Variability of some diterpene esters in coffee beverages as influenced by brewing procedures

Lipophilic and Hydrophilic Metabolites as Descriptors of Different Coffee Beverages

Coffee is a widely consumed beverage rich in bioactive phytochemicals. This study investigated the effect of brewing method on the profile of potential bioactive compounds in different coffee beverages using metabolomics and lipidomics based on UHPLC-MS/QTOF. The oil contents of the espresso coffee (EC), pot coffee (PC), instant coffee (IC), and filter coffee (FC) beverages studied were 0.13% ± 0.002, 0.12% ± 0.001, 0.04% ± 0.002, and 0.03% ± 0.003, respectively. Univariate analysis indicated significant differences (P < 0.001) in oil content when EC and PC beverages were compared with IC and FC beverages. Principal component analysis revealed similarities in the lipid profiles of FC and EC beverages and the hydrophilic profiles of PC and FC beverages. The EC beverage had the highest intensity of hydrophilic compounds such as adenine, theobromine, chlorogenic acid, and caffeine. The PC beverage was the most abundant in triglycerides, phosphatidylcholine, and diterpenes. Cafestol and kahweol esters, but not their free forms, were the most abundant diterpenes in the PC beverage. This work provides information on the differences in the profile of potentially bioactive compounds in four commonly consumed coffee beverage types and, thus, on the possible differences in the health effects of these coffee beverage types.

Extraction of Diterpene-Phytochemicals in Raw and Roasted Coffee Beans and Beverage Preparations and Their Relationship

Cafestol and kahweol are expressive furane-diterpenoids from the lipid fraction of coffee beans with relevant pharmacological properties for human health. Due to their thermolability, they suffer degradation during roasting, whose products are poorly studied regarding their identity and content in the roasted coffee beans and beverages. This article describes the extraction of these diterpenes, from the raw bean to coffee beverages, identifying them and understanding the kinetics of formation and degradation in roasting (light, medium and dark roasts) as the extraction rate for different beverages of coffee (filtered, Moka, French press, Turkish and boiled). Sixteen compounds were identified as degradation products, ten derived from kahweol and six from cafestol, produced by oxidation and inter and intramolecular elimination reactions, with the roasting degree (relationship between time and temperature) being the main factor for thermodegradation and the way of preparing the beverage responsible for the content of these substances in them.

Authentication of Coffee Blends by 16-O-Methylcafestol Quantification Using NMR Spectroscopy

In 2019, a coffee chain in Taiwan was found to be mixing relatively cheap Robusta beans into products marketed as 100% Arabica. Many studies show 16-OMC is a remarkable marker to distinguish Robusta from Arabica beans, and nuclear magnetic resonance (NMR) is a convenient and efficient technique for 16-OMC quantification. Here, a 500 MHz NMR was employed to determine the content of 16-OMC in coffee for adulterate evaluation. A total of 118 samples were analyzed including products from the coffee chain, raw materials (single coffee beans), and other commercial products. The contents of 16-OMC in single Robusta beans were between 1005.55 and 3208.32 mg/kg and were absent from single Arabica beans. The surveillance results indicate that 17 out of 47 blend products claiming to contain 100% Arabica had 16-OMC quantifications in the range of 155.74–784.60 mg/kg. Furthermore, all 17 products were produced by the same coffee chain. We confirmed that coffee chain adulterated Arabica with Robusta in parts of their products, which claimed to include 100% Arabica. Moreover, this work highlights the free form of 16-OMC was esterified by coffee instantly. The decomposition products of 16-OMC were observed obviously in green Robusta while the mechanisms remain unclear. Future research should focus more on these aspects to further increase our understanding of these mechanisms.

Coffee Consumption and the Risk of Metabolic Syndrome in the ‘Seguimiento Universidad de Navarra’ Project

