Modulatory effect of green coffee bioactives on high-fat diet-induced obesity in C57BL6 mice model

OBJECTIVES

The aim of the present study was to determine the efficacy of green coffee bioactives in ameliorating the effects of high-fat diet (HFD)-induced obesity through in vitro and in vivo assessments.

METHODS

Green coffee extract (GCE) was obtained by implementing a novel green extraction technique. The efficacy of GCE to inhibit in vitro pancreatic amylase and lipase was evaluated. Further, in vivo studies were conducted using a C57BL6 mice model grouped as starch-fed diet control, HFD control, HFD + positive control, HFD + GCE (100 mg/kg body weight), and HFD + GCE (200 mg/kg body weight). Animal body weight, diet intake, and fecal fat excretion were measured during the feeding period. On completion of the experiment, blood serum was collected for biochemical analysis, and organs were harvested for assessing the obesity-related biomarkers.

RESULTS

The obtained GCE was enriched with polyphenols and alkaloids. GCE led to significant (P < 0.05) in vitro inhibition of pancreatic amylase and lipase. GCE supplementation considerably prevented weight gain in treated groups post-consumption of HFD. It also led to increased fecal fat excretion and regulated the high-fat-mediated blood glucose levels. GCE effectively modulated the blood lipid profile, morphology of adipose and liver tissues, and liver antioxidant defense enzymes and resulted in hepatoprotective effects. It also downregulated the genes associated with lipid biosynthesis.

CONCLUSIONS

GCE exhibits promising results in suppressing the consequences associated with HFD-induced obesity. It has the potential to be incorporated into food products benefiting consumer health and food industries.

Chemical analysis and NIR spectroscopy in the determination of the origin, variety and roast time of Mexican coffee

Coffee is a product whose quality and price are associated with its geographical, genetic and processing origin; therefore, the development of analytical techniques to authenticate the above mentioned is important to avoid adulteration. The objective of this study was to compare conventional analytical methods with NIR technology for the authentication of roasted and ground coffee samples from different producing regions in Mexico (origins) and different varieties. A second objective was to determine, under the same processing conditions, if roasting times can be differentiated by using this technology. A total of 120 samples of roasted and ground commercial coffee were obtained from the states of Chiapas, Oaxaca, Tabasco and Veracruz in Mexico, 30 locally available samples per state. Samples from Veracruz included three different varieties, grown on the same farm and processed under the same conditions. One of these varieties was selected to evaluate the chemical composition of samples roasted at 185 °C using four different roasting times (15, 17, 19 and 21 min). Samples from different producing regions showed significant differences (P < 0.05) in fat content (from 7.45 ± 0.42% in Tabasco to 18.40 ± 2.95% in Chiapas), which was associated with the altitude of coffee plantations (Pearson's r = 0.96). The results indicate that NIR technology generates sufficient useful information to authenticate roasted and ground coffee from different geographical origins in Mexico and different varieties from the same coffee plantation, with similar results to those obtained by conventional analytical methods.

The effect of chlorogenic acid from green coffee as a natural antioxidant on the shelf life and composition of hazelnut paste

In this study, the effect of chlorogenic acid obtained as an antioxidant from Green Coffee Extract (GCE) on the shelf life of Hazelnut Paste (HP) was investigated at 4, 25, and 40 °C for 3 months. The analysis of variance showed that the effect of AR (Additive Ratio) × T (Temperature) × t (Storage Time) interaction on Peroxide Number (PV), tocopherols, and phenolics (TPC) of GCE-HP mixtures was found to be significant (P < 0.05). ARxt factor on Hunter L*, a*, and b* color values, DPPH-radical scavenging activity and antioxidant activity (AA), Txt factor on oleic/linoleic acid ratio (O/L), and ARxT and ARxt interactions on free fatty acid were more effective (P < 0.05). Regression equations of O/L, PV, AA, and TPC can be used to calculate the shelf life of HP due to high R2 values (87.14-94.46%). In addition, according to the O/L regression equation, the shelf life of the HP control samples was 28 days at 22 °C, increased to 60 days at 0.5%-GCE and 90 days at 25.68 °C at 0.75%-GCE (R2 = 87.14%, P < 0.001). GCE (0.5-0.75%) was a promising antioxidant in increasing the shelf life of HP.

A comprehensive review on clinically proven medicinal plants in the treatment of overweight and obesity, with mechanistic insights

Background and objectives

Obesity has become a global health issue, more precisely, a pandemic throughout the present world due to its high prevalence in the recent era. Increased risk of morbidity and mortality in obese patients can be attributed to its association with the development of different life-threatening conditions. Plants are considered one of the most important sources of bioactive molecules which are used against a wide range of health disorders. This systematic review explores the efficacy as well as the safety profile of commonly used medicinal plants in the management of obesity that may help people to maintain a healthy weight.

Methods

This review is based on comprehensive literature searches from PubMed, Science Direct, Scopus, and Google Scholar databases using the keywords- "plants in obesity", "plants used in weight reduction" or keywords that are similar to those. Medicinal plants which have been clinically proven for their anti-obesity effect have only been selected for this study and attempts to investigate beneficial effects and adverse effects along with their mechanism of action have also been taken in this review.

