Identification of Lampung fine Robusta peaberry green coffee beans with different fermentation methods using portable front-face fluorescence spectroscopy

High-quality Robusta peaberry coffees in Lampung underwent various processing techniques, including two distinct fermentation methods: Codot-based fermentation (CF) and natural-based fermentation (NF). The variation in fermentation techniques significantly affects the flavor and cost of Lampung's excellent Robusta peaberry coffees. This study examines the potential application of untargeted portable front-face fluorescence spectroscopy and chemometrics to differentiate Lampung fine Robusta peaberry coffees based on various fermentation procedures. Two varieties of green coffee beans were prepared for sampling: CF (n = 60) and NF (n = 60). Three kernels of green coffee beans from CF and NF were placed in a sample holder for each sample. The fluorescence spectral data were obtained using a portable front-face fluorescence spectrometer, including a 365 nm light-emitting diode (LED) as the excitation source. The creation of supervised classification models for CF and NF utilized three distinct classifiers: partial least squares-discriminant analysis (PLS-DA), principal component analysis-linear discriminant analysis (PCA-LDA), and linear discriminant analysis (LDA). The findings indicate that employing preprocessed spectral data yielded a classification accuracy of 100% (p < 0.01) across all classifiers. The current results affirm that assessing Lampung fine Robusta peaberry coffees utilizing various fermentation processes through low-cost front-face fluorescence spectroscopy is feasible.