Caffeine Concentrations Research Articles

Sucralose and caffeine as chemical indicators of domestic wastewater contamination in the Laurentian Great Lakes Basin.

Surface waters within the basin of the Laurentian Great Lakes are impacted by microbial contamination from municipal wastewater and agricultural runoff, as well as from other sources. In particular, microbial contamination of drinking water is an ongoing problem within many Indigenous communities located in the basin. However, it is difficult to identify the sources of microbial contamination using the traditional monitoring approaches with fecal indicator bacteria, such as total coliforms and Escherichia coli (E. coli). In this study, we evaluated whether surface waters in the basin are contaminated with fecal bacteria of human origin using chemical indicators of domestic wastewater (i.e., caffeine and sucralose) and with Bacteroidales 16S rRNA markers. Study areas included the Grand River watershed within the Lake Erie basin and three nearshore locations within the Great Lakes basin. Two of these sites are sources of drinking water for Indigenous communities. We assessed whether there were relationships between the concentrations of fecal indicator microorganisms and chemical indicators of domestic wastewater at selected study locations. Analysis of genetic markers indicated that about 30% of the Bacteroidales bacteria present at a site in the Grand River were of human fecal origin and the balance were of bovine or general animal origin. The presence of caffeine and sucralose in surface waters indicated that there was upstream contamination by domestic wastewater. However, in the drinking water treatment plant operated by Six Nations of the Grand River, the levels of these chemical indicators and fecal bacteria were reduced by the advanced water treatment technologies. The concentrations of sucralose and caffeine collectively were strongly correlated with the levels of total coliforms in samples from the Grand River (R2 = 0.75) and with levels of E. coli in samples from the Great Lakes basin (R2 = 0.97), but there appeared to be an upper threshold for this relationship. These data indicate that analysis of caffeine and sucralose and genetic markers for strains of Bacteroidales fecal bacteria may be useful tools for identifying the sources of microbiological contamination of surface waters and drinking water.

Co-tracing of groundwater emerging and conventional contaminants in karst area of Southwest China: Distribution, source, and source-specific health risks

Groundwater pollution, especially the co-contamination of emerging contaminants (ECs) and conventional contaminants, is increasingly recognized as a critical global concern. Karst aquifers are found throughout the world, providing critical water sources and sustaining rivers and ecosystems, and are particularly vulnerable to pollution. In this study, the characteristics of the contamination, potential sources, and source-specific health risks related to ECs and trace elements (TEs) in groundwater were investigated in Guiyang (a typical karst city in southwest China). The distribution of TEs followed a descending pattern from urban to suburban to rural areas. Interestingly, the median concentrations (217 ng/L) of Caffeine (CAF) in rural areas surpassed those in urban areas (145 ng/L) and even exceeded these in densely populated areas. Additionally, ECs and TEs in groundwater are significantly influenced by population density and land use types within a 1000-meter buffer zone around the sampling sites. Hierarchical cluster analysis and positive matrix factorization suggested that five principal sources of contamination were identified: domestic wastewater (29.7 %), industrial production (25.2 %), agricultural activities (16.3 %), natural and industrial sources (14.9 %), and pharmaceuticals (13.9 %). Monte Carlo simulations revealed that the non-carcinogenic risks to children in urban areas are significant, with 30.0 % of these risks exceeding the safety threshold. Source-specific health risk assessments indicated that industrial production is the primary source of risk. Furthermore, this study introduces a co-tracing method to trace the sources of groundwater contamination in karst systems. The co-tracing method based on the ECs and TEs allows for a deeper understanding of contaminant transfer and its fate in karst groundwater.

Acute ingestion of caffeinated chewing gum reduces fatigue index and improves 400-meter performance in trained sprinters: a double-blind crossover trial.