Results

A significant reduction of weight in both human and other animals are exhibited by the extracts of Phaseolus vulgaris, green coffee, Yerba Mate, green tea, Gynostemma pentaphyllum, and the combination of Cissus quadrangularis/Irvingia gabonensis. All of those plant extracts seemed to work on different physiological pathways and none of those extracts showed any notable adverse effects in human or animal models.

Conclusion

Our review suggests that the discussed medicinal plants are effective in reducing the weight of obese patients without causing notable adverse reactions. Although further study is necessary to confirm their exact molecular mechanism and safety in human use.

The Effect of Green Coffee Bean Extract on Cardiovascular Risk Factors: A Systematic Review and Meta-analysis

BACKGROUND AND AIM

Cardiovascular disease remains the primary cause of noncommunicable disease- related death. The present systematic review and meta-analysis was performed to assess the possible benefit of the green coffee bean extract on cardio-metabolic markers.

METHODS

PubMed, Scopus, Web of Science, and Cochrane Library were systematically searched to identify clinical trials that examined the effect of green coffee bean extract on cardio-metabolic risk factors including serum lipid profiles, glycemic status-related markers, blood pressure, and anthropometric indices. Since the included RCTs were carried out in different settings, random effect models were used to conduct all meta-analyses.

RESULTS

Fifteen studies (19 arms) consisting of 637 participants were included. The results indicated that green coffee bean extract significantly reduced levels of total cholesterol (-5.93 mg/dl; 95% CI: -9.21, -2.65; I²: 0%), fasting plasma glucose (-2.21 mg/dl; 95% CI: -3.94, -0.48; I²: 32%), systolic blood pressure (-3.08 mmHg; 95% CI: -4.41, -1.75; I²: 26%), diastolic blood pressure (-2.27 mmHg; 95% CI: -3.82, -0.72; I²: 61%), body weight (-1.24 kg; 95% CI: -1.82, -0.66; I²: 15%), and BMI (-0.55 kg/m²; 95% CI: -0.88, -0.22; I²: 73%). Although the pooled effect size of LDL-C, fasting insulin, and waist circumstance were significant, the results were significantly influenced by individual studies. No significant effect was detected for triglycerides, HDL-C, HbA1C, and HOMA-IR. However, the nonsignificant pooled effect size for triglyceride levels was influenced by one individual study.

CONCLUSION

The present study suggests that green coffee been extract consumption can improve total cholesterol, triglycerides, body weight, blood pressure, and fasting plasma glucose.

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

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

Green coffee VS dietary supplements: A comparative analysis of bioactive compounds and antioxidant activity

The aim of this work was to assess and compare both the antioxidant potential and content of the selected biologically active substances in green coffee samples and dietary supplements based on green coffee extracts. The newly developed method using HPLC coupled with Corona detector (HPLC-CAD) allowed the analysis of chlorogenic acid, caffeine, caffeic acid, coumaric acid, and ferulic acid in a single run. The method was validated and characterized by a wide concentration range (5-75 μg/mL), sensitivity, accuracy (92.7-112%), repeatability (RSD <5.32%), and precision (1.80-4.04%). The assessment of antioxidant potential was done by the spectrophotometric Folin-Ciocalteu method. Green coffee samples and extract characterized by comparable or, in the case of some samples, even higher antioxidant properties than dietary supplements. There was found a great variety of CGA levels in dietary supplements (0.33-329 mg/g) compared to the green coffee samples (32.7 mg/g - 47.6 mg/g). The highest caffeine content (156 mg/tablet) was determined in one dietary supplement, while green coffee samples contained its lower levels (20.9 mg/g). The quality of some supplements is not satisfactory as their composition does not comply with the manufacturer's declaration. There were found discrepancies between the value determined and declared by the producer (<243%).

Green Coffea robusta (Coffea canephora) from Lampung province effect toward free radicals in chickens infected with Salmonella enteritidis bacteria

Background

Foodborne diseases are caused by acquired pathogenic bacteria such as Salmonella enteritidis. It causes an intestinal imbalance and the microbial toxins found in the gastrointestinal tract induce symptoms such as diarrhea. Coffee contains active ingredients such as antioxidants and is used as an anti-inflammatory agent by reducing pro-inflammatory cytokine levels in the body.

Aim

The purpose of this study was to determine the interaction between Lampung's robusta coffee and tissue damage in chickens infected by S. enteritidis.

Methods

This study used first-day-old Isa brown layer chickens (n = 60), which were divided into five treatment groups. The negative control group consisted of healthy and normal chickens, whereas the positive control group consisted of chickens infected with S. enteritidis bacteria at a concentration of 10⁸ CFU/ml. Groups T1, T2, and T3 were given coffee extract with doses of 500 mg/kg BW (low dose), 1,000 mg/kg BW (moderate dose), and 1,500 mg/kg BW (high dose), respectively, and then infected with S. enteritidis bacteria at a concentration of 10⁸ CFU/ml. The coffee extract and bacteria were given orally via a feeding tube at a volume of 0.5 ml per chick. The extract was given for 14 days (from day 3 to day 16), and the bacteria were given on days 16 and 17. On day 18, the chickens were necropsied. The malondialdehyde (MDA) level was analyzed using one-way analysis of variance test with the GLM procedure (<0.05), while the tissue histopath was analyzed using a descriptive qualitative study to examine the ileal damage.

