Chemometric Analysis of UV Characteristic Profile and Infrared Fingerprint Variations ofCoffea arabicaGreen Beans under Different Space Management Treatments

Abstract

Ultraviolet characteristic profiles and infrared spectroscopic (FTIR) fingerprints of green bean extracts of Coffea arabica L., cv. IAPAR 59, cultivated in two planting patterns, rectangular and square, and at two different densities, 10,000 and 6,000 plants ha -1 , identified as R 10 , R 6 , S 10 , and S 6 were analyzed with principal component and hierarchical cluster analyses. A simplex centroid design for four solvents (ethanol, acetone, dichloromethane, hexane) was used for sample extraction. The largest chlorogenic acid (CGA) contents were found at the lower planting density. The dichloromethane extracts of the S 10 treatment showed the highest levels of unsaponifiable lipids (cafestol and kahweol). The R 6 treatment showed a slightly higher content of cafestol and kahweol. Cluster analysis of FTIR fingerprints confirmed that the CGA and caffeine levels differentiate the spatial arrangements. The FTIR fingerprints suggest that green beans from S 6 and R 10 were richer in lipids and the other two treatments had more sugars and proteins.

How Does LC/MS Compare to UV in Coffee Authentication and Determination of Antioxidant Effects? Brazilian and Middle Eastern Coffee as Case Studies

“…A typical platform for plant extract profiling includes chromatographic techniques, such as ultra-high-performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-ESI–HRMS), which presents an excellent combination of separation and sensitivity with different modes of ionization [ 12 , 13 ]. Compared to UHPLC-ESI–HRMS, which enables the profiling of phytoextracts, UV spectrometry has been previously applied for the quantification of bioactive metabolites and the fingerprinting of herbal extracts [ 14 ] and coffee seeds as a fast, reliable, cheap, simple, and non-destructive technique [ 15 , 16 ], though with lower identification potential. With both analytical platforms, experimentalists are challenged with huge datasets, especially if derived from many samples, as is typical in quality control studies warranting analysis with chemometric tools for better data visualization and sample classification.…”

Irrigation and Light Access Effects on Coffea arabica L. Leaves by FTIR‑Chemometric Analysis

“…The bands between 1780 to 1600 cm -1 correspond to the carbonyl (C=O) stretching vibration of organic compounds, 6 which can be attributed to diverse compounds such as carotenoids, chlorogenic acids, alkaloids, polysaccharides, hemicellulose, among others, depending on the functional group. 6,9,[50][51][52][53] The bands between 1300 to 1000 cm -1 are assigned to C-O bond of esters, ethers, alcohols, among others. 48,51,54,55 Crude extracts obtained by solvents without ethanol possibly contain lipid compounds, while extracts obtained with solvents containing ethanol extract these compounds as well as other metabolites containing more functional groups.…”

Metabolomics-Based Approach for Coffee Beverage Improvement in the Context of Processing, Brewing Methods, and Quality Attributes

“…The UV-VIS technique has been previously applied for coffee fingerprinting, where UV spectral bands provided semi qualitative and quantitative analytical information about selected bioactive components, i.e., phenolic acids, methylxanthines, chlorogenic acids, and pentacyclic alcohols. Moreover, as a cheaper, simpler, and non-destructive technique, UV fingerprinting can be considered an alternative tool to UPLC/MS for coffee sample quality control analyses [ 26 , 27 ]. Similarly, infrared Fourier transform (FTIR) spectroscopy is recognized as a direct spectroscopic technique for discrimination between defective and non-defective roasted coffee seeds [ 23 ].…”