Light Roast Research Articles

Emissions of Polychlorinated Dibenzo-p-Dioxins/Dibenzofurans during Coffee Roasting: Exploring the Influence of Roasting Methods and Formulations

Polychlorinated dibenzo-p-dioxin/dibenzofuran (PCDD/F) emissions during the roasting of green Arabica coffee and coffee formulations containing alcohol, sugar, and honey were investigated in this study. Fast and slow roasting methods, which took 5.62 and 9.65 min to achieve a light roast, respectively, were used to evaluate the emissions. The concentrations in the flue gas during the fast roasting of green coffee (0.0296 ng Nm−3 and 0.00364 ng WHO-TEQ Nm−3) were 13.9% and 70.5% higher than during slow roasting, respectively. However, this was only the trend for some formulations, and no significant differences in concentrations were found between the methods at p = 0.05. Thus, the slow roasting method might not necessarily reduce formation when additives are included. The emission factors were 2.86 ng kg−1 and 0.352 ng WHO-TEQ kg−1, and 4.17 ng kg−1 and 0.176 ng WHO-TEQ kg−1 for the fast and slow roasting of green coffee, respectively. Further investigations are warranted to understand the formation mechanism, assess potential health risks, and explore mitigation strategies. These findings have implications for both coffee processing industries and regulatory bodies, as understanding the impact of roasting methods and additives could inform the development of cleaner production practices and targeted emission reduction policies.

Insights into acrylamide and furanic compounds in coffee with a focus on roasting methods and additives

Roasting is necessary for bringing out the aroma and flavor of coffee beans, making coffee one of the most consumed beverages. However, this process also generates a series of toxic compounds, including acrylamide and furanic compounds (5-hydroxymethylfurfural, furan, 2-methylfuran, 3-methylfuran, 2,3-dimethylfuran, and 2,5-dimethylfuran). Furthermore, not much is known about the formation of these compounds in emerging coffee formulations containing alcohol and sugars. Therefore, this study investigated the effect of roasting time and degree on levels of acrylamide and furanic compounds in arabica coffee using fast and slow roasting methods. The fast and slow roasting methods took 5.62 min and 9.65 min, respectively, and reached a maximum of 210 °C to achieve a light roast. For the very dark roast, the coffee beans were roasted for 10.5 min and the maximum temperature reached 245 °C. Our findings showed that the levels of acrylamide (375 ± 2.52 μg kg−1) and 5-HMF (194 ± 11.7 mg kg−1) in the slow-roasted coffee were 35.0 % and 17.4 % lower than in fast-roasted coffee. Furthermore, light roast coffee had significantly lower concentrations of acrylamide and 5-HMF than very dark roast, with values of 93.7 ± 7.51 μg kg−1 and 21.3 ± 10.3 mg kg−1, respectively. However, the levels of furan and alkylfurans increased with increasing roasting time and degree. In this study, we also examined the concentrations of these pollutants in new coffee formulations consisting of alcohol-, sugar-, and honey-infused coffee beans. Formulations with honey and sugar resulted in higher concentrations of 5-HMF, but no clear trend was observed for acrylamide. On the other hand, formulations with honey had higher concentrations of furan and alkylfurans. These results indicate that optimizing roasting time and temperature might not achieve the simultaneous reduction of all the pollutants. Additionally, sugar- and honey-infused coffee beans are bound to have higher furanic compounds, posing a higher health risk.

Perbedaan Metode Pengolahan Pascapanen dalam Memengaruhi Kadar Kafein Roasted Bean Kopi Robusta Argopuro

