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

The high-resolution molecular portrait of coffee: A gateway to insights into its roasting chemistry and comprehensive authenticity profiles

The direct-infusion of 130 coffee samples into a Fourier-transform ion cyclotron mass spectrometer (FT-ICR-MS) provided an ultra-high resolution perspective on the molecular complexity of coffee: The exceptional resolving power and mass accuracy (± 0.2 ppm) facilitated the annotation of unambiguous molecular formulas to 11,500 mass signals. Utilizing this molecular diversity, we extracted hundreds of compound signals linked to the roasting process through guided Orthogonal Partial Least Squares (OPLS) analysis. Visualizations such as van Krevelen diagrams and Kendrick mass defect analysis provided deeper insights into the intrinsic compositional nature of these compounds and the complex chemistry underlying coffee roasting. Predictive OPLS-DA models established universal molecular profiles for rapid authentication of Coffea arabica versus Coffea canephora (Robusta) coffees. Compositional analysis revealed Robusta specific signals, indicative of tryptophan-conjugates of hydroxycinnamic acids. Complementary LC-ToF-MS2 confirmed their compound class, building blocks and structures. Their water-soluble nature allows for application across raw and roasted beans, as well as in ready-made coffee products.

UPLC-ESI-TOF MS Profiling Discriminates Biomarkers in Authentic and Adulterated Italian Samples of Saffron (Crocus sativus L.)

Italian saffron (Crocus sativus L.) is gaining visibility due to its high quality and difference in growing area. In this study, the metabolite composition and quality of Italian saffron samples purchased from local producers and supermarkets were investigated using an untargeted metabolomics approach using UPLC-ESI-TOF MS with simultaneous acquisition of low- and high-collision energy mass spectrometry (MSe). Unsupervised statistical method (PCA) highlighted significant differences in the metabolomes, even if not related to the geographical origin. OPLS-DA revealed 9(S)-,10-(S)-,13-(S)-tri-hydroxy-11-(E)-octadecenoic acid as the most decisive compound to distinguish supermarket saffron, while oxidized crocins represented the most valuable markers to further describe the quality of saffron, even in locally produced samples. Known adulterations with paprika and turmeric were detected at a limit of 10%, and the increasing signals of cyclocurcumin was a significant biomarker for turmeric contamination. The results were underlined with conventional and kinetic antioxidant assays.

A comprehensive strategy for quality evaluation of Changan powder by fingerprinting combined with rapid qualitative and quantitative multi-ingredients profiling

INTRODUCTION

Changan powder (CAP) is mainly used to treat various intestinal diseases. Few studies on CAP have been reported; therefore, it is necessary to clarify the material basis of CAP to lay the foundation for further elucidating its functional mechanism and support the rational use of drugs.

OBJECTIVES

In the present study, we aimed to propose a methodology for the quality control of CAP based on qualitative and quantitative analysis of its components.

METHODS

An ultra-performance liquid chromatography coupled with Fourier transform ion cyclotron resonance mass spectrometry (UPLC-FT-ICR-MS) method was developed to identify chemical components in CAP. In addition, fingerprints of 10 different batches of CAP were established, and quantitative analysis based on UPLC was performed to analyze the quality of CAP.

RESULTS

A total of 58 compounds were preliminarily characterized. The similarity of 10 batches of CAP was greater than 0.995, and 23 common peaks were calibrated. Investigation of the quantitative analytical methodology showed that the four components had good linear relationships within their respective concentration ranges (r2 ≥ 0.9992), and the relative standard deviation (RSD) of precision and stability was less than 2%. The RSD of sample recovery ranged from 0.78% to 1.52%.

CONCLUSION

The established method can quickly and effectively identify the chemical components of CAP and accurately quantify the known components in CAP. The established fingerprinting and content determination method is stable, reliable, and easy to operate and can be applied in quality control and in vivo research on CAP.

Impact of roasting conditions on physicochemical, taste, volatile, and odor-active compound profiles of Coffea arabica L. (cv. Yellow Bourbon) using electronic sensors and GC-MS-O using a multivariate approach

This study investigated the effects of roasting conditions on the physicochemical, taste, and volatile and odor-active compound (OAC) profiles of Coffea arabica L. At 150 ℃, roasting increased chlorogenic acid, total flavonoids, and caffeine concentrations. However, umami and sourness sensor decreased during the roasting process. At 210 ℃ roasting, total flavonoid and caffeine concentrations increased during the roasting process. Aldehydes, ketones, and sulfur-containing compounds dramatically increased during the roasting at 210 ℃ for 20 and 30 min in E-nose analysis. Pyrazines were mainly generated during the roasting at 210 ℃ for 20 and 30 min, and pyrazines showed the highest concentrations among all OACs in GC-olfactometry (GC-O) analysis. E-tongue data showed the separation of beans by roasting temperature. However, the E-nose and GC-O data showed the separation of beans by both roasting temperature and time via multivariate analysis. We identified similar results and patterns in the E-nose and GC-O analyses.

