Determination of the Authenticity of Orange Juice by Discriminant Analysis of near Infrared Spectra

1993 ◽  
Vol 1 (1) ◽  
pp. 33-44 ◽  
Author(s):  
D.G. Evans ◽  
C.N.G. Scotter ◽  
L.Z. Day ◽  
M.N. Hall

Near infrared spectroscopy was used to discriminate between three sources of orange juice. Three pretreatments and five data transformations to improve discrimination were compared. Principal components analysis of 92 calibration samples was followed by canonical variates analysis using up to 25 principal components. Success rates were compared across pretreatments and transformations for the calibration and test data (50 samples). 100% prediction success was obtained with 25 principal components following no pretreatment and no transformation. Principal component loadings were interpretable.

2014 ◽  
Vol 895 ◽  
pp. 323-333 ◽  
Author(s):  
Sharudin Omar Baki ◽  
L.S. Tan ◽  
C.S. Kan ◽  
Halimah Mohamed Kamari ◽  
A.S.M. Noor ◽  
...  

Multicomposition of Er3+-Yb3+codoped tellurite oxide, TeO2-ZnO-PbO-TiO2-Na2O glass has been investigated. Detailed spectroscopic study of the Judd-Ofelt analysis has been performed from the measured absorption spectrum in order to obtain the intensity parameters Ωt(t=2, 4, 6). The calculated Ωtvalues were then utilized in the determination of transition probabilities, radiative lifetimes and branching ratios of the Er3+transitions between theJ(upper)-J(lower) manifolds. Both visible upconversion and near-infrared spectra were characterized under the 980 nm laser diode excitation at room temperature.


1992 ◽  
Vol 46 (11) ◽  
pp. 1685-1694 ◽  
Author(s):  
Tomas Isaksson ◽  
Charles E. Miller ◽  
Tormod Næs

In this work, the abilities of near-infrared diffuse reflectance (NIR) and transmittance (NIT) spectroscopy to noninvasively determine the protein, fat, and water contents of plastic-wrapped homogenized meat are evaluated. One hundred homogenized beef samples, ranging from 1 to 23% fat, wrapped in polyamide/polyethylene laminates, were used. Results of multivariate calibration and prediction for protein, fat, and water contents are presented. The optimal test set prediction errors (root mean square error of prediction, RMSEP), obtained with the use of the principal component regression method with NIR data, were 0.45, 0.29 and 0.50 weight % for protein, fat, and water, respectively, for plastic-wrapped meat (compared to 0.40, 0.28 and 0.45 wt % for unwrapped meat). The optimal prediction errors for the NIT method were 0.31, 0.52 and 0.42 wt % for protein, fat, and water, respectively, for plastic-wrapped meat samples (compared to 0.27, 0.38, and 0.37 wt % for unwrapped meat). We can conclude that the addition of the laminate only slightly reduced the abilities of the NIR and NIT method to predict protein, fat, and water contents in homogenized meat.


2013 ◽  
Vol 834-836 ◽  
pp. 935-938
Author(s):  
Lian Shun Zhang ◽  
Chao Guo ◽  
Bao Quan Wang

In this paper, the liquor brands were identified based on the near infrared spectroscopy method and the principal component analysis. 60 samples of 6 different brands liquor were measured by the spectrometer of USB4000. Then, in order to eliminate the noise caused by the external factors, the smoothing method and the multiplicative scatter correction method were used. After the preprocessing, we got the revised spectra of the 60 samples. The difference of the spectrum shape of different brands is not much enough to classify them. So the principal component analysis was applied for further analysis. The results showed that the first two principal components variance contribution rate had reached 99.06%, which can effectively represent the information of the spectrums after preprocessing. From the scatter plot of the two principal components, the 6 different brands of liquor were identified more accurate and easier than the spectra curves.


NIR news ◽  
2019 ◽  
Vol 30 (3) ◽  
pp. 6-8
Author(s):  
Mirosław Antoni Czarnecki ◽  
Michał Kwaśniewicz

This work shows the effect of the chain length on near-infrared spectra of 1-alcohols and is based on a recent paper by Kwaśniewicz and Czarnecki ( Appl Spectrosc 2018, 72: 288). Near-infrared spectra of 1-alcohols from methanol to 1-decanol in the pure liquid phase were recorded from 5200 to 9000 cm−1. The similarities and differences between the spectra were analyzed by the classical and chemometric methods (principal component analysis). The obtained results reveal that the near-infrared spectra of methanol, ethanol, and 1-propanol are appreciably different from the spectra of higher 1-alcohols. As shown, the degree of self-association of 1-alcohols decreases with the increase in the chain length.


2012 ◽  
Vol 20 (3) ◽  
pp. 397-406
Author(s):  
Qingbo Fu ◽  
Xinping He ◽  
Hui Suo ◽  
Jinming Wang ◽  
Chun Zhao

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