This study investigated the effects of caffeinated chewing gum on fatigue index and 400-meter performance in trained sprinters. Nineteen participants (age: 20.9 ± 1.0 years; height: 175.6 ± 4.9 cm; mass: 66.5 ± 5.6 kg; training age: 7.9 ± 1.0 years) were randomly assigned to either a caffeine trial (CAF) or a placebo trial (PL) using a double-blind, randomized crossover design. The participants in the CAF trial chewed a gum containing 3 mg/kg of caffeine for a period of 10 minutes, while those in the PL trial chewed a gum containing a placebo with no caffeine. Following a 15-minute period of rest, the fatigue index was tested by six maximal 35-meter sprints with a 10-second rest between efforts. After this, at least 30 minutes of rest was permitted, during which time the participants engaged in brief warm-up activities prior to the commencement of the 400-meter sprint test. Saliva samples were collected before chewing gum, before the fatigue test and before 400-meters sprinting. The fatigue index was significantly lower in the CAF trial compared to the PL trial (CAF: 8.1 ± 2.5%; PL: 9.6 ± 4.8%; p = 0.046, Cohen's d = 039). The CAF trial demonstrated significantly lower sprint time for the 300-400 meter segment (CAF: 14.73 ± 1.35 seconds; PL: 15.23 ± 1.30 seconds; p = 0.019, Cohen's d = 0.37) and total sprint time compared to the PL trial (CAF: 53.87 ± 2.88 seconds; PL: 54.68 ± 3.37 seconds; p = 0.003, Cohen's d = 0.27). Saliva caffeine and α-amylase concentration were significantly higher in the CAF trial compared to the PL trial (p < 0.05). The present study demonstrated that caffeine gum supplementation prior to exercise significantly reduced the fatigue index and increased the capacity to maintain speed, particularly in the final 300 to 400 meters, as well as enhancing 400-meter sprint performance.

Experimental evolution of Saccharomyces cerevisiae for caffeine tolerance alters multidrug resistance and target of rapamycin signaling pathways.

Caffeine is a natural compound that inhibits the major cellular signaling regulator target of rapamycin (TOR), leading to widespread effects including growth inhibition. Saccharomyces cerevisiae yeast can adapt to tolerate high concentrations of caffeine in coffee and cacao fermentations and in experimental systems. While many factors affecting caffeine tolerance and TOR signaling have been identified, further characterization of their interactions and regulation remain to be studied. We used experimental evolution of S. cerevisiae to study the genetic contributions to caffeine tolerance in yeast, through a collaboration between high school students evolving yeast populations coupled with further research exploration in university labs. We identified multiple evolved yeast populations with mutations in PDR1 and PDR5, which contribute to multidrug resistance, and showed that gain-of-function mutations in multidrug resistance family transcription factors Pdr1, Pdr3, and Yrr1 differentially contribute to caffeine tolerance. We also identified loss-of-function mutations in TOR effectors Sit4, Sky1, and Tip41 and showed that these mutations contribute to caffeine tolerance. These findings support the importance of both the multidrug resistance family and TOR signaling in caffeine tolerance and can inform future exploration of networks affected by caffeine and other TOR inhibitors in model systems and industrial applications.

Sonocatalytic degradation of caffeine using CeO2 nanorods: Modeling by artificial neural network

This study has investigated the utilization of CeO2 nanorods (NRs) in the sonocatalytic degradation of caffeine. The degradation performance was determined by examining the influence of three parametric conditions, namely, the initial pH of the solution (3.5 – 7.5), initial concentration of caffeine (5 – 30 mg/L), and dosage of CeO2 NRs (0.5 – 2.0 g/L). All experiments were conducted in an ultrasonic bath (37 kHz, 150 W) that served as a sonocatalytic reactor. The mathematical modeling of the process with the catalyst was developed using Feedforward artificial neural networks (FFNN). The FFNN was employed to develop suitable modeling for determining the performance of the sonocatalytic degradation of caffeine (%) using CeO2 NRs. A three-layer FFNN with [4−10-1] topology was successfully developed to predict the sonocatalytic degradation of caffeine using CeO2 NRs. The FFNN was able to offer highly accurate predictions with the overall R2 and MSE validation values of 0.991 and 0.00225, respectively. The ANN model has also provided excellent predictive performance by achieving the highest R2 value. Thus, these results showed the promising finding of the sonocatalysis degradation of caffeine using CeO2 NRs via experiments and the ANN model.

Development of a simple estimation method of serum caffeine concentration using a point-of-care test kit for urinary caffeine.

