Profiling of phenolic compounds using UPLC–MS for determining the geographical origin of green coffee beans from Ethiopia

A total of 100 samples of green coffee (Coffea arabica L.) beans from the major producing regions of Ethiopia were studied using ultra performance liquid chromatography–mass spectroscopy to determine if the phenolic content could be linked to their geographical origins for authentication purposes. Principal component analysis allowed the most discriminating compounds to be identified. Based on their concentrations, 3-O-caffeoylquinic and 4,5-O-dicaffeoylquinic acids were found to be characteristic markers for Northwest and East (Harar) region coffees, respectively. Sub-regional coffee types from West, except Jimma B, could be distinguished by their 3,5-O-dicaffeoylquinic to 4,5-O-dicaffeoylquinic acid concentration ratios, while Yirgachefe coffees from South could be distinguished by their 4,5-O-dicaffeoylquinic to 3,4-O-dicaffeoylquinic acid concentration ratios. Linear discriminant analysis provided a classification model with recognition and prediction abilities of 91% and 90%, respectively, at regional level, and 89% and 86%, respectively, at sub-regional level. This is important for the detection of fraud, including the selling of inferior Ethiopian coffees under the label of the more expensive Harar coffees.     

Impact of “ecological” post-harvest processing on the volatile fraction of coffee beans: I. Green coffee

Green coffees produced by three variants of the wet process and a new “ecological” process were characterised for their aroma using combined headspace solid-phase microextraction/gas chromatography–mass spectroscopy (HS-SPME/GC–MS) and headspace solid-phase microextraction/gas chromatography–olfactometry (HS-SPME/GC–O). The effect of each post-harvest processing operation on the volatile fraction of the coffee produced was studied, particularly the effect of reducing the amount of water used in the process. The comparison of the green coffees from the different treatments revealed the importance of mucilage removal in distinguishing between the samples, and showed the merits of microbial mucilage removal in water to obtain coffees with a better aroma quality. These latter coffees were in fact characterised by pleasant and fruity aromatic notes, whereas those obtained after mechanical mucilage removal used in the ecological process were characterised by volatile compounds with an unpleasant note.     

Rapid identification and determination of 11 polyphenols in Herba lycopi by HPLC–MS/MS with multiple reactions monitoring mode (MRM)

A new and rapid method was developed for simultaneous identification and determination of 11 polyphenols in Herba lycopi, i.e. rosmarinic acid, protocatechuic aldehyde, protocatechuic acid, caffeic acid, ferulic acid, apigenin, luteolin, quercetin, isorhamnetin, chlorogenic acid and rutin, using high performance liquid chromatography (HPLC) coupled with triple quadrupole mass spectrometry (MS/MS). Quantitation was based on multiple reactions monitoring (MRM) using the precursor → production combination for the determination of 11 analytes. The analysis was performed on an Eclipse Plus C₁₈ column (I.D. 4.6 mm × 100 mm, 3.5 μm particle size). An electrospray ionization (ESI)-tandem interface in the negative mode was employed prior to mass spectrometric detection. With the optimized conditions, the 11 biomarkers were detected properly within 3 min. Limits of detection (LOD) ranged from 0.6 to 2.6 ng/ml. The average recoveries ranged from 95.42 to 101.11% with RSDs ≤ 2.23%. The applicability of this analytical approach was confirmed by the successful analysis of 3 samples. The established method was validated and found to be sensitive and reliable for the determination of 11 analytes in Herba lycopi.     

Stable isotope analysis for green coffee bean: A possible method for geographic origin discrimination

Isotope ratio mass spectrometry (IRMS) and elemental analysis (EA) were applied in order to achieve geographic origin discrimination between 68 green coffee bean samples from 20 different geographic origins distributed over Central America, Pacific, South America, Africa, Asia and Oceania. Multivariate analysis of isotopic composition of the bean (δ¹³C VPDB, δ¹⁵N VAIR, δ¹⁸O VSMOW) and elemental composition (carbon and nitrogen percentage) allowed some discrimination of the geographic origin of some of the coffees included in this study. The observed differences on stable isotopic and elemental composition were mainly explained by altitude and precipitation values associated with the different geographic locations.     