This study aims to determine the caffeine content of Argopuro Jember robusta coffee beans based on differences in post-harvest processing methods. The research was conducted at the Jember State Polytechnic Agricultural Products Processing (PHP) Laboratory and the Jember State University Integrated Testing Unit Laboratory in June-September 2022. The samples were robusta coffee logs originating from the Argopuro area of ​​Jember. The post-harvest coffee processing process is divided into four (4) methods, namely natural processing (dry process), semi-wet processing, wet (full wash process), and honey processing. Green beans from the results of each processing method are roasted at light, medium, and dark levels. The roasted bean caffeine content test from each post-harvest processing method at each roasting level was carried out descriptively (simple, without repetition). Overall, the caffeine content of the roasted beans produced in this study still meets the SNI 01-3542-2004 standard, a maximum of 2%. The caffeine content of Argopuro Jember robusta coffee roast beans at the light roast level ranges from 1.44-1.65%, 1.38-1.92% for medium roast, and 1.61-1.81% for dark roast. The highest caffeine content in roasted beans at each roasting level is 1.65% (dry process), 1.92% (full wash process), and 1.81% (full wash process), respectively. Meanwhile, roasted beans with the lowest caffeine content with a value of 1.38% are produced using the semi-wet process processing method at a medium roast level. The fluctuations in caffeine values ​​produced in this study indicate that post-harvest processing methods do not affect the caffeine content of roasted beans at light, medium, or dark roast levels.

Investigation of volatile compounds of Liberica coffee beans fermented at varying degrees of roasting

Liberica coffee (Coffea liberica Bull ex Hiern) has gained worldwide popularity, because it has a unique taste and aroma, and it is able to adapt to peatlands and is more tolerant of disease. Previous studies suggested that fermentation with hydrolytic bacteria could improve flavors, mostly determined by volatile compounds by the roasting process. However, studies about the volatile compounds and their roles in the taste and aroma of this coffee are still limited. This study aimed to investigate volatile compounds from fermented Liberica coffee beans roasted at light roast (150-160°C, 2.2 Mbar, 12 mins); medium roast (175-185°C, 2.2 Mbar, 7.30 mins); and dark roast (200-220°C, 2.2 Mbar, 10 mins). Samples were collected from various fermentation times 0, 4, 8, and 12 hrs and dried. Green beans with a moisture content of 12% were roasted in 3 roast stages. In this work, the extraction of volatile coffee compounds was performed using solid phase microextraction (SPME) and subsequently analyzed by gas chromatography-mass spectrometry (GC-MS). To determine the significance of fermentation time and degree of coffee roasting in the area, a two-way univariate analysis of variance (ANOVA) test was used, followed by a Tukey's honest significant difference (HSD) test with a statistical significance level of p<0.05. The results showed that a total of 59 of the 130 volatile compounds had a significant difference at different roasting degrees to the area of compounds with a statistical significance level of p<0.05. Those compounds consisted of 5 aldehydes, 18 furans, 4 ketones, 9 phenols, 13 pyrazines, 5 pyridines and 5 pyrroles.

Pengaruh Konsentrasi Sorbitol dan Variasi Tingkat Penyangraian Terhadak Karakteristik Fisikokimia dan Organoleptik Kopi Robusta Cililin

Cililin is one of the robusta coffee producing regions in Indonesia, but there are still many people who do not know robusta coffee from Cililin, so an effort is needed to improve its quality. Coffee that goes through heating stages such as drying or roasting will cause several other chemical ingredients to change. Coffee processing can affect the characteristics and taste of the coffee produced. Soaking with sorbitol solution can retain moisture (humectant) in food and in processing that undergoes high temperature treatment so that it will not cause browning reactions One of the stages carried out in coffee processing using high temperatures is the roasting process. Therefore, a study was conducted to determine the effect of the difference in sorbitol concentration with roasting level on the characteristics of the Cililin robusta coffee products produced. This study consisted of two factors, namely sorbitol concentration (a1=10%, a2=15%, a3=20%) and roasting rate (b1 = Light Roast, b2 = Medium Roast, b3 = Dark Roast). Data processing using Two Way Anova on SPSS application version 26.0. The results showed that concentration had an effect on water content, color test and organoleptic response in color, aroma, and texture attributes, but did not affect the characteristics of caffeine levels, and pH. Roasting rate affects coffee characteristics, namely moisture content, caffeine content, pH, color test, and organoleptic response in color, aroma, and texture attributes. The interaction between sorbitol concentration and roasting rate affects the characteristics of robusta cililin coffee, namely moisture content and color test. However, it has no effect on the characteristics of caffeine levels, and pH. Keywords: Cililin Robusta Coffee, Sorbitol, Roasting Level

