을 작성하였으며, 검량식 평가를 위한 벌꿀시료는 50점을 사용하였다. 근적외선 스펙트럼에 대한 수학적 처리를 하여 검량식을 얻었으며 회귀분석방법은 PLS법이 가장 적합하였다. 이화학적 분석과 NIR을 이용해 얻은 분석치를 비교한 결과 수분의 RSQ는 0.997, SEP는 0.10%로 매우 신뢰성 있는 결과를 얻을 수 있었다. fructose와 glucose는 RSQ가 0.926, 0.951로 나타났으며 SEP는 각각 0.54%, 0.52%이었으며, sucrose와 maltose는 SEP가 각각 0.25%, 0.22%로 나타났다. HMF의 SEP는 2.96 mg/kg이었으며 산도는 SEP가 0.73 meq/kg이었다. 탄소동위원소비율은 SEP가 $1.08{\textperthousand}$로 오차가 컸으나 RSQ값이 0.950으로 비교적 안정된 결과를 얻을 수 있어 근적외선 분광분석법으로도 꽃꿀의 순도를 판별할 수 있는 가능성이 제시되었다.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1281-1281
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• 2001

Near-infrared (NIR) spectra have bean measured for high-density (HDPE), linear low-density (LLDPE), and low-density (LDPE) polyethylene in pellet or thin films. The obtained spectra have been analyzed by conventional spectroscopic analysis methods and chemometrics. By using the second derivative, principal component analysis (PCA), and two-dimensional (2D) correlation analysis, we could separate many overlapped bands in the NIR. It was found that the intensities of some bands are sensitive to density and crystallinity of PE. This may be the first time that such bands in the NIR region have ever been discussed. Correlations of such marker bands among the NIR spectra have also been investigated. This sort of investigation is very important not only for further understanding of vibration spectra of various of PE but also for quality control of PE by vibrational spectroscopy. Figure 1 (a) and (b) shows a NIR reflectance spectrum of one of the LLDPE samples and that of PE, respectively. Figure 2 shows a PC weight loadings plot of factor 1 for a score plot of PCA for the 16 kinds of LLDPE and PE based upon their 51 NIR spectra in the 1100-1900 nm region. The PC loadings plot separates the bands due to the $CH_3$ groups and those arising form the $CH_2$ groups, allowing one to make band assignments. The 2D correlation analysis is also powerful in band enhancement, and the band assignments based upon PCA are in good agreement with those by the 2D correlation analysis.(Figure omitted). We have made a calibration model, which predicts the density of LLDPE by use of partial least square (PLS) regression. From the loadings plot of regression coefficients for the model , we suggest that the band at 1542, 1728, and 1764 nm very sensitive to the changes in density and crystalinity.