The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
Ralf Zimmermann - One of the best experts on this subject based on the ideXlab platform.
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Smart Online Coffee Roasting Process Control: Modelling Coffee Roast Degree and Brew Antioxidant Capacity for Real-Time Prediction by Resonance-Enhanced Multi-Photon Ionization Mass Spectrometric (REMPI-TOFMS) Monitoring of Roast Gases
Foods, 2020Co-Authors: Hendryk Czech, Jan Heide, Sven Ehlert, Thomas Koziorowski, Ralf ZimmermannAbstract:Process control with high time resolution is essential to maintain high product quality in Coffee Roasting. However, analytical techniques for quality assurance or measurements of desired Coffee properties are often labor-intensive and can only be conducted after dropping the Coffee beans. Resonance-enhanced multi-photon ionization time-of-flight mass spectrometry (REMPI-TOFMS) at 248 nm and 266 nm was applied to analyze the composition of the roast gas from small-scale Arabica Coffee Roasting. Coffee beans were dropped after different Roasting times, ground and analyzed by Colorette to obtain the roast degree. Additionally, the antioxidant capacity of the Coffee brew was determined by Folin–Ciocalteu (FC) assay. Models for the prediction of Colorette and FC values from REMPI mass spectra were constructed by partial least squares (PLS) regression. REMPI-TOFMS enables the prediction of Colorette values with a root-mean-square error in prediction (RMSEP) below 5 for both wavelengths. FC values could be predicted using REMPI at 248 nm with an RMSEP of 80.3 gallic acid equivalents (GA-eq) mg L−1, while REMPI at 266 nm resulted in RMSEP of 151 GA-eq mg L−1. Finally, the prediction of Colorette and FC value at 5 s time resolution were demonstrated with online measurements.
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Toward Smart Online Coffee Roasting Process Control: Feasibility of Real-Time Prediction of Coffee Roast Degree and Brew Antioxidant Capacity by Single-Photon Ionization Mass Spectrometric Monitoring of Roast Gases
Journal of Agricultural and Food Chemistry, 2020Co-Authors: Jan Heide, Hendryk Czech, Sven Ehlert, Thomas Koziorowski, Ralf ZimmermannAbstract:Precise controlling and monitoring the status of the Coffee Roasting process is essential for consistent product quality and optimization toward targeted Coffee properties. In small-scale Roasting ...
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On‐line process monitoring of Coffee Roasting by resonant laser ionisation time‐of‐flight mass spectrometry: bridging the gap from industrial batch Roasting to flavour formation inside an individual Coffee bean
Journal of Mass Spectrometry, 2013Co-Authors: Romy Hertz-schünemann, Ralph Dorfner, Chahan Yeretzian, Thorsten Streibel, Ralf ZimmermannAbstract:Resonance-enhanced multiphoton ionisation time-of-flight mass spectrometry (REMPI-TOFMS) enables the fast and sensitive on-line monitoring of volatile organic compounds (VOC) formed during Coffee Roasting. On the one hand, REMPI-TOFMS was applied to monitor Roasting gases of an industrial roaster (1500 kg/h capacity), with the aim of determining the roast degree in real-time from the transient chemical signature of VOCs. On the other hand, a previously developed μ-probe sampling device was used to analyse Roasting gases from individual Coffee beans. The aim was to explore fundamental processes at the individual bean level and link these to phenomena at the batch level. The pioneering single-bean experiments were conducted in two configurations: (1) VOCs formed inside a bean were sampled in situ, i.e. via a drilled μ-hole, from the interior, using a μ-probe (inside). (2) VOCs were sampled on-line in close vicinity of a single Coffee bean's surface (outside). The focus was on VOCs originating from hydrolysis and pyrolytic degradation of chlorogenic acids, like feruloyl quinic acid and caffeoyl quinic acid. The single bean experiments revealed interesting phenomena. First, differences in time–intensity profiles between inside versus outside (time shift of maximum) were observed and tentatively linked to the permeability of the bean's cell walls material. Second, sharp bursts of some VOCs were observed, while others did exhibit smooth release curves. It is believed that these reflect a direct observation of bean popping during Roasting. Finally, discrimination between Coffea arabica and Coffea canephora was demonstrated based on high-mass volatile markers, exclusively present in spectra of Coffea arabica. Copyright © 2013 John Wiley & Sons, Ltd.
