Caffeine content and antioxidant activity of various brews of specialty grade coffee

Abstract

Background. The aim of the study was to evaluate the caffeine level and antioxidant activity of brews of specialty grade coffee compared to popular coffee brands. Materials and methods. Ten types of coffee were used, including 7 specialty Arabica, 1 Robusta and 2 popular cheap coffee brands. For caffeine determination, HPLC analysis and the spectrophotometric method were used as reference. The total polyphenol content and antioxidant capacity (DPPH and FRAP methods) were evaluated. For two selected high-quality coffees, the influence of the brewing method on the antioxidant activity and caffeine content in the brews was assayed. Results. Regarding the caffeine content, differences between specialty coffee brews and popular products were not found, and an average level amounted to 56 and 40 mg/ml, respectively. In contrast, the antioxidant capacity of specialty coffee brews was significantly higher than for popular ones, independently of the test used. The highest scavenging ability and total phenolic content was found for S3 specialty coffee (46.15% of DPPH inhibition and 58.7 mg GAE/ml, respectively), whereas the lowest was found for popular coffee (about 35% of DPPH inhibition and about 41 mg/GAE/ml). For two selected high-quality coffees, the influence of the brewing method on the antioxidant activity and caffeine content in the brews was tested. It was found that the use of a dripper (overflow brewing method) provides the brew with the best antioxidant properties but with moderate caffeine levels. Conclusion.It was found that 'specialty' quality coffees do not differ from popular brands in terms of caffeine content, but significantly outweigh them in terms of antioxidant activity. This property can be beneficial in the case of a high consumption of coffee, due to antiradical protective effects without the risk of caffeine overdose.

Analysis of Caffeine and Antioxidant Content of Ethiopian Coffee Varieties from Different Growing Areas

“…The amounts of caffeine in the coffee varieties forest coffee, bourbon, mixed heirloom, and catuai were all 0.36 mg/g, while those in heirloom 2 were 0.37 mg/g. The investigated caffeine level values for the various species are consistent with Miłek et al [24] published data.…”

Targeted and Non-Targeted HPLC Analysis of Coffee-Based Products as Effective Tools for Evaluating the Coffee Authenticity

“…Depending on the analyte, various extraction methods have already been developed. A simple solid–liquid infusion using hot water [ 11 , 34 , 47 , 59 , 88 , 139 , 140 , 141 , 142 , 143 ] or organic solvents [ 40 , 78 , 124 , 144 ] is the most common technique of PPs and caffeine isolation. Other extraction techniques, namely percolation [ 145 ], ultrasound-assisted [ 78 , 138 , 146 ] or microwave-assisted extractions [ 138 ], QuEChERS [ 78 ], and deep eutectic solvent-based extraction [ 95 ] have been used rarely.…”

“…Other extraction techniques, namely percolation [ 145 ], ultrasound-assisted [ 78 , 138 , 146 ] or microwave-assisted extractions [ 138 ], QuEChERS [ 78 ], and deep eutectic solvent-based extraction [ 95 ] have been used rarely. Since the coffee brewing method plays an essential role in the composition and health properties of the resulting beverage, many studies dealing with this issue have already been published [ 11 , 142 , 147 , 148 , 149 ]. In the study of Budryn et al [ 147 ], the influence of coffee genotypes (Arabica vs. Robusta) on the efficiency of various extraction methods (brewing with boiling water and boiling in water at normal and elevated pressure) was investigated.…”

“…It was found that there is a significant difference in caffeine content between the analysed samples, while the change in chlorogenic acids content is not statistically significant. In the study by Miłek et al [ 142 ], the influence of different brewing methods (aeropress, mocca i.e., percolator, and dripper) on the antioxidant capacity and caffeine content of the resulting infusions was also tested for two selected high-quality coffees. It was found that the use of a dripper provides the beverage with the best antioxidant properties, but a low concentration of caffeine.…”

“…A comparison of specialty coffee types of different botanical and geographical origin (seven Arabica samples and one Robusta sample) with commercial coffee brands (two samples) in terms of caffeine concentration, antioxidant capacity (determined by spectrophotometric DPPH and FRAP methods), and total phenolic content (determined by Folin-Ciocalteu method) was also performed in the study by Miłek et al [ 142 ]. In addition to HPLC-UV/VIS, a reference spectrophotometric method was used for the determination of caffeine, which is based on the isolation of caffeine from alkalized infusion by liquid–liquid extraction into chloroform.…”