Effect of Different Roasting Levels and Manual Brewing Techniques on the Sensory Profile of Liberica Coffee with Honey Process

Liberica coffee is less popular than Arabica and Robusta coffees. One reason is that Liberica coffee has a less pleasant flavor than its other counterparts. Exploration on Liberica coffees and the processing impact on quality is still limitedly published. The objectives of this research are to evaluate the effect of different roasting levels and manual brewing techniques on the sensory profile of Liberica coffee. The green coffee beans used in this study are processed using honey. The Qualitative Descriptive Analysis (QDA) method evaluated sensory profiles, while a preference test was also performed. The brewed coffee’s basic physicochemical characteristics (color, pH, and Total Dissolved Solids (TDS)) were measured. The sensory evaluation applied a factorial Randomized Block Design with two factors, i.e., roasting level (light, medium, dark) and manual brewing technique (V60, French press), while the physicochemical characteristics analysis followed a nested design. The results showed that different roasting levels and manual brewing techniques significantly impacted 11 coffee sensory attributes, pH values, and panelists' preferences. The most preferred Liberica coffee honey processing treatment was light roast level with the V60 manual brewing technique.

New Insights into the Umami and Sweet Taste of Oolong Tea: Formation of Enhancer N-(1-carboxyethyl)-6-(hydroxymethyl) pyridinium-3-ol (Alapyridaine) in Roasting Via Maillard Reaction.

Roasting is pivotal for enhancing the flavor of Wuyi rock tea (WRT). A study investigated a novel compound that enhances the umami taste of WRT. Metabolomics of Shuixian tea (SXT) and Rougui tea (RGT) under light roasting (LR), medium roasting (MR), and heavy roasting (HR) revealed significant differences in nonvolatiles compounds. Compared LR reducing sugars and amino acids notably decreased in MR and HR, with l-alanine declining by 69%. Taste-guided fractionation identified fraction II-B as having high umami and sweet intensities. A surprising taste enhancer, N-(1-carboxyethyl)-6-(hydroxymethyl) pyridinium-3-ol (alapyridaine), was discovered and identified. It formed via the Maillard reaction, positively correlated with roasting in SXT and RGT. Alapyridaine levels were highest in SXT among the five oolong teas. Roasting tea with glucose increased alapyridaine levels, while EGCG inhibited its formation. HR-WRT exhibited enhanced umami and sweet taste, highlighting alapyridaine's impact on WRT's flavor profile. The formation of alapyridaine during the roasting process provides new insights into the umami and sweet perception of oolong tea.

Effect of Light, Medium, and Dark Roasting on Antioxidant Activity of Gununghalu Arabica Coffee (Coffea arabica L.)

Coffee is one of the popular drinks for Indonesian people. Coffee consumption in Indonesia has increased very rapidly. The influence of lifestyle and the increasing number of cafes and coffee shops contribute to the increase in coffee consumers. One downstream processing of coffee beans is roasting coffee beans, which consists of light, medium, and dark roasting. This study aimed to determine the antioxidant activity of Gununghalu Arabica Coffee (Coffea arabica L.) with Light Roasting, Medium Roasting, and Dark Roasting Techniques. This research is an experimental study, where the antioxidant activity analysis was carried out using the DPPH method (2,2-diphenyl-1-picrylhydrazyl). Gununghalu Arabica coffee with light, medium, and dark roasting techniques positively containing flavonoids, alkaloids, saponins, tannins, and terpenoids. The results showed that the IC50 value of Gununghalu Arabica coffee for light, medium, and dark roasting was 102.94 ppm, 70.66 ppm, and 87.66 ppm. The test results show that the antioxidant activity of Gununghalu Arabica coffee with light roasting techniques are moderate, while medium and dark roasting techniques are strong. The results of this study are expected to provide implications for the development of coffee processing techniques to have maximum health benefits.

