scholarly journals Influence of Altitude on Caffeine, 5-Caffeoylquinic Acid, and Nicotinic Acid Contents of Arabica Coffee Varieties

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Bealu Girma ◽  
Abera Gure ◽  
Feyisa Wedajo
Keyword(s):  
Nicotinic Acid ◽  
High Performance ◽  
Array Detector ◽  
Roasted Coffee ◽  
Arabica Coffee ◽  
Caffeoylquinic Acid ◽  
Coffee Beans ◽  
Roasting Process ◽  
Target Analytes ◽  
Roasted Coffee Beans

The influence of altitude on caffeine, 5-caffeoylquinic acid (5-CQA), and nicotinic acid contents of Arabica coffee varieties grown in Southwest Ethiopia was investigated. High-performance liquid chromatography with diode array detector (HPLC-DAD) was used for the determination of the target analytes. Coffee samples were collected from four coffee varieties, named as 74112, 7454, 7440, and 74110, which are cultivated in high, mid, and low altitudes in the study area. The findings of the study showed that the contents of caffeine and 5-CQA in both raw and roasted coffee beans decrease as the growing altitude increases and, thus, for all varieties, their highest concentrations were recorded in lowland coffee beans. Nevertheless, the contents of nicotinic acid increase as the altitude rises and, thus, the highest nicotinic acid content was recorded in highland coffee samples. Besides, after roasting, the contents of caffeine were increased, whereas the contents of 5-CQA were lowered, indicating the possibility of its degradation during the roasting process. Both green and roasted coffee beans also contained relatively higher concentrations of nicotinic acids. Other than the growing altitudes, the contents of caffeine, 5-CQA, and nicotinic acid in coffee beans also vary with coffee varieties. Therefore, coffee varieties that are cultivated at various altitudes may have different biochemical compositions such as caffeine, CGAs, and nicotinic acid that could greatly influence the flavor, aroma, and stimulating attributes of coffee cup quality as well as dietary benefits.

scholarly journals Temperature coverage simulation of horizontal cylinder type coffee roasting machine

2021 ◽  
Vol 922 (1) ◽  
pp. 012031
Author(s):  
F Fachruddin ◽  
S Syafriandi ◽  
R Fadhil
Keyword(s):  
Bulk Density ◽  
Horizontal Cylinder ◽  
Roasted Coffee ◽  
Actual Temperature ◽  
Coffee Beans ◽  
Roasting Process ◽  
Study Results ◽  
Roasting Temperature ◽  
Roasted Coffee Beans ◽  
Coffee Roasting

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).

scholarly journals Detection roasting level of Lintong coffee beans by using euclidean distance

2021 ◽  
Vol 10 (6) ◽  
pp. 3072-3082
Author(s):  
Yohanssen Pratama ◽  
I Gde Eka Dirgayussa ◽  
Paian Fernando Simarmata ◽  
Mia Hotmaria Tambunan
Keyword(s):  
Euclidean Distance ◽  
Color Change ◽  
Roasted Coffee ◽  
Green Beans ◽  
Color Changes ◽  
Coffee Beans ◽  
Roasting Process ◽  
Roasted Coffee Beans ◽  
Light Medium ◽  
Coffee Roasting

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.

scholarly journals Quantification of Caffeine and Chlorogenic Acid in Green and Roasted Coffee Samples Using HPLC-DAD and Evaluation of the Effect of Degree of Roasting on Their Levels

Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7502
Author(s):  
Shady Awwad ◽  
Reem Issa ◽  
Lilian Alnsour ◽  
Dima Albals ◽  
Idrees Al-Momani
Keyword(s):  
Chlorogenic Acid ◽  
Acid Content ◽  
High Performance ◽  
Hot Water ◽  
Array Detector ◽  
Phase System ◽  
Roasted Coffee ◽  
Coffee Beans ◽  
Different Origins ◽  
Antioxidant Effects

Chlorogenic acid and caffeine are among the important components in coffee beans, determining the taste and aroma. In addition, phenols and antioxidants content possess vital health values. The main aim of this study is to determine the levels of caffeine and chlorogenic acid in several coffee samples of different origins and degrees of roasting. The coffee samples were extracted using hot water. The levels of caffeine and chlorogenic acid were quantified using high-performance liquid chromatography (HPLC) equipped with a diode array detector, a reverse phase system, and an ODS column (C18). Total phenol and antioxidant contents were previously determined for the same samples. The results showed that the highest content of caffeine was found in the medium roasted coffee (203.63 mg/L), and the highest content of chlorogenic acid content was found in the green coffee (543.23 mg/L). The results demonstrated a negative correlation between the chlorogenic acid levels with the degree of roasting, while it showed a positive correlation between the caffeine levels with the degree of roasting till a certain point where the levels dropped in the dark roasted coffee. The origin of coffee samples did not show any effect on any of the measured variables. Antioxidant effects of coffee samples were largely determined by chlorogenic acid content.

scholarly journals Microwave-assisted Extraction of Ochratoxin A from Roasted Coffee Beans: An Alternative Analytical Approach

