Total Chlorogenic Acid Content Research Articles

The protective effect of Artemisia Capillaris Thunb. Extract against UVB-induced apoptosis and inflammation through inhibiting the cGAS/STING pathway

Exposure to ultraviolet B (UVB) radiation represents a significant environmental threat to human skin. This study investigates the protective mechanism of Artemisia Capillaris Thunb. (AC) extract against UVB-induced apoptosis and inflammation in HaCaT keratinocytes. AC extract demonstrated a significant protective effect, as evidenced by reduced early apoptosis, late apoptosis, and necrosis, as well as decreased apoptotic cell status upon UVB exposure. Additionally, AC extract effectively inhibited UVB-induced DNA damage, as indicated by diminished γ-H2AX foci formation. Restoration of mitochondrial damage and normalization of mitochondrial membrane potential, along with the reduction of intracellular and mitochondrial reactive oxygen species (ROS) levels, were observed with AC extract pre-treatment. The extract also exhibited anti-inflammatory properties, evidenced by the decreased release of IL-1α, IL-6, and PGE2 from keratinocytes. Additional research on the molecular mechanisms uncovered that the AC extract alters the cGAS/STING pathway, suppressing the mRNA (cGAS, STING, IRF3, IRF7 and TBK1) and protein levels (cGAS, STING, IRF3, IRF7 and NF-κB) linked to this particular pathway. The HPLC analysis identified chlorogenic acid and its derivatives as the major components in AC, constituting up to 16.44% of the total chlorogenic acid content. The cGAS/STING signaling pathway was found to be suppressed by chlorogenic acid and its derivatives, as indicated by molecular docking studies and RT-qPCR analysis. This suppression contributes to the protective effects against cell apoptosis and inflammation induced by UVB. To summarize, AC extract, which is abundant in chlorogenic acid and its derivatives, shows potential in protecting keratinocytes from damage caused by UVB by regulating the cGAS/STING signaling pathway.

Fatty acids and chlorogenic acid content in Plectranthus edulis root tubers.

This study quantified the fatty acid profile and total chlorogenic acid content of various Ethiopian cultivars of the Plectranthus edulis tuber, traditionally known as 'Agew Dinich'. Lipid extraction utilized the Folch method and the acid-catalyzed derivatization method to derivatize the fatty acids into fatty acid methyl ester (FAME) were used. Whereas maceration was used to extract chlorogenic acid from the fresh and freeze- dried tuber samples. Analysis revealed a total of thirteen fatty acids in all P. edulis samples, with nine classified as saturated and four as unsaturated. Palmitic acid was the most abundant fatty acid in P. edulis and accounted for 40.57%-50.21% of the total fatty acid content. The second and third most abundant fatty acids in the P. edulis sample were stearic and linoleic acids, which accounted for 8.38%-12.92% and 8.12%-11.28%, respectively. We reported chlorogenic acid for the first time in this potato species and found it to contain a concentration of 211± 4.2-300±24.7 mg/100g of dry weight basis when the determination was made using fresh samples. On the other hand, these samples yielded a chlorogenic acid concentration ranging from 115 ±8.6 mg/100g-175±3.9 mg/100g of freeze-dried powder samples. These findings suggest that P. edulis tubers could represent a significant dietary source of both chlorogenic acid and fatty acids.

Effect of Brewing Methods on Acrylamide Content and Antioxidant Activity: Studying Eight Different Filter Coffee Preparations.

The aim of this study was to investigate the parameters affecting the extraction of positive molecules such as chlorogenic acids and antioxidants, as well as potentially carcinogenic substances such as acrylamide, in different coffee brewing methods. Three coffee varieties, each assigned a different roasting degree, were used to prepare coffee brews following eight different preparation methods. Acrylamide was quantified using the HPLC-MS/MS instrument, while chlorogenic acids and caffeine were quantified using the HPLC-DAD system. Three spectrophotometric analyses were also performed (DPPH, TFC and TPC) to evaluate antioxidant activity. The results showed that the main brewing parameters, which have the greatest influence on the final content of these compounds, were the volume of water used, more specifically the brewing ratio (coffee to water ratio), the extraction time and the particle size of the coffee powder. In addition, the variables that have the greatest impact on the discrimination of the preparation methods studied are total chlorogenic acid content, TFC, TPC, caffeine and the DPPH assay. For this reason, the recipe and infusion parameters used for each of the extraction systems are the key factors that determine the extraction of coffee components and, consequently, the quality of the cup.