Evaluation and Validation of Two Chromatographic Methods (HPLC-Fluorescence and LC–MS/MS) for the Determination and Confirmation of Ochratoxin A in Pig Tissues

Two different analytical methods for the determination and confirmation of ochratoxin A (OTA) in blood serum, kidney, and liver of pigs have been compared. Sample cleanup was based on liquid–liquid phase extraction. The detection of OTA was accomplished with high-performance liquid chromatography (HPLC) combined either with fluorescence detection (FLD) or electrospray ionization (ESI+) tandem mass spectrometry (MS/MS). The comparative method of evaluation was based on the investigation of 90 samples of blood serum, kidney, and liver per animal originating from different regions of Serbia. The analytical results are discussed in view of the respective method validation data and the corresponding experimental protocols. In general, analytical data obtained with liquid chromatography (LC)-MS/MS detection offered comparable good results in the sub-ppb concentration level indicating that the electrospray tandem mass spectrometric (LC–MS/MS) method was more selective and sensitive for the analysis and confirmation of OTA in pig tissues than the HPLC method after the methylation of OTA.     

The Use of an Electronic Aroma-sensing Device to Assess Coffee Differentiation—Comparison with SPME Gas Chromatography–Mass Spectrometry Aroma Patterns

In the food industry, routine analysis of food flavours is done with physical–chemical analytical tools such as GC-MS or with sensory analysis techniques. These techniques are not only time consuming but also require expensive apparatus. An alternative technique to evaluate food quality has been developed: the gas sensor arrays. Gas sensors have a characteristic electric resistance, which varies rapidly with the adsorption of volatile molecules. In this paper, we compared the aroma of nine coffee varieties by means of electronic aroma detection using an AromaScan apparatus equipped with a multisampler headspace device. The aroma patterns were evaluated and compared using the AromaScan software based on the Sammon mapping technique. Although this method is not able to give any structural information it allowed the separation of Arabica andRobusta coffees into two distinct groups. Coffees were also differentiated by geographic origin. The sensor array technique was compared with solid-phase microextraction-gas-chromatography (SPME-GC) results. Sampling conditions used for SPME were optimized with respect to headspace developing temperature and adsorption time. Results of the SPME-GC analyses were treated by principal component analysis (PCA). Thirty major peaks were chosen. The compounds responsible for the differentiation ofArabica and Robusta in the product space were tentatively identified by GCMS. Separations obtained by each method were similar. Both methods clearly separate Arabica and Robusta varieties. The SPME-GC method results did not show any separation according to geographic origin, whilst by electronic sensor array device a trend in this sense could be drawn. The sensor array technique was faster than the GCMS, taking only 7 min; GCMS analysis took 1 h. An abnormal sample, classified as fermented by the sensory panel, sent as blind test, was clearly separated in both methods.     

Impact of “ecological” post-harvest processing on coffee aroma: II. Roasted coffee

The purpose of this study was to determine how water and microbial stages in post-harvest processing affect the volatile content of coffee. Following our aroma analysis carried out on green coffees, we turned our attention to roasted coffees. Coffees produced by three variants of the wet method, and by an ecological process, were compared after roasting. Three degrees of roasting were applied to gain a clearer picture of the differences in roasted coffee aromas by means of a volatile compound analysis. Changes in the post-harvest process actually led to aroma differences in roasted coffees, and with light roasting it was possible to more effectively distinguish between the four treatments based on aroma criteria. Coffee produced by the traditional wet method, with microbial stages, had a better aroma quality than coffee produced by the ecological method, which was purely mechanical. Moreover, in the microbial method, mucilage removal under water gave coffees with more fruity, floral and caramel notes, whereas dry mucilage removal gave more neutral coffees. These results confirmed the importance of microbial mucilage removal under water and tallied with the results of our previous study on green coffee. This work provides coffee producers and roasters with an insight into the volatile composition of roasted coffee depending on the post-harvest process used and degree of roasting applied.     