Serum caffeine concentration is an indicator of caffeine intoxication; however, it is difficult to measure it in most emergency departments. We developed a simple estimation method using a point-of-care test kit for urinary caffeine. Caffeine-spiked human serum (100, 50, 25, and 10µg/mL) was diluted 10-, 20-, 50-, and 100-fold with phosphate-buffered saline and applied to the kit. After 5min incubation, the kit was scanned by a flatbed scanner and the membrane image was processed with ImageJ. When the 20-fold diluted serum was applied, serum samples with initial caffeine concentration ≤ 25 and ≥ 50µg/mL were caffeine-negative and -positive, respectively. When the 100-fold diluted serum was applied, none of the caffeine-spiked serum samples gave positive results. Therefore, we proposed the following test procedure: (i) 20-fold diluted serum was initially tested and (ii) 100-fold diluted serum was additionally tested when the initial result was caffeine positive. Using this procedure, caffeine concentration is expected to be classified into three levels: ≤ 25, > 25- ≤ 100, and > 100µg/mL, which almost correspond to no or mild, severe, and potentially fatal intoxication, respectively. The test procedure was validated using postmortem heart blood from two cases of fatal caffeine intoxication (caffeine concentration: 276 and 175µg/mL) and two cases of other intoxication. Our developed method using point-of-care urinary caffeine test kits enabled simple estimation of serum caffeine concentration.

Plasma, brain and spinal cord concentrations of caffeine are reduced in the SOD1G93A mouse model of amyotrophic lateral sclerosis following oral administration

Modifications to the small intestine and liver are known to occur during the symptomatic disease period of amyotrophic lateral sclerosis (ALS), a member of the motor neuron disease (MND) family of neurodegenerative disorders. How these modifications impact on oral absorption and pharmacokinetics of drugs remains unknown. In this study, model drugs representing different mechanisms of intestinal transport (caffeine for passive diffusion, digoxin for P-glycoprotein efflux, and sulfasalazine for breast cancer resistance protein efflux) were administered via oral gavage to postnatal day 114–120 male and female SOD1G93A mice (model of familial ALS) and wild-type (WT) littermates. Samples of blood, brain and spinal cord were taken at either 15, 30, 60 or 180 min after administration. In addition, the in vivo gastric emptying of 70 kDa fluorescein isothiocyanate-dextran (FITC-dextran) and the ex vivo intestinal permeability of caffeine were assessed. The area under the plasma concentration–time curves (AUCplasma) of digoxin and sulfasalazine were not significantly different between SOD1G93A and WT mice for both sexes. However, the AUCplasma of caffeine was significantly lower (female: 0.79-fold, male: 0.76-fold) in SOD1G93A compared to WT mice, which was associated with lower AUCbrain (female: 0.76-fold, male: 0.80-fold) and AUCspinal cord (female: 0.81-fold, male: 0.82-fold). The AUCstomach of caffeine was significantly higher (female: 1.5-fold, male: 1.9-fold) in SOD1G93A compared to WT mice, suggesting reduced gastric emptying in SOD1G93A mice. In addition, there was a significant reduction in gastric emptying of FITC-dextran (0.66-fold) and ex vivo intestinal permeability of caffeine (0.52-fold) in male SOD1G93A compared to WT mice. Reduced systemic and brain/spinal cord exposure of caffeine in SOD1G93A mice may therefore result from alterations to gastric emptying and small intestinal permeability. Specific dosing requirements may therefore be required for certain medicines in ALS to ensure that they remain in a safe and effective concentration range.

Trophic fate and biomagnification of organic micropollutants from staple food to a specialized predator

The environmental burden of organic micropollutants has been shown in aquatic ecosystems, while trophic fate of many compounds in terrestrial food chains remains highly elusive. We therefore studied concentrations of 108 organic micropollutants in a common European mammal, the bank vole (Clethrionomys glareolus), and 82 of the compounds in a specialized predator, Tengmalm's owl (Aegolius funereus) relying to >90 % on voles as its prey. We studied compounds in whole voles (n = 19), pools of 4–8 bank voles (npools = 4), owl blood (n = 10) and in owl eggs (n = 10) in two regions in Sweden. For comparison, we also included previously published data on 23 PFAS (per- and polyfluoroalkyl substances) in bank vole liver (npools = 4) from the same regions. In voles, concentrations of the organic micropollutants caffeine (maxIndividual 220 ng/g ww) and DEET (N,N-diethyl-m-toluamide) (maxPool 150 ng/g ww) were 2–200 times higher in voles relative to owl blood and eggs. Conversely, concentrations of nicotine, oxazepam, salicylic acid, and tributyl citrate acetate were 1.3–440 times higher in owls. Several PFAS showed biomagnification in owls as revealed by maximum biomagnification factors (BMFs); PFNA (perfluorononanoate) BMF = 5.6, PFTeDA (perfluorotetradecanoic acid) BMF = 5.9, and PFOS (perfluorooctane sulfonate) BMF = 6.1. Concentrations of organic micropollutants, alongside calculated BMFs, and Tengmalm's owl's heavy reliance on bank vole as staple food, suggest, despite small sample size and potential spatio-temporal mismatch, accumulation of PFAS (especially PFNA, PFTeDA, and PFOS) in owls and biomagnification along the food chain. Concentrations of PFAS in owl eggs (e.g., 21 ng/g ww PFOS) highlight the likely pivotal role of maternal transfer in contaminant exposure for avian embryos. These concentrations are also of concern considering that certain predators frequently consume owl eggs, potentially leading to additional biomagnification of PFAS with yet undetermined consequences for ecosystem health.

