Detection roasting level of Lintong coffee beans by using euclidean distance
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Coffee roasting is the process by which raw coffee beans (green beans) are roasted until they reach a certain roast level. In general, the roast level of roasted coffee beans is divided into 3 levels, namely the roast level of light, medium and dark. One way to find out the roast level of roasted coffee beans is to see the color change of the coffee beans. However, it is very difficult to know the exact color conditions of each roast level of roasted coffee beans and this can be overcome by build an automatic coffee roasting equipment. In this research, an automatic coffee roaster was done with a system that is able to control the roasting temperature and stirring of coffee beans. This tool can also monitor the change in color of the coffee beans during the roasting process. The system that has been implemented can detect color changes and classify the level of dark roast of roasted coffee beans using the Euclidean distance algorithm. The Euclidean distance give a threshold to classified the roast level. The system accuracy for predicting coffee beans color at the level of dark roast is 90% and 80% for overall.Keywords:
Roasting
Green coffee
Coffee bean
Caffeine is one of the most well known stimulants which can potentially increase mental performance, release fatigue and decrease depression. Green beans from different soils and climates contain different levels of caffeine, and as well as extracted coffee with different roasting and extracting methods. An investigation looking at pH, acidity, extractable solid and caffeine contents was assessed according to roasting and extracting conditions of various coffee beans. Brazilian coffee beans did not show much variation in pH with respect to roasting and extracting temperature, however, acidity increased in low roasting and extracting temperatures. This was however most prominently observed in Ethiopian and Indonesian coffee beans. The large expansion of coffee bean cells renders them highly porous to the passage of water, consequently extracted solids were found to increase with increasing temperature. This was especially apparent in Columbian coffee which had the highest extracted solids. The amount of caffeine extracted from coffee beans also increased with the higher temperature extraction. The Indonesian and Vietnam robusta coffee varieties showed the highest caffeine content.
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Polycyclic aromatic hydrocarbon (PAH) and nitrated PAH (N-PAH) emissions during coffee roasting were investigated. The fast roasting of green coffee resulted in mass and toxic concentrations approximately 1.6 and 3.2 times higher than in the slow roasting method (5,069 ng Nm-3 and 14.1 ng BaP-TEQ Nm-3, respectively). However, when considering all the coffee formulations, only the mass concentrations between the two roasting methods were statistically different (p = 0.05). The initial concentrations of total mass PAHs and PAH4 (BaA, Chr, BbF, and BaP) in green coffee beans (A) were 57.8 ng g-1 and 0.591 ng g-1, respectively. Following roasting, the PAH concentrations decreased to 34.8 ng g-1 and 40.5 ng g-1 during fast and slow roasting, respectively, with PAH4 concentrations below the detection limit (LOQ = 0.2 ng g-1). N-PAHs in the flue gas, green coffee, and roasted coffee beans were also below detection limits, except for the case of fast roasting of B-3 (coffee infused with bourbon whiskey and granulated sugar) where concentrations were 0.503 ng g-1. The flue gas profile was predominantly composed of naphthalene. On the other hand, the coffee bean profile had significant fractions of three-ringed compounds. Generally, the PAH congener profiles for both the fast and slow roasting methods were similar. For N-PAHs, only 2-nitropyrene was detected in the fast roasting of B-3. The PAH diagnostic ratios indicated that the source of PAHs in green coffee was pyrogenic in nature and more specifically, petroleum combustion. Finally, the emission factors for the fast and slow roasting of green coffee were 1.36 mg kg-1 of coffee (7.49 mg BaP-TEQ kg-1) and 0.483 mg kg-1 (1.35 mg BaP-TEQ kg-1), respectively. These results narrow the research gap on toxic emissions during coffee roasting and would be of particular interest in independent coffee shops where roasting is done in-house.
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This research is about the observation of the fatty acids which is the precursor of the aroma and the cause of the acidification in the coffee roasting conditions for the roasted coffee and brewed coffee. For this research, the 2 types of coffee beans from the respective 5 different countries were selected. Among 10 different coffee beans, one coffee bean were selected to make two different test groups by the heat supply methods - one test group roasted from high temperature to low temperature and the other test group roasted from low temperature to high temperature. Each group has samples of the roasted coffee, the brewed coffee and the green coffee. The test was conducted with these coffee beans. It was verified that the coffee is a safe food by the analysis of acrylamide produced during the high temperature roasting - detected under 300ppb by LC and MS/MS. It was also verified and concluded that the acrylamide can be lowered even with the light roasted coffee with high temperature roasting process. Per the fatty acid, the linolenic acid were detected 80% higher from the roasted coffee than the green coffee by the GC equipment. It was also detected that the unsaturated fatty acid were a little bit higher with the coffee beans with the other heat supply methods. when measured by Satorius MA 30, the yield of the solid of coffee extracts with the same roasting degree were somewhat different by the heat supply methods. It is speculated this difference was caused by the heat utilization. From this research, it was verified that there is the fatty acid and the amount of the solid of the coffee extracts by the roasting degree but it can also be varied by the heat supply methods. From now on, it is expected that there will be more diversity of the coffee by the various heat supply methods and further study for the coffee roasting by the heat efficiency and heat supply methods.
