scholarly journals Determination of Caffeine and Hydrogen Peroxide Antioxidant Activity of Raw and Roasted Coffee Beans Around Habru Woreda, Ethiopia Using UV-Vis Spectroscopy

2021 ◽  
Vol Volume 13 ◽  
pp. 101-113
Author(s):  
Beshir Legas Muhammed ◽  
Mohammed Hussen Seid ◽  
Adere Tarekegne Habte
Author(s):  
Deepti Bajaj ◽  
Suhas Ballal

Coffee, one of the most commonly consumed beverages is a very rich source of antioxidants alongside various other health benefits. The roasted beans of coffee are the seed of berry obtained from coffea species. These roasted coffee beans are utilized to prepare coffee. India is today producer of 16 unique varieties of coffee most of which originate from southern India. The goodness of coffee and Ganoderma can do wonders to human health. This study is aimed to have an analysis of antioxidant properties of instant coffee, filter coffee, coffee with Ganoderma extracts and ginger coffee by estimating the Ascorbic Acid equivalents (AAE). The essence of the study is the presence of additions and the antioxidant activity of the coffee samples in their presence. The two infusions used in the study are extracts of Ganoderma and ginger. The study also aims to have a inter group analysis of antioxidant properties of all the samples. The study was conducted using basic colorimetric techniques.


2019 ◽  
Vol 11 (2) ◽  
pp. 103-109
Author(s):  
Septiani Mangiwa ◽  
Agnes Eri Maryuni

Coffee bean are rich of secondary metabolits that able to inhibit free radical compounds. This antioxidant activity may reduce many diseases correlated with it. The aims of this study were to determined the phytochemical content and antioxidant activity of roasted coffee bean from Wamena and Moenemani regency, Papua. Roasted coffee beans were extracted by maceration for 24 hr with methanol. Harborne standard method was used for the phytochemical analysis  and DPPH assay was used to  determine the antioxidant activity. IC50 was measured by spectrophotometric assay using spectrophotometer Uv-Vis at 517 nm wavelenghth. Result showed that both Arabica roasted coffee beans from Wamena and Moanemany had the capacity to inhibit free radical  at 61,71% and 69,7% with IC50 at  107,97 and 100,91 ppm, respectively . Phytochemical investigation revealed that the bioactive compounds from Moanemani and Wamena coffee beans were similar, which composed of alkaloids, flavonoids, terpenoids, saponins, and tanins. In conclusion, the methanolic extract of roasted Arabica coffee beans from Wamena and Moanemani can be used as the source of natural antioxidant.Keywords: Arabica roasted coffee beans; phytochemical; antioxidant; DPPH method.


Antioxidants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 408
Author(s):  
Mesfin Haile ◽  
Hyung Min Bae ◽  
Won Hee Kang

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.


2015 ◽  
Vol 12 (5) ◽  
pp. 7293-7302 ◽  
Author(s):  
ALEXANDROS PRIFTIS ◽  
DIMITRIOS STAGOS ◽  
KONSTANTINOS KONSTANTINOPOULOS ◽  
CHRISTINA TSITSIMPIKOU ◽  
DEMETRIOS A. SPANDIDOS ◽  
...  

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1347
Author(s):  
Ja-Myung Yu ◽  
Mingi Chu ◽  
Hyunbeen Park ◽  
Jooyeon Park ◽  
Kwang-Geun Lee

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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