Bacillus sp. KS38 strain for sustainable caffeine degradation: Isolation, identification and optimization using response surface methodology

Caffeine, a significant naturally occurring alkaloid in beverages like tea and coffee, can be degraded by bacteria. Prolonged caffeine consumption can stimulate adrenal glands, cause irregular muscle activity, cardiac arrhythmias, and withdrawal symptoms such as headaches and fatigue. Beyond its health-related concerns, the environmental impact of caffeine degradation is noteworthy. Effluents from coffee industries contain high caffeine concentrations, and the discharge of such effluents into lakes poses a risk to the portability of drinking water. This study isolated a novel bacterium from agricultural soil, identified as Bacillus sp. KS38 through 16 S rRNA gene sequencing, which can metabolize caffeine as the sole carbon and nitrogen source. The bacterium exhibited Gram-positive characteristics. Response surface methodology (RSM) optimized bacterial growth conditions. The relevant parameter for the degradation of caffeine was obtained by first screening the parameters using the Plackett-Burman design. Using central composite design (CCD) and RSM, the important parameters were determined to achieve the ideal degradation conditions. The identified the ideal degradation conditions: 0.66 g/L caffeine, 0.85 g/L glucose, pH 6.83, and 20.5 °C. RSM predicted a bacterial growth of 0.591, which was confirmed experimentally. This bacterium has potential applications in wastewater treatment and caffeine bioremediation.

Novel continuous cold brewing method for coffee using a combined screw extraction and mechanical expression approach

This study investigated a novel continuous cold brewing method accomplished through a combined countercurrent single-screw extraction process and mechanical expression approach. The effects of four processing parameters (grind size (GS), motor rotation speed (RPM), press cone piston pressure (PCPP), and dry unbrewed coffee grounds feed rate (GFR)) on the particle size of coffee grounds, the mass balance of coffee grounds and water/brew in the brewer, and the physicochemical quality (total dissolved solids (TDS), extraction yield (EY), titratable acidity (TA), total polyphenols (TPP), pH, caffeine and 5-caffeoylquinic (5-CQA) concentration) of the brew were evaluated. The processing parameters significantly affected the mechanical interactions between the coffee grounds and brewer, resulting in changes in the packing density of coffee grounds, the moisture content of the spent coffee grounds, the extent of grind size reduction, and the amount of fines in the brew. These changes affected the physicochemical quality of the resultant brew leading to significant differences in TA, TPP, and 5-CQA, which were positively correlated with TDS.

OLIVE PITS-BASED CARBON BLACK AGGLOMERATE AS AN ADSORBENT FOR PIPETTE-TIP SOLID-PHASE EXTRACTION FOR THE DETERMINATION OF CAFFEINE IN ENERGY DRINKS

