Determination of Total Chlorogenic Acids in Commercial Green Coffee Extracts

An optical fiber chlorogenic acid sensor using a Chitosan membrane coated bent optical fiber probe

Hydrogel polymers have hydrophilic function groups bonded on the polymer's backbone network. Water molecules and compounds soluble in aqueous solution can permeate into hydrogel's network. This property was employed in this work in developing an optical fiber chemical sensor for detecting chlorogenic acid (CGA). A Chitosan membrane was coated on a bent optical fiber probe (BOFP) by simply dipping the BOFP into a Chitosan solution, which was made by dissolving solid Chitosan in a 2 % acetic acid solution, and pulling out. When such a Chitosan-coated BOFP was exposed to CGA in an aqueous sample solution, CGA molecules permeate into the Chitosan membrane, and were detected through monitoring the compound's intrinsic optical absorption signal at 400 nm. Chitosan has one amine group on each of its glucose rings, which helps the membrane concentrating CGA (a weak acid) from aqueous sample solution. Therefore, the sensor shows high sensitivity in detecting CGA with a detection limit of 0.018 μg/mL. The sensor's response to CGA is reversible, because CGA permeation into/out of the polymer network is a reversible process. The effectiveness of the developed sensor for detecting CGA was verified though analyzing CGA in green coffee extract products. The analytical results obtained with the developed sensor agree well with results obtained with a traditional UV/Vis optical absorption spectrometric method. The effectiveness of the sensor for analyzing CGA in green coffee extract samples was also verified through standard addition and recovery experiment with obtained recovery rate ranging from 97 % to 100 %.

Investigating the role of chlorogenic acids and coffee type in coffee-induced teeth discoloration

OBJECTIVE

Coffee is one of the most popular beverages in the world, with millions of people consuming it every day. The effect of coffee on teeth discoloration has long been a concern for both coffee drinkers and dental professionals. To address this concern, this study aimed to investigate the role of chlorogenic acids (CGAs) and the type of coffee in coffee-induced teeth discoloration.

MATERIALS AND METHODS

High-performance liquid chromatography with a photodiode array detector was used to determine the CGA contents of instant coffee produced by five manufacturers (Starbucks, Dunkin' Donuts, Kanu, Ediya, Coffee Bean). A total of 180 bovine tooth specimens were immersed in the coffee samples for varying durations (3, 9, 24, 48, and 72 h), and the discoloration levels were measured using a spectrophotometer. A linear mixed-effects model analysis was used to determine the significance of L*, a*, and b* values in relation to the duration of coffee immersion and coffee type.

RESULTS

Both immersion time and coffee type had significant effects on tooth discoloration (p < 0.001), with some types of coffee being more strongly associated with tooth discoloration than others. The amount of CGAs present in coffee was found to be positively correlated with the degree of discoloration (p = 0.030).

CONCLUSIONS

Prolonged exposure to coffee can exacerbate teeth staining, and different types of coffee can cause varying degrees of discoloration. Furthermore, coffee with higher levels of CGAs may lead to greater tooth discoloration.

Chlorogenic acid induces apoptosis and cell-cycle arrest in colorectal cancer cells

BACKGROUND

Apoptotic agents from natural products like phenolic compounds can be used effectively in the treatment of cancer. Chlorogenic acid (CGA) is one of the phenolic compounds in medicinal plants with anti-cancer properties. In this research, we aimed to explore the anti-cancer mode of action of CGA on colorectal cancer (CRC) cells in vitro conditions.

METHODS

HT-29 and HEK-293 cells were cultured after MTT assay for 24 h with CGA 100 µM, and without CGA. Then, flow cytometry assays and the expression of apoptosis-related genes including caspase 3 and 9, Bcl-2 and Bax, and cell cycle-related genes including P21, P53 and NF-κB at mRNA and protein levels were examined. Finally, we measured the amount of intracellular reactive oxygen species (ROS).

RESULTS

The cell viability of all two-cell lines decreased in a dose-dependent manner. Moreover, CGA induces cell cycle arrest in HT-29 cells by increasing the expression of P21 and P53. It also induces apoptosis in HT-29 cells by mitigating Bcl-2 and NF-κB expression and elevating caspase 3 and 9 expression and ROS levels.