Tocopherols in coffee brews: Influence of coffee species, roast degree and brewing procedure

Tocopherols in roasted coffee and coffee brews were analysed by HPLC/diode-array/fluorescence detection. Only α and β vitamers were identified in the samples. The influence of several factors on espresso coffee content, as well as on tocopherol extractability, was ascertained, namely, coffee species, roast degree, brew volume and preparation method. Pure arabica espressos contained 2.2 and 3.9 μg of α- and β-tocopherol, respectively, while robusta espressos showed significantly lower amounts (p < 0.05): 1.3 and 1.1 μg, correspondingly. Total contents (α + β) in espressos prepared from commercial blends ranged from 2.2 to 4.8 μg. Overall, tocopherol amounts in the brews corresponded to only 1% of those found in the coffee cake. However, espressos prepared from servings contained ～5-fold higher amounts of tocopherol than those prepared by the classic method. The medium-roast degree seems to be more favourable for the extraction of compounds than light or dark roasts. Compared with other coffee beverages, an arabica espresso cup contained an intermediate level of total tocopherols: 7.0 μg/30 mL, against 4.4 μg for filter (150 mL), 13.6 μg for press-pot (60 mL), 19.7 μg for moka (60 mL), 25.4 μg for Turkish, and 40.1 μg for boiled (150 mL) coffees.     

Element analysis of dried figs (Ficus carica L.) from the Mediterranean areas

The minerals content of 36 dried figs samples collected from three Mediterranean areas in 2018 was presented in this study. The aim of this research was to evaluate whether the mineral elements amounts were significantly different among the production regions. Samples grown in Italy, Greece and Turkey were analyzed in this study. Samples were found to be a good source of potassium (average content between 3.5 ± 0.2 g kg⁻¹ and 8.12 ± 0.88 g kg⁻¹), calcium (between 1.46 ± 0.24 g kg⁻¹ and 4.49 ± 0.28 g kg⁻¹), magnesium (between 0.84 ± 0.04 g kg⁻¹ and 1.28 ± 0.15 g kg⁻¹), and sodium (between 0.45 ± 0.04 g kg⁻¹ and 0.70 ± 0.11 g kg⁻¹). Cadmium ad lead concentrations were always below the regulated values and below the quantification limit in all Italian samples, whereas chromium was detected in all samples from Greece (0.05 ± 0.01 mg kg⁻¹) and Turkey (0.03 ± 0.01 mg kg⁻¹), and in 65 % of samples from Italy (0.08 ± 0.02 mg kg⁻¹). Results confirm the good figs quality related to their essential trace elements content and they highlight the safety of these food products correlated to the intake of toxic elements. Furthermore, statistical analysis of the results pointed out that the mineral elements amount is significantly different among the three sample groups, hence it is possible to discriminate figs according to their geographical origin by PCA.     

Isolation of green coffee chlorogenic acids using activated carbon

Chlorogenic acids, which are interesting natural antioxidants widespread in the plant kingdom, were extracted and purified from Mexican green coffee beans (Coffea arabica) using different methods. The final objective was to find an easy way to extract high-value molecules from a complex mixture, avoiding as much as possible the use of toxic solvents. Three extraction methods (hot water at 80 °C, aqueous methanol 70% (v/v), and aqueous isopropanol 60% (v/v)) were tested in combination with two isolating methods (activated carbon, different solvents). The extracted amounts of chlorogenic acids with the six treatments (4.67–5.87% dry basis) presented no significant differences. The one using hot water for extraction and of activated carbon for isolation, was the simplest and the most environmentally friendly. Thus it can be used as a previous step to obtain from green coffee a mixture rich in chlorogenic acids which can be further fractionated to purify a specific chlorogenic acid (i.e. in this work, 5-O-caffeoyl quinic acid using a silica gel column). Chlorogenic acids can be used as natural antioxidants in food or non-food products. To the best of our knowledge, activated carbon has not been used to isolate chlorogenic acids from green coffee.     

