Quantification of caffeine, trigonelline and nicotinic acid in espresso coffee: the influence of espresso machines and coffee cultivars

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.

ASSESSMENT OF SIMULATED SURGICAL DEXTERITY AFTER MODIFIABLE EXTERNAL EXPOSURES AMONG NOVICE VERSUS EXPERIENCED VITREORETINAL SURGEONS

PURPOSE

To evaluate novice and senior vitreoretinal surgeons after various exposures. Multiple comparisons ranked the importance of these exposures for surgical dexterity based on experience.

METHODS

This prospective cohort study included 15 novice and 11 senior vitreoretinal surgeons (<2 and >10 years' practice, respectively). Eyesi-simulator tasks were performed after each exposure. Day 1, placebo, 2.5 mg/kg caffeine, and 5.0 mg/kg caffeine; day 2, placebo, 0.2 mg/kg propranolol, and 0.6 mg/kg propranolol; day 3, baseline simulation, breathalyzer readings of 0.06% to 0.10% and 0.11% to 0.15% blood alcohol concentrations; day 4, baseline simulation, push-up sets with 50% and 85% repetitions maximum; and day 5, 3-hour sleep deprivation. Eyesi-generated score (0-700, worst-best), out-of-tolerance tremor (0-100, best-worst), task completion time (minutes), and intraocular pathway (in millimeters) were measured.

RESULTS

Novice surgeons performed worse after caffeine (-29.53, 95% confidence interval [CI]: -57.80 to -1.27, P = 0.041) and alcohol (-51.33, 95% CI: -80.49 to -22.16, P = 0.001) consumption. Alcohol caused longer intraocular instrument movement pathways (212.84 mm, 95% CI: 34.03-391.65 mm, P = 0.02) and greater tremor (7.72, 95% CI: 0.74-14.70, P = 0.003) among novices. Sleep deprivation negatively affected novice performance time (2.57 minutes, 95% CI: 1.09-4.05 minutes, P = 0.001) and tremor (8.62, 95% CI: 0.80-16.45, P = 0.03); however, their speed increased after propranolol (-1.43 minutes, 95% CI: -2.71 to -0.15 minutes, P = 0.029). Senior surgeons' scores deteriorated only following alcohol consumption (-47.36, 95% CI: -80.37 to -14.36, P = 0.005).

CONCLUSION

Alcohol compromised all participants despite their expertise level. Experience negated the effects of caffeine, propranolol, exercise, and sleep deprivation on surgical skills.

Weight-adjusted caffeine and β-blocker use in novice versus senior retina surgeons: a self-controlled study of simulated performance

BACKGROUND/OBJECTIVES

Tremor and expertise are potentially influenced variables in vitreoretinal surgery. We investigated whether surgeon experience impacts the association of microsurgical performance with caffeine and β-blockers weight-adjusted intake.

SUBJECTS/METHODS

Novice and senior surgeons (<2 and >10 practice years, respectively) were recruited in this self-controlled, cross-sectional study. A simulator's task sequence was repeated over 2 days, 30 min after the following exposures: day 1, placebo, 2.5 mg/kg caffeine, 5.0 mg/kg caffeine, and 0.6 mg/kg propranolol; and day 2, placebo, 0.2 mg/kg propranolol, 0.6 mg/kg propranolol, and 5.0 mg/kg caffeine. Outcomes were total score (0-700, worst-best), simulation time (minutes), intraocular trajectory (centimeters), and tremor-specific score (0-100, worst-best).

RESULTS

We recruited 15 novices (9 men [60%], 1.33 ± 0.49 practice years) and 11 seniors (8 men [72.7%], 16.00 ± 4.24 practice years). Novices performed worse after 2.5 mg/kg caffeine and improved following 0.2 mg/kg propranolol in total score (557 vs. 617, p = 0.009), trajectory (229.86 vs. 208.07, p = 0.048), time (14.9 vs. 12.7, p = 0.048), and tremor-score (55 vs. 75, p = 0.009). Surgical performance improved with propranolol post-caffeine but remained worse than 0.2 mg/kg propranolol in total score (570 vs. 617, p = 0.014), trajectory (226.59 vs. 208.07, p = 0.033), and tremor-score (50 vs. 75, p = 0.029). Seniors' tremor-score was lower after 2.5 mg/kg caffeine compared to 0.2 mg/kg propranolol (8 vs. 37, p = 0.015). Tremor-score following propranolol post-caffeine remained inferior to 0.6 mg/kg propranolol alone (17 vs. 38, p = 0.012).

CONCLUSION

While caffeine and propranolol were associated with performance changes among novices, only tremor was affected in seniors, without dexterity changes. The pharmacologic exposure impact on surgical dexterity seems to be offset by increased experience.

IBA and melatonin increase trigonelline and caffeine during the induction and initiation of adventitious roots in Coffea arabica L. cuttings

Caffeine and trigonelline are found in Coffea arabica, and show antioxidant roles and growth and development functions. However, there are no reports on trigonelline and caffeine in relation to coffee rooting. The aim was to evaluate the impact of application of indole-3-butyric acid (IBA) and melatonin on caffeine and trigonelline at different stages of adventitious rooting in cuttings. In addition, to study the correlation between these metabolites and H2O2, phenols, and antioxidant enzymes. Four treatments (Control, melatonin 21 µM (M21), melatonin 43 µM (M43), and IBA 7380 µM (IBA)) were used, with four replications. The growth and biochemical parameters of the antioxidant system were performed in induction, initiation, and extension rooting stages. Higher concentrations of trigonelline and caffeine quantified in the induction and initiation stages were positively correlated with higher percentage of rooted cuttings. Trigonelline and caffeine were positively correlated with H2O2 in all stages of development of adventitious roots. The correlations of trigoneline and caffeine with phenols and antioxidant enzymes reveal different profiles, depending on the phases. The results indicate that IBA and melatonin increase trigonelline and caffeine during the induction and initiation of adventitious roots in Coffea arabica cuttings, which is correlated with a higher percentage of rooted cuttings.

Influence of Flow Rate, Particle Size, and Temperature on Espresso Extraction Kinetics

Brewing espresso coffee (EC) is considered a craft and, by some, even an art. Therefore, in this study, we systematically investigated the influence of coffee grinding, water flow rate, and temperature on the extraction kinetics of representative EC components, employing a central composite experimental design. The extraction kinetics of trigonelline, caffeine, 5-caffeoylquinic acid (5-CQA), and Total Dissolved Solids (TDS) were determined by collecting and analyzing ten consecutive fractions during the EC brewing process. From the extraction kinetics, the component masses in the cup were calculated for Ristretto, Espresso, and Espresso Lungo. The analysis of the studied parameters revealed that flow rate had the strongest effect on the component mass in the cup. The intensity of the flow rate influence was more pronounced at finer grindings and higher water temperatures. Overall, the observed influences were minor compared to changes resulting from differences in total extracted EC mass.