Vegetal wastes are an interesting source for the synthesis of nanostructured carbon materials, which are potentially useful in various applications. Carbon black agglomerates (CBA) obtained from olive pits, synthesized in our previous research, had a low crystalline structure typical of this type of materials, with a pore size of 2.27 nm, confirming their micro/mesoporous structure, and with a high surface value of around 587 m2/g. These materials were used for the extraction of caffeine in energy drinks using a green-approach micro-sample technique called pipette-tip solid-phase extraction. This microextraction technique features reduced consumption of organic solvents, of the amount of sorbent and extraction time, thus making the whole sample pretreatment process faster and greener. In this work, we proposed an analytical method for the analysis of caffeine in commercial energy drinks, using CBA with a great extraction capacity due to its high porous surface area. The developed methodology has proven to be useful from a green chemistry point of view, using only one milligram of nanostructured sorbent, minimal solvent consumption, a reduced volume of sample, as well as easy and rapid automatization for the analysis of commercial energy drinks. For the quantification of the analyte in the energy drinks, a one-point standard addition calibration was applied to correct the matrix effect. Similar caffeine concentrations per milliliter were found in the three analyzed samples, likewise, the amounts of caffeine close to those reported by the manufacturers were established for two of the samples analyzed.

Impact of advanced age on the gastric emptying of water under fasted and fed state conditions

Although older people are the main users of oral medications, few studies are reported on the influence of advanced age on gastric emptying rate of non-caloric liquids. This study aimed at evaluating the gastric emptying of 240 ml water in healthy older and young adults in fasted and fed state conditions using the established method of salivary caffeine kinetics. The gastric emptying of water was evaluated in 12 healthy older volunteers (mean age: 73 ± 6 years) and 12 healthy younger volunteers (mean age: 25 ± 2 years) with the ingestion of a rapid disintegrating tablet containing 20 mg of 13C3-caffeine. The gastric emptying of water was assessed indirectly by calculating the AUC ratios of salivary caffeine concentrations in specific time segments. Comparison of the AUC ratios showed no statistically significant difference between young and older volunteers in both fasted and fed state conditions (p > 0.05). Advanced age itself seems to have no relevant effect on gastric emptying of water in either fasted or fed state conditions and the phenomenon of Magenstrasse appears to follow a similar pattern in healthy older adults as in healthy younger adults.

Glutathione-Based Photoaffinity Probe Identifies Caffeine as a Positive Allosteric Modulator of the Calcium-Sensing Receptor.

The calcium-sensing receptor (CaSR), abundantly expressed in the parathyroid gland and kidney, plays a central role in calcium homeostasis. In addition, CaSR exerts multimodal roles, including inflammation, muscle contraction, and bone remodeling, in other organs and tissues. The diverse functions of CaSR are mediated by many endogenous and exogenous ligands, including calcium, amino acids, glutathione, cinacalcet, and etelcalcetide, that have distinct binding sites in CaSR. However, strategies to evaluate ligand interactions with CaSR remain limited. Here, we developed a glutathione-based photoaffinity probe, DAZ-G, that analyzes ligand binding to CaSR. We showed that DAZ-G binds to the amino acid binding site in CaSR and acts as a positive allosteric modulator of CaSR. Oxidized and reduced glutathione and phenylalanine effectively compete with DAZ-G conjugation to CaSR, while calcium, cinacalcet, and etelcalcetide have cooperative effects. An unexpected finding was that caffeine effectively competes with DAZ-G's conjugation to CaSR and acts as a positive allosteric modulator of CaSR. The effective concentration of caffeine for CaSR activation (<10 μM) is easily attainable in plasma by ordinary caffeine consumption. Our report demonstrates the utility of a new chemical probe for CaSR and discovers a new protein target of caffeine, suggesting that caffeine consumption can modulate the diverse functions of CaSR.

Electrochemical determination of caffeine in coffee and non-alcoholic drinks using g-C3N4-ZnO modified glassy carbon electrode

Caffeine is a very important ingredient for preserving the nutritional quality of foods. But, when ingested in excess, it is responsible for numerous health problems, hence the analysis of caffeine in drinks and food products is a pivotal. This study employed g-C3N4/ZnO nanocomposite (NC) to analyze caffeine in coffee and soft drinks. Scanning electron microscopy (SEM), Fourier transform infrared (FTIR), X-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET) were employed for structural characterization. Caffeine oxidation was successfully accomplished by modifying glassy carbon electrodes (GCEs) with g-C3N4/ZnO NC. The sensitivity of caffeine detection using g-C3N4/ZnO/GCE was noticeably improved because of its better electrocatalytic activity. The sensor showed good analytical performances like selectivity, inter-electrode reproducibility, and stability. It also responded a wide range to caffeine concentrations between 1 and 1000 µM. The estimated limit of detection (LOD) and quantification (LOQ) were found to be 0.063 µM and 0.211 µM, respectively. Caffeine content of real samples has also been effectively determined with recovery values of 91.41–103.84 %.