(1) Background: Metabolic Syndrome (MetS) affects over a third of the United States population, and has similar prevalence in Europe. Dietary approaches to prevention are important. Coffee consumption has been inversely associated with mortality and chronic disease; however, its relation to the risk of MetS is unclear. We aimed to investigate the association between coffee consumption and incident MetS in the ‘Seguimiento Universidad de Navarra’ cohort. (2) Methods: From the SUN project, we included 10,253 participants initially free of MetS. Coffee consumption was assessed at baseline, and the development of MetS was assessed after 6 years of follow-up. All data were self-reported by participants. MetS was defined according to the Harmonizing Definition. We used multivariable logistic regression models to estimate odds ratios and 95% confidence intervals for incident MetS according to four categories of coffee consumption: <1 cup/month; ≥1 cup/month to <1 cup/day; ≥1 cup/day to <4 cups/day; ≥4 cups/day. (3) Results: 398 participants developed MetS. Coffee consumption of ≥1 to <4 cups/day was associated with significantly lower odds of developing MetS (multivariable adjusted OR = 0.71, 95% CI (0.50–0.99)) as compared to consumption of <1 cup/month. (4) Conclusions: In a Mediterranean cohort, moderate coffee consumption may be associated with a lower risk of MetS.

Association between espresso coffee and serum total cholesterol: the Tromsø Study 2015-2016

Background

Coffee raises serum cholesterol because of its diterpenes, cafestol and kahweol, and the effect varies by brewing method. Population-based research on espresso coffee’s impact on serum cholesterol is scarce. Our aim was to examine how various brewing methods, in particular espresso, were associated with serum total cholesterol (S-TC).

Methods

We used cross-sectional population data from the seventh survey of the Tromsø Study in Northern Norway (N=21 083, age ≥40 years). Multivariable linear regression was used to assess the association between S-TC as the dependent variable and each level of coffee consumption using 0 cups as the reference level, adjusting for relevant covariates and testing for sex differences.

Results

Consumption of 3–5 cups of espresso daily was significantly associated with increased S-TC (0.09 mmol/L, 95% CI 0.01 to 0.17 for women and 0.16 mmol/L, 95% CI 0.07 to 0.24 for men), compared with participants drinking 0 cups of espresso per day. Consumption of ≥6 cups of boiled/plunger coffee daily was also associated with increased S-TC (0.30 mmol/L, 95% CI 0.13 to 0.48 for women and 0.23 mmol/L, 95% CI 0.08 to 0.38 for men), compared with participants drinking 0 cups of boiled/plunger coffee. Consumption of ≥6 cups of filtered coffee daily was associated with 0.11 mmol/L (95% CI 0.03 to 0.19) higher S-TC levels for women but not for men. Instant coffee consumption had a significant linear trend but showed no dose–response relationship when excluding participants not drinking instant coffee. There were significant sex differences for all coffee types except boiled/plunger coffee.

Conclusion

Espresso coffee consumption was associated with increased S-TC with significantly stronger association for men compared with women. Boiled/plunger coffee was associated with increased S-TC in both sexes and with similar magnitude as shown in previous research. Filtered coffee was associated with a small increase in S-TC in women. Further research on espresso and S-TC is warranted.

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

Coffee is a worldwide beverage of increasing consumption, owing to its unique flavor and several health benefits. Metabolites of coffee are numerous and could be classified on various bases, of which some are endogenous to coffee seeds, i.e., alkaloids, diterpenes, sugars, and amino acids, while others are generated during coffee processing, for example during roasting and brewing, such as furans, pyrazines, and melanoidins. As a beverage, it provides various distinct flavors, i.e., sourness, bitterness, and an astringent taste attributed to the presence of carboxylic acids, alkaloids, and chlorogenic acids. To resolve such a complex chemical makeup and to relate chemical composition to coffee effects, large-scale metabolomics technologies are being increasingly reported in the literature for proof of coffee quality and efficacy. This review summarizes the applications of various mass spectrometry (MS)- and nuclear magnetic resonance (NMR)-based metabolomics technologies in determining the impact of coffee breeding, origin, roasting, and brewing on coffee chemical composition, and considers this in relation to quality control (QC) determination, for example, by classifying defected and non-defected seeds or detecting the adulteration of raw materials. Resolving the coffee metabolome can aid future attempts to yield coffee seeds of desirable traits and best flavor types.

Constipation and Cigarette Smoking Are Independent Influences for Parkinson’s Disease

Background

Tobacco smokers have reduced Parkinson’s disease (PD) risk. Some patients with PD experience constipation long before they develop mobility problems, and constipation is a frequent complaint of people who try to stop smoking. Recently, the gut microbiome has been implicated in PD.

Methods

In the present study, we analyzed the relationship between smoking and constipation in subjects with PD and controls. We wished to determine whether the effects of smoking and constipation were independent or whether they might be interrelated. To evaluate the relationship, we used a cohort of subjects from the UK Biobank (UKB).