Molecular and MALDI-TOF MS characterisation of Hyalomma aegyptium ticks collected from turtles and their associated microorganisms in Algeria

The identification of ticks and their associated pathogens is important for knowledge on tick-borne diseases. The objective of this study was to use morphological, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and/or molecular biology tools to identify ticks collected from turtles in north-eastern Algeria, as well as to investigate the microorganisms associated with these ticks. A total of 471 adult ticks were collected and identified morphologically as Hyalomma aegyptium, of which 248 (52.7%) were female and 223 (47.3%) were male. amongst them, 230 specimens were randomly selected for molecular and MALDI-TOF MS analysis. Molecular biology confirmed that our ticks were Hy. aegyptium. MALDI-TOF MS analysis revealed that 100% of the spectra were of excellent quality. Four spectra were selected to update our own database MALDI-TOF MS arthropod. The blind test of the 226 remaining spectra showed that all ticks were correctly identified, with scores ranging from 1.774 to 2.655 with a mean of 2.271 ± 0.16 of which, 223 (98.6%) had log score value (LSV)>1.8. Molecular biology screening showed that the ticks carried the DNA of Borrelia turcica, Rickettsia africae, Rickettsia aeschlimannii, Rickettsia sibirica mongolitimonae and with the Anaplasmataceae were close to a potentially new, undescribed Ehrlichia sp. This study confirms that MALDI-TOF MS is a reliable tool for the identification of ticks and that ticks collected from turtles in Algeria are carriers of several species of microorganisms which may be responsible for diseases in humans and animals.     

Reference measurements of mercury species in seafood using isotope dilution inductively coupled plasma mass spectrometry

Species-specific isotope dilution inductively coupled plasma mass spectrometry (SS ID ICP-MS) and high-performance liquid chromatography (HPLC) were used to obtain accurate and SI traceable results for methyl mercury in seafood samples such as clam, oyster and fish homogenate. The mass fractions of (62.3 ± 2.3) μg kg⁻¹, (5.44 ± 0.36) μg kg⁻¹ and (531 ± 19) μg kg⁻¹ were obtained for MeHg (as Hg) in IAEA-461, IAEA-470 and IAEA-476, respectively. Direct isotope dilution mass spectrometry was performed for total mercury content then the content of inorganic mercury in selected samples was obtained by calculation. It was found that the content of inorganic Hg in IAEA-461, IAEA-470, and IAEA-476 was as: 328 μg kg⁻¹, 16 μg kg⁻¹, and 62 μg kg⁻¹, respectively. Mathematical modelling of analytical procedure and evaluation of all parameters influencing final results were adequate for validation of measurement procedure, establishing traceability and estimating expanded uncertainty. Developed procedures were successfully applied in the characterization process of fish homogenate candidate reference material and in the calculation of assigned values in the frame of IAEA-476 inter-laboratory comparison study. Compatibility between obtained results and those derived from the certification campaign, organized by International Atomic Energy Agency on the same sample matrix (<2.6 % difference) further validated performed ID ICP-MS protocols.     

Fatty acid composition and δ13C isotopic ratio characterisation of pumpkin seed oil

This study aimed to verify the authenticity and geographical origin of pumpkin seed oil using chemical analysis by gas chromatography (GC) and isotopic characterisation by gas chromatography combustion stable isotope ratio mass spectrometry (GC/C/IRMS) combined with chemometric analysis. Thirty-eight pumpkin seed samples from various parts of the world were collected and authentic oils were prepared. Pumpkin seed oils are highly unsaturated, oleic acid varies from 26.8 to 43.6% and the content of linoleic acid is between 37.2 and 54.9%. The average δ¹³C values of the main fatty acids are −29.2 ± 1.2‰, −30.3 ± 1.6‰, −27.9 ± 1.7‰ and −28.1 ± 1.7‰ for C_16:0, C_18:0, C_18:1, C_18:2, respectively. To determine adulteration, rapeseed, sunflower and soybean oil, were added to pumpkin seed oil in varying percentages (1–10%). A 100% correct classification of both geographical and botanical origin was achieved based on the composition and δ¹³C values of fatty acids. Principal component analysis (PCA) and regularised discriminant analysis (RDA) analysis gave comparable results.     