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on line process monitoring of Coffee Roasting by resonant laser ionisation time of flight mass spectrometry bridging the gap from industrial batch Roasting to flavour formation inside an individual Coffee bean
Journal of Mass Spectrometry, 2013Co-Authors: Romy Hertzschunemann, Ralph Dorfner, Chahan Yeretzian, Thorsten Streibel, Ralf ZimmermannAbstract:Resonance-enhanced multiphoton ionisation time-of-flight mass spectrometry (REMPI-TOFMS) enables the fast and sensitive on-line monitoring of volatile organic compounds (VOC) formed during Coffee Roasting. On the one hand, REMPI-TOFMS was applied to monitor Roasting gases of an industrial roaster (1500 kg/h capacity), with the aim of determining the roast degree in real-time from the transient chemical signature of VOCs. On the other hand, a previously developed μ-probe sampling device was used to analyse Roasting gases from individual Coffee beans. The aim was to explore fundamental processes at the individual bean level and link these to phenomena at the batch level. The pioneering single-bean experiments were conducted in two configurations: (1) VOCs formed inside a bean were sampled in situ, i.e. via a drilled μ-hole, from the interior, using a μ-probe (inside). (2) VOCs were sampled on-line in close vicinity of a single Coffee bean's surface (outside). The focus was on VOCs originating from hydrolysis and pyrolytic degradation of chlorogenic acids, like feruloyl quinic acid and caffeoyl quinic acid. The single bean experiments revealed interesting phenomena. First, differences in time–intensity profiles between inside versus outside (time shift of maximum) were observed and tentatively linked to the permeability of the bean's cell walls material. Second, sharp bursts of some VOCs were observed, while others did exhibit smooth release curves. It is believed that these reflect a direct observation of bean popping during Roasting. Finally, discrimination between Coffea arabica and Coffea canephora was demonstrated based on high-mass volatile markers, exclusively present in spectra of Coffea arabica. Copyright © 2013 John Wiley & Sons, Ltd.
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looking into individual Coffee beans during the Roasting process direct micro probe sampling on line photo ionisation mass spectrometric analysis of Coffee Roasting gases
Analytical and Bioanalytical Chemistry, 2013Co-Authors: Romy Hertzschunemann, Sven Ehlert, Thorsten Streibel, Ralf ZimmermannAbstract:A micro-probe (μ-probe) gas sampling device for on-line analysis of gases evolving in confined, small objects by single-photon ionisation time-of-flight mass spectrometry (SPI-TOFMS) was developed. The technique is applied for the first time in a feasibility study to record the formation of volatile and flavour compounds during the Roasting process within (inside) or in the direct vicinity (outside) of individual Coffee beans. A real-time on-line analysis of evolving volatile and semi-volatile organic compounds (VOC and SVOC) as they are formed under the mild pyrolytic conditions of the Roasting process was performed. The soft-ionisation mass spectra depict a molecular ion signature, which is well corresponding with the existing knowledge of Coffee Roasting and evolving compounds. Additionally, thereby it is possible to discriminate between Coffea arabica (Arabica) and Coffea canephora (Robusta). The recognized differences in the Roasting gas profiles reflect the differences in the precursor composition of the Coffee cultivars very well. Furthermore, a well-known set of marker compounds for Arabica and Robusta, namely the lipids kahweol and cafestol (detected in their dehydrated form at m/z 296 and m/z 298, respectively) were observed. If the variation in time of different compounds is observed, distinctly different evolution behaviours were detected. Here, phenol (m/z 94) and caffeine (m/z 194) are exemplary chosen, whereas phenol shows very sharp emission peaks, caffeine do not have this highly transient behaviour. Finally, the changes of the chemical signature as a function of the Roasting time, the influence of sampling position (inside, outside) and cultivar (Arabica, Robusta) is investigated by multivariate statistics (PCA). In summary, this pilot study demonstrates the high potential of the measurement technique to enhance the fundamental knowledge of the formation processes of volatile and semi-volatile flavour compounds inside the individual Coffee bean.
Chahan Yeretzian - One of the best experts on this subject based on the ideXlab platform.