Mechanisms of action of coffee bioactive compounds - a key to unveil the coffee paradox

The knowledge of the relationship between the chemical structure of food components with their mechanisms of action is crucial for the understanding of diet health benefits. This review relates the chemical variability present in coffee beverages with the mechanisms involved in key physiological events, supporting coffee as a polyvalent functional food. Coffee intake has been related with several health-promoting properties such as neuroprotective (caffeine, chlorogenic acids and melanoidins), anti-inflammatory (caffeine, chlorogenic acids, melanoidins, diterpenes), microbiota modulation (polysaccharides, melanoidins, chlorogenic acids), immunostimulatory (polysaccharides), antidiabetic (trigonelline, chlorogenic acids), antihypertensive (chlorogenic acids) and hypocholesterolemic (polysaccharides, chlorogenic acids, lipids). Nevertheless, caffeine and diterpenes are coffee components with ambivalent effects on health. Additionally, a large range of potentially harmful compounds, including acrylamide, hydroxymethylfurfural, furan, and advanced glycation end products, are formed during the roasting of coffee and are present in the beverages. However, coffee beverages are part of the daily human dietary healthy habits, configuring a coffee paradox.

Risk Assessment of Trigonelline in Coffee and Coffee By-Products

Trigonelline is a bioactive pyridine alkaloid that occurs naturally in high concentrations in coffee (up to 7.2 g/kg) and coffee by-products (up to 62.6 g/kg) such as coffee leaves, flowers, cherry husks or pulp, parchment, silver skin, and spent grounds. In the past, coffee by-products were mostly considered waste and discarded. In recent years, however, the use of coffee by-products as food has attracted interest because of their economic and nutritional value and the environmental benefits of sustainable resource use. Their authorization as so-called novel foods in the European Union may lead to increased oral exposure of the general population to trigonelline. Therefore, the aim of this review was to assess the risk to human health of acute and chronic exposure to trigonelline from coffee and coffee by-products. An electronic literature search was performed. Current toxicological knowledge is limited, with few human data available and a lack of epidemiological and clinical studies. There was no evidence of adverse effects after acute exposure. No conclusion can be drawn on chronic exposure to isolated trigonelline due to the lack of data. However, trigonelline ingested as a component of coffee and coffee by-products appears to be safe for human health, based on the safe traditional use of these products.

Comprehensive Analysis of Metabolites in Brews Prepared from Naturally and Technologically Treated Coffee Beans

Coffee is one of the most popular beverages in the world. Therefore, this study analyzed 49 coffee samples of Arabica and Robusta species of different geographical origins and the treatment of beans including three degrees of roasting with the use of LC-MS/MS. This is the first study to present a comprehensive analysis of Kopi Luwak coffee brew metabolites in comparison to fully washed coffees and the drying post-harvest treatment of Arabica or Robusta coffee brews. Kopi Luwak showed higher levels of caffeine and theophylline in comparison to the analyzed washed and unwashed Arabica coffees, as well as a different proportion of caffeoylquinic isomers. There was no difference between Kopi Luwak and other Arabica coffees in terms of the concentration of vitamin B₃, amines, and phenolic acids. This was confirmed in PCA. The steaming and roasting of beans as well as the addition of black beans influence the concentration of 4-CQA and the nicotinic, ferulic, and quinic acids content.

Risk Assessment of Coffee Cherry (Cascara) Fruit Products for Flour Replacement and Other Alternative Food Uses

Coffee bean harvesting incurs various by-products known for their long traditional use. However, they often still end up being a waste instead of being used to their full potential. On the European market, coffee cherry (cascara) products are not yet common, and a novel food approval for beverages made from coffee cherry pulp was issued only recently. In this article, exposure and risk assessment of various products such as juice, jam, jelly, puree, and flour made from coffee cherry pulp and husk are reviewed. Since caffeine in particular, as a bioactive ingredient, is considered a limiting factor, safe intake will be derived for different age groups, showing that even adolescents could consume limited quantities without adverse health effects. Moreover, the composition can be influenced by harvesting methods and processing steps. Most interestingly, dried and powdered coffee cherry can substitute the flour in bakery products by up to 15% without losing baking properties and sensory qualities. In particular, this use as a partial flour substitute is a possible approach to counteract rising grain prices, transport costs, and disrupted supply chains, which are caused by the Russia-Ukraine war and changing climatic conditions. Thus, the supply of affordable staple foods could be partially ensured for the inhabitants of countries that depend on imported wheat and cultivate coffee locally by harvesting both beans and by-products.

Drivers of coffee liking: Effect of physicochemical characteristics and aromatic profile on consumers' acceptability of mono-origin and mono-variety coffees

Few studies have investigated at the same time how physicochemical, volatile, and sensory characteristics affect coffee liking. The aim of this study is to evaluate the influence of geographical origin and variety on physicochemical parameters and volatile compounds composition of mono-origin and mono-variety coffees. Check-all-that-apply (CATA) method was used with the aim of identifying the drivers of coffee liking. Moisture content, bulk density, solubility index, color parameters, and phenols and caffeine content were useful parameters for discriminating Robusta from Arabica variety, but not samples from different origins. The hierarchical cluster and principal component analyses performed on the headspace compositions showed a quite sharp ability to group the samples based on their variety. Based on CATA results, roasted attribute, related to the presence of pyrazines, was considered a positive driver of coffee liking unlike grassy and acidic attributes (associated to the presence of acids and aldehydes, respectively). Findings from this study can be a useful tool for coffee manufacturers for a winning market strategy, helping them in the choice of the most suitable raw materials and process conditions in order to produce a well-balanced beverage by enhancing all the possible positive drivers of acceptability and reducing the negative ones.

Profile of Bioactive Compounds, Aromas, and Cup Quality of Excelsa Coffee (Coffea liberica var. dewevrei) Prepared from Diverse Postharvest Processes

The study is aimed at evaluating bioactive compounds, volatile compounds, and cup quality of Excelsa coffee (Coffea liberica var. dewevrei) from different postharvest processing procedures, i.e., natural, honey, semiwashed, and wine. The green beans from each procedure were roasted at light to medium levels. Sample analysis was performed using HPLC and GC-MS instruments for bioactive compounds and volatile compounds, respectively, followed by a cupping test. As the results, postharvest processing significantly altered content of bioactive compounds (caffeoylquinic acids (CQAs) and alkaloids) in Excelsa green beans; the lowest quantity of CQAs and alkaloids was found in wine and semiwashed green beans, respectively. Significant degradation of 5-CQA and its transformation to 3-CQA and 4-CQA occurred in all light-medium roasting levels. In general, alkaloids were stable during roasting, and only trigonelline was slightly declined. Roasting process also generated 17 potent volatile compounds in Excelsa beans including 2-ethylpyrazine, 2,3-dimethylpyrazine, 2,5-dimethylpyrazine, 2,5-dimethyl-3-ethylpyrazine, guaiacol, 4-vinyl-guaiacol, and isovaleric acid and its esters. Furthermore, cupping test revealed that Excelsa coffee samples obtained from different postharvest processing were categorized as very good coffee (cupping score > 80). This finding may encourage the commercialization of all observed Excelsa coffee beans.