DNA Mutagenicity of Hydroxyhydroquinone in Roasted Coffee Products and Its Suppression by Chlorogenic Acid, a Coffee Polyphenol, in Oxidative-Damage-Sensitive SAMP8 Mice

Hydroxyhydroquinone (HHQ) is an oxidative component produced by roasting coffee beans and has been reported to generate relatively large amounts of reactive oxygen species (ROS). In this study, we used senescence-accelerated mouse prone 8 (SAMP8) mice to determine whether HHQ consumption increases oxidative-stress-induced injury, because in SAMP8 mice, the activity of 8-oxoguanine DNA glycosylase 1, which repairs oxidative modifications in DNA, is decreased. The results showed that two out of twelve (16.7%) HHQ-treated mice presented polyuria and glucosuria around 2 months after the start of treatment, indicating that HHQ may act as a mutagen against SAMP8 mice, which is sensitive to oxidative damage. No abnormalities were observed in the chlorogenic acid (coffee polyphenol, CPP)-treated group. The concentration of hydrogen peroxide in the serum of SAMP8 mice was significantly higher than that in SAMR1 (senescence-resistant) control mice, and the concentration was further increased in the HHQ-treated group. CPP, when coexisting with HHQ at the rate contained in roasted coffee, decreased the amount of hydrogen peroxide in the serum of SAMP8 mice. Although CPP can act both oxidatively and antioxidatively as a polyphenol, CPP acts more antioxidatively when coexisting with HHQ. Thus, the oxidative effect of HHQ was shown to be counteracted by CPP.

From polyphenol to o-quinone: Occurrence, significance, and intervention strategies in foods and health implications

Polyphenol oxidation is a chemical process impairing food freshness and other desirable qualities, which has become a serious problem in fruit and vegetable processing industry. It is crucial to understand the mechanisms involved in these detrimental alterations. o-Quinones are primarily generated by polyphenols with di/tri-phenolic groups through enzymatic oxidation and/or auto-oxidation. They are highly reactive species, which not only readily suffer the attack by nucleophiles but also powerfully oxidize other molecules presenting lower redox potentials via electron transfer reactions. These reactions and subsequent complicated reactions are capable of initiating quality losses in foods, such as browning, aroma loss, and nutritional decline. To attenuate these adverse influences, a variety of technologies have emerged to restrain polyphenol oxidation via governing different factors, especially polyphenol oxidases and oxygen. Despite tremendous efforts devoted, to date, the loss of food quality caused by quinones has remained a great challenge in the food processing industry. Furthermore, o-quinones are responsible for the chemopreventive effects and/or toxicity of the parent catechols on human health, the mechanisms by which are quite complex. Herein, this review focuses on the generation and reactivity of o-quinones, attempting to clarify mechanisms involved in the quality deterioration of foods and health implications for humans. Potential innovative inhibitors and technologies are also presented to intervene in o-quinone formation and subsequent reactions. In future, the feasibility of these inhibitory strategies should be evaluated, and further exploration on biological targets of o-quinones is of great necessity.

Identification of alkaline-induced thiolyl-chlorogenic acid conjugates with cysteine and glutathione

Alkaline reactions of chlorogenic acid (CGA) yield undesirable development of brown or green pigments, limiting the utilization of alkalized CGA-rich foods. Thiols such as cysteine and glutathione mitigate pigment formation through several mechanisms, including redox coupling to reduce CGA quinones, and thiol conjugation, which forms colorless thiolyl-CGA compounds that do not readily participate in color-generating reactions. This work provided evidence of the formation of both aromatic and benzylic thiolyl-CGA conjugate species formed with cysteine and glutathione under alkaline conditions in addition to hydroxylated conjugate species hypothesized to arise from reactions with hydroxyl radicals. Formation of these conjugates proceeds more quickly than CGA dimerization and amine addition reactions mitigating pigment development. Differentiation between aromatic and benzylic conjugates is enabled by characteristic fragmentation of CS bonds. Acyl migration and hydrolysis of the quinic acid moiety of thiolyl-CGA conjugates yielded a variety of isomeric species also identified through untargeted LC-MS methods.

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

Adjuvant diet therapy is an important means of comprehensive treatment of cancer. It is recognized by patients for its high safety, painlessness, and ease to operate. However, the development of adjuvant dietary therapy is limited by unclear targets and unclear anticancer mechanisms. In this work, caffeic acid was found as an inhibitor of TMEM16A with an IC₅₀ of 29.47 ± 3.19 μM by fluorescence quenching and whole-cell patch-clamp experiments. Caffeic acid regulated the proliferation, migration, and apoptosis of lung cancer cells targeting TMEM16A, which was detected by CCK-8, colony formation, wound healing, and Annexin V assays. In addition, molecular docking combined with site-directed mutagenesis confirmed that the binding sites of caffeic acid to TMEM16A were D439, E448, and R753. Western blot results indicated that caffeic acid regulated the growth of lung cancer through the MAPK pathway. In vitro experiments showed that the inhibitory effect of caffeic acid combined with hydroxydaunorubicin (DOX) on lung cancer cell growth was better than a double concentration of any single dose. In vivo pharmacokinetic experiments and tumor xenograft experiments indicated that the combination of 5.4 mg/kg caffeic acid and 4.1 mg/kg DOX achieved 85.6% tumor suppression rate and offset the side effects. Therefore, caffeic acid is a safe and efficient antitumor active ingredient of food that can enhance the antitumor effect of DOX.