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On-line analysis of Coffee Roasting with ion mobility spectrometry–mass spectrometry (IMS–MS)
International Journal of Mass Spectrometry, 2017Co-Authors: Alexia N. Gloess, Chahan Yeretzian, Richard Knochenmuss, Michael GroesslAbstract:Abstract On-line analysis of Coffee Roasting was performed using ion mobility spectrometry–mass spectrometry (IMS–MS) with corona discharge ionization. This is the first time that formation of volatile organic compounds (VOCs) during Coffee Roasting was monitored not only in positive but also in negative ion mode, and not only with mass spectrometry, but also with ion mobility spectrometry. The temporal evolution of more than 150 VOCs was monitored during the Roasting of Brazilian Coffea arabica. Mass-selective ion mobility spectrometry allowed a separation of isobaric and isomeric compounds. In positive ion mode, isomers of alkyl pyrazines were found to exhibit distinct time-intensity profiles during Roasting, providing a unique insight into the complex chemistry of this important class of aroma active compounds. Negative ion mode gave access to species poorly detectable by other on-line methods, such as acids. In this study, the release of fatty acids during Coffee Roasting was investigated in detail. These increase early on in the Roasting process followed by a decrease at the same time as other VOCs start to be formed.
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Antioxidant Generation during Coffee Roasting: A Comparison and Interpretation from Three Complementary Assays.
Foods, 2014Co-Authors: Sebastian E. W. Opitz, Stefan Schenker, Samo Smrke, Bernard A. Goodman, Marco Keller, Chahan YeretzianAbstract:Coffee is a major source of dietary antioxidants; some are present in the green bean, whereas others are generated during Roasting. However, there is no single accepted analytical method for their routine determination. This paper describes the adaption of three complementary assays (Folin-Ciocalteu (FC), ABTS and ORAC) for the routine assessment of antioxidant capacity of beverages, their validation, and use for determining the antioxidant capacities of extracts from Coffee beans at different stages in the Roasting process. All assays showed a progressive increase in antioxidant capacity during Roasting to a light roast state, consistent with the production of melanoidins having a higher antioxidant effect than the degradation of CGAs. However, the three assays gave different numbers for the total antioxidant capacity of green beans relative to gallic acid (GA), although the range of values was much smaller when chlorogenic acid (CGA) was used as reference. Therefore, although all three assays indicated that there was an increase in antioxidant activity during Coffee Roasting, and the large differences in responses to GA and CGA illustrate their different sensitivities to different types of antioxidant molecule.
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On‐line process monitoring of Coffee Roasting by resonant laser ionisation time‐of‐flight mass spectrometry: bridging the gap from industrial batch Roasting to flavour formation inside an individual Coffee bean
Journal of Mass Spectrometry, 2013Co-Authors: Romy Hertz-schünemann, Ralph Dorfner, Chahan Yeretzian, Thorsten Streibel, Ralf ZimmermannAbstract:Resonance-enhanced multiphoton ionisation time-of-flight mass spectrometry (REMPI-TOFMS) enables the fast and sensitive on-line monitoring of volatile organic compounds (VOC) formed during Coffee Roasting. On the one hand, REMPI-TOFMS was applied to monitor Roasting gases of an industrial roaster (1500 kg/h capacity), with the aim of determining the roast degree in real-time from the transient chemical signature of VOCs. On the other hand, a previously developed μ-probe sampling device was used to analyse Roasting gases from individual Coffee beans. The aim was to explore fundamental processes at the individual bean level and link these to phenomena at the batch level. The pioneering single-bean experiments were conducted in two configurations: (1) VOCs formed inside a bean were sampled in situ, i.e. via a drilled μ-hole, from the interior, using a μ-probe (inside). (2) VOCs were sampled on-line in close vicinity of a single Coffee bean's surface (outside). The focus was on VOCs originating from hydrolysis and pyrolytic degradation of chlorogenic acids, like feruloyl quinic acid and caffeoyl quinic acid. The single bean experiments revealed interesting phenomena. First, differences in time–intensity profiles between inside versus outside (time shift of maximum) were observed and tentatively linked to the permeability of the bean's cell walls material. Second, sharp bursts of some VOCs were observed, while others did exhibit smooth release curves. It is believed that these reflect a direct observation of bean popping during Roasting. Finally, discrimination between Coffea arabica and Coffea canephora was demonstrated based on high-mass volatile markers, exclusively present in spectra of Coffea arabica. Copyright © 2013 John Wiley & Sons, Ltd.