A novel process line for the valorization of industrial spent coffee grounds through coffee roasting technology and ultrasonic‐assisted extraction

AbstractBACKGROUNDThe main by‐product of the coffee industry is spent coffee grounds (SCG). To the best of our knowledge, this is the first occasion where industrial SCG has been used to build a batch‐valorization line combining barrel coffee roasters as an innovative drying process and ultrasound‐assisted extraction technology under the biorefinery concept, seeking to extract chlorogenic acids (CGA).RESULTSA Probat Sample Barrel Roaster were used to determine the optimal temperature, volume flow of fan, and time for a novel drying method. Drying optimization was carried out in order to reach 5.0% moisture content, reduce water activity and maximize total CGA content. Optimal conditions of 140 °C, 160.0 m3 h−1and 11.43 min for temperature, volume flow of fan, and time, respectively, were obtained with a desirability of 70%. Likewise, the optimal temperature, power and frequency settings for an ultrasonic extraction procedure of CGA from dried SCG were evaluated. To maximize the total CGA content, the ultrasonic technique was optimized. Temperature 50 °C, frequency 37 kHz and power 100 W with a desirability of 80% were necessary for optimality. The study was completed with a kinetic analysis using a second‐order rate model, Peleg's kinetic model and the phenomenological model.CONCLUSIONIndustrial coffee by‐products can be processed and valorizing using barrel coffee roasters as a novel technique. For process design, the kinetic parameters of ultrasound‐assisted extraction are a helpful tool. A new mathematical model is presented that takes into account the impact of changing temperature on the ultrasonic process. © 2022 Society of Chemical Industry (SCI).

New rapid detection method of total chlorogenic acids in plants using SERS based on reusable Cu2O–Ag substrate

A new method for rapidly detecting of total chlorogenic acids (CGAs) in plants by surface-enhanced Raman spectroscopy (SERS) based on reusable Cu2O–Ag substrate was developed in this study. The Cu2O–Ag substrate prepared by the in-situ growth method had high uniformity with peak intensity relative standard deviation (RSD) of 5.27%, repeatability with peak intensity RSD of 3.58%, and sensitivity with an analytical enhancement factor of 1.27 × 105 for detecting CGAs. Furthermore, the substrate had excellent reusability, after it was reused for seven cycles, the signal strength of CGAs was still above 80% of initial. Compared with the standard method of high-performance liquid chromatography (HPLC), the SERS method can successfully analyze the contents of total CGAs in plants, such as Stevia rebaudiana leaves, coffee beans, Lonicera japonica leaves, and Eucommia ulmoides flowers, with recovery rate from 93.26% to 112.65%, and the limit of detection was 0.13 μg/mL. The total CGAs content of Stevia rebaudiana leaves samples detected by HPLC and SERS have good consistency with R = 0.9760 and RMSE = 3286 mg/kg. Furthermore, the SERS method only needed less than 1 min, one standard and reusable substrate in this study to analyze, which can further reduce the cost of method analysis. Therefore, the SERS method with the appropriate substrate can provide a rapid, accurate, and economic way to detect the total CGAs in plants.

Bioactive compounds, antioxidant activity, physical and sensory characteristics of Mırra coffee

Mırra is a coffee beverage widely consumed in Syria and Turkey, and often produced from roasted and ground coffee beans. Recently, it is prepared from classical instant coffee. In this study, some physicochemical, bioactive and sensory properties of Mırra samples were determined. The average viscosity, °Brix, HMF, total phenolic content, DPPH and ABTS values were 1.36 cP, 3.70, 71.60 mg/L, 3431.55 mg GA eq./L, 6.24 mmol Trol. eq./mL and 35.23 mmol Trol. eq./mL for Mırra samples made by traditional process, and 4.85 cP, 16.36, 303.3 mg/L, 11276.47 mg GA eq./L, 23.89 mmol Trol. eq./mL and 89.70 mmol Trol. eq./mL for Mırra samples made with classic instant coffee, respectively. All Mırra samples also contained high levels of caffeine (1416.93 - 4347.46 mg/L). Chlorogenic acid, 4-O-caffeoylquinic acid and trans-5-O-caffeoylquinic acid were identified in Mırra samples. Total chlorogenic acid contents of Mırra samples were ranged from 1097.85 to 5283.21 mg/L. In all sensory parameters, Mırras with °Brix value over 5.75 had high scores. Results show that Mırra has high antioxidant activity. However, Mırra consumption may have negative health effects for risk groups due to the high caffeine content.