Measurement of the total choline content in 48 commercial dairy products or dairy alternatives

In this work, the total choline and choline-containing moieties (free choline, glycerophosphocholine, phosphocholine, phosphatidylcholine, lysophosphatidylcholine and sphingomyelin) of 48 dairy products or dairy alternatives available in Canada were determined by hydrophilic interaction liquid chromatography-tandem mass spectrometry (LC–MS/MS). The average total choline content for one serving of fluid milk and alternative (i.e. 250 mL as defined by Canada's Food Guide) was 32.9 ± 2.4 mg for cow's milk, 24.9 ± 0.1 mg for goat's milk and 31.2 ± 4.2 mg for soy beverage. The average total choline content for one serving of yogurt (175 g) was 25.6 ± 3.2 mg. One serving of cheese (50 g) provided 7.1 ± 1.1 mg of total choline on average. Our data show that for dairy products there is a negative correlation between the total choline content on a dry weight basis and the fat content (r = −0.734, P < 0.001). Overall, we determined the choline content of a variety of dairy products which can supplement the data in the existing United States Department of Agriculture (USDA) choline database and be used in accurately estimating dietary choline intake in epidemiological studies. Hence, dairy products are a good source of choline with low fat products generally being a better source of choline than high fat dairy products.     

Determination of free amino acids in five commercial sweetpotato cultivars by hydrophilic interaction liquid chromatography-mass spectrometry

A sensitive and rapid method was developed for the determination of free amino acid profiles in sweetpotatoes. The method utilized an ultra-high-performance liquid chromatography system with hydrophilic interaction liquid chromatography (HILIC) separation coupled with tandem mass-spectrometry (MS/MS) detection without the need for chemical derivatization. Separation of 36 amino acid standards was achieved on a silica HILIC column in a single MS/MS run of 19 min. This validated method was applied for the analysis of the free amino acid composition of five commercial sweetpotato cultivars (Covington, Beauregard, Hatteras, Murasaki-29 and O’ Henry) from two planting lots grown in experimental fields. Analysis of variance with Tukey’s test was used to determine the differences in individual free amino acid content among the analyzed samples, and principle component analysis (PCA) was implemented to evaluate the variation in amino acid profiles of different sweetpotato cultivars. Asparagine was the most abundant free amino acid and its content varied significantly among the cultivars (p < 0.05). Fifteen additional amino acids also varied among cultivars and contributed to the differentiation of the genotypes by PCA based on their complete amino acid profiles. The efficient, reliable, sensitive method described herein could be used in quantifying amino acids in food matrices similar to sweetpotatoes.     

Body composition differences between adults with multiple sclerosis and BMI-matched controls without MS

BackgroundPersons with multiple sclerosis (MS) have many health conditions related to overweight and obesity, but little is known about how body composition among those with MS compares to those without MS at the same weight.ObjectiveTo compare differences in whole body and regional body composition between persons with and without MS matched for sex and body mass index (BMI).MethodsPersons with MS (n = 51) and non-MS controls (n = 51) matched for sex and BMI. Total mass, lean mass, fat mass, and percent body fat (%BF) of total body and arm, leg, and trunk segments were assessed using dual-energy X-ray absorptiometry (DXA).ResultsMen with MS had significantly less whole body lean mass (mean difference: 9933.5 ± 3123.1 g, p < 0.01) and higher fat mass (mean difference: 6079.0 ± 2137.4 g, p = .01) and %BF (mean difference: 9.43 ± 2.04%, p < 0.01) than BMI-matched non-MS counterparts. Further, men with MS had significantly lower lean mass in the arm (p = 0.02) and leg (p < 0.01) and higher fat mass in the arm (p = 0.01), leg (p = 0.03) and trunk (p = 0.03) than men without MS. Men with MS had significantly higher %BF in all three regions (p < 0.01) than men without MS. There were no differences between women with and without MS.ConclusionsWe observed significant differences in whole body and regional body composition between BMI-matched men with and without MS. Additional research is needed to further explore differences in body composition, adipose distribution, and the impact of these differences on the health and function of men with MS.     

