Potential application of UV-visible spectroscopy and PLS-DA method to discriminate Indonesian CTC black tea according to grade levels

International Conference on Science, Infrastructure Technology and Regional Development

自然科学（总论）

Suhandy, D.^1^3 ; Yulia, M.^2^3

Department of Agricultural Engineering, University of Lampung, Jl. Prof. Dr. Soemantri Brojonegoro No.1, Bandar Lampung

35145, Indonesia^1

Department of Agricultural Technology, Lampung State Polytechnic, Jl. Soekarno Hatta No. 10, Rajabasa Bandar Lampung

35141, Indonesia^2

Spectroscopy Research Group (SRG), Laboratory of Bioprocess and Postharvest Engineering, Faculty of Agriculture, University of Lampung, Bandar Lampung, Lampung, Indonesia^3

关键词: Coefficient of determination;    Distilled water;    Moving averages;    Spectral data;    Spectral pre treatments;    Total variance;    UV visible spectroscopy;    UV-visible spectrometers;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/258/1/012042/pdf
DOI  :  10.1088/1755-1315/258/1/012042

学科分类：自然科学（综合）

来源: IOP

【 摘 要 】

In this research, UV-visible spectroscopy combined with PLS-DA method was used to discriminate Indonesian CTC black tea with two different grade levels. A total of 20 CTC black tea samples (1 gram of each samples) were collected from PT Perkebunan VIII plantation in West Java province of Indonesia. The samples consisted of two different grade levels, Broken Pekoe or BP1 (10 samples) and FNGS II (10 samples). The extraction of tea samples was performed by using hot distilled water. The spectral data of aqueous tea samples were obtained using a UV-visible spectrometer in the range of 190-1100 nm. The result of PCA showed that the tea samples can be well clustered into two groups according to grade levels using two PCs which accounted for 99% of the total variance (PC1=89% and PC2=10%). The best PLS-DA model had coefficient of determination (R2) of 0.99 with RMSEC = 0.043. The result of the PLS-DA model showed that with the moving average smoothing combined with mean normalization spectral pre-treatment samples from the two different grade levels could be 100% correctly discriminated. The results demonstrated that UV-visible spectroscopy with PLS-DA method could be successfully applied to discriminate Indonesian CTC black tea according to grade levels.