Results

The results showed that the MDA levels (nmol/l) decreased in treatment groups T1, T2, and T3 compared to the positive control. On the contrary, we found improvements in the ileum histopathology of group T1 and T2 in the form of normal and regular intestinal epithelium arrangement of the ileum, long intestinal villi, and decreased total leukocytes.

Conclusion

Green coffee robusta has the potential to increase antioxidants and reduce inflammation in the small intestine of chickens infected with S. enteritidis.

Green coffee methanolic extract and silymarin protect against CCl4-induced hepatotoxicity in albino male rats

BACKGROUND

During the last few decades, patients worldwide have been interested in using alternative medicine in treating diseases to avoid the increased side effects of chemical medications. Green coffee is unroasted coffee seeds that have higher amounts of chlorogenic acid compared to roasted coffee. Green coffee was successfully used to protect against obesity, Alzheimer disease, high blood pressure and bacterial infection.

METHODS

This study aimed to investigate the probable protective activity of the green coffee methanolic extract, silymarin and their combination on CCl₄-induced liver toxicity in male rats. Thirty Sprague - Dawley male albino rats were divided into 5 groups; control negative (G1) just got the vehicle (olive oil) and the other four groups received CCl₄ dissolved in olive oil through an intraperitoneal injection and were divided into untreated control positive group (G2), the third group (G3) was treated with green coffee methanolic extract, the fourth group (G4) was treated with silymarin, and the fifth group (G5) was treated with a combination of green coffee methanolic extract and silymarin.

RESULTS

In the positive control group treated with CCl₄ (G2), the CCl₄-induced toxicity increased lipid peroxidation, IL-6, kidney function parameters, liver function enzymes, total cholesterol, triglycerides and low-density lipoproteins, and decreased irisin, antioxidants, CYP450 and high-density lipoprotein levels. Hepatic tissues were also injured. However, treating the injured rats in G3, G4 and G5 significantly improved the altered parameters and hepatic tissues.

CONCLUSIONS

Green coffee methanolic extract, silymarin, and their combination succeeded in protecting the male rats against CCl4 hepatotoxicity due to their antioxidant activity. Effect of green coffee methanolic extract mixed with silymarin in G5 was more efficient than that of green coffee methanolic extract in G3 or silymarin in G4.

Limited genotypic and geographic variability of 16-O-methylated diterpene content in Coffea arabica green beans

The acknowledged marker of Robusta coffee, 16-O-methylcafestol (16-OMC), can be quantified by NMR as a mixture with 16-O-methylkahweol (16-OMK), which accounts for approximately 10% of the mixture. In the present study, we detected and quantified 16-O-methylated diterpenes (16-OMD) in 248 samples of green Coffea arabica beans by NMR. We did not observe any differences between genotypes introgressed by chromosomal fragments of Robusta and non-introgressed genotypes. Environmental effects suggesting a possible protective role of 16-OMD for adaptation, as well as genotypic effects that support a high heritability of this trait were observed. Altogether, our data confirmed the presence of 16-OMD in green Arabica at a level approximately 1.5% that of a typical Robusta, endorsing the validity of 16-OMD as a marker for the presence of Robusta.

Ochratoxin A and citrinin in green coffee and dietary supplements with green coffee extract

The aim of this study was to determine the degree of mold contamination and mycotoxin levels in commercially available green coffee products and dietary supplements with green coffee extract. The study included 34 samples from green coffee products: raw beans (n = 16), ground coffee (n = 15) and instant coffee (n = 3), as well as 22 samples from dietary supplements in form of capsules (n = 19), tablets (n = 2) and sachets (n = 1). Total mold count was determined with spread-plate method. Anamorphic mold were identified based on their microscopic morphology and the type of sporulation. Concentrations of mycotoxins, ochratoxin A and citrinin, were quantified by means of HPLC-fluorescence detection. Molds, typically Aspergillus spp. and Penicillium spp., were found in 94% of green coffee beans, 100% of ground and instant coffee samples, and 55% of dietary supplement samples. None of the samples contained detectable levels of citrinin. Ochratoxin A (0.4 ng/g) was detected in only one sample of raw green coffee beans, but in up to 40% and 67% of ground and instant coffee samples, respectively. Mean concentrations of ochratoxin A in ground and instant coffee samples were 3.28 ng/g and 4.09 ng/g, respectively, and maximum concentrations amounted to 6.65 ng/g and 7.44 ng/g, respectively. Ochratoxin A (mean concentration 9.60 ng/g, maximum level 31.4 ng/g) was also detected in up to 58% of the supplement capsules, but in none of tablets and sachets.