Results

In 501,174 subjects, the decreased risk of Parkinson’s disease with increased smoking was significant (p < 0.001, two-tailed Fisher’s exact test). The increased risk of constipation in subjects with PD was significant (p = 0.001, two-tailed Fisher’s exact test). Logistic regression was performed; sex, age, constipation, and smoking were the independent variables, and PD present or absent was the dependent variable. The PD odds ratio (OR) for males was 1.790 (95% confidence interval (CI): 1.629-1.966) times that for females, indicating that PD is more common in men. The risk of PD increased by 1.140 (95% CI: 1.131-1.149) with every year of age. Constipation increased the risk of PD by 4.043 (95% CI: 1.901-8.599). Smoking diminished PD risk by 0.772 (95% CI: 0.690-0.863). Drinking coffee was associated with a reduced risk of PD (OR: 0.815 (95% CI: 0.730-0.909). Drinking tea reduced PD risk by 0.979 (95% CI: 0.962-0.997) for each cup per day. The effects of sex, age, constipation, smoking, drinking coffee, and drinking tea were independent and significant.

Conclusion

Our analysis suggests that the favorable effect of smoking on PD is independent of the detrimental effect of constipation. Smoking reduces PD risk because it not only stimulates the bowel to empty and prevents constipation but also alters the gut microbiome. Another factor, perhaps the tobacco component diterpenoids, may be responsible for the PD risk-reducing effect.

Coffee intake and trace element blood concentrations in association with renal cell cancer among smokers

PURPOSE

To determine whether higher coffee intake may reduce the risk of renal cell cancer (RCC) associated with lead (Pb) and other heavy metals with known renal toxicity.

METHODS

We conducted a nested case-control study of male smokers (136 RCC cases and 304 controls) within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study. Cases diagnosed with RCC at 5 or more years following cohort enrollment were matched to controls on age (± 7 years) and whole blood draw date (± 30 days). Conditional logistic regression (using two-sided tests) was used to test for main effects and additive models of effect modification.

RESULTS

After a mean follow-up of 16.3 years, coffee consumption was not significantly associated with renal cell cancer risk, when adjusting for blood concentrations of Cd, Hg, and Pb and RCC risk factors (age, smoking, BMI, and systolic blood pressure) (p-trend, 0.134). The association with above median blood Pb and RCC (HR = 1.69, 95% CI 1.06, 2.85) appeared to be modified by coffee consumption, such that RCC risk among individuals with both increased coffee intake and higher blood lead concentration were more than threefold higher RCC risk (HR = 3.40, 95% CI 1.62, 7.13; p-trend, 0.003).

CONCLUSION

Contrary to our initial hypothesis, this study suggests that heavy coffee consumption may increase the previously identified association between higher circulating lead (Pb) concentrations and increased RCC risk. Improved assessment of exposure, including potential trace element contaminants in coffee, is needed.

The Cardiovascular Benefits of Caffeinated Beverages: Real or Surreal? /"Metron Ariston - All in Moderation"

Caffeinated beverages are the most widely consumed beverages globally with coffee and tea as the two most prominent sources of caffeine. Caffeine content varies across different types of beverages. In addition to caffeine, coffee and tea have other biologically active compounds, and all may affect general and cardiovascular (CV) health. Moderate caffeine consumption (<300-400 mg/day), regardless of the source, is considered safe by both European and US Health Authorities, as it is not associated with adverse health and CV effects, while it may confer certain health benefits. There is a nonlinear association between coffee ingestion and CV risk; moderate coffee drinking is inversely significantly associated with CV risk, with the highest benefit at 2-4 cups per day, while heavy coffee drinking might confer increased risk. With regards to tea, due to a lower caffeine content per serving, its consumption is only limited by the total caffeine daily intake. Both these caffeinated beverages, coffee and tea, have additional phenolic compounds, with anti-oxidant and anti-inflammatory activities, which confer cardioprotective benefits. Of the several coffee compounds, chloroacetic acids and melanoidins offer such beneficial effects, while diterpenes may have unfavorable effects on lipids. Most of the tea ingredients (polyphenols) are cardioprotective. A major concern relates to energy drinks with their much higher caffeine content which puts individuals, especially adolescents and young adults, at high health and CV risk. All these issues are herein discussed, including pertinent studies and meta-analyses, pathogenetic mechanisms involved and relevant recommendations from health authorities.