Biological Properties of Vitamins of the B-Complex, Part 1: Vitamins B1, B2, B3, and B5

This review summarizes the current knowledge on essential vitamins B1, B2, B3, and B5. These B-complex vitamins must be taken from diet, with the exception of vitamin B3, that can also be synthetized from amino acid tryptophan. All of these vitamins are water soluble, which determines their main properties, namely: they are partly lost when food is washed or boiled since they migrate to the water; the requirement of membrane transporters for their permeation into the cells; and their safety since any excess is rapidly eliminated via the kidney. The therapeutic use of B-complex vitamins is mostly limited to hypovitaminoses or similar conditions, but, as they are generally very safe, they have also been examined in other pathological conditions. Nicotinic acid, a form of vitamin B3, is the only exception because it is a known hypolipidemic agent in gram doses. The article also sums up: (i) the current methods for detection of the vitamins of the B-complex in biological fluids; (ii) the food and other sources of these vitamins including the effect of common processing and storage methods on their content; and (iii) their physiological function.

Influence of coffee brewing methods on the chromatographic and spectroscopic profiles, antioxidant and sensory properties

Cold brewing coffee has gained increasing popularity as a novel brewing method. A completely different flavour profile during cold brewing extraction (smooth and mild) is a result of the low-energy process, prolonged water-grind contact times and long preparation time. The aim of our research was to compare coffee drinks obtained with an innovative device for a faster, dynamic cold coffee extraction process (Hardtank) to drinks prepared traditionally in 24 h and hot brewed drinks. This study investigated the differences in chemical composition (volatile, non-volatile and lipid compounds), sensory properties and antioxidant capacity of coffee drinks from various extraction processes carried out at variable brewing temperatures, times and percolation modes. The results showed that the new cold maceration technique using coffee bed percolation (Hardtank) improved the quality of cold coffee drinks, making them similar in taste to hot coffee drinks. Among the studied extractions, the combination of a lower temperature (19.3 °C) and percolation process appeared to be the ideal setting for the most efficient extraction of compounds such as chlorogenic acids, gallic acid, caffeine, trigonelline, 5-(hydroxymethyl)furfural and lipids and consequently for their intake. In addition, FTIR spectra indicated an even 4 times greater quantity of lipids in Hardtank drinks than in classic cold brew and up to 5 times more lipids than in hot brew coffee, which contribute to the formation of the aroma and flavour. The decreased extraction time and use of coffee bed percolation could be beneficial for the quality and taste of cold brew products.

A MULTIFACTORIAL APPROACH FOR IMPROVING THE SURGICAL PERFORMANCE OF NOVICE VITREORETINAL SURGEONS

PURPOSE

To quantitatively analyze and compare the novice vitreoretinal surgeons' performance after various types of external exposures.

METHODS

This prospective, self-controlled, cross-sectional study included 15 vitreoretinal fellows with less than 2 years of experience. Surgical performance was assessed using the Eyesi simulator after each exposure: Day 1, placebo, 2.5, and 5 mg/kg caffeine; Day 2, placebo, 0.2, and 0.6 mg/kg propranolol; Day 3, baseline simulation, breathalyzer reading of 0.06% to 0.10% and 0.11% to 0.15% blood alcohol concentration; Day 4, baseline simulation, push-up sets with 50% and 85% repetition maximum; Day 5, 3-hour sleep deprivation. Eyesi-generated total scores were the main outcome measured (0-700, worst to best).

RESULTS

Performances worsened after increasing alcohol exposure based on the total score (χ2 = 7; degrees of freedom = 2; P = 0.03). Blood alcohol concentration 0.06% to 0.10% and 0.11% to 0.15% was associated with diminished performance compared with improvements after propranolol 0.6 and 0.2 mg/kg, respectively (∆1 = -22 vs. ∆2 = +13; P = 0.02; ∆1 = -43 vs. ∆2 = +23; P = 0.01). Propranolol 0.6 mg/kg was positively associated with the total score, compared with deterioration after 2.5 mg/kg caffeine (∆1 = +7 vs. ∆2 = -13; P = 0.03).

CONCLUSION

Surgical performance diminished dose dependently after alcohol. Caffeine 2.5 mg/kg was negatively associated with dexterity, and performance improved after 0.2 mg/kg propranolol. No changes occurred after short-term exercise or acute 3-hour sleep deprivation.

Coffee Leaves: An Upcoming Novel Food?

Unlike those of coffee beans, the healthy properties of coffee leaves have been overlooked for a long time, even if they are consumed as a beverage by local communities of several African countries. Due to the presence of xanthines, diterpenes, xanthones, and several other polyphenol derivatives as main secondary metabolites, coffee leaves might be useful to prevent many daily disorders. At the same time, as for all bioactive molecules, careless use of coffee leaf infusions may be unsafe due to their adverse effects, such as the excessive stimulant effects on the central nervous system or their interactions with other concomitantly administered drugs. Moreover, the presence of some toxic diterpene derivatives requires careful analytical controls on manufactured products made with coffee leaves. Accordingly, knowledge about the properties of coffee leaves needs to be increased to know if they might be considered a good source for producing new supplements. The purpose of the present review is to highlight the biosynthesis, metabolism, and distribution of the 4 main classes of secondary metabolites present in coffee leaves, their main pharmacological and toxicological aspects, and their main roles in planta. Differences in coffee leaf chemical composition depending on the coffee species will also be carefully considered.

Characterization of the Aroma Profile and Main Key Odorants of Espresso Coffee

Espresso coffee (EC) is a common coffee preparation technique that nowadays is broadly widespread all over the globe. Its popularity is in part attributed to the intense aroma and pleasant flavor. Many researchers have studied and reviewed the aroma of the coffee, but there is a lack of specific review focused on EC aroma profile even if it is intensively investigated. Thus, the objective of the current review was to summarize the aroma profile of EC and how different preparation variables can affect EC flavor. Moreover, a collection of diverse analytical procedures for volatile analysis was also reported. The findings of this survey showed that the volatile fraction of EC is extremely complex, but just some compounds are responsible for the characteristic aroma of the coffee, such as some aldehyde, ketones, furanones, furans, sulfur compounds, pyrazines, etc. In addition, during preparation, some variables, e.g., temperature and pressure of water, granulometry of the coffee particle, and brew ratio, can also modify the aroma profile of this beverage, and therefore its quality. A better understanding of the aroma fraction of EC and how the preparation variables should be adjusted according to desired EC would assist coffee workers in obtaining a higher quality product.