Effects of brewing conditions and coffee species on the physicochemical characteristics, preference and dynamics of sensory attributes perception in cold brews

The study aimed to assess the dominant sensory attributes and preference for cold brews prepared with different coffee species under different brewing conditions. Four beverages were brewed using Arabica and Robusta coffees with either a coarser coffee grind and extraction at 5 °C or a finer grind and extraction at 15 °C. Coffee flavor and bitter taste were dominant sensory attributes of all beverages, regardless of material and preparation. While there were no differences in preference, the composition and dominant sensory attributes differed among the cold brews. The use of different coffee species had a greater impact on the composition and the perception of the attributes of the cold brews than brewing conditions. Sourness and coffee flavor were more dominant in Arabica cold brews, which had higher trigonelline content and acidity, but bitter taste dominance was further reported. Meanwhile, bitterness and astringent sensation were more dominant in Robusta cold brews, with higher caffeine and total chlorogenic acid content; however, a high coffee flavor dominance was also observed.

Effects of coffee roasting technologies on cup quality and bioactive compounds of specialty coffee beans.

The effects of drum, fluidized bed, and traditional type of coffee roasting technologies on the cup quality and bioactive compounds of Yirgacheffe, Harar, and Sidama variety specialty coffee beans grown in Ethiopia were investigated at light, medium, and dark degree of roast from 150°C to 200°C for 7 to 15 min. No significant differences in cup quality were detected among the roasted coffee varieties disregard of the type of roasters. Varietal difference was found to have significant (p < .05) effect on caffeine content of the coffee beans. A significant reduction in trigonelline and total chlorogenic acids content of the coffee beans was observed during roasting process, with darker roasts attaining the least values. Drum roaster was found to be the best type of coffee roaster for specialty coffee beans at medium degree of roast with the highest cup quality, optimum bioactive compounds content, and minimum acrylamide formation. However, traditional roaster resulted at the least average cup score of 80% among the three coffee samples and the highest acrylamide content of 2.306 mg/L for Yirgacheffe coffee sample at light degree of roast. There are still some bottlenecks that need to be addressed via advancements using novel food processing technologies in order to devise the next generation of coffee processing.

Characterization of chlorogenic acids (CGA) and nine isomers in an F2 population derived from Coffea arabica L.

Chlorogenic acids (CGA) and their isomers have been associated with sensory attributes of the coffee beverage such as acidity, astringency, and bitterness. They have been linked to coffee rust resistance and acknowledged as bioactive compounds due to their antioxidant power with benefits for human health. The total chlorogenic acids (TCGA) and nine isomers of three groups, caffeoylquinic acid or CQA (5-CQA, 4-CQA, 3-CQA),dicaffeoylquinic acid or diCQA (3,4-diCQA; 3,5-diCQA, 4,5-diCQA) and feruloylquinic acid or FQA (5-FQA, 4-FQA, 3-FQA) were determined in an F2 population of Coffea arabica from the crossbreed (Bourbon x Maragogype) x Timor Hybrid. TCGA contents were quantified by UV-VIS spectrophotometryand High-Resolution Liquid Chromatography - HPLC. The group of caffeoylquinic acids (CQA) represented 82% of the TCGA. From the diCQA, 4,5-diCQA showed lower contents, whereas the highest isomer was 3,5-diCQA. Results per quartile for TCGA-UV and for every isomer showed statistical differences among group averages per isomer. The populationbehaved as a parental Maragogype according to contents of 5-CQA, 3,5-diCQA, and TCGA-UV. TCGA contents were higher in the parental GQ956 derived from the Timor hybrid 832-1, with resistance to coffee rust. From the three groups, the first characteristic of parental Bourbon showed a higher concentration of diCQA and FQA; the second one showeda lower concentration of TCGA and CQA isomers and the third group higher TCGA and 5-CQA concentrations. This research allowed establishing the basis for plant selection in the F2 generation of C. arabica due to the TCGA content and isomers derived from CQA, diCQA, and FQA.