Neuromodulatory effects of green coffee bean extract against brain damage in male albino rats with experimentally induced diabetes

Diabetes mellitus is an increasing metabolic disease worldwide associated with central nervous system disorders. Coffee is a widely consumed beverage that enriched with antioxidants with numerous medicinal applications. Accordingly, the present study aimed to investigate the therapeutic potential of orally administered green coffee bean water extract (GCBWE) against cortical damage induced by high fat diet (HFD) followed by a single injection of streptozotocin (STZ) in rats. Metformin (Met) was used as standard antidiabetic drug. Animals were allocated into six groups: control, GCBWE (100 mg/kg), HFD/STZ (40 mg/kg), HFD/STZ + GCBWE (50 mg/kg), HFD/STZ + GCBWE (100 mg/kg) and HFD/STZ + Met (200 mg/kg) which were treated daily for 28 days. Compared to control rats, HFD/STZ-treated rats showed decreased levels of cortical dopamine, norepinephrine and serotonin with marked increases in their metabolites. Further, HFD/STZ treatment resulted in notable elevations in malondialdehyde, protein carbonyl and total nitrite levels paralleled with declines in antioxidant markers (SOD, CAT, GPx, GR and GSH) and down-regulations of Sod2, Cat, GPx1 and Gsr gene expression. Neuroinflammation was evident in diabetic animals by marked elevations in TNF-α, IL-1β and up-regulation of inducible nitric oxide synthase. Significant rises incaspase-3 and Bax with decline in Bcl-2 level were noticed in diabetic rats together with similar results in their gene expressions. Cortical histopathological examination supported the biochemical and molecular findings. GCBWE administration achieved noteworthy neuroprotection in diabetic animals in most assessed parameters. The overall results suggested that antioxidant, anti-inflammatory; anti-apoptotic activities of GCBWE restored the cortical neurochemistry in diabetic rats.

Molecular networking based LC/MS reveals novel biotransformation products of green coffee by ex vivo cultures of the human gut microbiome

INTRODUCTION

Unroasted green coffee bean is an increasingly popular beverage and weight loss supplement that contains higher levels of chlorogenic acid derivatives and lower alkaloid levels than roasted beans. Nonetheless, how the gut microbiome metabolizes green coffee constituents has not been studied.

OBJECTIVES

To identify possible biotransformation products of green coffee extract by the human gut microbiome, and the potential implications of this process on its biological effects or fate inside the body.

METHODS

Molecular networking via the GNPS platform was employed for the visualization of green coffee metabolite profiles acquired using LC-tandem mass spectrometry post-incubation with an ex vivo culture of the human gut microbiome.

RESULTS

36 Metabolites were annotated including four unreported alkyl cinnamate esters in green coffee along with six novel biotransformation products.

CONCLUSION

Our finding reveals new biotransformation products of cinnamate esters by the gut microbiome mediated via oxidative reactions such as dehydrogenation and hydroxylation, along with methylation, decarboxylation, and deglycosylation. These findings reveal potential interactions between the gut microbiome and green coffee constituents, and paves the way towards studying the effects of these interactions on both microbiome and the human host.

The effects of green coffee extract supplementation on glycemic indices and lipid profile in adults: a systematic review and dose-response meta-analysis of clinical trials

Background

The role of coffee consumption in the risk of cardiovascular diseases has been debated for many years. The current study aimed to summarize earlier evidence on the effects of green coffee extract (GCE) supplementation on glycemic indices and lipid profile.

Methods

We searched available online databases for relevant clinical trials published up to October 2019. All clinical trials investigating the effect of GCE supplementation, compared with a control group, on fasting blood glucose (FBG), serum insulin, total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL), and high-density lipoprotein (HDL) were included. Overall, 14 clinical trials with a total sample size of 766 participants were included in the current meta-analysis.

Results

We found a significant reducing effect of GCE supplementation on FBG (weighted mean difference (WMD): -2.35, 95% CI: − 3.78, − 0.92 mg/dL, P = 0.001) and serum insulin (WMD: -0.63, 95% CI: − 1.11, − 0.15 μU/L, P = 0.01). With regard to lipid profile, we observed a significant reduction only in serum levels of TC following GCE supplementation in the overall meta-analysis (WMD: -4.51, 95% CI: − 8.39, − 0.64, P = 0.02). However, subgroup analysis showed a significant reduction in serum TG in studies enrolled both genders. Also, such a significant reduction was seen in serum levels of LDL and HDL when the analyses confined to studies with intervention duration of ≥8 weeks and those included female subjects. In the non-linear dose-response analyses, we found that the effects of chlorogenic acid (CGA) dosage, the main polyphenol in GCE, on FBG, TG and HDL were in the non-linear fashions.

Conclusion

In conclusion, we found that GCE supplementation improved FBG and serum levels of insulin and TC. Also, there was a significant improvement in other markers of lipid profile in some subgroups of clinical trials.

The effect of green coffee extract supplementation on anthropometric measures in adults: A comprehensive systematic review and dose-response meta-analysis of randomized clinical trials

BACKGROUND AND AIM

Two meta-analyses summarized data on the effects of green coffee extract (GCE) supplementation on anthropometric measures. However, the accuracy of those meta-analyses is uncertain due to several methodological limitations. Therefore, we aimed to conduct a comprehensive systematic review and dose-response meta-analysis to summarize all available evidence on the effects of GCE supplementation on anthropometric measures by considering the main limitations in the previous meta-analyses.