The Effect of Brewing Process Parameters on Antioxidant Activity and Caffeine Content in Infusions of Roasted and Unroasted Arabica Coffee Beans Originated from Different Countries

Coffee is one of the most often consumed beverages almost all over the world. The multiplicity of beans, as well as the methods and parameters used to brew, encourages the optimization of the brewing process. The study aimed to analyze the effect of roasting beans, the brewing technique, and its parameters (time and water temperature) on antioxidant activity (determined using several in vitro methods), total polyphenols, flavonoids, and caffeine content. The infusions of unroasted and roasted Arabica beans from Brazil, Colombia, India, Peru, and Rwanda were analyzed. In general, infusions prepared from roasted beans had higher antioxidant activity and the content of above-mentioned compounds. The hot brew method was used to obtain infusions with a higher antioxidant activity, while the cold brew with higher caffeine content. The phenolic compound content in infusions prepared using both techniques depended on the roasting process. Moreover, the bean’s origin, roasting process, and brewing technique had a significant effect on the tested properties, in contrary to brewing time and water temperature (below and above 90 °C), which had less impact. The results confirm the importance of coffee brewing optimization.

Influence of Various Factors on Caffeine Content in Coffee Brews

Coffee brews are one of the most popular drinks. They are consumed for caffeine and its stimulant properties. The study aimed to summarize data on the influence of various factors on caffeine content in brews prepared with different methods. The study was carried out using a literature review from 2010-2020. PubMed and Google Scholar databases were searched. Data on caffeine content was collected by analyzing the following factors: the influence of species, brewing time, water temperature, pressure, degree of roast, grinding degree, water type, water/coffee ratio as well as other factors (such as geographical origin). To sum up, converting caffeine content to 1 L of the brew, the highest content is that of brews prepared in an espresso machine (portafilter), with the amount of 7.5 g of a coffee blend (95% Robusta + 5% Arabica), and water (the volume of coffee brew was 25 mL) at a temperature of 92 °C and a pressure of 7 bar, but the highest content in one portion was detected in a brew of 50 g of Robusta coffee poured with 500 mL of cold water (25 °C) and boiled.

Use of non-volatile compounds for the classification of specialty and traditional Brazilian coffees using principal component analysis

Coffee beans contain different volatile and non-volatile compounds that are responsible for their flavor and aroma. Herein, principal component analysis (PCA) was employed to correlate the non-volatile composition of specialty and traditional coffees with drink quality. The quantified non-volatile compounds included caffeine, chlorogenic acid, caffeic acid, and nicotinic acid in both types of coffee samples, while 5-hydroxymethylfurfural was only quantified in the specialty coffee samples. The most abundant compounds present in specialty coffees were associated with the aroma and flavor, affording a high drink quality. In traditional coffees, the most abundant compounds included nicotinic acid and caffeine, indicating a stronger roasting process, loss of sensory characteristics, and blended formulations. PCA showed a distinction between the traditional and specialty coffees such that a relationship between the contents of the compounds in each type of coffee, quality, and classification could be established.

Association of Weight-Adjusted Caffeine and β-Blocker Use With Ophthalmology Fellow Performance During Simulated Vitreoretinal Microsurgery

Importance

Vitreoretinal surgery can be technically challenging and is limited by physiologic characteristics of the surgeon. Factors that improve accuracy and precision of the vitreoretinal surgeon are invaluable to surgical performance.

Objectives

To establish weight-adjusted cutoffs for caffeine and β-blocker (propranolol) intake and to determine their interactions in association with the performance of novice vitreoretinal microsurgeons.

Design, Settings, and Participants

This single-blind cross-sectional study of 15 vitreoretinal surgeons who had less than 2 years of surgical experience was conducted from September 19, 2018, to September 25, 2019, at a dry-laboratory setting. Five simulations were performed daily for 2 days. On day 1, performance was assessed after sequential exposure to placebo, low-dose caffeine (2.5 mg/kg), high-dose caffeine (5.0 mg/kg), and high-dose propranolol (0.6 mg/kg). On day 2, performance was assessed after sequential exposure to placebo, low-dose propranolol (0.2 mg/kg), high-dose propranolol (0.6 mg/kg), and high-dose caffeine (5.0 mg/kg).

Interventions

Surgical simulation tasks were repeated 30 minutes after masked ingestion of placebo, caffeine, or propranolol pills during the 2 days.

Main Outcomes and Measures

An Eyesi surgical simulator was used to assess surgical performance, which included surgical score (range, 0 [worst] to 700 [best]), task completion time, intraocular trajectory, and tremor rate (range, 0 [worst] to 100 [best]). The nonparametric Friedman test followed by Dunn-Bonferroni post hoc test was applied for multiple comparisons.

Results

Of 15 vitreoretinal surgeons, 9 (60%) were male, with a mean (SD) age of 29.6 (1.4) years and mean (SD) body mass index (calculated as weight in kilograms divided by height in meters squared) of 23.15 (2.9). Compared with low-dose propranolol, low-dose caffeine was associated with a worse total surgical score (557.0 vs 617.0; difference, -53.0; 95% CI, -99.3 to -6.7; P = .009), a lower antitremor maneuver score (55.0 vs 75.0; difference, -12.0; 95% CI, -21.2 to -2.8; P = .009), longer intraocular trajectory (2298.6 vs 2080.7 mm; difference, 179.3 mm; 95% CI, 1.2-357.3 mm; P = .048), and increased task completion time (14.9 minutes vs 12.7 minutes; difference, 2.3 minutes; 95% CI, 0.8-3.8 minutes; P = .048). Postcaffeine treatment with propranolol was associated with performance improvement; however, surgical performance remained inferior compared with low-dose propranolol alone for total surgical score (570.0 vs 617.0; difference, -51.0; 95% CI, -77.6 to -24.4; P = .01), tremor-specific score (50.0 vs 75.0; difference, -16.0; 95% CI, -31.8 to -0.2; P = .03), and intraocular trajectory (2265.9 mm vs 2080.7 mm; difference, 166.8 mm; 95% CI, 64.1-269.6 mm; P = .03).

Conclusions and Relevance

The findings suggest that performance of novice vitreoretinal surgeons was worse after receiving low-dose caffeine alone but improved after receiving low-dose propranolol alone. Their performance after receiving propranolol alone was better than after the combination of propranolol and caffeine. These results may be helpful for novice vitreoretinal surgeons to improve microsurgical performance.

Spent coffee ground as renewable energy source: Evaluation of the drying processes

Spent coffee ground (SCG) is an environmental nuisance material, but, if appropriately processed it can be converted into pellets, and thus, used as an energy source. The moisture content of the final product should be below 10%, to ensure safe storage, and elimination of microorganism growth (particularly moulds). The present study aims to identify the optimal drying process for removing moisture from SCG and to investigate changes to the composition of SCG due to drying, at temperatures around 75 °C, so that the dried SCG to qualify as renewable energy source. Three drying processes were employed for SCG drying (with initial moisture content of about 65%): oven drying, solar drying and open air sun drying, while SCG samples were placed in aluminium trays with thicknesses of 1.25, 2.5 and 4 cm. Based on the experimental results for SCG samples with thickness 2.5 cm, the open air sun drying process required 10 h to reach final moisture content of 37%, while solar drying achieved 10% moisture content in 10 h and oven drying achieved 7% moisture content in 6 h. The solar drying process proved as the most advantageous, due to low energy requirements and adequate quality of dried SCG. Also, experiments indicated that SCG storage at "normal room conditions" resulted to equilibrium moisture content in SCG of 8%, regardless of the initial moisture content. Furthermore, instrumental analyses of the SCG, revealed changes to its composition for a number of chemical groups, such as aldehydes, ketones, phytosterols, alkaloids, lactones, alcohols, phenols, pyrans and furans, among others. It was also identified that the SCG colour was affected due to the drying process.