CONCLUSIONS

Considering the cytotoxicity and cell cycle arrest and induction of apoptosis in the colon cancer cell line by CGA, it can be concluded that CGA is a suitable option for the treatment of colon cancer.

Erigeron annuus Extract Alleviates Insulin Resistance via Regulating the Expression of Mitochondrial Damage and Endoplasmic Reticulum Stress-Related Genes

Diabetes is a prevalent and debilitating metabolic disorder affecting a large population worldwide. The condition is characterized by insulin resistance and impaired function of pancreatic β-cells, leading to elevated blood glucose levels. In this study, the antidiabetic effects of Erigeron annuus extract (EAE) on zebrafish with damaged pancreatic islets caused by insulin resistance were investigated. The study utilized the zebrafish model to monitor live pancreatic islets. RNA sequencing was also conducted to determine the mechanism by which EAE exerts its antidiabetic effect. The results showed that EAE was effective in recovering reduced islets in excess insulin-induced zebrafish. The effective concentration at 50% (EC₅₀) of EAE was determined to be 0.54 μg/mL, while the lethal concentration at 50% (LC₅₀) was calculated as 202.5 μg/mL. RNA sequencing indicated that the mode of action of EAE is related to its ability to induce mitochondrial damage and suppress endoplasmic reticulum stress. The findings of this study demonstrate the efficacy and therapeutic potential of EAE in treating insulin resistance in zebrafish. The results suggest that EAE may offer a promising approach for the management of diabetes by reducing mitochondrial damage and suppressing endoplasmic reticulum stress. Further research is required to establish the clinical application of EAE in diabetic patients.

Use of Coffee Bean Bagasse Extracts in the Brewing of Craft Beers: Optimization and Antioxidant Capacity

Coffee bean bagasse is one of the main by-products generated by industrial coffee production. This by-product is rich in bioactive compounds such as caffeine, caffeic and chlorogenic acid, and other phenols. The aims of this work are to optimize the extraction conditions of phenolic compounds present in coffee bean bagasse and incorporate them into stout-style craft beers, as well as to determine their effect on the phenol content and antioxidant capacity. The optimal conditions for extraction were 30% ethanol, 30 °C temperature, 17.5 mL of solvent per gram of dry sample, and 30 min of sonication time. These conditions presented a total phenol content of 115.42 ± 1.04 mg GAE/g dry weight (DW), in addition to an antioxidant capacity of 39.64 ± 2.65 μMol TE/g DW in DPPH^• and 55.51 ± 6.66 μMol TE/g DW for FRAP. Caffeine, caffeic and chlorogenic acids, and other minor compounds were quantified using HPLC-DAD. The coffee bean bagasse extracts were added to the stout craft beer and increased the concentration of phenolic compounds and antioxidant capacity of the beer. This work is the first report of the use of this by-product added to beers.

New rapid detection method of total chlorogenic acids in plants using SERS based on reusable Cu2O-Ag substrate

A new method for rapidly detecting of total chlorogenic acids (CGAs) in plants by surface-enhanced Raman spectroscopy (SERS) based on reusable Cu₂O-Ag substrate was developed in this study. The Cu₂O-Ag substrate prepared by the in-situ growth method had high uniformity with peak intensity relative standard deviation (RSD) of 5.27%, repeatability with peak intensity RSD of 3.58%, and sensitivity with an analytical enhancement factor of 1.27 × 10⁵ for detecting CGAs. Furthermore, the substrate had excellent reusability, after it was reused for seven cycles, the signal strength of CGAs was still above 80% of initial. Compared with the standard method of high-performance liquid chromatography (HPLC), the SERS method can successfully analyze the contents of total CGAs in plants, such as Stevia rebaudiana leaves, coffee beans, Lonicera japonica leaves, and Eucommia ulmoides flowers, with recovery rate from 93.26% to 112.65%, and the limit of detection was 0.13 μg/mL. The total CGAs content of Stevia rebaudiana leaves samples detected by HPLC and SERS have good consistency with R = 0.9760 and RMSE = 3286 mg/kg. Furthermore, the SERS method only needed less than 1 min, one standard and reusable substrate in this study to analyze, which can further reduce the cost of method analysis. Therefore, the SERS method with the appropriate substrate can provide a rapid, accurate, and economic way to detect the total CGAs in plants.