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The coffee industry relies on fundamental research to improve the techniques and processes related to its products. While recent theoretical and modelling work has focused on the heat and mass transfer processes within roasting coffee beans, modelling and analysis of chemical reactions in the context of multiphase models of roasting beans has not been well studied. In this paper, we incorporate modified evaporation rates and chemical reaction groups to improve existing mathematical models of roasting coffee beans. We model the phase change from liquid to vapour water within the bean during roasting using first-order Arrhenius-like global reactions, and for other components of the bean, we consider a three-component solid phase model which includes sucrose, reducing sugars and other organic compounds, which allows for porosity of the solid matrix to vary during the roasting process. We non-dimensionalize and then solve the multiphase model numerically, comparing the simulations with data we have collected through full bean and chopped bean experiments. We demonstrate that numerical solutions of the enhanced multiphase model with global water reactions and three-component solid phase reactions agree with experimental data for the average moisture content in whole beans and small chunks of bean, but that the data allows for a range to possible parameter values. We discuss other experimental data that might be collected to more firmly determine the parameters and hence the behaviour more generally. The indeterminacy of the parameters ensures that the additional effects included in the model will enable better understanding the coffee bean roasting process.
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COCOA BEAN
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Roasting
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Arabica coffee
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Compounds which can be formed over the course of roasting coffee beans were investigated and isolated. One of these compounds was identified as 3-hydroxy-6-methylpyridine (3,6-Py). 3,6-Py and the coffee prepared from light-roasted coffee beans which contain this compound tended to suppress increases in plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities induced by carbon tetrachloride in mice, indicating that 3,6-Py formed during the roasting of coffee beans may be able to mitigate liver injury. The amounts of 3,6-Py were higher in French-roasted than light-roasted coffee beans of the Brazil Santos and Colombia Excelso varieties, suggesting that this compound might be produced under a more severe roasting condition. However, suppressive activity against liver injury was stronger in coffee from light-roasted than French-roasted beans. As the amounts of chlorogenic acid, which is known to have hepatoprotective activity, were higher in coffee from the light-roasted than French-roasted beans, stronger hepatoprotective activity in the coffee from light-roasted beans might be mainly concerned with its higher content of chlorogenic acid.
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Chlorogenic Acid
Green coffee
Coffee bean
CCL4
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Roasting
Green coffee
Chlorogenic Acid
Coffee bean
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This study aims to compare the water content of green beans and roasted coffee bean based on the processing method and roasting level. The research was conducted at the TEFA Coffee Stub-Agricultural Plant Processing Laboratory, Politeknik Negeri Jember in April-July 2022. The coffee samples were Robusta coffee originating from the Gumitir area, Jember. This research consists of two main stages, green bean processing (dry (natural), honey, semi-wet, and full wash process) and roasting process based on light, medium, and dark levels. The analysis result showed that there was a decrease in the water content of coffee beans in each processing method as the roasting level increased. Overall, the water content of roast beans from full wash processing has the highest level compared to roast beans from other processed methods. The water content of green beans was originally 12.65%, decreased to 3.91%, 3.90%, and 3.38% after roasting with light, medium, and dark levels. The darker the roast level, the more weight loss. A significant decrease in water content was obtained in green beans processed by the honey method. Initially, the green bean water content was 13.05%, decreasing to 2.36%, 2.14, and 1.34% at each roasting level. Meanwhile, the green beans produced from natural processing (dry process), semi-wet, and full wash resulted in a decrease in water content that was not significant as the roasting level increased. Based on the results of this study, it is necessary to carry out further research related to the relationship between processing methods and roasting level on the physicochemical characteristics of coffee beans by optimizing.
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Abstract This study aims to simulate the temperature distribution of coffee roasting machines and study the profile of coffee beans roasted using a horizontal cylinder-type roaster. The coffee used in this study is arabica. The simulation method for the temperature estimation in the coffee roasting process uses the Solidworks Flow Simulation 2016 software, while the actual temperature measurement using a thermocouple is simulated with the Surfer software version 16. Furthermore, each stage of the coffee roasting process has been carried out, including the weight of the material, the roasting temperature, and the bulk density. The final step is to observe the profile of the roasted coffee beans at every minute of treatment. The study results indicate a difference between the approximate temperature simulation (top 176.85°C, bottom 191.97°C) and the actual temperature measured results (upper 214°C, bottom 220°C). The weight of the material (coffee green bean), the roasting temperature, and the bulk density during the test experienced regular movements from the beginning to the end of the treatment. The profile of roasted coffee beans shows a darker color movement along with the longer roasting time used. The profile of the roasted coffee beans will be beneficial in determining at which level of roasting you want (light, medium, medium-dark, dark).
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Thermocouple
Arabica coffee
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As considerable inconsistencies are found in the literature regarding the influence of roasting and subsequent operations on the ochratoxin A (OTA) content of green coffee, experiments were undertaken to assess the evolution of OTA along an industrial soluble coffee manufacturing line. Both the variability and the amount of OTA naturally present in a lot of Thai Robusta green coffee were drastically reduced during soluble coffee manufacture. A small proportion of OTA was eliminated during green coffee cleaning, but the most significant reduction took place during roasting. The roast and ground coffee contained only 16% of the OTA originally present in the green coffee. Two phenomena are responsible for the elimination of OTA during roasting: a thermal degradation and a removal with chaff. Thermal degradation is the most important route of elimination, with <20% accounted for by the chaff. A further 20% reduction was observed during soluble coffee manufacture, so that the powder contained only 13% of the OTA initially present in the green beans.
Roasting
Green coffee
Chaff
Coffee grounds
Coffea canephora
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