METHODS

We searched available online databases for relevant publications up to January 2020, using relevant keywords. All randomized clinical trials (RCTs) investigating the effects of GCE supplementation, compared with a control group, on anthropometric measures [including body weight, body mass index (BMI), body fat percentage, waist circumference (WC) and waist-to-hip ratio (WHR)] were included.

RESULTS

After identifying 1871 studies from our initial search, 15 RCTs with a total sample size of 897 participants were included in the systematic review and meta-analysis. We found a significant reducing effect of GCE supplementation on body weight (weighted mean difference (WMD): -1.23, 95 % CI: -1.64, -0.82 kg,P < 0.001), BMI (WMD: -0.48, 95 % CI: -0.78, -0.18 kg/m², P = 0.001), and WC (WMD: -1.00, 95 % CI: -1.70, -0.29 cm, P = 0.006). No significant effect of GCE supplementation on body fat percentage and WHR was seen. In the dose-response analyses, there was no significant association between chlorogenic acid (CGA) dosage, as the main polyphenol in green coffee, and changes in anthropometric measures.

CONCLUSION

We found that GCE supplementation had a beneficial effect on body weight, BMI and WC. It provides a cost-effective and safe alternative for the treatment of obesity. Additional well-designed studies are required to further confirm our findings.

A new analytical method for the simultaneous quantification of isoflavones and lignans in 25 green coffee samples by HPLC-MS/MS

Green coffee, the raw material of roasted coffee and coffee beverages, is one of the most widely traded commodities worldwide. There is a dearth of studies on its content in phytoestrogens such as isoflavones and lignans. Previously, we developed an efficient method for the simultaneous quantification of 6 isoflavones (daidzin, genistin, daidzein, genistein, formononetin and biochanin A) and 3 lignans (secoisolariciresinol, matairesinol and lariciresinol) in green coffee by using HPLC-MS/MS. Several extraction processes were evaluated and the best performing, base hydrolysis followed by enzymatic digestion, was validated and used to analyse 25 different coffee samples, 1 Coffea canephora and 24 Coffea arabica, from different countries. Lignans (total content: 286.5-8131.8 µg kg-1) were found in higher concentration than isoflavones (total content: 3.4-300.0 µg kg-1) and the most abundant were secoisolariciresinol (172.6-5714.1 µg kg-1) and lariciresinol (113.9-2417.7 µg kg-1). Notably, the Ethiopian coffee samples contained the highest levels of these compounds.

The effect of roasting on the total polyphenols and antioxidant activity of coffee

The total polyphenolic content and the antioxidant activity have been analyzed in ground beans of green, light, medium and dark roasted coffee by UV-VIS spectrometry. Water coffee extracts showed the highest levels of polyphenols in green and light roasted coffees where the total polyphenolic content (TPC) ranged from 49.19 ± 0.70 to 74.05 ± 0.28 and from 59.79 ± 1.45 to 38.34 ± 1.26 g GAE.kg^-1, respectively. In medium roast samples it ranged from 43.90 ± 3.07 to 74.05 ± 0.28g GAE.kg^-1 and in dark roast from 37.44 ± 0.63 to 47.41 ± 0.69 g GAE.kg^-1. The total antioxidant capacity (TAC) reached the highest values (DPPH inhibition ranging from 69.08 ± 1.33% to 78.55 ± 0.89%) in light roasted coffees. Dark roasted coffees showed both the lowest content of polyphenols as well as the total antioxidant capacity. In case of TPC, statistically significant differences (P˂0.001) have been identified between green coffee and other roasted degrees. Also, dark coffee showed statistically noticeable differences (P˂0.001) in TPC in relation to other roasted stages. Statistically important difference (P˂0.001) has been discovered between the total antioxidant capacity of dark roasted coffee and other roasting levels. The results demonstrated that roasting process affects both the oxidative activity as well as polyphenolic content.

Glass transition of green and roasted coffee investigated by calorimetric and dielectric techniques

Solid and liquid components coexist into glassy and amorphous structures of food complex matrixes. Both states admit movements, promoting physical modifications to a more thermodynamically stable system. Green and roasted coffee beans are principally characterized by a glassy structure that slowly evolves during storage. The aim of this study was to assess calorimetric and dielectric properties in combination, as a useful multi-analytical technique to improve the understanding of the motion mechanism of localized molecules. After equilibration at different water activities (a_w) for the determination of sorption isotherms of green and roasted coffee, the glass transition temperature (Tg) of the samples has been measured by using differential scanning calorimetry (DSC). Increasing the a_w from 0.155 to 0.512, the Tg shifted from 48.76 (±0.04) to 34.89 (±0.02) °C for green coffee and from 45.73 (±0.05) to 40.15 (±0.10) °C for the roasted one. The spectroscopic fingerprint of the matrix has been determined by dielectric measurements in terms of "gain" spectra (related to the imaginary part of permittivity). The maximum values of the determination coefficient (R²), obtained by linear correlation between spectral data and water activity or glass transition values for a specific frequency of the whole range (1.6 GHz-2.7 GHz), were 0.999 and 0.943 for green, and 0.997 R² and 0.925 R² for roasted coffee respectively.