Potential Antimicrobial Properties of Coffee Beans and Coffee By-Products Against Drug-Resistant Vibrio cholerae

Vibrio cholerae is the causative organism of the cholera epidemic, and it remains a serious global health problem, particularly the multidrug-resistant strain, despite the development of several generic drugs and vaccines over time. Natural products have long been exploited for the treatment of various diseases, and this study aimed to evaluate the in vitro antibacterial activity of coffee beans and coffee by-products against V. cholerae antimicrobial resistant strains. A total of 9 aqueous extracts were investigated, including light coffee (LC), medium coffee (MC), dark coffee (DC), dried green coffee (DGC), dried red coffee (DRC), fresh red coffee (FRC), Arabica leaf (AL), Robusta leaf (RL), and coffee pulp (CP). The influential coffee phytochemicals, i.e., chlorogenic acid (CGA), caffeic acid (CA), and caffeine, were determined using HPLC. The antibacterial properties were tested by agar well-diffusion techniques, and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were further determined against 20 V. cholerae isolates. The results revealed that all tested strains were sensitive to coffee extracts, with MIC and MBC values in the range of 3.125-25.0 mg/mL and 12.5-50.0 mg/mL, respectively. With a MIC of 6.25 mg/mL, DGC, DRC, and CP appeared to be the most effective compounds against 65, 60, and 55% of clinical strains, respectively. The checkerboard assay revealed that the combination of coffee extract and tetracycline was greater than either treatment alone, with the fractional inhibitory concentration index (FICI) ranging from 0.005 to 0.258. It is important to note that CP had the lowest FICI (0.005) when combined with tetracycline at 60 ng/mL, which is the most effective dose against V. cholerae six-drug resistance strains (azithromycin, colistin, nalidixic acid, sulfamethoxazole, tetracycline, and trimethoprim), with a MIC of 47.5 μg/mL (MIC alone = 12.5 mg/mL). Time killing kinetics analysis suggested that CA might be the most effective treatment for drug-resistant V. cholerae as it reduced bacterial growth by 3 log10 CFU/mL at a concentration of 8 mg/mL within 1 h, via disrupting membrane permeability, as confirmed by scanning electron microscopy (SEM). This is the first report showing that coffee beans and coffee by-product extracts are an alternative for multidrug-resistant V. cholerae treatment.

Adverse effects associated with use of specific dietary supplements: The US Military Dietary Supplement Use Study

Dietary supplements (DSs) are used by 50% of Americans and 70% of United States military service members (SMs); some have adverse effects (AEs). This cross-sectional investigation examined AEs associated with specific DSs. A stratified random sample of SMs from the Air Force, Army, Marine Corps, and Navy was obtained. Volunteers completed a questionnaire reporting AEs for 96 generic and 62 specific DSs. The highest prevalence (≥1 AE) in specific DS categories was 35% prohormones, 33% weight loss supplements, 26% pre/post workout supplements, 14% herbal products, 12% multivitamin/multiminerals, 11% protein/amino acids, 9% muscle building supplements, 7% other DSs, 6% joint health products, and 5% individual vitamins/minerals. Specific DSs of concern (with proportion reporting AEs) included: Libido Max® (35%), Hydroxycut Hardcore® (33%), OxyElite® (33%), Roxylean® (31%), Growth Factor 9® (30%), Super HD® (29%), Hydroxycut Advanced® (29%), Lipo 6® (28%), The Ripper® (27%), Test Booster® (27%), Xenadrine Xtreme Thermogenic® (27%), C4 Extreme® (26%), and C4 Origional® (25%). Products marketed for weight loss, use before/after workout, and prohormones had the highest AE prevalence. DSs can contain substances with independent/additive AEs and/or interact with other ingredients or prescribed medications. Methods described here could provide a continuous surveillance system detecting dangerous DSs entering the market.

Rapid and simultaneous determination of trigonelline, caffeine, and chlorogenic acid in green coffee bean extract

A simple, inexpensive, and rapid method for simultaneous determination of trigonelline, caffeine, and chlorogenic acid from green coffee bean extract was proposed based on salting-out assisted liquid-liquid extraction, using QuEChERS salt and acetonitrile followed by UV-Vis analysis. The proposed method represents acceptable linearity for trigonelline (0.9978), caffeine (0.9995), and chlorogenic acid (0.9996) with excellent correlation (0.93 and 0.83) for trigonelline and caffeine, respectively, when compared to RP-HPLC-DAD. The proposed method could be used in coffee industries for quality control and geographical origin traceability studies of green coffee samples.