Acrylamide formation and antioxidant activity in coffee during roasting - A systematic study

The aim of this study was to investigate the effect of the coffee roasting process on both toxic and some beneficial antioxidant compounds, applying a systematic and broad approach. Arabica and Robusta green coffee beans were roasted in a lab-scale roaster for different times in order to achieve five roasting degrees (from light to dark) and to assess the evolution of acrylamide (AA), trigonelline, nicotinic acid and caffeoylquinic acids contents (determined by HPLC) as well as antioxidant activity (evaluated by Folin-Ciocalteu, FRAP, DPPH, ABTS assays). The results confirmed that the AA levels and antioxidant activity reached a maximum in the first coffee roasting degrees and then decreased prolonging the heating process, both in Arabica and Robusta samples. Nevertheless, the thermal reduction observed was greater for AA compared to antioxidant activity, which was only slightly reduced due to the balance between the degradation and the neoformation of antioxidant compounds.

Absorption, Pharmacokinetics, and Urinary Excretion of Pyridines After Consumption of Coffee and Cocoa-Based Products Containing Coffee in a Repeated Dose, Crossover Human Intervention Study

SCOPE

The present study assesses the absorption, pharmacokinetics, and urinary excretion of coffee pyridines and their metabolites after daily regular exposure to specific dosages of coffee or cocoa-based products containing coffee (CBPCC), considering different patterns of consumption.

METHODS AND RESULTS

In a three-arm, crossover, randomized trial, 21 volunteers are requested to randomly consume for 1 month: one cup of espresso coffee per day, three cups of espresso coffee per day, or one cup of espresso coffee plus two CBPCC twice per day. The last day of the one-month treatment, blood and urine samples are collected for 24 h. Trigonelline, N-methylpyridinium, N-methylnicotinamide, and N-methyl-4-pyridone-5-carboxamide are quantified. Trigonelline and N-methylpyridinium absorption curves and 24-h urinary excretion reflect the daily consumption of different servings of coffee or CBPCC, showing also significant differences in main pharmacokinetic parameters. Moreover, inter-subject variability due to sex and smoking is assessed, showing sex-related differences in the metabolism of trigonelline and smoking-related ones for N-methylpyridinium.

CONCLUSION

The daily exposure to coffee pyridines after consumption of different coffee dosages in a real-life setting is established. This data will be useful for future studies aiming at evaluating the bioactivity of coffee-derived circulating metabolites in cell experiments, mimicking more realistic experimental conditions.

A Cup of Hemp Coffee by Moka Pot from Southern Italy: An UHPLC-HRMS Investigation

After a long period defined by prohibition of hemp production, this crop has been recently re-evaluated in various industrial sectors. Until now, inflorescences have been considered a processing by-product, not useful for the food industry, and their disposal also represents an economic problem for farmers. The objects of the present work are coffee blends enriched with shredded inflorescences of different cultivars of industrial hemp that underwent solid/liquid extraction into the Italian “moka” coffee maker. The obtained coffee drinks were analyzed by Ultra-High-Performance Liquid Chromatography-High Resolution Mass Spectrometry (UHPLC-HRMS) tools for their quali-quantitative phytocannabinoid profiles. The results showed that they are minor constituents compared to chlorogenic acids and caffeine in all samples. In particular, cannabidiolic acid was the most abundant among phytocannabinoids, followed by tetrahydrocannabinolic acid. Neither Δ⁹-tetrahydrocannabinol (THC) nor cannabinol, its main oxidation product, were detected. The percentage of total THC never exceeded 0.04%, corresponding to 0.4 mg/kg, far below the current maximum limits imposed by the Italian Ministry of Health. This study opens up a new concrete possibility to exploit hemp processing by-products in order to obtain drinks with high added value and paves the way for further in vitro and in vivo investigations aimed at promoting their benefits for human health.

The combination of coffee compounds attenuates early fibrosis-associated hepatocarcinogenesis in mice: involvement of miRNA profile modulation

Aberrant microRNA expression implicates on hepatocellular carcinoma (HCC) development. Conversely, coffee consumption reduces by ~40% the risk for fibrosis/cirrhosis and HCC, while decaffeinated coffee does not. It is currently unknown whether these protective effects are related to caffeine (CAF), or to its combination with other common and/or highly bioavailable coffee compounds, such as trigonelline (TRI) and chlorogenic acid (CGA). We evaluated whether CAF individually or combined with TRI and/or CGA alleviates fibrosis-associated hepatocarcinogenesis, examining the involvement of miRNA profile modulation. Then, male C3H/HeJ mice were submitted to a diethylnitrosamine/carbon tetrachloride-induced model. Animals received CAF (50 mg/kg), CAF+TRI (50 and 25 mg/kg), CAF+CGA (50 and 25 mg/kg) or CAF+TRI+CGA (50, 25 and 25 mg/kg), intragastrically, 5×/week, for 10 weeks. Only CAF+TRI+CGA combination reduced the incidence, number and proliferation (Ki-67) of hepatocellular preneoplastic foci while enhanced apoptosis (cleaved caspase-3) in adjacent parenchyma. CAF+TRI+CGA treatment also decreased hepatic oxidative stress and enhanced the antioxidant Nrf2 axis. CAF+TRI+CGA had the most pronounced effects on decreasing hepatic pro-inflammatory IL-17 and NFκB, contributing to reduce CD68-positive macrophage number, stellate cell activation, and collagen deposition. In agreement, CAF+TRI+CGA upregulated tumor suppressors miR-144-3p, miR-376a-3p and antifibrotic miR-15b-5p, frequently deregulated in human HCC. CAF+TRI+CGA reduced the hepatic protein levels of pro-proliferative EGFR (miR-144-3p target), antiapoptotic Bcl-2 family members (miR-15b-5p targets), and the number of PCNA (miR-376a-3p target) positive hepatocytes in preneoplastic foci. Our results suggest that the combination of most common and highly bioavailable coffee compounds, rather than CAF individually, attenuates fibrosis-associated hepatocarcinogenesis by modulating miRNA expression profile.

