Identification and Quantitation of Reaction Products from Chlorogenic Acid, Caffeic Acid, and Their Thermal Degradation Products with Odor-Active Thiols in Coffee Beverages

Abstract

A holistic ultraperformance liquid chromatography (UPLC)–time of flight (TOF)–mass spectrometry-based approach was used to screen for storage-induced reaction products consisting of the volatile key coffee thiols methanethiol, 2-furfurylthiol, 2-methyl-3-furanthiol, 3-mercapto-3-methylbutanol, and 3-mercapto-2-butanone and low-molecular weight phenolic constituents of coffee beverages including chlorogenic acid, caffeic acid, and their thermal degradation products hydroxyhydroquinone, catechol, and 4-ethylcatechol. Multiple marker compounds could be detected in thiol-enriched coffee brews after UPLC-TOF-MS profiling and statistical data analysis. Subsequently, marker compounds were synthesized and structurally characterized via high-resolution mass spectrometry and 1D- and 2D-NMR experiments. Quantification of these reaction products in fresh and stored coffee beverages was realized in native coffee and after stir bar sorptive extraction with liquid desorption by means of UHPLC-MS/MS. The quantitative data revealed the biggest influence of storage time on the formation of reaction products between hydroxyhydroquinone and methanethiol and 2-furfurylthiol, while other reaction products were only slightly affected by storage and thus most likely formed during the roasting process.

An integrated strategy for the geographical origin traceability of Goji berries by antioxidants characteristic fingerprint based online ultra‐performance liquid chromatography‐2,2‐diphenyl‐1‐picrylhydrazyl‐ photodiode array detector‐mass spectrometry combined with multivariate statistics analysis

“…The max adsorption wavelength was 205 and 286 nm. It was preliminarily identified as Lycibarbarspermidine F isomer [3, 23, 24].…”

“…With the help of UPLC-PDA-ESI-Q-TOF/MS, 19 compounds were tentatively identified by comparing their precursor ions, fragment ion, and the max UV absorption wavelength with those of references [2,3,[23][24][25][26][27][28]. The chemical constituents of the 19 fractions eluted from the UPLC are shown in Table 2.…”

“…The max adsorption wavelength was 205 and 286 nm. It was preliminarily identified as Lycibarbarspermidine F isomer [3,23,24]. Among these compounds, there are four flavonoids, eight arginine derivatives, five phenolic acids, and one alkaloid.…”

Caffeic Acid, an Active Ingredient in Coffee, Combines with DOX for Multitarget Combination Therapy of Lung Cancer

“…Caffeic acid is one of the main active ingredients of coffee; in addition, the content of it in propolis, perilla, hawthorn, lemon, and other common foods is also high. 17 Studies show that caffeic acid reduces noise-induced oxidative damage in the cochlea, 18 treats atopic dermatitis, 19 and inhibits esophageal 20 and liver cancer. 21 However, most studies focused on the signaling transduction mechanism and did not identify its target at the cell membrane.…”

“…Therefore, this study aimed to screen safe and efficient TMEM16A inhibitors from the effective constituents of functional food. Caffeic acid is one of the main active ingredients of coffee; in addition, the content of it in propolis, perilla, hawthorn, lemon, and other common foods is also high . Studies show that caffeic acid reduces noise-induced oxidative damage in the cochlea, treats atopic dermatitis, and inhibits esophageal and liver cancer .…”