Determination of free quinic acid in food matrices by Hydrophilic Interaction Liquid Chromatography with UV detection

A new method using Hydrophilic Interaction Liquid Chromatography and UV detection was developed for the determination of free quinic acid in fourteen commercial beverages (fruit juices, red wine, coffee, vinegar, and edible mushroom extract). Samples were directly injected into the HPLC system after dilution and centrifugation. All separations were carried out by gradient elution on a ZIC^®-cHILIC column, using an eluent consisting of acetonitrile and aqueous phosphate buffer at pH 6. Quinic acid eluted in 12 min as a symmetric peak well separated from all other peaks in the chromatograms. The total turnaround time per sample was 60 min. The method was validated using cranberry juice as model beverage matrix. Linearity was demonstrated on spiked juice between 200 and 600 μg/mL (r² = 0.999), and precision and accuracy were satisfactory (RSD ≤ 10% and recovery 100 ± 1%, respectively).The method was proven to be suitable for its purpose. Quinic acid levels ranged from undetectable (<15 μg/mL in red grape juice, elderberry juice, and in red wine vinegar) to 740 ± 30 μg/mL (in mushroom extract). The results were discussed in comparison with the previous reports on similar matrices using different HPLC separation modes.     

Application of solid-phase extraction to brewed coffee caffeine and organic acid determination by UV/HPLC

A solid-phase extraction (SPE) method was adapted to perform brewed coffee sample clean-up for seven organic acids (acetic, citric, formic, malic, pyruvic, quinic and succinic) and caffeine determination by reversed-phase UV high performance liquid chromatography (RP/UV-HPLC). For all analytes the method showed good precision and linearity and, as an application, 20 brewed coffee samples from the two types of coffee (robusta vs. arabica) were tested. Brewed coffee samples were prepared according to ISO 6668 [1991. Green coffee—preparation of samples for use in sensory analysis] and the results were compared to sensory evaluation obtained from a panel of coffee tasters. Robusta coffee demonstrated the highest content of caffeine. Total acid content varied with coffee type and also with the geographic origin of the green coffee. Roasting conditions also seem to affect final acidity in brewed coffee for both coffee types analysed.     

Nutritional content,mercury, and trace element analyses of two skate (Rajidae) species in the Gulf of Alaska

Seafood is recognized as an important source of proteins and long chain omega-3 fatty acids. However, one of the primary concerns with seafood consumption is the level of heavy metals, particularly mercury, present in fish tissues, which may influence the demand of certain fishery products. We sampled muscle and liver tissues from 20 big (Beringraja binoculata) and 20 longnose (Raja rhina) skates collected near Kodiak and Cordova, Alaska, and analyzed their nutritional content (protein, moisture and lipid content and fatty acid profiles), heavy metal (mercury, arsenic, cadmium, lead) and trace element (selenium) load. Big and longnose skate muscle was composed of lean protein (14.7% ± 0.7% SD) with 1.2% (±0.4%) lipids and 83% (±0.8%) moisture. Skate livers were very high in lipids, between 52.5 and 57.5% and had high percentages of omega-3 fatty acids (30.2%). Mercury in these skates had mean levels of 0.21 mg/kg, lower than average levels found in Pacific halibut (Hippoglossus stenolepis). Overall, the risk/benefit ratio of consuming skate muscle was slightly positive (3.62%) based on the balance of mercury toxicity and omega-3 fatty acid benefits. Big skates were overall more beneficial to consume, and only longnose skates from Cordova had a negative risk/benefit ratio. These data can be used by the fishing industry to understand current and future market demands for skate products, and to be aware of any health concerns of consuming Gulf of Alaska skates.     

Nutrient profile of black coffee consumed in Serbia: Filling a gap in the food composition database

Accurate food composition data is essential in calculating the nutrient intake of a population based upon its consumption statistics. In the Serbian Food Composition Database (FCDB) there is a lack of reliable analytical data for black coffee, even though this is one of the most abundantly consumed beverages. In addition to evaluating the nutritional significance of black coffee consumption in Serbia, this work provides analytical data for inclusion in the Serbian FCDB, and the interchange through EuroFIR FoodEXplorer. Macronutrient, caffeine, chlorogenic acids (CGA), fatty acids and mineral content were analysed in a composite sample of roasted ground coffee, as well as in weak and strong infusions prepared in a traditional way. The macronutrient content of black coffee is in accordance with data from other FCDBs, confirming it to be of low-energy value and a modest contribution to the dietary intake of macronutrients. At the same time, consuming 200 mL (2 cups) of a strong infusion per day could provide more than 7.5% of the daily reference intake of potassium. The obtained results for caffeine and CGA in the investigated coffee infusions highlight the generally high daily consumption of these biologically active non-nutrient compounds among the Serbian population.