Use of electrochemical techniques for determining the effect of brewing techniques (espresso, Turkish and filter coffee) and roasting levels on total antioxidant capacity of coffee beverage

Abstract

In this study, we determined how roasting levels (light, medium, and dark) of Arabica coffee seed and three brewing techniques—decoction methods (Turkish coffee), infusion method (filter coffee), and pressure methods (Espresso)—affect the total antioxidant capacity in a cup of coffee beverage by electrochemical methods such as square wave stripping voltammetry (SWSV), differential pulse stripping voltammetry (DPSV), and cyclic voltammetry (CV). The highest antioxidant capacity was found in espresso coffee prepared with light roasted coffee seeds, as equivalent of rutin and caffeic acid at 9.4 ± 0.2 g/L and 19.7 ± 0.7 g/L, respectively with SWSV on a carbon paste electrode (CPE). The antioxidant capacity of coffee beverages was influenced by the roasting degree, extraction time, and brewing methods, significantly. SWSV, DPSV, and CV voltammetric methods, fast, reliable, fully validated and without any pretreatment, are alternatives to conventional analytical methods for evaluation of antioxidant values in coffee brews. Practical applications This research will contribute to the literature considerably since we have established that the antioxidant capacity can be measured by electrochemical methods rapidly with high reliable results. According to the study, the brewing method and roasting temperature significantly affected the antioxidant capacity, and thus, it is important to know how brewing methods, roasting temperatures, and other conditions changes the coffee quality. The results can be used to prepare healthy coffee beverages.

Impact of roasting degree on sensory profile of Turkish coffee and espresso assessed by Turkish and Brazilian panelists

“…Espresso is one of the most popular brewing types, and pressure generated by an espresso machine is an especially important F I G U R E 1 Schematic representation of brewing techniques for Turkish coffee (traditional method) and espresso (Gok, 2021;Yildirim et al, 2022).…”

“…Generally, it consists of three stages: (1) ground coffee absorbs water; (2) soluble solids, volatile and nonvolatile aroma compounds transfer from ground coffee into hot water; and (3) extracted coffee is separated from the residue (Angeloni et al, 2019). Turkish coffee is completed with only the first and second stages so that the spent solids remain together with extracted coffee (Elmacı & Gok, 2021; Yildirim et al, 2022). Sensory characteristics of coffee drinks depend on several factors related to the brewing process such as the contact time between water and ground coffee, extraction time, ground coffee/water ratio, water temperature and pressure, grinding size, type of filter, and the boiling process (Angeloni et al, 2019; Caprioli et al, 2015; Cordoba et al, 2019; Cordoba et al, 2020; Gok, 2021; López et al, 2016).…”

“…Sensory characteristics of coffee drinks depend on several factors related to the brewing process such as the contact time between water and ground coffee, extraction time, ground coffee/water ratio, water temperature and pressure, grinding size, type of filter, and the boiling process (Angeloni et al, 2019; Caprioli et al, 2015; Cordoba et al, 2019; Cordoba et al, 2020; Gok, 2021; López et al, 2016). There are numerous coffee brewing and extraction methods based on geographic, cultural, and social perspectives as well as personal favorites (Caprioli et al, 2015; Gok, 2021; Yildirim et al, 2022).…”

“…Mainly three methods were used: decoction methods (boiled coffee, Turkish coffee, percolator coffee, and vacuum coffee), infusion methods (filter coffee and Napoletana), and pressure methods (Plugger, Moka, and espresso) (Cordoba et al, 2020; Gok, 2021; Yildirim et al, 2022). The espresso and Turkish coffee methods are the common coffee brewing methods, and the differences between their extraction systems are shown in Figure 1.…”

“…Schematic representation of brewing techniques for Turkish coffee (traditional method) and espresso (Gok, 2021; Yildirim et al, 2022). …”