Electronic nose coupled with artificial neural network for classifying of coffee roasting profile

Coffee known for its diverse aromas shaped by postharvest treatments, particularly the roasting process, plays a pivotal role in determining the quality of the brewed beverage. This study focuses on classifying the aroma of Arabica coffee beans based on roasting temperature, employing an electronic nose equipped with a TGS gas array sensor. The classification methodology integrates deep learning through an artificial neural network (ANN), along with a calculation analysis utilizing the Pearson correlation coefficient. Raw Robusta coffee beans were subjected to five distinct roasting treatments (185 °C, 195 °C, 205 °C, 215 °C, and 225 °C), resulting in light roasts, light to medium roasts, medium to dark roasts, medium to dark roasts, and dark roasts. The repeatability test affirms the TGS sensor's reliability, exhibiting a standard deviation (STD) below 20%. Notably, the TGS 2612 and TGS 2611 sensors, dedicated to odor detection, demonstrated excellent validity with an STD below 10% across various roasting temperatures. Classification results from deep learning cross-validation showcase impressive accuracy: 98.2% for Light Roasts, 98.4% for Light to Medium Roasts, 98.8% for Medium Roasts, 97.8% for Medium Roasts, and 95.9% for Dark Roasts. In conclusion, this study reveals that the E-nose, utilizing the TGS gas sensor array with deep learning analysis, effectively detects and classifies coffee types based on roasting time with high accuracy.

Pengaruh Metode Pengolahan dan Level Roasting Terhadap Karakteristik Kopi Robusta Argopuro Jember

Jember, located in East Java, is renowned for its exceptional production of robusta coffee. The objective of this study was to analyze the physical properties of roasted robusta coffee beans sourced from Argopuro, Jember. The study utilized a fully Randomized Factorial Design incorporating two factors: processing method and roasting intensity. The processing method comprised four levels: natural process, honey process, semi-wet process, and full-wash process. Concurrently, the roasting level treatment consisted of three levels: light, medium, and dark. The observations encompassed the density of green beans, the density of roast beans, and the yield of roast beans. The green beans utilized in this investigation adhered to the quality criteria specified in the Indonesian National Standard (SNI) Grade 2. The research findings indicated that the processing technique had no substantial impact on the density of green beans. Neither the processing method nor the roasting level treatments had a different effect on the density or yield of the roasted beans. Nevertheless, the application of different roasting levels did result in a significant effect on both the density and yield of roasted coffee beans. The natural process approach yielded the maximum green bean density, weighing 365 kg/m3. The dark roast level resulted in the maximum bean density across all processing methods, including the natural, honey, semi-wet, and full-wash processes. The specific values for each method were 735.3 kg/m3, 637.3 kg/m3, 698.4 kg/m3, and 637.5 kg/m3, respectively. Moreover, the light roast level achieved the maximum output of roast beans, reaching 88.83%.

로스팅 단계 및 추출방식에 따른 커피의 클로로겐산 함량 최적화 연구

This study aims to identify roasting stages and extraction methods that minimize the degradation of chlorogenic acid in three of the most popular coffee beans in Korea, to lay the groundwork for producing functional coffee with maximized chlorogenic acid. An automatic roaster ensuring consistent execution of the programmed roasting process was used for precision. The results showed the highest chlorogenic acid content in Yirgacheffe Kokehoney from Ethiopia, with the light roasting stage yielding the greatest retention. Regarding extraction methods, a high-pressure extraction with an espresso machine outperformed the hand drip method in preserving chlorogenic acid. Therefore, it is recommended to light roast Ethiopian beans and extract them using an espresso machine, or to dark roast Indonesian Mandeling and employ a hand drip method for minimal chlorogenic acid loss. This study enhances the academic understanding of coffee by providing a theoretical exploration of chlorogenic acid's benefits to human health and identifying key roasting points to minimize its loss. By offering foundational data for the development of coffee products with minimized chlorogenic acid loss, this research contributes to the creation and distribution of high-chlorogenic acid coffee products, thereby aiding in the advancement of local economic development.