Aptamer assisted ultrafiltration cleanup with high performance liquid chromatography-fluorescence detector for the determination of OTA in green coffee

One of the most common mycotoxin contaminating feed and foodstuffs is Ochratoxin A (OTA). OTA has a chronic toxic effect and proved to be mutagenic, nephrotoxic, teratogenic, immunosuppressive, and carcinogenic. Aptamer with their specific affinity for OTA was used in this paper to create an analytical technique. Several methods have been reported for the determination of OTA in foods. However, most of these methods could not be applied to a complex food as green coffee because the interfering native fluorescent products made the quantification very difficult. In this work, we mixed two separations based techniques to identify and quantify OTA in green coffee. Aptamer assisted ultrafiltration as separation technique based on the size of molecules was applied to separate the free OTA, the quantification of OTA was established by a high-performance liquid chromatography (HPLC-FD) with a limit of detection (LOD) of 0.05 ng/mL for OTA. Artificially contaminated green coffee displayed a good range of OTA recoveries up to 97.7%. This method can be applied to the quantitative determination of OTA in green coffee at levels below the maximum levels proposed by the European Commission for green coffee. It also confirm that aptamers can be used as biorecognition element in diagnostic assays with commercial application for mycotoxin analysis.

Concentration of Micro- and Macro-Elements in Green and Roasted Coffee: Influence of Roasting Degree and Risk Assessment for the Consumers

The aim of the present study was to determine concentrations of 15 macro- and micro-elements in 10 commercially available plantation Arabica coffee brands. The elemental concentration was studied in 50 samples of green and roasted coffee beans of various roasting degrees and their infusions. There were four different roasting degrees: City + (C+), Full city (FC), Full city ++ (FC++), and Dark (D). The attention was given to the impact of the roasting process on the elemental composition. Statistically significant differences were found between the green coffee beans and the different roasting degrees in both macro- and micro-elements. The results showed that roasting degrees affected the concentration of elements in resulting infusions. Dietary intakes for macro- and micro-elements based on RDA and PTWI (in the case of Al) were calculated. Based on the RDA values for macro- and micro-elements, it can be concluded that coffee infusions are not an important source of elements in nutrition. In the case of Al, consumption of coffee was considered non-hazardous based on the PTWI value.

Simultaneous quantification of caffeine and chlorogenic acid in coffee green beans and varietal classification of the samples by HPLC-DAD coupled with chemometrics

A chromatographic procedure (HPLC-DAD) using a relatively rapid gradient has been combined with a chemometric curve deconvolution method, multivariate curve resolution-alternating least squares (MCR-ALS), in order to quantify caffeine and chlorogenic acid in green coffee beans. Despite that the HPLC analysis (at these specific operating conditions) presents some coeluting peaks, MCR-ALS allowed their resolution and, consequently, the creation of a calibration curve to be used for the quantification of the analytes of interest; this procedure led to a high accuracy in the quantification of caffeine and chlorogenic acid present in the samples. In a second part of this study, the possibility of classifying the green coffee beans on the basis of their cultivar (Arabica or Robusta), by partial least squares discriminant analysis (PLS-DA) and soft independent modeling of class analogies (SIMCA), has been explored. SIMCA resulted in 100% of sensitivity and specificity for the Arabica class, while for the Robusta, it reached 66.7% of sensitivity and 100% of specificity, or 100% of sensitivity and 100% of specificity, depending on the extraction procedure followed prior to the chromatographic analysis; PLS-DA achieved 100% of correct classification independently of the procedure used for the extraction.

Effect of Green Coffee Consumption on Resting Energy Expenditure, Blood Pressure, and Body Temperature in Healthy Women: A Pilot Study

KEY TEACHING POINTS

• There are several findings, and chlorogenic acid may have antihypertensive effects. • There is a significant correlation between green coffee chlorogenic acid amount and REE. • Intracellular and extracellular liquid amounts decrease following green coffee consumption (215-280 mg caffeine), and these changes are observed in individuals whose usual dietary caffeine intake is relatively both low and high. • The body temperature values of individuals whose usual dietary caffeine intake was in the 50th percentile or greater (relatively high) increased after green coffee consumption.

Urine metabolomics shows an induction of fatty acids metabolism in healthy adult volunteers after supplementation with green coffee (Coffea robusta L.) bean extract

BACKGROUND AND OBJECTIVE

Green coffee bean extract is used as herbal medicine or supplement for weight reduction and obesity. The active constituents are considered caffeine and chlorogenic acid (CGA) derivatives. The mode of action of CGA is still unclear and can be related to peroxisome proliferator-activated receptor α (PPAR-α) and liver X receptor Rα (LXR-α). Metabolomics may be an innovative tool for the description and discovery of the multiple target nature of such phytocomplex.

METHODS

24 h urine samples were collected once a week from ten healthy adult volunteers consuming daily 400 mg of dry Green coffee bean extract (GCBE, 4.9% of chlorogenic acid) each day for 30 days (5 harvesting days, considering also the first day of supplementation). Urine samples were analyzed by LC-QTOF using both untargeted and targeted approaches. The latter was used to monitor two urinary markers of oxidative stress (allantoin, 8-OHdG).

