Detection roasting level of Lintong coffee beans by using euclidean distance

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.

Temperature coverage simulation of horizontal cylinder type coffee roasting machine

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).

Testing coffee roasting machine with electric heater as energy source

The roasting process is the process of frying something without using oil. The roasting processes raw materials into cooked or ready-to-eat ingredients. The purpose of the roasting is to get a certain taste using heat transfer methods either without media or using sand. When the roasting process occurs, the coffee beans undergo physical changes, one of which is the water content due to heat transfer from the roasting medium to the material. During the roasting process, evaporation of water content occurs and the coffee beans will experience a decrease in mass. Coffee bean roasting machines with stove heat sources from gas fuel are currently being developed. The use of gas fuel is sometimes difficult to regulate a constant temperature because it depends on the valve setting to exit the gas flow on the stove. On the other hand if incomplete combustion occurs it will affect the flavour of the roasted coffee beans. The purpose of this study was to test a coffee roasting machine with an electric element heat source. Roasting machine testing with a time of 50 minutes produces an average temperature of 196.64 °C with a final moisture content of 3.61%.

Methods for quality coffee roasting degree evaluation: a literature review on risk perspective

The demand for specialty coffee has increased over the past few years, and several cafes and coffee roasteries are starting to enter the market. Coffee roasting is considered art rather than science that requires a lot of experience from a master roaster. The key parameters used to identify the roast status of the beans are the initial temperature and roasting time from bean samples. The degree of roasting is often the first consideration for consumers when buying coffee. Some of the flavor attributes used to assess coffee are body, aroma, and acidity. Many studies have been done to evaluate the quality of roasted coffee experimentally using different parameters. However, these techniques could not be implemented in real-time and have their limitations. The current need for roasteries is a method of controlling the quality of roasted coffee through risk and a real-time approach. This paper presents a review carried out the methods used to determine roasting degree on risk perspective. This review has covered recent research on coffee roasting evaluation methods on physical, physicochemical, and chemical composition changes.

Perbaikan Tingkat Risiko Musculoskeletal Disorders Berdasarkan Pendekatan Nordic Body Map dan Rapid Upper Limb Assessment Pada Hasil Rancang Bangun Mesin Roasting Kopi Digital Otomatis

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.

Prevalence of toxigenic fungi and mycotoxins in Arabic coffee (Coffea arabica): Protective role of traditional coffee roasting, brewing and bacterial volatiles

Fungal infection and synthesis of mycotoxins in coffee leads to significant economic losses. This study aimed to investigate the prevalence of toxigenic fungi, their metabolites, and the effect of traditional roasting and brewing on ochratoxin A (OTA) and aflatoxins (AFs) contents of naturally contaminated coffee samples. In addition, in vivo biocontrol assays were performed to explore the antagonistic activities of Bacillus simplex 350–3 (BS350-3) on the growth and mycotoxins synthesis of Aspergillus ochraceus and A. flavus. The relative density of A. niger, A. flavus, Penicillium verrucosum and A. carbonarius on green coffee bean was 60.82%, 7.21%, 3.09% and 1.03%, respectively. OTA contents were lowest in green coffee beans (2.15 μg/kg), followed by roasted (2.76 μg/kg) and soluble coffee (8.95 μg/kg). Likewise, AFs levels were highest in soluble coffee (90.58 μg/kg) followed by roasted (33.61 μg/kg) and green coffee (9.07 μg/kg). Roasting naturally contaminated coffee beans at three traditional methods; low, medium and high, followed by brewing resulted in reduction of 58.74% (3.50 μg/kg), 60.88% (3.72 μg/kg) and 64.70% (4.11 μg/kg) in OTA and 40.18% (34.65 μg/kg), 47.86% (41.17 μg/kg) and 62.38% (53.73 μg/kg) AFs contents, respectively. Significant inhibitions of AFs and OTA synthesis by A. flavus and A. carbonarius, respectively, on infected coffee beans were observed in presence of Bacillus simplex BS350-3 volatiles. Gas chromatography mass spectrochemistry (GC-MS/MS) analysis of head-space BS350-3 volatiles showed quinoline, benzenemethanamine and 1-Octadecene as bioactive antifungal molecules. These findings suggest that marketed coffee samples are generally contaminated with OTA and AFs, with a significant level of roasted and soluble coffee contaminated above EU permissible limits for OTA. Further, along with coffee roasting and brewing; microbial volatiles can be optimized to minimize the dietary exposure to mycotoxins.