Influence of Altitude on Caffeine, 5-Caffeoylquinic Acid, and Nicotinic Acid Contents of Arabica Coffee Varieties

The influence of altitude on caffeine, 5-caffeoylquinic acid (5-CQA), and nicotinic acid contents of Arabica coffee varieties grown in Southwest Ethiopia was investigated. High-performance liquid chromatography with diode array detector (HPLC-DAD) was used for the determination of the target analytes. Coffee samples were collected from four coffee varieties, named as 74112, 7454, 7440, and 74110, which are cultivated in high, mid, and low altitudes in the study area. The findings of the study showed that the contents of caffeine and 5-CQA in both raw and roasted coffee beans decrease as the growing altitude increases and, thus, for all varieties, their highest concentrations were recorded in lowland coffee beans. Nevertheless, the contents of nicotinic acid increase as the altitude rises and, thus, the highest nicotinic acid content was recorded in highland coffee samples. Besides, after roasting, the contents of caffeine were increased, whereas the contents of 5-CQA were lowered, indicating the possibility of its degradation during the roasting process. Both green and roasted coffee beans also contained relatively higher concentrations of nicotinic acids. Other than the growing altitudes, the contents of caffeine, 5-CQA, and nicotinic acid in coffee beans also vary with coffee varieties. Therefore, coffee varieties that are cultivated at various altitudes may have different biochemical compositions such as caffeine, CGAs, and nicotinic acid that could greatly influence the flavor, aroma, and stimulating attributes of coffee cup quality as well as dietary benefits.

Kahweol Found in Coffee Inhibits IL-2 Production Via Suppressing the Phosphorylations of ERK and c-Fos in Lymphocytic Jurkat Cells

Interleukin-2 (IL-2) is a cytokine involved in the development and maturation of the subsets of T cells, critically associated with the progression of several immune-related diseases (e.g. liver disease, bowel disease). Interestingly, a recent study suggests that coffee may contain several compounds to inhibit IL-2 expression in activated T-lymphocytic cells. However, there is little information about the potential effects of several coffee compounds (e.g. kahweol, cafestol, trigonelline, niacin and chlorogenic acids) on IL-2 expression in activated T-lymphocytic cells. Therefore, in this paper, their effects on IL-2 expression were evaluated in PHA/PMA-activated lymphocytic Jurkat cells. Among the tested compounds, only kahweol and cafestol were able to reduce IL-2 production significantly in the cells (p < 0.05). However, the inhibition of kahweol was a bit stronger than cafestol. Therefore, the molecular mechanism underlying the IL-2 inhibition was investigated using kahweol. Kahweol (≤ 20 µM) was able to inhibit the phosphorylations of ERK and c-Fos (p < 0.05) with little effects on p38 and JNK phosphorylations in the Jurkat cells. Subsequently, the inhibition of ERK/c-Fos led to the reduction of IL-2 mRNA expression in the Jurkat cells. In summary, the data suggest that kahweol may be a potential coffee compound to reduce IL-2 production via inhibiting the phosphorylations of ERK/c-Fos in PHA/PMA-activated lymphocytic Jurkat cells.

Optimization of the Extraction from Spent Coffee Grounds Using the Desirability Approach

The purpose of this work was the optimization of the extraction from spent coffee grounds, specifically 100% Arabica coffee blends, using a desirability approach. Spent coffees were recovered after the preparation of the espresso coffee under the typical conditions used in coffee bars with a professional machine. Spent coffee was subjected to different extraction procedures in water: by changing the extraction temperature (60, 80, or 100 °C) and the solvent extraction volume (10, 20, 30 mL for 1 g of coffee) and by maintaining constant the extraction time (30 min). The ranges of the process parameters, as well as the solvent to be used, were established by running preliminary experiments not reported here. The variables of interest for the experimental screening design were the content of caffeine, trigonelline, and nicotinic acid, quantitatively determined from regression lines of standard solutions of known concentrations by a validated HPLC-VWD method. Since solvent extraction volumes and temperatures were revealed to be the most significant process variables, for the optimization of the extraction process, an approach based on Response Surface Methodology (RSM) was considered. In particular, a Box-Wilson Central Composite Design, commonly named central composite design (CCD), was used to find the optimal conditions of the extraction process. Moreover, the desirability approach was then applied to maximize the extraction efficiency by searching the optimal values (or at least the best compromise solution) for all three response variables simultaneously. Successively, the best extract, obtained in a volume of 20 mL of water at an extraction temperature of 80 °C, was analyzed for total phenol content (TPC) through the Folin–Ciocalteu assay, and the antioxidant capacities (AC) through the trolox equivalent (TE) antioxidant capacity (DPPH), ferric-ion reducing antioxidant parameter (FRAP), and radical cation scavenging activity and reducing power (ABTS). The TPC and the AC for spent coffee were high and comparable to the results obtained in previous similar studies. Then, the extract was evaluated by inductively coupled plasma mass spectrometry (ICP–MS), revealing that potassium was the most abundant element, followed by phosphorus, magnesium, calcium, sodium, and sulfur, while very low content in heavy metals was observed. Preliminary in vitro assays in keratinocyte HaCaT cells were carried out to assess the safety, in terms of cytotoxicity of spent coffee, and results showed that cell viability depends on the extract concentration: cell viability is unmodified up to a concentration of 0.3 mg/mL, over which it becomes cytotoxic for the cells. Spent coffee extract at 0.03 and 0.3 mg/mL showed the ability to reduce intracellular reactive oxygen species formation induced by hydrogen peroxide in HaCaT cells, suggesting its antioxidant activity at intracellular levels.

Extraction-Free, Direct Determination of Caffeine in Microliter Volumes of Beverages by Thermal Desorption-Gas Chromatography Mass Spectrometry

An extraction-free method requiring microliter (μL) volumes has been developed for the determination of caffeine in beverages. Using a pyrolysis-gas chromatography mass spectrometry system, the conditions required for the direct thermal desorption-gas chromatography mass spectrometry (TD-GC/MS) determination of caffeine were optimised. A 5 μL aliquot was introduced to the thermal desorption unit, dried, and thermally desorbed to the GC/MS. The response was linear over the range 10 to 500 μg/mL (R² = 0.996). The theoretical limit of detection (3 σ) was 0.456 μg/mL. No interferences were recorded from endogenous beverage components or from commonly occurring drugs, such as nicotine, ibuprofen, and paracetamol. Replicate caffeine determinations on fortified latte style white coffee and Pepsi Max® gave mean recoveries of 93.4% (%CV = 4.1%) and 95.0% (%CV = 0.98%), respectively. Good agreement was also obtained with the stated values of caffeine for an energy drink and for Coca-Cola®. These data suggest that the method holds promise for the determination of caffeine in such samples.

Herbal medicines for the liver: from bench to bedside

The liver is one of the most complex organs of the human body and is involved in various metabolic processes. Due to its anatomical proximity to the digestive tract, its blood flow, and its contribution to the detoxification process, the liver is susceptible to a wide variety of disorders. Hepatic diseases can be caused by alcoholism, viral infections, malnutrition and xenobiotics, which result in a high frequency of patients with liver disease and subsequent increase in the number of deaths from these diseases, for which adequate treatments are not yet available. Therefore, the search for new alternatives to treat these liver conditions is mandatory. In recent decades, there has been an increase in interest in medicinal herbs due to their safety and hepatoprotective properties that arise from their anti-inflammatory, antioxidant, antifibrotic, antiviral, immunomodulatory and anticancer properties. Epidemiological and clinical studies have shown that the consumption of these compounds is associated with a decrease in the risk of developing liver diseases; thus, medicinal herbs have emerged as a viable option for the treatment of these hepatic pathologies. However, more basic and clinical studies are needed before reaching a final recommendation to treat human liver diseases. This review provides molecular and clinical information on some natural compounds and medicinal herbs that have hepatoprotective effects and could be useful for the treatment of hepatic disorders.