RESULTS

Metabolomics analysis (PLS-DA) revealed changes in urine composition before and during the treatment with GCBE. Markers related to treatment were metabolites related to polyphenol administration as hippuric acid, benzoic acid derivatives, dihydroferulic and dihydrosinapic acid sulphate, but also carnitine derivatives and dicarboxylic acids. On the other hand, no changes in the levels of allantoin and 8-OHdG were observed.

CONCLUSION

This preliminary study showed the possible usefulness of metabolomics approach in the evaluation of GCBE consumption in healthy subjects. The observed changes in urinary composition can be related to the catabolism of GCBE constituents and to induced fatty acid metabolism, mainly related to carnitine derivatives. This latter result could be considered, at least in part, as a further proof of the mode of action of green coffee extract.

Influence of the Form of Administration of Chlorogenic Acids on Oxidative Stress Induced by High fat Diet in Rats

Green coffee is one of health-promoting supplements of the diet, applied in the form of either preparations or enriched food products. Its positive impact is manifested by mitigation of the development of certain tumors, e.g., in the colon and liver, and type 2 diabetes. Many studies proved that chlorogenic acids are the main active substances in green coffee. The bioavailability of these compounds depends among others on their interactions with other components of the diet, mainly proteins. When they are used as food ingredients, their bioavailability is additionally decreased because of the decomposition or interactions with other ingredients during food processing. The undesirable changes may be limited among others by microencapsulation, for example with β-cyclodextrin. In this study, rats were fed the pro-oxidative high fat diet, which was supplemented with chlorogenic acids from green coffee that were used in four forms such as: a purified extract, complexes of chlorogenic acids and β-cyclodextrin, and bread supplemented with either the extract or the β-cyclodextrin inclusion complex. Chlorogenic acids added to bread because of the reduced absorption from the crumb in the small intestine and increased passage to the colon, contributed to the beneficial modification of enzymatic activities of intestinal microbiota. When added directly to the diet, they contributed to the improved antioxidant status in the liver and kidneys, lowered glucose level and increased HDL level. A high ratio of reduced to oxidized glutathione in the liver and a high concentration of antioxidants in the blood serum were observed after administration of chlorogenic acids in the form of inclusion complexes with β-cyclodextrin, indicating that microencapsulation increased their bioaccessibility due to the limited interactions with other components of the diet.

Transferring results from NIR-hyperspectral to NIR-multispectral imaging systems: A filter-based simulation applied to the classification of Arabica and Robusta green coffee

Due to the differences in terms of both price and quality, the availability of effective instrumentation to discriminate between Arabica and Robusta coffee is extremely important. To this aim, the use of multispectral imaging systems could provide reliable and accurate real-time monitoring at relatively low costs. However, in practice the implementation of multispectral imaging systems is not straightforward: the present work investigates this issue, starting from the outcome of variable selection performed using a hyperspectral system. Multispectral data were simulated considering four commercially available filters matching the selected spectral regions, and used to calculate multivariate classification models with Partial Least Squares-Discriminant Analysis (PLS-DA) and sparse PLS-DA. Proper strategies for the definition of the training set and the selection of the most effective combinations of spectral channels led to satisfactory classification performances (100% classification efficiency in prediction of the test set).

Elemental composition of green coffee and its contribution to dietary intake

The concentration of twenty-seven elements (Li, Be, B, Mg, Al, P, K, Ca, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Sr, Mo, Cd, Sn, Sb, Ba, Hg, Pb, Bi, Th, and U) in green coffee samples and their infusions were determined by using inductively coupled plasma-mass spectrometry (ICP-MS). Prior to analysis, green coffee samples were prepared by microwave digestion, while infusions were analyzed without any pre-treatment. The accuracy and precision of the proposed methods were verified by recovery experiments. Considering samples; K, Cu, and Al had the highest mean concentrations with 6714.5μgg(-1), 12.1μgg(-1), and 25.9μgg(-1) among major, trace and toxic elements, respectively. The impact of brewing type on leachability of elements was also studied and the results outlined that mean leachability of elements to Turkish coffee were greater than to mud coffee. Furthermore, dietary element intakes through green coffee consumption were also estimated. This is the first study presenting wide range of elements in green coffee brews and calculating dietary intakes.

Data dimensionality reduction and data fusion for fast characterization of green coffee samples using hyperspectral sensors

Hyperspectral sensors represent a powerful tool for chemical mapping of solid-state samples, since they provide spectral information localized in the image domain in very short times and without the need of sample pretreatment. However, due to the large data size of each hyperspectral image, data dimensionality reduction (DR) is necessary in order to develop hyperspectral sensors for real-time monitoring of large sets of samples with different characteristics. In particular, in this work, we focused on DR methods to convert the three-dimensional data array corresponding to each hyperspectral image into a one-dimensional signal (1D-DR), which retains spectral and/or spatial information. In this way, large datasets of hyperspectral images can be converted into matrices of signals, which in turn can be easily processed using suitable multivariate statistical methods. Obviously, different 1D-DR methods highlight different aspects of the hyperspectral image dataset. Therefore, in order to investigate their advantages and disadvantages, in this work, we compared three different 1D-DR methods: average spectrum (AS), single space hyperspectrogram (SSH) and common space hyperspectrogram (CSH). In particular, we have considered 370 NIR-hyperspectral images of a set of green coffee samples, and the three 1D-DR methods were tested for their effectiveness in sensor fault detection, data structure exploration and sample classification according to coffee variety and to coffee processing method. Principal component analysis and partial least squares-discriminant analysis were used to compare the three separate DR methods. Furthermore, low-level and mid-level data fusion was also employed to test the advantages of using AS, SSH and CSH altogether. Graphical Abstract Key steps in hyperspectral data dimenionality reduction.

