Luwak Coffee Classification Using UV-Vis Spectroscopy Data: Comparison of Linear Discriminant Analysis and Support Vector Machine Methods

UV-Vis spectroscopy has been used as a promising method for coffee quality evaluation including in authentication of several high-economic coffee types. In this paper, we have compared the abilities of linear discriminant analysis (LDA) and support vector machines classification (SVMC) methods for Luwak coffee classification. UV-Vis spectral data of 50 samples of pure Luwak coffee and 50 samples of pure non-Luwak coffee were acquired using a UV-Vis spectrometer in transmittance mode. The results show that UV-Vis spectroscopy combined with LDA and SVMC was an effective method to classify Luwak and non-Luwak coffee samples. The classification result was acceptable and yielded 100% classification accuracy for both LDA and SVMC methods. However, due to the simplicity and volume of the required calculation, in this present study LDA method is superior to SVMC method

Klasifikasi Madu Berdasarkan Jenis Lebah (Apis dorsata versus Apis mellifera) Menggunakan Spektroskopi Ultraviolet dan Kemometrika

In this research, spectral data in UV region (200-400 nm) alongside PCA and SIMCA chemometrics were used to classify two types of honey obtained from different honeybees (Apis dorsata versus Apis mellifera). A total of 200 Durian monofloral honey samples from Apis dorsata and 120 samples for Longan monofloral honey from Apis mellifera were prepared. Therefore, spectral data were recorded based on the following parameters: range of acquisition 200-400 nm, transmittance mode, and interval 1 nm. In addition, the original spectra were transformed using three different algorithms: moving average smoothing with 11 segments, standard normal variate (SNV), and Savitzky-Golay 1st derivative with 11 segments and 2 ordos. The result of PCA using transformed spectra in the range of 250-400 nm explained the possibility of clearly separating Durian and Longan honey along the PC1 axis, with 98% variance, while the SIMCA showed a 100% proper classification rate for all prediction samples. In addition, several important wavelengths were identified alongside high x-loadings values at 270 and 300 nm. These results were closely related to the absorbance of important phenolic compounds in honey, including benzoic, salicylic, and aryl-alyphatic acids. The results demonstrate a probability to establish simple and low-cost honey authentication systems, using UV spectroscopy and chemometrics on free-chemical in sample preparations. Keywords: authentication, Apis dorsata, Apis mellifera, SIMCA, UV spectroscop

Luwak Coffee Classification Using UV-Vis Spectroscopy Data: Comparison of Linear Discriminant Analysis and Support Vector Machine Methods

UV-Vis spectroscopy has been used as a promising method for coffee quality evaluation including in authentication of several high-economic coffee types. In this paper, we have compared the abilities of linear discriminant analysis (LDA) and support vector machines classification (SVMC) methods for Luwak coffee classification. UV-Vis spectral data of 50 samples of pure Luwak coffee and 50 samples of pure non-Luwak coffee were acquired using a UV-Vis spectrometer in transmittance mode. The results show that UV-Vis spectroscopy combined with LDA and SVMC was an effective method to classify Luwak and non-Luwak coffee samples. The classification result was acceptable and yielded 100% classification accuracy for both LDA and SVMC methods. However, due to the simplicity and volume of the required calculation, in this present study LDA method is superior to SVMC method

Penggunaan UV-Vis Spektroskopi dan Kemometrika untuk Uji Keaslian Kopi Codot Lampung

Codot coffee from Tanggamus, Lampung is one of Indonesian specialty coffee with a very limited production. In this research, an authentication study for the Codot ground roasted coffee was conducted using UV-vis spectroscopy and chemometrics. A total of 330 samples of pure and adulterated Codot coffee was prepared. The adulterated Codot coffee samples were intentionally created by adding a regular coffee (non-Codot coffee) into pure Codot coffee samples with three levels of adulterations: low (10-20%), medium (30-40%), and high level (50-60%). All samples were 0,29 mm in particle size. The extraction procedure was performed with hot distilled water (98°C). The spectral data of coffee samples were acquired using a benchtop UV-visible spectrometer in the range of 190-1100 nm using a transmittance mode. The result showed that the pure and adulterated samples could be discriminated along PC1 and PC2 axis. The classification model was developed using LDA with 90,91% of accuracy could be obtained. The LDA model was used to classify the new samples and resulted in a sensitivity (SEN) of 100%, specificity (SPEC) of 76,67%, precision (PREC) of 78,13%, and accuracy (ACC) of 87,27% could be obtained. Using PLS regression, a PLS model was developed to quantify the percentages of Codot coffee adulteration and resulted in high of coefficient of determination both in calibration and validation (R2kal = 0,99 and R2val = 0,98). These results showed that UV-vis spectroscopy and chemometrics are suitable for authentication of Codot specialty coffee with RMSEP = 2,68% and RPD in prediction of 6,49.   Keywords: authentication, LDA, PCA, PLS regression, UV-vis spectroscop

