Browsing by Author "Tokusoglu, Ozlem"

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Citation Count: 1
Impact of roasting degree on sensory profile of Turkish coffee and espresso assessed by Turkish and Brazilian panelists
(Wiley-hindawi, 2022) Elmaci, Ilkay; Gök, İlkay; Gök, İhsan; Gastronomi ve Mutfak Sanatları / Gastronomy and Culinary Arts
This study aimed to assess the effect of roasting degree and brewing techniques on the sensory profile of Turkish coffee and espresso. Descriptive analysis of coffee samples was carried out for 20 flavor attributes by 10 Turkish and 10 Brazilian assessors. Light, medium, and dark roasted coffee beans were brewed with the decoction method and pressure method. Turkish coffee samples were prepared by automatic machine and cezve, which is the traditional method. The roasting degree and brewing method had a significant impact on the sensory profile of coffee samples. Turkish assessors perceived lightly roasted coffee beverages as sour (6.53 and 6.56 for Turkish coffee with machine and espresso) and pungent notes (7.46 for espresso), while Brazilian assessors perceived them as fruity (5.63 for espresso) and sweet attributes (5.76 and 5.90 for Turkish coffee with cezve and espresso). Roasted (7.83), burnt/acrid (7.96), and bitter (8.13) notes became dominant with the degree of roasting in espresso coffees in the Turkish panel. Brazilian assessors perceived Turkish coffee samples made with cezve and dark roasted beans as roasted (6.53), burnt/acrid (6.66), bitter (6.80), and ashy-sooty (7.26) notes.
Citation Count: 2
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
(Wiley, 2022) Yildirim, Sevinc; Gök, İlkay; Gök, İhsan; Tokusoglu, Ozlem; Gastronomi ve Mutfak Sanatları / Gastronomy and Culinary Arts
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.