Chemometrics-based aroma profiling for revealing origin, roasting indices, and brewing method in coffee seeds and its commercial blends in the Middle East

Coffee is among the most consumed beverages worldwide. The present study reports on the aroma composition associated with coffee seeds brewing. Aroma of authentic coffee specimens of Coffea arabica and C. robusta alongside with typical products consumed in the Middle East were analyzed using HS-SPME coupled with GC-MS. In addition, multivariate data analysis (MVA) was employed. Results revealed for 102 volatiles with a distinct aroma profile between the different brewing methods. Infusion demonstrated higher esters level, while decoction and maceration were more abundant in sesquiterpenes and terpene alcohols, respectively. Besides, heat-induced products, i.e., 4-vinyl guaiacol was identified as potential roasting index in instant coffee and roasted C. robusta brews. Blending with cardamom further masked the smoky odor of such compounds by its fragrant terpinyl acetate. This study provides the first report on the chemical sensory attributes of Middle Eastern coffee blends and further reveal for the impact of brewing, roasting on its aroma composition.

New trends in coffee diterpenes research from technological to health aspects

The coffee oil is rich in diterpenes, mainly cafestol and kahweol, which are predominantly present in the esterified form with different fatty acids. Despite their beneficial effects including anti-angiogenic and anti-carcinogenic properties, they have been also associated with negative consequences such as elevation of blood cholesterol. Considering the coffee, it is an important human beverage with biological effects, including potentially health benefits or risks. Therefore, it may have important public health implications due to its widespread massive consumption, with major incidence in the varieties Arabica and Robusta. According to literatures, cafestol (182-1308 mg/100 g), kahweol (0-1265 mg/100 g) and 16-O-methycafestol (0-223 mg/100 g) are the main diterpenes in green and roasted coffee beans. Nevertheless, the coffee species, genetic background, and technological parameters like roasting and brewing have a clear effect on coffee diterpene content. Besides that, bibliographic data indicated that limited studies have specifically addressed the recent analytical techniques used for determination of this class of compounds, being HPLC and GC the most common approaches. For these reasons, this review aimed to actualize the occurrence and the profile of diterpenes in coffee matrices, focusing on the effect of species, roasting and brewing and on the other hand, introduce the current state on knowledge regarding coffee diterpenes determination which are nowadays highly regarded and widely used. In general, since diterpenes exhibit different health effects depending on their consumption dosage, several parameters needs to be carefully analyzed and considered when comparing the results.

In Vitro Hypocholesterolemic Effect of Coffee Compounds

(1) Background: Cholesterol bioaccessibility is an indicator of cholesterol that is available for absorption and therefore can be a measure of hypocholesterolemic potential. In this work, the effect of commercial espresso coffee and coffee extracts on cholesterol solubility are studied in an in vitro model composed by glycodeoxycholic bile salt, as a measure of its bioaccessibility. (2) Methods: Polysaccharide extracts from coffees obtained with different extraction conditions were purified by selective precipitation with ethanol, and their sugars content were characterized by GC-FID. Hexane extraction allowed us to obtain the coffee lipids. Espresso coffee samples and extracts were tested regarding their concentration dependence on the solubility of labeled 13C-4 cholesterol by bile salt micelles, using quantitative 13C NMR. (3) Results and Discussion: Espresso coffee and coffee extracts were rich in polysaccharides, mainly arabinogalactans and galactomannans. These polysaccharides decrease cholesterol solubility and, simultaneously, the bile salts' concentration. Coffee lipid extracts were also found to decrease cholesterol solubility, although not affecting bile salt concentration. (4) Conclusions: Coffee soluble fiber, composed by the arabinogalactans and galactomannans, showed to sequester bile salts from the solution, leading to a decrease in cholesterol bioaccessibility. Coffee lipids also decrease cholesterol bioaccessibility, although the mechanism of action identified is the co-solubilization in the bile salt micelles. The effect of both polysaccharides and lipids showed to be additive, representing the overall effect observed in a typical espresso coffee. The effect of polysaccharides and lipids on cholesterol bioaccessibility should be accounted on the formulation of hypocholesterolemic food ingredients.