Analysing extraction uniformity from porous coffee beds using mathematical modelling and computational fluid dynamics approaches

Achieving a uniform extraction of soluble material from a porous matrix is a generic problem in various separation and filtration operations, with applications in the food processing, chemical and pharmaceutical industries. This paper describes models of fluid flow and transport of soluble material within a packed granular bed in the context of coffee extraction. Coffee extraction is described by diffusion of soluble material from particles of one or more representative sizes into fluid flowing through the packed bed. One-dimensional flow models are compared to computational fluid dynamics (CFD) models. A fine and a coarse coffee grind are considered. Model results are compared to experimental data for a packed cylindrical coffee bed and the influence of a change in geometry to a truncated cone is considered. Non-uniform flow in the truncated cone causes significant variation in the local extraction level. Coffee extraction levels during brewing are analysed using extraction maps and the degree of variation is represented on the industry standard coffee brewing control chart. A high variation in extraction yield can be expected to impart bitter flavours into the brew and thus is an important variable to quantify.

Espresso coffee design based on non-monotonic granulometric distribution of aromatic profile

Coffee beverages may be obtained using several extraction methods, among which espresso coffee (EC) represents now a worldwide adopted system. Recent advances in coffee grinding equipment allow today to achieve a detailed control of granulometric distribution, and the grinding process is an essential step of coffee production cycle both for the aromatic profile composition and for the chemical properties of the beverage (Severini, 2015). The comminution process consists of the breaking down particles into smaller fragments; as well-known, its main objective is to increase the overall particle surface area exposed to water leading to a more efficient extraction of soluble substances (Illy, 2005a). Basically, the coffee brewing process includes two steps: a washing phase concerning the snapshot dissolution of free solubles at the particle surface followed by diffusion phase of solubles within the porous particles (Spiro 1992, Baggenstoss 2008). The variability in particle size distribution on the quality of EC has been studied by various authors. Severini et al. has tackled the influence of the grinding level on the aromatic profiles and chemical attributes (percolation time, caffeine content, pH and titratable acidity) as a consequence of changes in the microstructural properties of the coffee cake. Generally speaking such results would imply that the final effect in terms of aromatic compounds extraction follows a monotonic law respect to granulometric size. This result is true in an average sense but it cannot be given for granted for any aromatic compounds if we refine the resolution of granulometric class. The reasons for which some aromatic compounds do not follow the supposed trend (the lower the grain size, the higher the aromatic compound content) can be most probably related to the internal distribution of precursors and to the different non-isotropic roasting grade of the bean, where the external part undergoes to an increased thermal load. This will change at the same time the kinetics and formation of aromatic compounds, and the mechanical properties as well, strictly correlated to the way the bean is crashed during the grinding phase and consequently to the granulometric distribution of different parts of the coffee bean. Results presented in this work allow to correlate choices in terms of granulometric distribution to characteristics aromatic compounds, in order to enhance specific flavors in espresso coffee.

Drinking for protection? Epidemiological and experimental evidence on the beneficial effects of coffee or major coffee compounds against gastrointestinal and liver carcinogenesis

Recent meta-analyses indicate that coffee consumption reduces the risk for digestive tract (oral, esophageal, gastric and colorectal) and, especially, liver cancer. Coffee bean-derived beverages, as the widely-consumed espresso and "common" filtered brews, present remarkable historical, cultural and economic importance globally. These drinks have rich and variable chemical composition, depending on factors that vary from "seeding to serving". The alkaloids caffeine and trigonelline, as well as the polyphenol chlorogenic acid, are some of the most important bioactive organic compounds of these beverages, displaying high levels in both espresso and common brews and/or increased bioavailability after consumption. Thus, we performed a comprehensive literature overview of current knowledge on the effects of coffee beverages and their highly bioavailable compounds, describing: 1) recent epidemiological and experimental findings highlighting the beneficial effects against gastrointestinal/liver carcinogenesis, and 2) the main molecular mechanisms in these in vitro and in vivo bioassays. Findings predominantly address the protective effects of coffee beverages and their most common/bioavailable compounds individually on gastrointestinal and liver cancer development. Caffeine, trigonelline and chlorogenic acid modulate common molecular targets directly implicated in key cancer hallmarks, what could stimulate novel translational or population-based mechanistic investigations.

Immediate risk of myocardial infarction following physical exertion, tea, and coffee: A case-crossover study in Thailand

BACKGROUND

Physical exertion and caffeine consumption are associated with acute myocardial infarction (MI). However, physical exertion and caffeine consumption have not been examined as immediate triggers of MI in low and middle-income countries.

OBJECTIVE

Using a self-matched case-crossover design, we examined the acute risk of MI in the hour following episodes of physical exertion, caffeinated coffee, and tea consumption among MI survivors in Thailand.

METHODS

A total of 506 Thai participants (women = 191, men = 315) were interviewed between 2014 and 2017 after sustaining an acute MI. We compared each subject's exposure to physical exertion and consumption of caffeine- containing beverages in the hour preceding the onset of MI with the subject's expected usual frequency in the prior year to calculate relative risks (RRs) and 95% confidence intervals (95%CIs).

RESULTS

Of the 506 participants, 47 (9.3%) engaged in moderate or heavy physical exertion, 6 (1.2%) consumed tea, and 21 (4.2%) consumed coffee within the hour before MI. The relative risk of MI after moderate or heavy physical exertion was 3.0 (95% CI 2.2-4.2) compared to periods of no exertion, with a higher risk among more sedentary participants compared to active participants. Compared to times with no caffeinated beverage consumption, there was a higher risk of MI in the hour following consumption of caffeinated tea (RR = 3.7; 95%CI: 1.5-9.3) and coffee (RR = 2.3; 95%CI: 1.4-3.6).

CONCLUSION

Physical exertion, coffee and tea consumption were associated with a higher risk of MI in the subsequent hour compared to times when the participants were sedentary or did not consume caffeinated beverages. Our study identifies high-risk populations for targeted screening and intervention to prevent acute MI.

Niacin, alkaloids and (poly)phenolic compounds in the most widespread Italian capsule-brewed coffees

Coffee is one of the most popular beverages worldwide and, nowadays, one of the most practical way for its preparation is by prepacked capsules. The aim of this study was comparing the content in caffeine, trigonelline, N-methylpyridinium (NMP), niacin, and chlorogenic acids of 65 different capsule-brewed coffees, commercialised by 5 of the most representative brands in Italy. Coffees were prepared from capsules following manufacturer’s instructions and analysed with an optimized UHPLC-MS/MS method able to assess all these phytochemicals in one single run. Inter-lot and capsule variability were also studied for a subset of coffee capsules. Except for decaffeinated coffees, caffeine amount accounted between 54 and 208 mg/serving. Regular espresso coffees showed higher trigonelline, NMP, and niacin concentrations than large (lungo) and decaffeinated samples, with average serving amounts of 17.96, 1.78, and 0.66 mg, respectively. Regarding chlorogenic acids, caffeoylquinic acids were the most relevant ones (20–117 mg/serving). Feruloylquinic acids were quantified between 8 and 50 mg/serving. Coumaroylquinic acids, hydroxycinnamate dimers, caffeoylshikimic acids, and caffeoylquinic lactones were also present at lower concentrations. Multivariate analysis provided comprehensive information on the phytochemical profile of the different types of coffee, showing a great variability among coffees with some brand-related insights. This study supports the need for accurately characterizing espresso coffees while investigating the beneficial effects of coffee on human health.

