Effect of Brewing Methods and Time on Secondary Metabolites, Total Flavonoid and Phenolic Content of Green and Roasted coffee Coffea arabica, Coffea canephora and Monsooned Malabar

Abstract

Coffea arabica, Coffea canephora (robusta) and monsooned malabar are the three types of coffee which are well known and used by most of population in India and all over the globe. For consuming coffee various brewing methods are used worldwide, French press, Espresso, Turkish coffee, being the common. Eleven brewing methods are introduced in the paper for brewing of green coffee, some of which are common for brewing tea. Among all the mentioned brewing methods, Decoction method showed the best results, as maximum amount of Flavonoids and Phenols were found to be present in green coffee arabica, values being 69.24 mg QE/g of coffee and 108.67 mg QE/g of coffee respectively, whereas, for Original Research Articlerobusta it was found to be 47.47 mg QE/g of coffee and 93 mg QE/g of coffee respectively. Brewing time is also considered as one of the major factors for coffee brewing, as if the time is too short, all the flavours will not dissolve and if too long, it may dissolve undesirable components as well. An increasing trend was seen in flavonoid and phenolic content in both arabica (TPC up to 84.11 mg QE/g of coffee) and robusta (TPC up to 78 mg QE/g of coffee) along with monsooned malabar (TPC up to 84.88 mg QE/g of coffee) with increase in brewing time. Another factor considered is the solvent used for brewing. A comparison was made between water and alcohol. Both the coffees, green and roasted showed a significant difference in the values when brewed in ethanol and in water. Results indicate that the brewing methods given may be used along with a variant brewing time depending on its phenolic content. Also, green coffee can be proved a boon with more health benefits as compared to roasted one.

Mineral Composition and Antioxidant Potential of Coffee Beverages Depending on the Brewing Method

“…These results are similar or lower than those reported by other authors but the infusions were made by traditional methods [43][44][45]. In soft and hard infusion, the total phenolic content for Arabica coffee was in the range of 94 to 96 mg QE/g of coffee, and in French Press was 100.78 mg QE/g of coffee [45]. Out of all coffee brewing methods investigated in the present study, the highest antioxidant potential, polyphenol content, and redox potential was observed in the brew made in the Aeropress.…”

“…In our study, the lowest total polyphenol content was found in the coffee from the French press (133.90 g gallic acid/L) and the highest was observed in the Aeropress brew (191.29 g gallic acid/L). These results are similar or lower than those reported by other authors but the infusions were made by traditional methods [43][44][45]. In soft and hard infusion, the total phenolic content for Arabica coffee was in the range of 94 to 96 mg QE/g of coffee, and in French Press was 100.78 mg QE/g of coffee [45].…”

Bioactive Building Blocks and Potential Pharmacological Perspectives of Green Coffee: A Review

“…Coffee, an evergreen arbour, has derived its name from 'Keffa' province, where shepherds from Abyssinia/Ethiopia discovered it in the 6th century [1]. This member of the genus Coffea and family Rubiaceae is native to Ethiopia.…”

“…Coffee encompasses about 90 different numbers of species [6,7,8]. Among various species such as Coffea canephora, Coffea liberica, Coffea excels, and Coffea stenophylla; only Coffea arabica (Arabica) and Coffea canephora (Robusta) are of commercial importance [1,6,8] and accounts for about 60% and 40% to the global coffee market, respectively [9,10,11,12]. Arabica and Robusta may seem similar, but there are various note-worthy differences among them [1].…”

“…In contrast, Arabica coffee is higher ranking than Robusta due to its organoleptic characteristics and therefore, is more costly [16]. Also, Arabica requires a variable environmental condition and produces less coffee per hectare than Robusta, increasing the growth cost [1].…”