Mineral Composition and Antioxidant Potential of Coffee Beverages Depending on the Brewing Method

Coffee, being one of the world’s most popular beverages, is a rich source of dietary antioxidants. The aim of this study was to determine the mineral content and antioxidant activity as well as acidity of coffee beverages depending on the brewing technique. We tested coffee brews made and served at a popular urban coffee shop (Szczecin, Poland). Five coffee brewing techniques were used: Aeropress, drip, espresso machine, French press, and simple infusion. Our findings showed that the brewing method had a significant effect on all parameters tested in the study. The antioxidant activity of the beverages was high (31%–42% inhibition of DPPH (2,2-diphenyl-1-picrylhydrazyl); reduction potential from 3435.06 mol Fe3⁺/mL to 4298.19 mol Fe3⁺/mL). Polyphenolic content ranged from 133.90 g (French press) to 191.29 g of gallic acid/L (Aeropress brew), depending on the coffee extraction method. Mineral content was also found to differ between brewing methods. Coffees prepared by simple infusion and Aeropress provided a valuable source of magnesium, manganese, chromium, cobalt, and potassium, whereas the drip brew was found to be a good source of silicon.

Misclassification of coffee consumption data and the development of a standardised coffee unit measure

Background

Associations of coffee consumption with multiple health outcomes have been researched extensively. Coffee consumption, usually reported in cups a day, is a heterogeneous measure due to numerous preparation methods and cup sizes, leading to misclassification. This paper develops a new ‘unit’ measure of coffee and uses coffee consumption data from a representative sample of the UK population to assess misclassification when cup volume and preparation type are not taken into account.

Methods

A coffee unit measure was created using published estimates of caffeine and chlorogenic acid concentrations, and applied across volumes and preparation types. Four-day food diary data in adults from the UK National Diet and Nutrition Survey (NDNS; 2012–2016) were used to quantify coffee intake. Participant self-reported cups a day were compared with cups a day standardised by (a) 227 mL volume and (b) 227 mL instant coffee equivalents (unit measure), and the degree of misclassification was derived. Sensitivity analyses were conducted to model coffee drinking preferences of different populations and caffeine:chlorogenic acid weighting assumptions of the unit measure.

Results

The NDNS sample consisted of 2832 adult participants. Coffee was consumed by 62% of participants. Types varied, with 75% of caffeinated coffee cups being instant, 17% filter, 3% latte, 2% cappuccino, 2% espresso and <1% other types. Comparing reported cups to volume-standardised cups, 84% of participants had correct classification, and 73% when using the coffee unit measure, 22% underestimated and 5% overestimated, largely by one cup. Misclassification varied by gender, age and income. Sensitivity analysis highlighted the benefits of using the unit measure over volume alone to cater for different populations, and stability of the unit composition assumption.

Conclusion

Cup volume and preparation type should be taken into account, through the application of a standardised coffee unit measure, when coffee consumption is classified in future research studies.

Coffee extract and caffeine enhance the heat shock response and promote proteostasis in an HSF-1-dependent manner in Caenorhabditis elegans

As the population ages, there is a critical need to uncover strategies to combat diseases of aging. Studies in the soil-dwelling nematode Caenorhabditis elegans have demonstrated the protective effects of coffee extract and caffeine in promoting the induction of conserved longevity pathways including the insulin-like signaling pathway and the oxidative stress response. We were interested in determining the effects of coffee and caffeine treatment on the regulation of the heat shock response. The heat shock response is a highly conserved cellular response that functions as a cytoprotective mechanism during stress, mediated by the heat shock transcription factor HSF-1. In the worm, HSF-1 not only promotes protection against stress but is also essential for development and longevity. Induction of the heat shock response has been suggested to be beneficial for diseases of protein conformation by preventing protein misfolding and aggregation, and as such has been proposed as a therapeutic target for age-associated neurodegenerative disorders. In this study, we demonstrate that coffee is a potent, dose-dependent, inducer of the heat shock response. Treatment with a moderate dose of pure caffeine was also able to induce the heat shock response, indicating caffeine as an important component within coffee for producing this response. The effects that we observe with both coffee and pure caffeine on the heat shock response are both dependent on HSF-1. In a C. elegans Huntington's disease model, worms treated with caffeine were protected from polyglutamine aggregates and toxicity, an effect that was also HSF-1-dependent. In conclusion, these results demonstrate caffeinated coffee, and pure caffeine, as protective substances that promote proteostasis through induction of the heat shock response.