Simultaneous roasting and extraction of green coffee beans by pressurized liquid extraction

Green coffee extracted by pressurized liquid extraction (PLE) was found to undergo a roasting process similar to traditional roasting. Liquid chromatography-tandem mass spectrometry was used to investigate the chlorogenic acid (CGA) composition and profiling changes by PLE under different extraction conditions and showed almost identical generation and degradation of CGAs occurring during traditional coffee roasting. Compared with the traditional extraction of roasted coffee, optimized PLE coffee showed three- and two-fold higher antioxidant activity and total CGA contents, respectively.Composition diversity and the content of volatile compounds in PLE coffee were found to increase as the PLE temperature increased but were lower than those of traditionally roasted coffee. The sensory attributes of PLE coffee were also evaluated to have be associated with a profile change in the volatile compounds and non-volatile CGA compounds.

Solvent extraction of caffeoylquinic acids from Artemisia selengensis Turcz leaves and their in vitro inhibitory activities on xanthine oxidase

In this study, the caffeoylquinic acid (CQA) extract solution of the Artemisia selengensis Turcz (AST) leaves prepared by 70% ethanol reflux method was separated with petroleum ether, ethyl acetate, and water-saturated n-butanol to obtain the proper solvent to purify CQAs. Results showed that the ethyl acetate fraction (EAF) exhibited the highest total chlorogenic acid content (TCC) (241.46 ± 0.00 mg/g dry fraction), followed by the water-saturated n-butanol fraction (nBuF) (TCC = 62.30 ± 0.82 mg/g dry fraction). Ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry and high-performance liquid chromatography photodiode array were used to qualitatively and quantitatively determine the CQAs in these two fractions. In EAF, four CQAs, namely, 3-CQA, 3,5-diCQA, 3,4-diCQA, and 4,5-diCQA, were identified with the contents of 5.69 ± 0.03, 106.65 ± 0.83, 15.65 ± 0.24, and 28.08 ± 0.82 mg/g, respectively. Six CQAs, namely, 3-CQA, 4-CQA, 1,3-diCQA, 3,5-diCQA, 3,4-diCQA, and 4,5-diCQA, with contents of 16.57 ± 0.23, 3.22 ± 0.55, 4.49 ± 0.01, 16.86 ± 0.24, 7.35 ± 0.11, and 6.41 ± 0.13 mg/g, respectively, were identified in nBuF. Quantitative analysis of the six CQAs in AST leaves have not been reported, and 1,3-diCQA has been found in AST leaves for the first time. Moreover, either EAF or nBuF and the six CQA reference compounds showed certain inhibitory activity on xanthine oxidase (XOD) in vitro. EAF demonstrated a stronger XOD inhibitory effect (IC50 = 1.67 mg/mL) than nBuF. Among the six CQA compounds, 3,4-diCQA had the lowest IC50 of 12.80 μM, whereas 1,3-diCQA and 3-CQA had IC50 values of 23.69 and 28.29 μM, respectively. The inhibitory activity of 4-CQA was weak. These findings indicated that CQAs are the major components inhibiting the XOD activity in vitro in AST leaves.

Characterization of Chlorogenic Acids in Coffee by Flow-Through Chronopotentiometry

In this study, flow-through chronopotentiometry (FTCP) has been developed as an electroanalytical method for characterization (identification and quantification) of chlorogenic acids (CGAs) in coffees. The characterization of CGAs in coffee was based on the electrochemical behavior of the main chlorogenic acid (CGAs) isomers presented in coffee (caffeoylquinic acids (CQAs), dicaffeoylquinic acids (diCQAs), and feruloylquinic acids (FQAs)) and the spiking of CGAs standards in coffee samples. The FTCP study has shown that electrochemical properties of CGAs strongly depend on their chemical structure and electronic properties, particularly on the presence of electron-donating −OH, −CH═CH− and −OCH3 groups and strong electron-withdrawing ester (−COOR) group presented in their structure. The FTCP measurements of coffee samples show that their electrochemical behavior is very similar to that of CGAs. Therefore, FTCP can be used for characterization of CGAs and determination of their content in coffees. 5-O-Caffeoylquinic acid (5-CQA), prevailed CGAs in coffees, was used as a standard for quantification of total CGA content in coffee. The linear calibration curve of 5-CQA was observed within the concentration range of 5 to 100 μmol L−1 with the limit of detection 5.7·10−7 mol L−1. The total CGA content of coffees has been expressed in 5-CGA equivalents per 100 g of coffee. It was shown that FTCP is a very sensitive, precise, and acurate method for determination of total CGA content in coffee. It should be noted that in presented investigation, FTCP was for the first time used for the study of electrochemical properties of polyphenolic antioxidants (including CGAs) and their characterization in some of the food samples.

