A novel basis for monitoring the coffee roasting process: Isomerization reactions of 3-caffeoylquinic and 4-caffeoylquinic acids

LWT ◽  
2021 ◽  
Vol 152 ◽  
pp. 112343
Author(s):  
Lukas Macheiner ◽  
Anatol Schmidt ◽  
Helmut K. Mayer
2020 ◽  
Vol 38 (No. 6) ◽  
pp. 388-396
Author(s):  
Eugenio Ivorra ◽  
Juan Camilo Sarria-González ◽  
Joel Girón-Hernández

Artificial vision has wide-ranging applications in the food sector; it is easy to use, relatively low cost and allows to conduct rapid non-destructive analyses. The aim of this study was to use artificial vision techniques to control and model the coffee roasting process. Samples of Castillo variety coffee were used to construct the roasting curve, with captured images at different times. Physico-chemical determinations, such as colour, titratable acidity, pH, humidity and chlorogenic acids, and caffeine content, were investigated on the coffee beans. Data were processed by (i) Principal component analysis (PCA) to observe the aggrupation depending on the roasting time, and (ii) partial least squares (PLS) regression to correlate the values of the analytical determinations with the image information. The results allowed to construct robust regression models, where the colour coordinates (L*, a*), pH and titratable acidity presented excellent values in prediction (R2Pred 0.95, 0.91, 0.94 and 0.92). The proposed algorithms were capable to correlate the chemical composition of the beans at each roasting time with changes in the images, showing promising results in the modelling of the coffee roasting process.


2011 ◽  
Vol 105 (2) ◽  
pp. 264-269 ◽  
Author(s):  
Angelo Fabbri ◽  
Chiara Cevoli ◽  
Laura Alessandrini ◽  
Santina Romani

2021 ◽  
Vol 922 (1) ◽  
pp. 012031
Author(s):  
F Fachruddin ◽  
S Syafriandi ◽  
R Fadhil

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).


2021 ◽  
Vol 10 (2) ◽  
pp. 191-200
Author(s):  
Ratih Rahmahwati

The roasting process of coffee beans in West Kalimantan, especially Pontianak city, is still done traditionally. The coffee roasting process is done manually by using a fire stove as a heater. Workers with standing posture stir the coffee beans continuously, and it can take 4 hours for 20 kilos of coffee beans. Standing work posture is required for stirring the coffee beans but can cause fatigue in workers due to long-standing times and high heating temperatures. This situation causes the roasting process to be less efficient and can cause the roasting process to be uneven. The purpose of this study was to identify musculoskeletal complaints of standing work posture in the manual coffee roasting process and provide an evaluation of corrective work posture when using the design results of an automatic digital roasting machine. The methods used in this study were the Nordic Body Map (NBM) and the Rapid Upper Limb Assessment (RULA) to assess the level of risk of posture for musculoskeletal complaints. The results of the identification of body points that experience fatigue were carried out by distributing NBM questionnaires and evaluating the worker's posture using RULA on CATIA V5R20. Based on the existing NBM, the risk score is 78, and the final RULA score is 6, which means that immediate corrective action is needed because the work posture is categorized as dangerous and does not meet ergonomic principles. Improvement of working posture is made by designing a roasting machine that is digital and automatic. So the workers do not need to mix the coffee beans manually. Based on roasting machine implementation results, there was a significant change in the NBM score and the final RULA score. The NBM results obtained a score of 55 which means that the risk is moderate with the risk of fatigue in the neck, right leg and, left leg. Meanwhile, evaluation of work posture based on RULA on CATIA obtained a final score of 3, which means that the work posture is not dangerous and does not require immediate improvement.  


2021 ◽  
Vol 10 (1) ◽  
pp. 29
Author(s):  
Mafaza Kanzul Fikri ◽  
Trapsilo Prihandono ◽  
Lailatul Nuraini

Abstract: An important stage that will determine the quality of ready-to-consume coffee is roasting. This method has been developed and used to obtain the best and specific quality of coffee brewing. In addition to the method used, the type of coffee greatly influences the quality characteristics of the brewed coffee produced. Coffee beans will not have a high commercial value before being subjected to a roasting process for the formation of the best aroma and taste. Roasting is a combination of time and temperature that changes the structure and chemical properties in coffee beans through the pyrolysis process. Even high-quality coffee beans cannot have maximum aroma and flavor if the roasting process is not done properly. This research uses a roasting machine type Hot Air Roasting or with other names Air Roasting is a different roasted coffee method. Coffee roasting process is not on the surface of the roaster but in the air, this coffee roasting method was introduced by Michael Sivetz, a chemical engineer and consultant of the world coffee industry. Based on the results of this study that the decrease in density discussed in the previous paragraph shows that the longer the roasting, the weight of coffee will decrease because the water content in coffee beans has begun to decrease. This shows that the longer the coffee beans are roasted, the better the results of heating. This research process uses a hot air type roasting machine. Hot water is one type of roasting machine that is good and efficient, because the heating carried out by the machine uses electrical energy. The final results obtained in this study the temperature continues to rise but the density decreases. This shows the inverse relationship between temperature and density of coffee and the best roasting results and can be used for brewing robusta coffee at 200 ° C in 15-20 minutes.    Keywords: Hot Air Roasting, Robusta Coffee


2018 ◽  
Vol 13 (3) ◽  
pp. 379
Author(s):  
Cinthia Da Conceição Garcia ◽  
Annibal Duarte Pereira Netto ◽  
Michelle Costa Da Silva ◽  
Alexandre Alves Catão ◽  
Iasmim Amorim De Souza ◽  
...  

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