Green coffee: economic relevance and a systematic review of the effects on human health

Coffee is probably the most popular beverage after water and is an important component in diet and health since its consumption is high worldwide. Globally, it is the most relevant food commodity being just behind crude oil. Besides its pleasant flavor, it is an antioxidant source due to polyphenols, which are protective compounds against several diseases. This study aimed to evaluate the economic relevance and perform a systematic review of green coffee's effects on human health. Databases such as MEDLINE-PubMed, EMBASE, COCHRANE, and GOOGLE SCHOLAR were searched, and PRISMA guidelines were followed. Green coffee is considered a novel food product because consumers usually consume only roasted coffee. It can be marketed as such or as an extract. Due to the content of bioactive compounds, which are partially lost during the roasting process, the extracts are usually marketed concerning the potential regarding health effects. Green coffee can be used as dietary supplements, cosmetics, and pharmaceuticals, as a source of antioxidants. It can benefit human health, such as improvement in blood pressure, plasma lipids, and body weight (thus contributing to the improvement of risk components of Metabolic Syndrome). Moreover, benefits for cognitive functions may also be included.

Effect of post-harvest drying process on chlorogenic acids, antioxidant activities and CIE-Lab color of Thai Arabica green coffee beans

Drying process affected the qualitative indicators of green coffees; chlorogenic acid (CGAs), total phenolic content (TPC), antioxidant activities and CIE-lab color to varying degrees. Sun drying and heat pump drying resulted in comparable levels of CGAs and antioxidant activities in green coffees; however, color parameters, especially lightness (L*), differed. Correlation analyses indicated a relationship between specific CGAs, antioxidant activities and color parameters among coffees. PLS analysis revealed that the high contents of 5-caffeoylquinic acid in green coffees did not correlate with antioxidant activities. Results from CGAs contents and PCA analysis provided a linkage to previous research relating important components and quality indices of both green and roasted coffees as affected by postharvest drying. Results indicated that heat pump drying at 50 °C is a viable alternative and possibly superior to sun drying for preserving certain desirable chemical and physical characteristics of green coffee.

Can We Prevent Coffee Stains on Teeth?

This study evaluates whether some common beverages treated before coffee could protect or increase tooth staining caused by coffee. Initial color of 50 incisor teeth were measured with a spectrophotometer and recorded according to CIELAB color system. Teeth were randomly divided into five groups, water (control), milk, green tea, orange juice, and cola (n = 10) and were kept in selected beverage for 10 min. Immediately afterward, they were immersed in coffee and allowed to stand for 24 h. The treatment was repeated for 5 days. At the end of the fifth day, L*a*b* color measurements of the teeth were repeated. Calcium, phosphorus, potassium, and magnesium changes on representative teeth surfaces were also investigated with X-ray fluorescence spectroscopy. Color differences were calculated with both CIE_ab and CIE₀₀ formulas. Groups were compared with Kruskal-Wallis test complemented by the Bonferroni correction and Mann-Whitney U test for pairwise comparisons (P = .05). The teeth submitted to coffee challenges after distillated water or beverages showed a perceptible color change. Soaking in cola or orange juice before coffee immersion caused severe tooth discoloration. All the beverages tested here were not able to protect the tooth from coffee staining. People should be informed that some acidic beverages consumed before a coffee can worsen the coffee-based tooth discolorations.

Comparative metabolism study on chlorogenic acid, cryptochlorogenic acid and neochlorogenic acid using UHPLC-Q-TOF MS coupled with network pharmacology

Chlorogenic acid (5-CQA), neochlorogenic acid (3-CQA), and cryptochlorogenic acid (4-CQA), usually simultaneously exist in many traditional Chinese medicines (TCMs). However, insufficient attentions have been paid to the comparative metabolism study on these three isomeric constituents with similar effects on anti-inflammation until now. In this study, a novel strategy was established to perform comparative analysis of their metabolic fates in rats and elucidate the pharmacological mechanism of anti-inflammation. Firstly, diagnostic product ions (DPIs) deduced from the representative reference standards were adopted to rapidly screen and characterize the metabolites in rat plasma, urine and faeces using UHPLC-Q-TOF MS. Subsequently, Network pharmacology was utilized to elucidate their anti-inflammatory mechanism. Consequently, a total of 73 metabolites were detected and characterized, including 50, 47 and 43 metabolites for 5-CQA, 4-CQA and 3-CQA, orderly. Moreover, the network pharmacology study indicated that these three isomeric constituents and their major metabolites with similar in vivo metabolic pathways exerted anti-inflammatory effects through co-owned 20 biological processes, which involved 10 major signal pathways and 159 potential targets. Our study shed light on the similarities and differences of the metabolic profiling and anti-inflammatory activity among these three isomeric constituents and set an example for the further researches on the active mechanism of isomeric constituents existing in TCMs based on comparative metabolism study.