Electrochemical Properties of Chlorogenic Acids and Determination of Their Content in Coffee Using Differential Pulse Voltammetry

The electrochemical properties of nine chlorogenic acids (CGAs) isomers: three caffeoylquinic acids, CQAs (5-CQA, 4-CQA, 3-CQA), three dicaffeoylquinic acids, diCQAs (3,4-diCQA, 3,5-diCQA, 4,5CQA) and three feruloylquinic acids, FQAs (5-FQA, 4-FQA, 3-FQA) were studied by differential pulse voltammetry (DPV) method. The study has shown that electrochemical properties of CQAs and diCQAs are strongly dependent on their chemical structure and electronic properties, particularly on presence of electron-donating –OH and –CH=CH– groups, and a strong electron-withdrawing effect of ester (–COOR) group presented in their structures. The electrochemical properties of FQAs were additionally influenced by the presence of methoxy group (–OCH3) attached on the aromatic ring. DPV measurements show that electrochemical oxidation of CQAs and diCQAs at a GCE is reversible, pH dependent, two- electron-two- proton process occured on catechol moiety in the structure of these molecules. Electrochemical oxidation of FQAs proceeded by an EC mechanism. In the first, electrochemical oxidation step, a phenoxy radical was formed by irreversible one-electron-one-proton process. In the second, chemical step, phenoxy radical undergoes hydrolysis generated a new more electroactive compound with methoxy-catechol moiety in the structure. This compound was reversible oxidised to methoxy-ortho-quionone structure by two-electron-two-proton process. The electrochemical properties of 5-CQA (main CGAs in coffee) were investigated more in detail. It was observed that anodic oxidation peak current of 5-CQA show its maximum in PBS solution of pH 7 and linear relationship within the concentration range of 5-50 mol L -1 , with LOD of 1.2·10 -6 mol L -1 . DPVs of coffee show that electrochemical properties of coffee extracts were very similar to that of investigated CGAs. Therefore, DPV was used for characterization of CGAs in coffees. It was shown that DPV is a very sensitive and selective method for determination of total CGAs content in coffee.

Distribution of Major Chlorogenic Acids and Related Compounds in Brazilian Green and Toasted Ilex paraguariensis (Maté) Leaves.

Ilex paraguariensis (maté) is one of the best sources of chlorogenic acids (CGA) in nature. When leaves are toasted, some isomers are partly transformed into 1,5-γ-quinolactones (CGL). Both CGA and CGL are important contributors to the brew's flavor and are thought to contribute to human health. In this study, we quantified 9 CGA, 2 CGL, and caffeic acid in 20 samples of dried green and toasted maté that are commercially available in Brazil. Total CGA content in green maté varied from 8.7 to 13.2 g/100 g, dry weight (dw). Caffeic acid content varied from 10.8 to 13.5 mg/100 g dw, respectively. Content in toasted maté varied from 1.5 to 4.6 g/100 g and from 1.5 to 7.2 mg/100 g dw, respectively. Overall, caffeoylquinic acid isomers (CQA) were the most abundant CGA in both green and toasted maté, followed by dicaffeoylquinic acids (diCQA) and feruloylquinic acids (FQA). These classes accounted for 58.5%, 40.0%, and 1.5% of CGA, respectively, in green maté and 76.3%, 20.7%, and 3.0%, respectively, in toasted maté. Average contents of 3-caffeoylquinolactone (3-CQL) and 4-caffeoylquinolactone (4-CQL) in commercial toasted samples were 101.5 mg/100 g and 61.8 mg/100 g dw, respectively. These results show that, despite overall losses during the toasting process, CGA concentrations are still substantial in toasted leaves, compared to other food sources of CGA and phenolic compounds in general. In addition to evaluating commercial samples, investigation of changes in CGA profile and formation of 1,5-γ-quinolactones was performed in experimental maté toasting.