Green Tea and Decaffeinated Light Roasted Green Coffee Extract Combination Improved Cardiac Insulin Resistance through Free Fatty Acids and Adiponectin/FAS Pathways Amelioration in Metabolic Syndrome Rat Model

Background: Insulin resistance has been independently associated with cardiac diseases. Free fatty acids are recently known to induce cardiac insulin resistance due to low-grade inflammation. Therefore, the improvement of free fatty acid levels can also improve cardiac insulin resistance. This study investigated the combination of green tea and decaffeinated-light roasted green coffee extract in the improvement of free fatty acid-induced cardiac insulin resistance by improving the adiponectin/FAS pathways. Methods: This study used 25 males Sprague-Dawley rats induced by a high-fat high sucrose diet and injection of low dose streptozotocin to make a metabolic syndrome (MS) rat model and standard chow as healthy control rats. The MS rats were treated with green tea (200 mg/ b. w.), decaffeinated-light roasted green coffee (300 mg/ b. w.), and the combination of both extracts in 9 weeks. Experimental groups in this study were divided into 5 groups: 1) MS (HFHS diet + STZ) group, 2) NC (normal chow) group, 3) GT (green tea extract) group, 4) GC (decaffeinated-light roasted green coffee extract), 5) CM (combination of both extracts) group. Adiponectin and HOMA-IR level was analysed using ELISA, and the gene expression of Adipo-R1, FAS, PI3K, PDK1, Akt, GLUT4 was measured by RT-PCR. Results: The combination of green tea and decaffeinated-light roasted green coffee showed synergistic effects in improving FFA levels. The adiponectin/FAS pathways was attenuated in the CM group. Moreover, the combination also showed improvement in cardiac insulin resistance markers such as IRS1/2, PI3K, PDK1, Akt, and GLUT4. Conclusions: The combination of green tea and decaffeinated-light roasted green coffee extract improved cardiac insulin resistance better than green tea and green coffee extract administration alone by reducing free fatty acids levels through adiponectin/FAS pathways modulation.

The effect of fluidized bed roaster temperature on the roasted coffee beans antioxidant activity and its sensory evaluation

A fluidized Coffee roaster has been developed. Application of the roaster on coffee beans roasting gave roasted coffee beans with characteristics of being clean and well-roasted. It also could preserve the coffee beans aroma and maintain the antioxidant activity. In this report, the effect of the roasting temperature on the antioxidant activity as well as the aroma and the taste of the roasted coffee beans was examined. The coffee beans used in this experiment were Arabica coffee originating from Tlahap, Temanggung, Indonesia. The roasting conditions were at the temperatures of 205 to 240 °C and it was performed to achieve three degrees of roasted coffee which were light roasts (205 °C), medium roasts (220 °C), and dark roasts (240 °C). The antioxidants were extracted using methanol as a solvent and the antioxidant activity was examined using the scavenging effect method. It was observed that light-roasted coffee, medium-roasted coffee, and dark-roasted coffee have antioxidant activity µg/g BHA equivalent of 58793.333, 39468.000, and 24721.500 respectively. The light-roasted coffee bean was considered the best result with a score of sensory evaluation of 82.25 which is categorized as a specialty grade of coffee.

The Effect of Temperature and Roasting Time on The Physical Properties of Arabica and Robusta Gayo Coffee Bean

The effect of variations in temperature and roasting time on the physical properties of coffee beans originating from the Gayo highlands with Arabica and Robusta types have been studied in this paper. Physical properties measured include weight loss, true density, porosity, and water content. The measurement procedure follows Standard Nasional Indonesia (SNI) 01-2907-2008. Three roasting levels were used in this study, i.e., Light Roast (159 -164 °C), Medium Roast (211 - 215 °C), and Dark Roast (above 232 °C) by an oven. The result showed that the weight loss for Arabica and Robusta coffee beans is from 11 - 19% and 14 - 29%, respectively. The true density for Arabica and Robusta coffee beans ranged from 0.905 - 1.085 g/cm3 and 0.950 - 1.156 g/cm3, respectively. The difference in porosity changes before and after roasting was 23 - 73% for Arabica and 33 - 68% for Robusta coffee beans. Meanwhile, the water content of Arabica and Robusta coffee beans after roasting is 0.7 - 5% and 0.6 - 6%, respectively. The value of the weight loss, true density, and water content of Arabica is lower than that of the Robusta coffee bean, while the porosity value of Arabica is higher than that of the Robusta coffee bean.

