Estimation of Sensory Analysis Cupping Test Arabica Coffee Using NIR Spectroscopy

Abstract

Abstract. Flavors have become the most important coffee quality parameters now day, many coffee consuming countries require certain taste scores for the coffee to be ordered, the currently used cupping method of appraisal is the method designed by The Specialty Coffee Association Of America (SCAA), from several previous studies was found that Near-Infrared Spectroscopy (NIRS) can be used to detect chemical composition of certain materials including those associated with flavor so it is possible also to be applied to coffee powder. The aim of this research is to get correlation between NIRS spectrum with cupping scoring by tester, then look at the possibility of testing coffee taste sensors using NIRS spectrum. The coffee samples were taken from various places, altitudes and postharvest handling methods, then the samples were prepared following the SCAA protocol, for sensory analysis was done in two ways, with the expert tester and with the NIRS test. The calibration between both found that Without pretreatment using PLS get RMSE cross validation 6.14, using Multiplicative Scatter Correction spectra obtained RMSE cross validation 5.43, the best RMSE cross-validation was 1.73 achieved by de-trending correction, NIRS can be used to predict the score of cupping.

Studi Miniatur Uv/Vis/Nir Spektrometer untuk Proses Kuantifikasi Mutu Biji Kopi dengan Protokol Cupping Test

“…Dalam kasus yang lain, Spektroskopi UV/Vis dengan analisis univariat, mampu secara bersamaan memprediksi kafein dan asam klorogenat (Navarra et al, 2017). Terdapat pula studi penggunaan teknik spektroskopi untuk langsung memprediksi mutu sensori kopi dan minuman penyegar (Basile et al, 2023;Safrizal et al, 2018).…”

“…Eksperimen dengan menggunakan panjang gelombang NIR di area yang lebih luas, menunjukkan hasil R 2 CV lebih dari 0.8 untuk memprediksi evaluasi sensori (Basile et al, 2023). Respon gugus kimia yang dominan di rentang lebih dari 800 nm mampu menunjukkan respon vibrasi ikatan C-H dan ikatan lainnya yang berkorelasi dengan komponen organik seperti CGA dan kafein yang berhubungan erat dengan kualitas sensori kopi (Munyendo et al, 2022;Safrizal et al, 2018). Meskipun respon perbedaan warna akibat lama waktu sangrai mampu dideteksi dengan instrumen SpectroVis, akan tetapi, nilai prediksi sensori masih tidak sebaik spektroskopi NIR yang bekerja pada rentang panjang gelombang yang lebih tinggi.…”