| Near-infrared spectroscopy (NIRS) is an efficient and fast analytical technique. It's developed very fast in resent years. Its main advantage is fast, non-destructive, simultaneous determination. Near-infrared (NIR) spectroscopy is based on the absorption of electromagnetic radiation at wavelengths in the range780-2526 nm (12820-3959cm-1), between the visible region and mid-infrared region. NIR spectra comprise broad bands arising from overlapping absorptions corresponding mainly to overtones and combinations of vibrational modes involving C-H, N-H, O-H and S-H chemical bonds. Most of organics have these chemical bonds, so the NIRS can be used in many fields. Advantages of NIRS are fast, no pre-processing, simultaneous determination, unpolluted, non-destructive. These advantages have made NIRS used in Agriculture, petrochemical, Pharmaceutical, Food Processing.Under the support of Chongqing Science and Technology Commission program (CSTC2008EA5008), this thesis study on the measurement of quality parameters of Fuling mustard tuber by Near Infrared Spectroscopy:1. Simultaneous determination of moisture, total acid(lactic acid) and amino acid in Fuling mustard tuber by Fourier transform near-infrared spectroscopy (FT-NIRS), the results shown that NIR quantitative analysis has high accuracy and could meet the requirement of Fuling mustard tuber in production;2. Employment of Near Infrared Spectroscopy to determine of pectin and total sugar in Fuling mustard tuber, prediction results are accurate and reliable; 3.Determination of the sodium chloride content in Fuling mustard tuber by near infrared spectroscopy. Sodium chloride is not absorbent in NIR region, but it can change the absorbance of water, so it can be used to determine the content; 4.Study on Fast discrimination of brands of Fuling mustard tuber using Near Infrared Spectra, the result showed that all of the samples could be classified correctly by the two methods; 5.Simultaneous determination of astragals polysacharin and astragaloside IV in huangqijing oral liquid by NIRS. This method can be applied in rapid analysis of huangqijing oral liquid, and it is fit for on-line detection.1. Simultaneous determination of moisture, total acid (lactic acid) and amino acid in Fuling mustard tuber by Fourier transform near-infrared spectroscopy (FT-NIRS)The measurement of moisture,titratable acidity and amino acid in Fuling mustard tuber by Fourier transform near-infrared spectroscopy (FT-NIRS)was studied. The original spectra of 58 Fuling mustard tubers were obtained using FT-NIRS machine. Then through math analysis, spectrum noise was decreased. Finally regression methods were used by partial least squares. The regression model of moisture,total acid and amino acid were constructed.The determination coefficient(R2)of the model were 95.78,97.54,95.04,and its root mean square error of cross-Validation(RMSECV)were 0.256,0.0347,0.0363.While the R2 and root mean square error of prediction set (RMSEP)were 95.62,95.39,94.6 and 0.107,0.0168,0.0388 in test set validation, respectively. Internal and external cross-certification test have shown that near-infrared quantitative analysis has high accuracy and could meet the requirement of prediction of moisture,total acid and amino acid content of Fuling mustard tuber in production.2. Employment of Near Infrared Spectroscopy to determine of pectin and total sugar in Fuling mustard tuber, prediction results are accurate and reliableThe measurement of pectin and total sugar in Fuling mustard tuber by Fourier transform near-infrared spectroscopy (FT-NIRS) was studied. The original spectra of 50 Fuling mustard tuber were obtained using FT-NIRS machine. Then through math analysis, spectrum noise was decreased. Finally regression methods were used by partial least squares. The regression model of pectin and total sugar were constructed.The determination coefficient(R2)of the model were sd98.31,98.35,and its root mean square error of cross-Validation(RMSECV)were 0.513,0.0531.While the R2 and root mean square error of prediction set (RMSEP)were 96.69,95.63and 0.572,0.0671 in test set validation,respectively.Internal and external cross-certification test have shown that near-infrared quantitative analysis has high accuracy and could meet the requirement of prediction of pectin and total sugar content of Fuling mustard tuber in production.3. Determination of the sodium chloride content in Fuling mustard tuber by near infrared spectroscopyThe measurement of sodium chloride in Fuling mustard tuber by Fourier transform near-infrared spectroscopy (FT-NIRS) was studied. The original spectral of 46 Fuling mustard tuber were obtained using FT-NIRS machine. Then through constant offset elimination, spectrum noise was decreased. Finally regression methods were used by partial least squares(PLS).The regression model of NaCl was constructed.The determination coefficient(R2) of the model were 99.25%,and its root mean square error of cross-Validation(RMSECV) was 0.0723.While the R2 and root mean square error of prediction set (RMSEP) were 98.55% and 0.0800 in test set validation,resp ectiv--ely.Internal and external cross-certification test have shown that near-infrared quantitative analysis has high accuracy and could meet the requirement of prediction of sodium chloride content in Fuling mustard tuber in production. And, the clustering analysis was used to identify the samples; it can easily distinguish the mustard tuber from the low and middle sodium chloride content. So, NIRS being able to be used in the quality control of Fuling mustard tuber.4. Study on Fast discrimination of brands of Fuling mustard tuber using Near Infrared SpectraA new method for the fast discrimination of brands of Fuling mustard tuber by means of near infrared spectroscopy (NIRS) was developed. The experiment adopted typical six brands of Fuling mustard tuber which we bought in the market. The near infrared spectral data were collected from the samples and were preprocessed through first derivation and vector normalization. A factorization algorithm was used to calculate the spectral distance among the samples and the Ward's algorithm was used to make clustering analysis on the samples. Then compare with the qualitative identification, the result showed that all of the samples could be classified correctly by the two methods.5. Simultaneous determination of astragals polysacharin and astragalosideâ…£in huangqijing oral liquid by NIRSA new method was established to simultaneously determine the astragalus polysacharin and astragalosideâ…£in Huangqijing oral liquid by Fourier transform near infrared spectroscopy (FT-NIR) with partial least square (PLS).The Rank of the model and the optimized parameters of the mathematical model by calibration samples were gotten by internal cross validation. Then the model was validated by the prediction set. The multicorrelation coefficients (R2) of the model to the astragalus polysacharin and astragalosideâ…£were 0.9797 and 0.9412 respectively. The root mean square error of cross validation (RMSECV) of the model to the astragalus polysacharin and astragaloside IV were 0.153and 0.0365, and the root mean square error of of prediction (RMSEP) were 0.178 and 0.0458 respectively. By statistical significance test, the results of determination were compared with those of standard methods with no significant difference at 0.05 levels. The result shows that the method proposed can be used to simultaneously determine the astragalus polysacharin and astragalosideâ…£in huangqijing oral liquid with high accuracy. |
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