Chemistry, pharmacology and new trends in traditional functional and medicinal beverages

Functional and medicinal beverages consumption plays an important role in human health, considering that metabolites, with a wide range of pharmacological effects, are inserted in the human diet. Nowadays, the most consumed beverages are obtained from Camellia sinensis leaves and coffee grain processing, and contain different classes of polyphenols and phenolic acids in their phytochemical composition. Besides C. sinensis and coffee, numerous plants have been receiving attention due to their phytochemical composition and pharmacological effects, such as yerba mate, hibiscus, chamomile, lemongrass, fennel and mentha. Furthermore, atomized or lyophilized medicinal plant extracts can be employed in many beverage formulations and the consumption of these products is an excellent delivery means for nutrients and bioactive compounds, such as: minerals, vitamins, terpenes, antioxidants, saponins, alkaloids and polysaccharides. Innovation in food processing in order to insert functional and medicinal beverages in the human diet poses a challenge for the coming years. The technological development of new processing forms and use of plants with bioactive metabolites could be an important tool in relation to this proposal. In this context, this review has aimed to summarize and analyze pharmacological, phytochemistry and technological aspects of species with classical ethnobotanical and traditional use.

Development of an extraction method for the quantification of lignans in espresso coffee by using HPLC-MS/MS triple quadrupole

Lignans are polyphenolic compounds that are considered phytoestrogens for their plant origins, and they possess different biological activities. Three different extraction methods, ie, "dilute and shoot", acidic hydrolysis, and enzymatic digestion, have been compared for extracting lignans (secoisolariciresinol (SECO), matairesinol (MAT), and lariciresinol (LARI)) from espresso coffee (EC) by using high-performance liquid chromatography (HPLC) tandem mass spectrometry (MS/MS). The best recovery values (SECO: 97%, LARI: 98%, and MAT: 93%) were obtained by using enzymatic hydrolysis with Clara-Diastase at 10% (w/v), keeping the sample at 37°C for 3 hours. For this reason, this method has been chosen and then applied to quantify lignans in 9 different EC samples from 5 different geographical origins (Brazil, Colombia, El Salvador, Ethiopia, and India). Secoisolariciresinol and LARI were found in all EC samples from 27.9 to 52.0 μg L^-1 and from 5.3 to 27.8 μg L^-1 respectively, contrary to MAT that it was not possible to detect it in each type of coffee. This method confirms the high specificity and sensitivity of MS/MS system for detecting bioactives in complex matrix such as coffee.

Caffeine in Kidney Stone Disease: Risk or Benefit?

Kidney stone disease is a global health care problem, with a high recurrence rate after stone removal. It is thus crucial to develop effective strategies to prevent the formation of new or recurrent stones. Caffeine is one of the main components in caffeinated beverages worldwide (i.e., coffee, tea, soft drinks, and energy drinks). Previous retrospective and prospective studies have reported contradictory effects of caffeine on kidney stone risk. Although it has a diuretic effect on enhancing urinary output, it may slightly increase the stone risk index. However, 3 large cohorts have suggested a preventive role of caffeine in kidney stone disease. In addition, a recent in vitro study has addressed relevant mechanisms underlying the preventive role of caffeine against stone pathogenesis. This review summarizes the relevant data from previous evidence and discusses the association between caffeine consumption and kidney stone risk reduction.

Toward a New Brewing Control Chart for the 21st Century

This paper describes new results from a base model of brewing from a bed of packed coffee grains. The model solves for the diffusion of soluble species out of a distribution of particles into the flow through the bed pore space. It requires a limited set of input parameters. It gives a simple picture of the basic physics of coffee brewing and sets out a set of reduced variables for this process. The importance of bed extraction efficiency is elucidated. A coffee brewing control chart has been widely used to describe the region of ideal coffee brewing for some 50 years. A new chart is needed, however, one that connects actual brewing conditions (weight, flow rate, brew time, grind, etc.) to the yield and strength of brews. The paper shows a new approach to brewing control charts, including brew time and bed extraction efficiency as control parameters. Using the base model, an example chart will be given for a particular grind ratio of coarse to fine particles, and an "espresso regime" will be picked out. From such a chart yield, volume and strength of a brew can be read off at will.

Fluid Intake and Beverage Consumption Description and Their Association with Dietary Vitamins and Antioxidant Compounds in Italian Adults from the Mediterranean Healthy Eating, Aging and Lifestyles (MEAL) Study

The aim of the present study was to investigate the total water intake (TWI) from drinks and foods and to evaluate the correlation between the different types of drinks on energy and antioxidant intake. The cohort comprised 1602 individuals from the city of Catania in Southern Italy. A food frequency questionnaire was administered to assess dietary and water intake. The mean total water intake was 2.7 L; more than about two thirds of the sample met the European recommendations for water intake. Water and espresso coffee were the most consumed drinks. Alcohol beverages contributed about 3.0% of total energy intake, and sugar sweetened beverages contributed about 1.4%. All antioxidant vitamins were significantly correlated with TWI. However, a higher correlation was found for water from food rather than water from beverages, suggesting that major food contributors to antioxidant vitamin intake might be fruits and vegetables, rather than beverages other than water. A mild correlation was found between fruit juices and vitamin C; coffee, tea and alcohol, and niacin and polyphenols; and milk and vitamin B12. The findings from the present study show that our sample population has an adequate intake of TWI and that there is a healthy association between beverages and dietary antioxidants.

Do flavanols-rich natural products relieve obesity-related insulin resistance?

Growing evidence support that insulin resistance may occur as a severe problem due to chronic energetic overfeeding and subsequent obesity. When an abundance of glucose and saturated fat enter the cell, impaired blood flow, hypoxia, inflammation and macrophage infiltration in obese adipose tissue may induce oxidative stress and insulin resistance. Excessive circulating saturated fatty acids ectopically accumulate in insulin-sensitive tissues and impair insulin action. In this context, excessive hepatic lipid accumulation may play a central, pathogenic role in insulin resistance. It is thought that dietary polyphenols may ameliorate obesity-related insulin resistance by attenuating inflammatory responses and oxidative stress. The most often occurring natural polyphenolic compounds are flavonoids. In this review, the possible mechanistic effect of flavonoid-rich natural products on insulin resistance-related metabolic pathways is discussed. Polyphenol intake can prevent high-fat-diet-induced insulin resistance via cell surface G protein-coupled estrogen receptors by upregulating the expression of related genes, and their pathways, which are responsible for the insulin sensitivity.