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on line process monitoring of Coffee Roasting by resonant laser ionisation time of flight mass spectrometry bridging the gap from industrial batch Roasting to flavour formation inside an individual Coffee bean
Journal of Mass Spectrometry, 2013Co-Authors: Romy Hertzschunemann, Ralph Dorfner, Chahan Yeretzian, Thorsten Streibel, Ralf ZimmermannAbstract:Resonance-enhanced multiphoton ionisation time-of-flight mass spectrometry (REMPI-TOFMS) enables the fast and sensitive on-line monitoring of volatile organic compounds (VOC) formed during Coffee Roasting. On the one hand, REMPI-TOFMS was applied to monitor Roasting gases of an industrial roaster (1500 kg/h capacity), with the aim of determining the roast degree in real-time from the transient chemical signature of VOCs. On the other hand, a previously developed μ-probe sampling device was used to analyse Roasting gases from individual Coffee beans. The aim was to explore fundamental processes at the individual bean level and link these to phenomena at the batch level. The pioneering single-bean experiments were conducted in two configurations: (1) VOCs formed inside a bean were sampled in situ, i.e. via a drilled μ-hole, from the interior, using a μ-probe (inside). (2) VOCs were sampled on-line in close vicinity of a single Coffee bean's surface (outside). The focus was on VOCs originating from hydrolysis and pyrolytic degradation of chlorogenic acids, like feruloyl quinic acid and caffeoyl quinic acid. The single bean experiments revealed interesting phenomena. First, differences in time–intensity profiles between inside versus outside (time shift of maximum) were observed and tentatively linked to the permeability of the bean's cell walls material. Second, sharp bursts of some VOCs were observed, while others did exhibit smooth release curves. It is believed that these reflect a direct observation of bean popping during Roasting. Finally, discrimination between Coffea arabica and Coffea canephora was demonstrated based on high-mass volatile markers, exclusively present in spectra of Coffea arabica. Copyright © 2013 John Wiley & Sons, Ltd.
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Modeling and validation of heat and mass transfer in individual Coffee beans during the Coffee Roasting process using computational fluid dynamics (CFD).
Chimia, 2013Co-Authors: Beatriz Alonso-torres, José Alfredo Hernández-pérez, Fernando Sierra-espinoza, Stefan Schenker, Chahan YeretzianAbstract:: Heat and mass transfer in individual Coffee beans during Roasting were simulated using computational fluid dynamics (CFD). Numerical equations for heat and mass transfer inside the Coffee bean were solved using the finite volume technique in the commercial CFD code Fluent; the software was complemented with specific user-defined functions (UDFs). To experimentally validate the numerical model, a single Coffee bean was placed in a cylindrical glass tube and roasted by a hot air flow, using the identical geometrical 3D configuration and hot air flow conditions as the ones used for numerical simulations. Temperature and humidity calculations obtained with the model were compared with experimental data. The model predicts the actual process quite accurately and represents a useful approach to monitor the Coffee Roasting process in real time. It provides valuable information on time-resolved process variables that are otherwise difficult to obtain experimentally, but critical to a better understanding of the Coffee Roasting process at the individual bean level. This includes variables such as time-resolved 3D profiles of bean temperature and moisture content, and temperature profiles of the Roasting air in the vicinity of the Coffee bean.
Dario Pozzetto - One of the best experts on this subject based on the ideXlab platform.
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Case study Waste heat recovery in a Coffee Roasting plant
2020Co-Authors: Michele De Monte, Elio Padoano, Dario PozzettoAbstract:The paper presents the possibility of introducing, in the event of substitution of an old plant, the recovery of heat produced during the Roasting process of Coffee. During the analysis, thermo and fluid dynamic operating parameters of the present plant were defined also with the support of an experimental measuring campaign. Energy recovery possibilities were, then, evaluated and a possible plant solution was examined taking into consideration its economic feasibility. The case study is also interesting because the methodology used for the analysis can be generally applied to production plants, which have hot air exhaust emissions. Waste heat recovery, actually, is an important topic not only for its economic benefits, but also for its environmental outcomes and resource saving. � 2003 Elsevier Science Ltd. All rights reserved.
