Classification of Lampung robusta Specialty Coffee According to Differences in Cherry Processing Methods Using UV Spectroscopy and Chemometrics

The postharvest processing factors including cherry methods highly influence the final quality of coffee beverages, especially in composition several metabolites such as glucose, fructose, amino acid (glutamic acid), and chlorogenic acids (CGA) well trigonelline contents. In this research, UV spectroscopy combined with chemometrics was used to classify a ground roasted Lampung robusta specialty according differences methods. A total 360 samples 1 g weight for each sample from three different were prepared samples: 100 pure dry (DRY), semi-dry (SMD), wet (WET) 60 adulterated (ADT) (SMD DRY WET coffee). All extracted using standard protocol explained by previous works. low-cost benchtop UV-visible spectrometer (Genesys™ 10S UV-Vis, Thermo Scientific, Waltham, MA, USA) utilized obtain spectral data interval 190–400 nm fast scanning mode. Using first principal components (PCs) 93% variance, there clear separation between samples. clustered into four possible groups methods: dry, semi-dry, wet, adulterated. Four supervised classification methods, partial least squares–discriminant analysis (PLS-DA), component analysis–linear discriminant (PCA-LDA), linear (LDA) support vector machine (SVMC) selected PCA-LDA is best method 91.7% accuracy prediction. PLS-DA, LDA SVMC give an 56.7%, 80.0% 85.0%, respectively. present research suggested that combining will be useful authentication.