Potensi Penggunaan UV-Visible Spectroscopy dan PLS-DA untuk Membedakan Kopi Luwak dan Bukan Luwak

The process of discrimination between origin coffee and civet coffee is very important to prevent counterfeiting civet coffee, especially in the form of powder. In this study we used the method of UV-Visible Spectroscopy and PLS-DA method for classifying two types of coffee that civet coffee and regular coffee (not the mongoose) of Robusta coffee types. Spectral data retrieval is done using a UV-VIS / NIR spectrometer (Jasco Corp., Tokyo, Japan). PLS-DA method was then used to build the model calibration and validation for the determination of the type of coffee. The results show that the model calibration PLS-DA has a value of R2 = 0.99, indicating a very strong relationship between the actual and predicted the type of coffee. RMSEC also very small value of 0.05. Validation of calibration models using full cross validation method also produces the coefficient of determination (R2), which was very high at 0.99 with a bias that is very small in the amount -0004. These results indicate that the model of PLS-DA has been successfully built and tested to make the process of discrimination civet coffee and coffee instead mongoose with very satisfactory results.Keywords: Civet coffee, UV-Visible spectroscopy, discrimination

Penentuan Kadar Gula Buah Salak Secara Tidak Merusak Menggunakan Near Infrared (Nir) Spectroscopy dan Interval Partial Least Squares (Ipls) Regression

The objectives of this research was to evaluate the feasibility of using NIR spectroscopy and interval partial least squares (iPLS) regression for nondestructive soluble solids content (SSC) determination in snake fruit. Spectra of snake fruit were acquired using a VIS-NIR USB4000 portable spectrometer in absorbance mode. The SSC was measured using a digital refractometer.  The calibration and validation models were developed using the iPLS regression using original spectra. The calibration results showed that the root mean square of cross-validation (RMSECV) of first six subintervals from 582-831 nm was lower than that of the average of RMSECV and these subintervals were selected for developing final iPLS regression. Using the selected subintervals the calibration has high quality of prediction with RPD = 3,35. Keywords: NIR spectroscopy, soluble solids content, absorbance mode, nondestructive   method, snake fruit, iPLS regressio

Klasifikasi Kopi Bubuk Spesialti Kalosi dan Toraja Menggunakan UV-Visible Spectroscopy dan Metode PLS-DA

 Specialty coffee is sold in a very expensive price. Specialty coffee is usually consumed as a single origin (without mixed with other coffee). For this reason, the detection of impurities (authentication) in specialty coffee is a very important process to be performed. In this study, UV-visible spectroscopy combined with PLS-DA method were used to discriminate between two specialty coffees from South Sulawesi (Kalosi and Toraja). A number of 100 ground roasted coffee samples were used for Kalosi and Toraja, respectively (1 gram each sample). A standard aqueous extraction procedure of the coffee samples using distilled water was performed and the spectral data of aqueous samples of Kalosi and Toraja coffee were acquired in transmittance mode using a UV-Visible spectrometer (Genesys™ 10S UV-Vis, Thermo Scientific, USA). The result showed that using PLS-DA method, all prediction samples were correctly classified into their corresponding classes with 100% rate for sensitivity, specificity, and accuracy, respectively

Uji Keaslian Kopi Bubuk Spesialti Arabika Gayo Aceh Menggunakan Spektroskopi UV dan Kemometrika