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Waste heat recovery in a Coffee Roasting plant
Applied Thermal Engineering, 2003Co-Authors: Michele De Monte, Elio Padoano, Dario PozzettoAbstract:Abstract The paper presents the possibility of introducing, in the event of substitution of an old plant, the recovery of heat produced during the Roasting process of Coffee. During the analysis, thermo and fluid dynamic operating parameters of the present plant were defined also with the support of an experimental measuring campaign. Energy recovery possibilities were, then, evaluated and a possible plant solution was examined taking into consideration its economic feasibility. The case study is also interesting because the methodology used for the analysis can be generally applied to production plants, which have hot air exhaust emissions. Waste heat recovery, actually, is an important topic not only for its economic benefits, but also for its environmental outcomes and resource saving.
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Waste heat recovery in a Coffee Roasting plant
Applied Thermal Engineering, 2003Co-Authors: Michele De Monte, Elio Padoano, Dario PozzettoAbstract:The paper presents the possibility of introducing, in the event of substitution of an old plant, the recovery of heat produced during the Roasting process of Coffee. During the analysis, thermo and fluid dynamic operating parameters of the present plant were defined also with the support of an experimental measuring campaign. Energy recovery possibilities were, then, evaluated and a possible plant solution was examined taking into consideration its economic feasibility. The case study is also interesting because the methodology used for the analysis can be generally applied to production plants, which have hot air exhaust emissions. Waste heat recovery, actually, is an important topic not only for its economic benefits, but also for its environmental outcomes and resource saving. © 2003 Elsevier Science Ltd. All rights reserved.
Fabio Junior Moreira Novaes - One of the best experts on this subject based on the ideXlab platform.
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new approaches to monitor semi volatile organic compounds released during Coffee Roasting using flow through active sampling and comprehensive two dimensional gas chromatography
Food Research International, 2019Co-Authors: Fabio Junior Moreira Novaes, Ademario Iris Da Silva, Chadin Kulsing, Yada Nolvachai, H R Bizzo, Francisco Radler De Aquino Neto, Claudia M Rezende, Philip J MarriottAbstract:Abstract A novel dynamic approach is described to profile volatile organic compound (VOC) and semi-VOC (SVOC) emission during Coffee Roasting aimed at analysing components present in the Roasting plume, and to monitor their evolution during the process. Two sorbents – coconut shell charcoal (CSC) and styrene-divinylbenzene resin (XAD-2) – were evaluated while collecting substances in four sequential time intervals (0–3, 3–6, 6–9 and 9–12 min). Extracted VOCs ( 400 Da. GC × GC resolved many co-eluting compounds observed in 1D GC and allowed chemical group type cluster analysis, revealing that many non-polar VOCs are observed within the 0–3 min interval, and that the release of polar and higher molar mass SVOCs were mostly found within the 3–6 min interval. These group-type cluster analyses offer a broad spectrum chemical profile of the released substances. It may also reveal detailed insights into the roast process evolution over time.
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New approaches to monitor semi-volatile organic compounds released during Coffee Roasting using flow-through/active sampling and comprehensive two-dimensional gas chromatography
Food Research International, 2019Co-Authors: Fabio Junior Moreira Novaes, Ademário Iris Da Silva Junior, Chadin Kulsing, Yada Nolvachai, H R Bizzo, Francisco Radler De Aquino Neto, Claudia M Rezende, Philip J MarriottAbstract:Abstract A novel dynamic approach is described to profile volatile organic compound (VOC) and semi-VOC (SVOC) emission during Coffee Roasting aimed at analysing components present in the Roasting plume, and to monitor their evolution during the process. Two sorbents – coconut shell charcoal (CSC) and styrene-divinylbenzene resin (XAD-2) – were evaluated while collecting substances in four sequential time intervals (0–3, 3–6, 6–9 and 9–12 min). Extracted VOCs ( 400 Da. GC × GC resolved many co-eluting compounds observed in 1D GC and allowed chemical group type cluster analysis, revealing that many non-polar VOCs are observed within the 0–3 min interval, and that the release of polar and higher molar mass SVOCs were mostly found within the 3–6 min interval. These group-type cluster analyses offer a broad spectrum chemical profile of the released substances. It may also reveal detailed insights into the roast process evolution over time.