Prediction of roasted coffee bean level from a coffee house-ware using fuzzy logic

Coffee is presently one of the most popular drinks consumed by people around the world. Different types of coffee typically depend on the types of coffee used, the level of roasting of the beans, the brewing methods used, and the extra ingredients added to the coffee. However, coffee characteristics are mainly influenced by a roasting process which highlight the aroma and flavor of coffee beans. In this study, we design a 2 kW household coffee roaster using heating coils as a heat source and controlled by the fuzzy logic algorithm built into the Arduino nano to predict the quality of roasted coffee. The quality of roasted coffee beans is divided in three categories: light roasting, medium roasting, and dark roasting. The body roasting machine consists of three parts; a roaster barrel, a propeller, and reduction gear, which rotates the roasting hopper and reverses the direction of rotation of the propeller. The roasted coffee beans in the tank are thoroughly heated by the heating coils, and the propeller is designed to provide an oblique to sweep the roasted coffee beans in the tank from the wall. The experiment is discussed in detail.

Bioactive compounds from roasted and green coffee obtained by supercritical fluid extraction decrease survival and induce apoptosis in prostate cancer cells

Prostate cancer is the most frequent and lethal neoplastic disease among men worldwide. There is growing interest in the biologically active compounds in coffee for their potential chemopreventive. The present study aimed to analyze the content of bioactive compounds, the antioxidant and antiproliferative activity of green arabica coffee and different roasts extracted by supercritical fluid. The concentration of caffeine, chlorogenic acid and caffeic acid were evaluated. Additionally, the colorimetric profile, antioxidant capacity, effect on cell viability, cell cycle and apoptosis of the extracts. Caffeine, caffeic acid and chlorogenic acid content were higher in green coffee extract than in roasted coffee (80.0mg/100g, 16.76 and 19.37mg/mL, respectively). The green coffee extract showed higher antioxidant activity and total phenolic content compared to the other coffee extracts by all methods tested; and among the roasted coffee extracts, light roast coffee stands out with the highest antioxidant capacity. After 48 hours of treatment, coffee extracts caused a reduction in the viability of PC-3 cells, with light roast coffee being more effective. Green and light roast coffee extracts induced a cell cycle arrest in the S phase and increased apoptosis. The present results strongly suggest that coffee extracts have an antiproliferative effect on prostate adenocarcinoma cells.

An environmental and economic sustainability assessment of coffee production in the UK

With around two billion cups consumed daily worldwide, the coffee industry faces pressures to improve its sustainability. Focusing on the UK as the fifth largest coffee consumer in Europe, this paper presents for the first time a life cycle environmental and economic sustainability assessment of coffee production at the product and sectoral levels. Both gate-to-gate and cradle-to-gate system boundaries are considered to identify opportunities for improvements in the manufacturing process and along the supply chain. Process design and simulation are combined with life cycle assessment and life cycle costing to evaluate the sustainability of the production of ground and instant coffee roasted to different levels. Based on the functional unit of 1 tonne of coffee produced, instant coffee has higher impacts and costs than ground coffee for both system boundaries because it requires double the amount of green coffee beans and 7–11 times more energy. For gate-to-gate, roasting and packaging are the main contributors to the impacts and costs; for cradle-to-gate, cultivation of coffee beans and packaging are the hotspots. Light roasts generally have lower impacts and costs due to lower material losses and energy requirements. At the sectoral level, the coffee industry emits 863–894 kt CO2 eq. annually, contributing 1.3% to the GHG emissions from the UK food and drinks sector. Key opportunities for improvements include switching to lighter roast and pouch packaging, as well as using air recirculation roasters and silverskin as fuel. These results will be of interest to the coffee industry, policy makers and consumers.