A Comparative Study of Caffeine Levels in Coffee and Cocoa in Kenyan Supermarkets and Shops

Background: Caffeine is an alkaloid belonging to the methylxanthine family. An overdose of caffeine causes the following side effects: restlessness, nervousness, excitement, insomnia, flushed face, diuresis, gastrointestinal disturbances, muscle twitching, rambling flow of thought and speech, and tachycardia or cardiac arrhythmia. This study aimed to determine the caffeine levels of various brands of coffee and cocoa and enlighten people on the safe and healthy consumption of the two products. Methods: Different brands of coffee and cocoa products were randomly sampled and purchased from supermarkets and shops in Nairobi, Kenya. Five samples of coffee and four brands of cocoa were purchased from a supermarket and taken to the laboratory for analysis. Caffeine was extracted, and quantitative analysis was done using High Performance Liquid Chromatography (HPLC). Results: The study found that coffee has a higher concentration of caffeine than cocoa. Coffee Brand A recorded the lowest level of caffeine with 30.9845 µ g/g, while Coffee Brand C recorded the highest level of caffeine with 426.9639 µ g/g. Among the Cocoa brands, Cocoa Brand B recorded the lowest level of caffeine (2.6367 µg/g), while Cocoa Brand C recorded the highest level of caffeine at 19.03 µ g/g. Conclusion: Therefore, there is a need to reduce coffee consumption per day because caffeine overdose can cause high blood pressure and other illnesses. Cocoa is recommended for consumption since it contains less caffeine per serving. Keywords: Caffeine, coffee, cocoa, Kenya

Transfer of Caffeine and Its Major Metabolites to Chicken Eggs.

This study aimed to determine whether the eggs of laying hens fed caffeine contain this compound and its primary metabolites (theophylline, theobromine, and paraxanthine). Laying hens were distributed into four experimental groups fed rations containing 0 (control), 150, 300, or 450 μg/g of caffeine. For residual analysis, six eggs per group were collected after 4, 8, and 12 weeks. The concentrations of caffeine, theophylline, theobromine, and paraxanthine were determined in the white and yolk of each egg by a high-performance liquid chromatography with photodiode array detector (HPLC-PDA) method. All four compounds were detected in the white and yolk of eggs produced by hens fed caffeine, but their levels in the egg white were approximately twice those in the yolk. The major metabolite found in eggs was theophylline (57.5% of caffeine metabolites in the egg white and 58.5% in the yolk), followed by theobromine (39.9% in the egg white and 41.5% in the yolk), and paraxanthine (2.64% in the egg white and non-detected in the yolk). In summary, caffeine and its metabolites, theophylline, theobromine, and paraxanthine, are transferred to the chicken eggs.

Escalating caffeine dose-dependently increases alcohol consumption in adult male, but not female, C57BL/6J mice

Although previous research has illustrated the effects of the consumption of alcohol and caffeine individually, less research has focused on the popular combination of the two drugs. The increase in alcohol consumption when combined with caffeine has led to the idea that the stimulant effects of caffeine may mask the depressant effects of alcohol, and this may contribute to increased binge drinking as the individual feels more awake and stimulated. Preclinical research has shown various effects of combined alcohol and caffeine where several studies show decreased alcohol consumption and others show increased alcohol consumption and even binge-like drinking. Results from a previous study in our lab indicate that intermittent access (IA) to steady levels of low (0.015 %) but not moderate (0.03 %) caffeine increased alcohol consumption in male C57BL/6J mice. The current studies further investigated the sex and dose differences in adult mice receiving varying concentrations of caffeine on combined alcohol intake. In Experiment 1, adult mice (n = 50, 25 males and 25 females) had IA to one of the following experimental bottles throughout the 4 week period: water, alcohol (10 % v/v), caffeine (0.015 % w/v), or 10 % alcohol +0.015 % caffeine. In Experiment 2, adult mice (n = 70, 35 males and 35 females) were given IA to one of the following experimental bottles: water, alcohol (10 % v/v; steady, maintained throughout the 4 weeks), caffeine (increasing 0.01 % to 0.015 % to 0.02 % to 0.03 % weekly), or 10 % alcohol+increasing caffeine (at the previously mentioned concentrations). When both caffeine and alcohol concentrations remained steady throughout the 4 weeks, there was no change in alcohol consumption. Chronic exposure to IA caffeine led to increased locomotor activity and decreased freezing episodes when tested in the open field test approximately 6 h after removal of the bottles. In Experiment 2, caffeine dose-dependently increased alcohol co-consumption in male mice whereas female mice consumed less alcohol when it was presented in conjunction with caffeine. The results in males are in line with clinical literature suggesting that the combination of alcohol and caffeine may lead to increased stimulation and alcohol drinking. Additionally, these studies provide evidence that the escalation of caffeine is crucial when investigating alcohol and caffeine co-consumption using the IA paradigm.