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mass spectrometry screening of arabica Coffee Roasting a non target and non volatile approach by easi ms and esi ms
Food Research International, 2016Co-Authors: Fabio Junior Moreira Novaes, Jeane Santos Da Rosa, Otniel Freitassilva, Janaina Ribeiro Costa Rouws, Iris Goncalves Da Silva Moreira, Debora A Azevedo, Nicolas V Schwab, Ronoel Luiz De Oliveira Godoy, Marcos N EberlinAbstract:Abstract Coffee Roasting needs precise control and innovative techniques that are economically viable to monitor and improve its consistency. In this study, mass spectrometry was used as a tool to screen chemical markers that appear on the surface of Coffee beans (whole bean) along the Roasting process. A non-target and non-volatile approach was used with an ambient technique (EASI) coupled to a single quadrupole mass analyzer to monitor Roasting chemical changes in the Coffee bean. Green (raw), soft, medium, dark and very dark roasted Coffee beans showed a decrease in ions in the range of m/z 500–600, whereas an increase in abundance in the m/z 800–900 range was clearly observed in the most roasted Coffees. A multivariate approach through PCA separated the different roasts in 70% of the variance using PC1 and PC2. The major ions in the range of m/z 500–600 were characterized by ESI-MS and also HPLC-fluorescence as the N-alkanoyltryptamides, surface constituents of Coffee wax layer which are almost fully degraded in darker roasts. The ions in the range of m/z 800–900 were characterized as di-and triacylglicerols and its increase during the Roasting process was systematically observed. For these classes of chemical markers of the Roasting process, ESI-MS showed also the sodium and potassium adducts with good relative abundances.
Philip J Marriott - One of the best experts on this subject based on the ideXlab platform.
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new approaches to monitor semi volatile organic compounds released during Coffee Roasting using flow through active sampling and comprehensive two dimensional gas chromatography
Food Research International, 2019Co-Authors: Fabio Junior Moreira Novaes, Ademario Iris Da Silva, Chadin Kulsing, Yada Nolvachai, H R Bizzo, Francisco Radler De Aquino Neto, Claudia M Rezende, Philip J MarriottAbstract:Abstract A novel dynamic approach is described to profile volatile organic compound (VOC) and semi-VOC (SVOC) emission during Coffee Roasting aimed at analysing components present in the Roasting plume, and to monitor their evolution during the process. Two sorbents – coconut shell charcoal (CSC) and styrene-divinylbenzene resin (XAD-2) – were evaluated while collecting substances in four sequential time intervals (0–3, 3–6, 6–9 and 9–12 min). Extracted VOCs ( 400 Da. GC × GC resolved many co-eluting compounds observed in 1D GC and allowed chemical group type cluster analysis, revealing that many non-polar VOCs are observed within the 0–3 min interval, and that the release of polar and higher molar mass SVOCs were mostly found within the 3–6 min interval. These group-type cluster analyses offer a broad spectrum chemical profile of the released substances. It may also reveal detailed insights into the roast process evolution over time.
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New approaches to monitor semi-volatile organic compounds released during Coffee Roasting using flow-through/active sampling and comprehensive two-dimensional gas chromatography
Food Research International, 2019Co-Authors: Fabio Junior Moreira Novaes, Ademário Iris Da Silva Junior, Chadin Kulsing, Yada Nolvachai, H R Bizzo, Francisco Radler De Aquino Neto, Claudia M Rezende, Philip J MarriottAbstract:Abstract A novel dynamic approach is described to profile volatile organic compound (VOC) and semi-VOC (SVOC) emission during Coffee Roasting aimed at analysing components present in the Roasting plume, and to monitor their evolution during the process. Two sorbents – coconut shell charcoal (CSC) and styrene-divinylbenzene resin (XAD-2) – were evaluated while collecting substances in four sequential time intervals (0–3, 3–6, 6–9 and 9–12 min). Extracted VOCs ( 400 Da. GC × GC resolved many co-eluting compounds observed in 1D GC and allowed chemical group type cluster analysis, revealing that many non-polar VOCs are observed within the 0–3 min interval, and that the release of polar and higher molar mass SVOCs were mostly found within the 3–6 min interval. These group-type cluster analyses offer a broad spectrum chemical profile of the released substances. It may also reveal detailed insights into the roast process evolution over time.