A comprehensive comparative study among the newly developed Pure Brew method and classical ones for filter coffee production

Pure Brew represents a real innovation because it allows one to obtain a fast-filter coffee with an espresso machine without the need for the barista to purchase additional equipment. This study investigated the difference between Pure Brew, French Press, V60 and AeroPress in terms of physical and chemical characteristics, extraction yields, volatile compounds by GC-MS and bioactive molecules by UHPLC-MS of resulting coffee, studying also powder particle size. Finally, main results showed that Pure Brew is comparable to other methods available on the market, but also showed the highest levels of caffeine (598.28 ± 8.84 and 556.13 ± 1.22 μg/mL) and total bioactive compounds (1726.8 ± 22.4 and 1407.89 ± 9.53 μg/mL) in medium and dark roasted coffee, compared to the other brewing methods. Pure Brew also displayed the most positive results in extraction yields, it falls into the ideal extraction percentage (18–22%) at the three different degrees of roasting, versus the other brewing methods. At the light roast, for Pure Brew were discovered the most olfactometrically impactful molecules of the study at GC-MS, 5-Methyl 2-furancarboxaldehyde, Furfural, and 2-Furanmethanol, connected with positive remarks, associated with almond and sweet.

Food borne toxicants in coffee: Acrylamide and furan derivative content in Arabica and Robusta coffees with different roasting profiles and varying degrees of roast

<sec><title/> To evaluate mitigation options for both acrylamide and furan and methylfurans a Vietnam Robusta grade 2 and a Brazil Arabica (unwashed) were roasted by tangential, drum and hot air roasting. Three different roasting profiles were followed and three samples (light, medium and dark roast) were obtained per profile. Decaffeinated and steam treated batches of the two coffees were roasted. Special roasts, such as double roast (on 2 days with cooling down in between) or roasting with a sudden temperature change were studied. The contaminants were analyzed by GC-MS – in case of the furans headspace GC-MS – using deuterated standards. </sec><sec><title/> The acrylamide contents were highest in light roasts, and decreased after that with longer roasting time. This was true for both the Robusta and Arabica samples. The content of furan and 2-, 3- and 2-5-methylfurans were low in light roasts and had a maximum in dark roasts. It is possible to minimize the content of either acrylamide and furans, however, a mitigation of both could not be established by changing the roasting parameters or using pretreatments. Among the furans determined 2-methylfuran was most abundant (average around 70%), followed by furan (average around 20%). The special roasts showed no options to minimize both contaminants as did the pretreatments. In the Vietnam Robusta furan related compounds were measured. 5-hydroxymethylfurfural and 5-hydroxymethylfurfuryl-2-carboxylic acid decreased with the degree of roast and time, while furfuryl alcohol and 2-furoic acid contents increased. </sec>

Preliminary Analysis of Unsaturated Fatty Acid Profiles of Coffea arabica L., in Samples with a Denomination of Origin and Speciality of Oaxaca, Mexico.

In February 2020, Coffea arabica L. grown on the coast and in the Southern Sierra Madre of the state of Oaxaca, Mexico obtained the denomination of origin. Which does not have data on color and chemical composition, the first associated with the degree of roasting and the second with lipids (17-18%), as the group of compounds responsible, in part, for flavor, consistency, and may contribute to health benefits. In the present work, color was determined on the CIE L*a*b* scale and the unsaturated fatty acids by Nuclear Magnetic Resonance (NMR) of 1H and 13C in samples of medium roasted specialty coffee from the "Pluma" coffee-growing region, Oaxaca, Mexico. The average value of L* luminosity in ground coffee was 42.1 ± 0.1 reported for a light roast. Unsaturated fatty acids were quantified from the lipid fraction of the gr1 ound grain by NMR 1H and 13C, obtaining on average the highest abundance of linoleic (41.7 ± 0.5 by 1 H and 41.24 ± 0.5 by 13C), followed by oleic (9.2 ± 0.2 by 1H and 7.4 ± 0.2 by 13C) and linolenic (1.5 ± 0.1 by H and 1.1 ± 0.2 by 13C). This study indicates that 1H and 13C NMR spectroscopy is a useful tool for the quantification of linolenic, linoleic, and oleic fatty acids by the method of key signal shifts of these acids found in lipid samples in roasted coffee grains.