Study of the chlorogenic acid content in yerba mate (Ilex paraguariensis St. Hil.): Effect of plant fraction, processing step and harvesting season

Chlorogenic acid (CGA) is a fine chemical used in different food and pharmaceutical industries. CGA is currently extracted from various plant materials, particularly green coffee beans. Yerba mate (Ilex paraguariensis St. Hil.) contains significant amounts of CGA with very low levels of extraction interfering substances (fatty materials). Both of these reasons prompted us to evaluate yerba mate as a novel source for extraction of this compound.CGA content was quantified in various yerba mate fractions during different processing steps, and in samples taken from two companies at early and late harvesting seasons. Samples were exhaustively extracted with hot water and total CGA content (including its three isomeric compounds) was determined by HPLC. Total CGA content (on a dry weight basis) ranged from 45.8±0.4 to 80.8±1.0g CGA kg−1 of leaves and from 31.6±0.6 to 78.9±5.3g CGA kg−1 of stems. A substantial reduction in CGA content was found along the processing steps. The highest CGA content was found in samples from freshly harvested (green) yerba mate, for both leaves and stems; with no significant differences in their CGA content (P<0.05). CGA content at the early harvesting season was substantially higher to that obtained at the end of the harvesting season, for both green leaves and stems.Green stems, a residue from yerba mate processing obtained at the early harvesting season, could be considered as a promising and valuable raw material for the production of CGA-enriched extracts.

English

Methods for separation of chlorogenic acid (CA) from tobacco by-products were established. The liquid chromatography tandem mass spectrometry (LC-MS) method for identification and analysis of chlorogenic acid from tobacco materials has been developed. CA was isolated by polyamide and further purified by silicagel column chromatography. Results reveal that polyamide is suitable for separation of CA from tobacco extract. After one run treatment with polyamide, the content of chlorogenic acids was 40.3%. The product was further purified using silicagel column chromatography; the content of total chlorogenic acid was increased 2.29-fold from 40.3 to 92.2%. The LC-MS results showed that total chlorogenic acids were made up of four components: 5-CQA, 3-CQA, 4-CQA and cis-5-CQA. The content of 5-CQA was the most (78.2%) and other three chlorogenic acid derivatives were 1.9, 10.1 and 2.0%, respectively. Key words : Tobacco by-products, chlorogenic acid, polyamide, silica gel column, LC-MS.

Analysis of Active Compounds and Antioxidant Activity Assessment of Six Popular Chinese Juhua Teas

Chrysanthemum is an important traditional Chinese medicine and is drunk daily as a herbal tea. Chlorogenic acids and flavonoids are generally considered as the bioactive compounds. In this work, six kinds of Juhua Tea were analyzed and their active compounds and antioxidant activities were compared. In total, 32 phenolic compounds were profiled and identified using HPLC-DAD/ESI-MSn, composed of chlorogenic acids (10), flavones (8), chalcones (8), flavanones (4) and flavonols (2). Chalcones were the main flavonoids in Kunlun Xueju (Coreopsis tinctoria) extract, while flavones and chlorogenic acids were dominant in the five Chrysanthemum teas. Total chlorogenic acids content (TCA) was highest in Tai Ju (Chrysanthemum morifolium cv. 'Tai Ju') (8.59 ± 0.87 mg/g DW), and total flavonoids content (TF) was highest in Kunlun Xueju (87.2 ± 7.0 mg/g DW), which were both lowest in Ganye Ju (Chrysanthemum eticuspe) (TCA 0.86 ± 0.26 mg/g DW, TF 1.43 ± 0.41 mg/g DW). Huangin Ju (Anthemis tinctoria) possessed the most flavones (19.7 ± 0.6 mg/g DW). Antioxidant capacity of each drink, assessed by Folin-Ciocalteu, DPPH, ABTS and FRAP assays, consistently showed that Kunlun Xueju extract possessed stronger antioxidant activity than the other five, suggesting that the flavonoids content accounted for the free radical scavenging. The present work provides a method for the characterization and quality control of Juhua Tea. Moreover, it is a guideline for consuming choice, due to the different biological functions resulting from chalcones, chlorogenic acids, and flavones.