[Fraud in nutritional supplements for athletes: a narrative review]

Introduction

The use of nutritional supplements (NSs) is a widespread practice in both professional and amateur athletes. Their choice must be based on criteria of safety, legality, and effectiveness. There are several risks that some of these products can trigger, this being a reason for fraud to the consumer. By way of example, the presence of a legal substance in doses higher than its recommendation may cause unwanted side effects; on the other hand, its presence in quantities lower than necessary (effective threshold) may not have the effect expected or announced by the product. Therefore, the objective of this review was to describe the existence of fraud in relation to nutritional labeling and/or to the content of NSs intended for athletes. A narrative review was conducted through PubMed in which 16 studies met the inclusion criteria. The results show that nutritional labeling differs from the actual amounts of ingredients. This type of fraud has been found in protein powder supplements, pre-workout mixtures, creatine, and beverages containing vitamins and minerals, among others. Fraud due to errors in the labeling by omission of substances present in the product or by errors in the analysis or declaration of quantities, is high. This lack of transparency in the actual composition of labels can contribute to sports performance and/or health problems in the athlete. Therefore, an improvement of the legislation on NS is necessary to ensure their safety, effectiveness, and legality.

Roadmapping as a Driver for Knowledge Creation: A Proposal for Improving Sustainable Practices in the Coffee Supply Chain from Chiapas, Mexico, Using Emerging Technologies

Technologies are essential for productive sectors to increase competitiveness and improve sustainable development. However, the technology benefits present a great delay in adoption in agricultural sectors, due to discrepancies between scientific research and local needs. This article presents a study for improving sustainability practices in the coffee supply chain, using emerging technologies, of two localities in the Frailesca region from Chiapas, Mexico, based on the current situation, expectations and actions expressed by 165 coffee producers and 12 representatives of two coffee producers’ organizations. Based on Mentzer theoretical support, the technology roadmaps, knowledge management and digital compass were used to draw coffee supply chain processes to identify concrete actions and explore technologies. The results show that the technological route must be focused on renewing and improving coffee quality, getting quality certifications and access to specialized markets. Digital quality management and advanced statistical process control seem to be the appropriate emerging technologies for enhancing the acquisition of resistant varieties, proper pest management, improvement in the collection of coffee beans, the right time and way to plant a coffee plant, soil analysis and for the management of weeds and water conservation and harvesting as sustainable practices in this region. In addition, statistical correlation showed that digital technologies can be better adopted, on average, by producers with 4–6 family members, aged between 40–44 years and without additional crops. The findings propose sustainable practices linked with emerging technologies, based on a technology roadmap and knowledge management methodologies for this region.

Chemometric-assisted construction of a biosensing device to measure chlorogenic acid content in brewed coffee beverages to discriminate quality

In this work we propose the use of statistical mixture design in the construction of a biosensor device based on graphite oxide, platinum nanoparticles and biomaterials obtained from Botryosphaeria rhodina MAMB-05. The biosensor was characterized by electrochemical impedance spectroscopy. Under optimized experimental parameters by factorial design, the biosensor was applied to the voltammetric determination of chlorogenic acid (CGA) measured as 5-O-caffeoylquinic acid (5-CQA). The biosensor response was linear (R² = 0.998) for 5-CQA in the concentration range 0.56-7.3 µmol L^-1, with limit of detection and quantification of 0.18 and 0.59 µmol L^-1, respectively. The new biosensing device was applied to quality control analysis based upon the determination of CGA content in specialty and traditional coffee beverages. The results indicated that specialty coffee had a significantly higher content of CGA. Principal component analysis of the voltammetric fingerprint of brewed coffees revealed that the laccase-based biosensor can be used for their discrimination.