Chemical partitioning and antioxidant capacity of green coffee (Coffea arabica and Coffea canephora) of different geographical origin

Green coffee beans of Coffea arabica and Coffea canephora accessions from different geographical origin (Brazil, Colombia, Ethiopia, Honduras, Kenya, Mexico, Peru, Uganda and Vietnam) were extracted and the extracts analyzed by HPLC-ESI-MS/MS for the identification and quantification of chlorogenic acids and caffeine content. Principal component and cluster analyses were used to identify chemical patterns separating the different species and accessions based on their geographical origin. C. canephora showed always a higher caffeine content with respect to C. arabica, whereas the C. arabica accessions from Kenya showed a higher chlorogenic acids and a lower caffeine content. The antioxidant capacity of green coffee extracts was assayed by the reducing power and DPPH assays. The antioxidant capacity correlated with the chlorogenic acids content. The results show that the C. arabica from Kenya possesses the highest chlorogenic acids/caffeine ratio and, among the C. arabica accessions, the highest antioxidant capacity. Therefore, the C. arabica from Kenya is the most suitable green coffee source for nutraceutical applications because of its high antioxidant capacity and low caffeine content.

Development of an instant coffee enriched with chlorogenic acids

The objective of this study was to present possible formulations for an instant coffee product enriched with chlorogenic acids for the Brazilian market. Formulations were prepared with different concentrations of freeze dried extracts of green Coffea canephora beans (G) added to freeze dried extracts of roasted Coffea arabica (A) and Coffea canephora (C). Medium (M) and dark (D) roasting degrees instant coffee were produced (AM, AD, CM and CD) to obtain four formulations with green extract addition (AMG, ADG, CMG and CDG). Chlorogenic acids were determined by HPLC, with average contents of 7.2 %. Roasted extracts and formulations were evaluated for 5-CQA and caffeine contents (by HPLC), browned compounds (absorbance 420 nm), and antioxidant activity (ABTS and Folin). Coffee brews of the four formulations were also assessed in a lab-scale test by 42 consumers for acceptance of the color, aroma, flavor and body, overall acceptance and purchase intent, using a 10 cm hybrid scale. The formulations obtained acceptance scores of 6.6 and 7.7 for all attributes, thus they were equally acceptable. Greater purchase intent was observed for ADG, CDG and CMG (6.9) in comparison to AMG (6.1). The formulations had, on average, 2.5 times more 5-CQA than the average obtained from conventional commercial instant coffees. In addition to being more economically viable, the formulations developed with C. canephora (CDG and CMG) showed greater antioxidant potential (32.5 g of Trolox/100 g and 13.8 g of gallic acid equivalent/100 g) due to a balance in the amount of bioactive compounds.

The content of Ca, Cu, Fe, Mg and Mn and antioxidant activity of green coffee brews

A simple and fast method of the analysis of green coffee infusions was developed to measure total concentrations of Ca, Cu, Fe, Mg and Mn by high resolution-continuum source flame atomic absorption spectrometry. The precision of the method was within 1-8%, while the accuracy was within -1% to 2%. The method was used to the analysis of infusions of twelve green coffees of different geographical origin. It was found that Ca and Mg were leached the easiest, i.e., on average 75% and 70%, respectively. As compared to the mug coffee preparation, the rate of the extraction of elements was increased when infusions were prepared using dripper or Turkish coffee preparation methods. Additionally, it was established that the antioxidant activity of green coffee infusions prepared using the mug coffee preparation was high, 75% on average, and positively correlated with the total content of phenolic compounds and the concentration of Ca in the brew.

GCMS investigation of volatile compounds in green coffee affected by potato taste defect and the Antestia bug

Potato taste defect (PTD) is a flavor defect in East African coffee associated with Antestiopsis orbitalis feeding and 3-isopropyl-2-methoxypyrazine (IPMP) in the coffee. To elucidate the manifestation of PTD, surface and interior volatile compounds of PTD and non-PTD green coffees were sampled by headspace solid phase microextraction and analyzed by gas chromatography mass spectrometry. Principal component analysis of the chromatographic data revealed a profile of surface volatiles distinguishing PTD from non-PTD coffees dominated by tridecane, dodecane, and tetradecane. While not detected in surface volatiles, IPMP was found in interior volatiles of PTD coffee. Desiccated antestia bugs were analyzed by GCMS, revealing that the three most prevalent volatiles were tridecane, dodecane, and tetradecane, as was found in the surface profile PTD coffee. Coffee having visible insect damage exhibited both a PTD surface volatile profile and IPMP in interior volatiles, supporting the hypothesis linking antestia bug feeding activity with PTD profile compounds on the surface and IPMP in the interior of the beans.