Investigation of Optimum Roasting Conditions to Obtain Possible Health Benefit Supplement, Antioxidants from Coffee Beans

ABSTRACTIn order to investigate the role of roasting conditions in antioxidant formation, methanol and hot water extracts from Robusta coffee beans roasted for various lengths of time and at various temperatures were analyzed for total phenolic acid, chlorogenic acid, and caffeine content, as well as for their antioxidant activities using 1,1-diphenyl-2-picryhydrazyl (DPPH), thiobarbituric acid (TBA), and malonaldehyde/gas chromatography (MA/GC) assays. The amount of total phenolics in methanol extracts decreased linearly over the roasting temperature from 63.51 ± 0.77 mg chlorogenic acid equivalent (CAE)/g coffee beans (roasted at 200°C) to 42.56 ± 0.33 mg CAE/g coffee beans (roasted at 240°C). The total chlorogenic acid content decreased when the roasting time was increased from 78.33 ± 1.41 mg/g (green coffee beans) to 4.31 ± 0.23 mg/g (roasted for 16 min at 250°C). All methanol extracts from roasted coffee beans possessed over 90% antioxidant activities in the DPPH assay. The antioxidant activity of methanol extracts ranged from 41.38 ± 1.77% (roasted at 250°C for 10 min) to 98.20 ± 1.49% (roasted at 230°C for 16 min) as tested by the TBA assay. The antioxidant activity of methanol extracts of green coffee beans and roasted coffee beans ranged from 93.01% (green coffee beans) to 98.62 ± 1.32% (roasted at 250°C for 14 min) in the MA/GC assays. All hot water extracts exhibited moderate pro-oxidant activities in TBA and MA/GC assays. The results indicated that roasting conditions of coffee beans play an important role in the formation of antioxidants in brewed coffee, which can be dietary supplements having beneficial effect to human health.

Inhibitory effects of chlorogenic acids from green coffee beans and cinnamate derivatives on the activity of porcine pancreas α-amylase isozyme I

Nine kinds of chlorogenic acids (CGAs) account for 80% of the total CGA content in green coffee beans. They consist of three subgroups of caffeoylquinic acids (CQAs), feruloylquinic acids (FQAs), and dicaffeoylquinic acids (diCQAs). We previously reported the inhibitory effects of 5-CQA on porcine pancreas α-amylase (PPA) isozymes, PPA-I and PPA-II. In this paper, we investigated the PPA-I inhibition by eight kinds of CGAs. The IC 50 values of CQAs, FQAs, and diCQAs against the PPA-I-catalysed hydrolysis of p-nitrophenyl-α-D-maltoside were 0.08–0.23 mM, 1.09–2.55 mM, and 0.02–0.03 mM, respectively. All CQAs and FQAs and 3,5-diCQA showed mixed-type inhibition with binding to the enzyme–substrate complex (ES) being stronger than to the enzyme (E). 3,4-DiCQA and 4,5-diCQA showed mixed-type inhibition, but, conversely are suggested to bind to E stronger than ES.

Influence of environmental factors, wet processing and their interactions on the biochemical composition of green Arabica coffee beans

Although cultivation of Arabica coffee trees at high elevation is known to favourably affect the final quality of the beverage, quantitative data describing the influence of climatic conditions on the chemical composition of the seed are still lacking. Similarly, post-harvest treatments of the beans are known to affect the generation of flavour, but the chemical transformations that occur during wet processing are poorly understood. To better characterise the effects of the environment, wet processing and their possible interactions, we quantified the changes in the main chemical components of the coffee seed (lipids, chlorogenic acids, sugars and caffeine) caused by wet processing, and analysed how these changes were affected by the variations induced by the environment before harvest. Using 16 experimental plots in Reunion Island displaying broad climatic variations, we showed that chlorogenic acids and fatty acids in the seed were controlled by the mean air temperature during seed development. By contrast, total lipid, total soluble sugar, total polysaccharide and total chlorogenic acid contents were not influenced by climate. Glucose content was positively affected by altitude, while sorbitol content after wet processing depended directly on the glucose content in fresh seeds.