Kopi arabika Gayo merupakan salah satu kopi spesialti dengan indikasi geografis yang menjadi salah satu target pengoplosan. Beras yang jumlahnya sangat banyak tersedia di Indonesia sangat potential menjadi bahan pengoplos kopi Gayo. Pada penelitian ini, kopi bubuk arabika Gayo dioplos atau dicampur menggunakan beras bubuk sangrai dengan kadar pengoplosan sebesar 10-50% (w/w). Sebanyak 197 sampel kopi Gayo murni dan campuran disiapkan sebagai sampel penelitian. Data spektra seluruh sampel diukur menggunakan spektrofotometer UV-visible pada panjang gelombang 200-400 nm. Spektra original ditransformasi menggunakan tiga algoritma yaitu moving average, standard normal variate dan Savitzky-Golay derivative. Model kalibrasi PLS (partial least square) dibangun menggunakan algoritma PLS1 dan divalidasi menggunakan metode validasi t-test. Model kalibrasi PLS terbaik diperoleh untuk spektra transformasi dengan interval 250-390 nm dengan sampel terpilih yaitu tanpa sampel pencilan. RPD (ratio prediction to deviation) dan RER (range error ratio) sebesar 3,87 dan 10,71 diperoleh untuk model kalibrasi PLS terbaik. Prediksi persentase beras dalam campuran kopi Gayo dilakukan dengan menggunakan model kalibrasi PLS terbaik dan menghasilkan prediksi yang bisa diterima dengan nilai bias dan SEP (standard error of prediction) yang rendah

Seleksi Panjang Gelombang yang Efisien pada Nir Spectroscopy untuk Pengukuran Kandungan Padatan Terlarut Buah Salak Pondoh Menggunakan Model Forward Interval PLS (FiPLS)

In this research, the feasibility of using NIR spectroscopy coupled with forward interval partial least squares (FiPLS) regression for nondestructive soluble solids content (SSC) determination in Pondoh snake fruit was investigated. Spectra of snake fruit were acquired using a VIS-NIR USB4000 portable spectrometer in absorbance mode. The SSC was measured using a digital refractometer.  The calibration and validation models were developed using the FiPLS regression using original spectra. The result showed that the optimal combinations of 7 spectral intervals among 11 intervals which selected by FiPLS yielded good results (RMSEC = 0.854783%, rc= 0.96, RMSECV = 0.899828%, rv = 0.95).  Keywords: soluble solids content, absorbance mode, nondestructive method, snake fruit, FiPLS regression, NIR spectroscop

PENGUATAN KAPASITAS PRODUKSI KOPI ROBUSTA PREMIUM GAPOKTAN TRIGUNA 4.5

Tujuan Kegiatan adalah (1) melakukan pembinaan penanganan pasca panen untuk mendapatkan tingkatan mutu kopi beras (green bean) premium (level 1-2), (2) meningkatkan keterampilan penyangraian dengan mesin penyangraian yang dilengkapi pengaturan suhu dan blower untuk proses pendinginan, dan (3) melakukan peningkatan keterampilan kemasan dan (4) melakukan pendampingan pengajuan merk produk kopi bubuk Gapoktan Triguna 4.5 ke DJKI.  Metode Pelaksanaan kegiatan adalah metode pemecahan masalah dilakukan dengan melakukan tahapan sebagai berikut : (1) sosialisasi kegiatan program yang akan disampaikan ke anggota Gapoktan, (2) Melakukan pendampingan dan pelatihan untuk meningkatkan keterampilan dalam pengoperasian mesin penyangraian dengan pengendalian temperature dan pendingin, dan (3) melakukan pendampingan pelatihan kemasan dan (4) pendaftaran merk produk Gapoktan Triguna 4.5. Metode yang digunakan adalah penyuluhan, diskusi, dan demontrasi cara baik penggunaan mesin penyangraian dan pengemasan produk. Hasil Kegiatan dapat diidentifikasikan bahwa proses penguatann kapasitas produksi harus berfokus pada penanganan pasca panen sesuai standar untuk menghasilkan kualitas biji kopi premium, penyangraian menggunakan mesin modern sehingga level penyangraian dapat disesuaikan dengan permintaan konsumen; peningkatan pengetahuan dan keterampilan pelatihan kemasan meningkat 100%, dan pendampingan pengajuan hak cipta merek Raosan berjalan dengan baik dan dapat digunakan oleh Gapoktan untuk memperluas jangkauan pemasarannya.Kata Kunci. Pascapanen, kopi premium, pengemasan, merek, gapoktan