Factors Influencing Consumer Preferences for Espresso and Omni Roasted Coffee: A Comprehensive Analysis

This qualitative study conducted in Buraydah, Saudi Arabia, explores coffee customers' shifting preferences, with a focus on the growing popularity of espresso and multi-roasted coffee. Through interviews with consumers, baristas, and coffee roasters, the study investigates the motivations behind these choices, which include health concerns, flavor exploration, and a dislike for highly acidic coffees. The findings highlight the appeal of concentrated flavor, higher caffeine concentration, and the ability to appreciate the varied qualities of coffee beans from different places. Omni roasted coffee, with its medium-dark roast, has a balanced flavor profile that works well with a number of brewing methods. The concept of coffee terroir, which highlights the distinct flavors associated with individual origins, influences customer preferences. These findings have ramifications for coffee growers and baristas, who can meet shifting customer needs by acquiring high-quality beans and perfecting brewing procedures. This study leads to a better knowledge of changing coffee preferences and gives practical insights for industry stakeholders.

Consumption Rate of Energy Drinks among Kabul University Students: Caffeine Contents and Microbiological Examinations of their Available Varieties at Kabul City

Energy drinks (EDs) have gained popularity as a beverage all around the world, but as their usage has grown, questions have been raised concerning their high caffeine concentration and potential for microbial contamination. The objective of this study was to evaluate EDs. consumption rate among Kabul University students, the determination of caffeine contents, microbiological quality, and pH of EDs available in Kabul City. 184 Kabul University students were selected using simple random selection to assess the types, amounts of consumption, and awareness about the side effects of EDs. The caffeine levels in EDs were quantified using a UV/Vis spectrophotometer. The EDs were cultured in various culture media for microbiological studies. 23 of the 184 students were regular users of EDs. The mean concentration of caffeine was 277.43 ppm with an SD of 137.49 to 143.10. The EDs had no microbiological contamination, and their pH ranged from 2.64 to 3.64. 12.5% of the students regularly used EDs, Caffeine levels in all of the evaluated EDs were below recommended levels, and none of them contained any bacteria contamination.

Quality and fertilizing ability of frozen-thawed porcine sperm separated using a migration sedimentation method.

We evaluated the quality and fertilizing ability of frozen-thawed porcine sperm that were selected using a commercially available device (MIGLIS, Menicon Life Science) consisting of three parts: an outer lid, an inner lid, and a tube. Firstly, to determine an adequate concentration of caffeine for separation, frozen-thawed sperm were incubated with different concentrations of caffeine (0, 1, 2.5, 5, and 10 mM) in a MIGLIS device. To determine the appropriate incubation time for separating sperm in the MIGLIS device, frozen-thawed sperm were incubated with 2.5 mM caffeine for 5, 10, 15, or 20 min. To evaluate the fertilization and embryo development of oocytes fertilized with frozen-thawed sperm separated into two regions (outer and inner) in the MIGLIS device, the separated sperm from the three boars was used to fertilize invitro-matured oocytes and cultured invitro for 7 days. Sperm quality parameters of sperm collected from the inner tube after incubation with 2.5 mM caffeine were superior to sperm incubated without caffeine. Moreover, sperm collected from the inner tube after incubation for 10 min had a higher progressive motility. The rate of blastocyst produced from spermatozoa collected from the inner tube after incubation with 2.5 mM caffeine for 10 min significantly increased compared to that produced from spermatozoa from the outer tube, regardless of the boar. In conclusion, sperm sorting using the MIGLIS device may be useful for separating high-quality sperm after incubation with 2.5 mM caffeine for 10 min to improve blastocyst formation.