Differences in volatile compounds and antioxidant activity of ripe and unripe green coffee beans (Coffea arabicaL. ‘Catimor’)

2017 ◽  
pp. 261-268
Author(s):  
F. Kulapichitr ◽  
C. Borompichaichartkul ◽  
S. Pratontep ◽  
K. Lopetcharat ◽  
S. Boonbumrung ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Volatile Compounds ◽  
Green Coffee ◽  
Green Coffee Beans ◽  
Coffee Beans

scholarly journals Comparison of the Antioxidant Activities and Volatile Compounds of Coffee Beans Obtained Using Digestive Bio-Processing (Elephant Dung Coffee) and Commonly Known Processing Methods

Antioxidants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 408
Author(s):  
Mesfin Haile ◽  
Hyung Min Bae ◽  
Won Hee Kang
Keyword(s):  
Antioxidant Activity ◽  
Volatile Compounds ◽  
Green Coffee ◽  
Roasted Coffee ◽  
Green Beans ◽  
Processing Methods ◽  
Green Coffee Beans ◽  
Coffee Beans ◽  
Roasted Coffee Beans ◽  
Elephant Dung

There are different types of coffee processing methods. The wet (WP) and dry processing (DP) methods are widely practiced in different parts of coffee-growing countries. There is also a digestive bioprocessing method in which the most expensive coffee is produced. The elephant dung coffee is produced using the digestive bioprocessing method. In the present experiment, the antioxidant activity and volatile compounds of coffee that have been processed using different methods were compared. The antioxidant activity, total phenolic content (TPC), total flavonoid content (TFC), and total tannin content (TTC) of green coffee beans from all treatments were higher as compared to roasted coffee beans. Regarding the green coffee beans, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of elephant dung coffee beans was higher as compared to that of the DP and WP coffee beans. The green coffee beans had higher DPPH activity and ferric reducing antioxidant power (FRAP) value compared to the roasted coffee beans. The green beans of elephant dung coffee had a high TPC than the beans obtained by WP and DP methods. TFC in elephant dung coffee in both green and roasted condition was improved in contrast to the beans processed using dry and wet methods. The elephant dung coffee had an increased TTC in comparison to the DP and WP coffee (green beans). About 37 volatile compounds of acids, alcohols, aldehydes, amide, esters, ethers, furans, furanones, ketones, phenols, pyrazines, pyridines, Heterocyclic N, and pyrroles functional classes have been found. Some of the most abundant volatile compounds detected in all treatments of coffee were 2-furanmethanol, acetic acid, 2-methylpyrazine, 2,6-dimethylpyrazine, pyridine, and 5-methylfurfural. Few volatile compounds have been detected only in elephant dung coffee. The principal component analysis (PCAs) was performed using the percentage of relative peak areas of the volatile compound classes and individual volatile compounds. This study will provide a better understanding of the impacts of processing methods on the antioxidants and volatile compounds of coffee.

scholarly journals Antioxidant Activity, Total Polyphenol, Flavonoid and Tannin Contents of Fermented Green Coffee Beans with Selected Yeasts

Fermentation ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 29 ◽  
Author(s):  
Mesfin Haile ◽  
Won Kang
Keyword(s):  
Antioxidant Activity ◽  
Green Coffee ◽  
Flavonoid Content ◽  
Tannin Content ◽  
Polyphenol Content ◽  
Total Polyphenol ◽  
Fermentation Time ◽  
Green Coffee Beans ◽  
Coffee Beans ◽  
The Mean

We examined the antioxidant activity, total polyphenol content (TPC), total flavonoid content (TFC), total tannin content (TTC) and physical characteristics of green coffee beans fermented with selected yeasts. There was no significant (p > 0.05) interaction effect between yeast-fermented coffee extracts and duration of fermentation on antioxidant activity (oxygen radical absorbance capacity [ORAC] and superoxide dismutase-like [SOD-like] activity). However, the mean of the antioxidant activity (ORAC and SOD-like activity) significantly (p < 0.05) increased in the fermented coffee extracts compared to unfermented coffee. There were significant (p < 0.05) interaction effects between yeast-fermented coffee extracts and duration of fermentation (24 h and 48 h) on the TPC, TFC, TTC and pH of the fermented solution and on the colors of the ground-roasted coffee. The TPC showed a pattern of increase in samples Ferm-1 and Ferm-3 as fermentation time increased from 24 h to 48 h. However, a decreasing TPC trend was observed in Ferm-2 as the number of fermentation hours increased from 24 to 48. The fermented coffee beans had a significantly higher flavonoid content than the unfermented coffee beans, while fermentation significantly decreased the tannin content compared to that in unfermented coffee.

scholarly journals Effect of Yeast Fermentation of Green Coffee Beans on Antioxidant Activity and Consumer Acceptability

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Han Sub Kwak ◽  
Yoonhwa Jeong ◽  
Misook Kim
Keyword(s):  
Antioxidant Activity ◽  
Clustering Analysis ◽  
Consumer Acceptance ◽  
Yeast Fermentation ◽  
Green Coffee ◽  
Agglomerative Hierarchical Clustering ◽  
Green Coffee Beans ◽  
Yeast Strains ◽  
Coffee Beans ◽  
High Antioxidant Activity

This study assessed the functionality and consumer acceptance of yeast fermented coffee beans. Green coffee beans were fermented for 24 h with three different yeast strains to increase functionality. The yeast fermentation was effective in fortifying the functionality of coffee by significantly increasing antioxidant activity according to the results of ORAC and SOD-like assay (P<0.05). The TPC and TFC contents in the fermented coffee beans were significantly higher than those in the controls (P<0.05). The consumer acceptance for the fermented coffee beans was slightly lower than that of the controls. Fermentation seemed to influence the aroma and flavor of coffee. However, agglomerative hierarchical clustering analysis revealed that approximately 39% of consumers significantly liked one of the fermented coffees (F3) more than the controls (P<0.05). These consumers indicated that the yeast fermentation of green coffee beans did not generate a negative aroma or flavor and can be attractive with high antioxidant activity.

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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