ATR-FTIR FOR CHARACTERIZING AND DIFFERENTIATING DRIED AND GROUND COFFEE CHERRY PULP OF DIFFERENT VARIETIES (Coffea Arabica L.)

Abstract

This study aimed to evaluate the performance of the infrared spectrum in the range of 4000−650 cm −1 for characterizing and differentiating dried and ground coffee cherry pulp of different varieties. The spectral data were subjected to first and second derivative treatments to perform the statistical analyses. Three varieties of coffee pulp were previously characterized for color, water activity, moisture, chlorogenic acids, and caffeine. The results of principal component analysis (PCA) showed that Fourier transform infrared (FTIR) spectroscopy is a viable technique for characterizing and differentiating dried and ground coffee cherry pulp among different varieties, showing the best differentiation with treatment of data from the first derivative, which was mainly associated with the caffeine content and chlorogenic acids. This study is the first investigation of FTIR spectroscopy with attenuated total reflectance for characterizing dried and ground coffee cherry pulp from coffee varieties grown in Colombia.

Quality Assessment of Ground Coffee Samples from Greek Market Using Various Instrumental Analytical Methods, In Silico Studies and Chemometrics

“…The intensities at 2922, 2855, 1640–1660, 1242–1218, and 1028 cm −1 , which were associated with the presence of caffeine [ 40 , 41 , 42 , 43 ], exhibited a significant or dramatic ( p < 0.05) decrease in decaffeinated blends compared to caffeinated ones. The intensities at 1381–1376, 1161–1153, and 1053 cm −1 , which were related to the presence of chlorogenic acid [ 44 , 45 , 46 ], displayed insignificant ( p > 0.05) variations among the studied blends, except for the aromatic blends, which exhibited increased ( p < 0.05) intensities at 1381–1376 and 1161–1153 cm −1 . Moreover, the absorption detected at 1603 cm −1 [ 47 ], which probably corresponds to the conjugated C=C stretch vibration found in diterpenes such as cafestol and kahweol, showed a significant ( p < 0.05) decrease from light to dark roast blends, without being affected by the decaffeination process.…”

Physicochemical and sensory characteristics of dehydrated coffee pulp in function of drying temperature

“…These acids correspond to a large family of esters formed between quinic acid and one to four residues of certain trans-cinnamic acids, most commonly caffeic, p-coumaric, anbarid, and feluric acids (Barrios-Rodríguez et al, 2021b). The ester bond C=O=C absorbs at 1,300-100 cm -1 (Silverstein et al, 1962).…”

Hawthorn Juice Simulation System for Pectin and Polyphenol Adsorption Behavior: Kinetic Modeling Properties and Identification of the Interaction Mechanism

“…The absorption peak at 149.87 cm −1 was due to the vibration of C-O in carboxyl, which indicated the existence of carboxyl in molecule. The absorption peak at 1083.99 cm −1 was caused by C-O vibration, which indicated that the molecule contains phenolic hydroxyl and alcoholic hydroxyl [ 48 ]. Compared with the absorption peaks of EC and HP alone, it could be seen that the absorption intensity was obviously reduced from 3421.72 cm −1 to 3419.79 cm −1 , which indicated that the O-H broadening was reduced due to the interaction between HP and EC.…”