2012 ◽  
Vol 1 (3) ◽  
pp. 121 ◽  
Author(s):  
Giulia Graziani ◽  
Antonello Santini ◽  
Rosalia Ferracane ◽  
Alberto Ritieni
Keyword(s):  
Ochratoxin A ◽  
High Performance ◽  
Microwave Assisted Extraction ◽  
Roasted Coffee ◽  
Microwave Assisted ◽  
Assisted Extraction ◽  
Coffee Beans ◽  
Conventional Extraction ◽  
Contamination Levels ◽  
Roasted Coffee Beans

<p>Microwave-assisted extraction (MAE) followed by high performance liquid chromatography (HPLC) with a fluorescent detector (DAD) was used and developed for the quantitative analysis of the mycotoxin ochratoxin A (OTA) in commercial roasted coffee beans. This alternative approach has been compared with the conventional extraction that uses hydrogen carbonate aqueous solution followed by OchraTest immunoaffinity analysis. The effect of two experimental tunable MAE parameters (temperature and pressure) on the extraction efficiency of OTA have been investigated using coffee samples forti?ed at different contamination levels. The optimum extraction conditions were obtained using a temperature of 50 °C and a 500 W microwave power. OTA quantity extracted using MAE was similar to that obtained by conventional extraction from samples fortified at 5, 10, and 100 ng g<sup>-1</sup> levels. At a 20 ng g<sup>-1</sup> level, MAE was more effective than the conventional method. The MAE setting parameters have been optimized showing both extraction time and solvent consumption have been considerably reduced, retaining high OTA recovery values.</p>

scholarly journals Effect of Roasting Conditions on Concentration in Elements of Vietnam Robusta Coffee

2014 ◽  
Vol 18 (2) ◽  
pp. 19-34 ◽  
Author(s):  
Tran Van Cuong ◽  
Liu Hong Ling ◽  
Guo Kang Quan ◽  
Shang Jin ◽  
Song Shu Jie ◽  
...  
Keyword(s):  
Absorption Method ◽  
Roasted Coffee ◽  
Robusta Coffee ◽  
Flame Atomic Absorption ◽  
Zn Concentration ◽  
Coffee Beans ◽  
Roasting Process ◽  
Roasting Temperature ◽  
Roasted Coffee Beans ◽  
Pb Concentration

Abstract Vietnam Robusta Coffee was roasted at different roasting degree and roasting temperature and 9 element concentrations (K, Mg, Ca, Na, Fe, Cu, Mn, Zn and Pb) of roasted coffee were analyzed by Flame atomic absorption method (FAAS) in this study. The results showed that the concentrations were ranged in 1447.97 ~ 1342.10 (mg/100g), 768.22 ~ 1259.44 (μg/g),10.35 ~ 13.15 (μg/g), and 17.38 ~ 20.97 (μg/g) for element of K, Ca, Cu and Mn in green and roasted coffee beans, respectively. All determined elements were the smallest value in green coffee, then increased with increasing roasting level and reached the highest value in Spain roast (roasting temperature of 250°C). Mg concentration ranged in 682.70 ~ 3647.73 (μg/g); Fe concentration ranged in 37.20 ~ 53.44 (μg/g); Zn concentration ranged in 5.97 ~ 6.89 (μg/g) and Pb concentration ranged in 2.18 ~ 15.04 (μg/100g). Concentrations of all determined elements didn’t change with the increased roasting process.

scholarly journals Analysis of Volatile Compounds in Coffee Prepared by Various Brewing and Roasting Methods

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1347
Author(s):  
Ja-Myung Yu ◽  
Mingi Chu ◽  
Hyunbeen Park ◽  
Jooyeon Park ◽  
Kwang-Geun Lee
Keyword(s):  
Volatile Compounds ◽  
Extraction Methods ◽  
Measured Signal ◽  
Roasted Coffee ◽  
Green Coffee Beans ◽  
Coffee Beans ◽  
Espresso Coffee ◽  
Roasting Temperature ◽  
Roasted Coffee Beans ◽  
Significant Factors

Volatile compounds of coffee brewed under various roasting conditions and by different brewing methods were analyzed. Green coffee beans (Coffea arabica) were roasted at 235 °C for 13 min, 240 °C for 15 min, and 245 °C for 17 min. Roasted coffee beans were ground into particles of three different sizes (710, 500, and 355 μm) and brewed by an espresso coffee machine and the cold brew method. Three types of water (filtered, tap, and bottled) were used for coffee extraction. SPME-GC-MS results indicated that increasing the roasting temperature and time increased the levels of 2,2′-methylene-bis-furan, guaiacol, and 4-ethylguaiacol (p < 0.05) and decreased the levels of furfural (p < 0.05). Grind size was inversely proportional to the measured signal of volatiles by GC-MS (p < 0.05). The measured GC/MS intensities of 2-methylpyrazine, 2,5-dimethylpyrazine, and 2-methoxy-4-vinylphenol were significantly higher in coffee brewed with filtered water (p < 0.05) than tap and bottled water. 2-Methylpyrazine, 1-methylpyrrole, and 2-acetylfuran were the most abundant components in the cold brew. Overall, roasting conditions and extraction methods were determined to be significant factors for volatile compounds in coffee. This is the first study showing the analysis of volatile compounds in coffee according to various types of water and extraction methods, such as espresso and cold brew coffee.

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