Tocopherols in coffee brews: Influence of coffee species, roast degree and brewing procedure

Tocopherols in roasted coffee and coffee brews were analysed by HPLC/diode-array/fluorescence detection. Only α and β vitamers were identified in the samples. The influence of several factors on espresso coffee content, as well as on tocopherol extractability, was ascertained, namely, coffee species, roast degree, brew volume and preparation method. Pure arabica espressos contained 2.2 and 3.9 μg of α- and β-tocopherol, respectively, while robusta espressos showed significantly lower amounts (p < 0.05): 1.3 and 1.1 μg, correspondingly. Total contents (α + β) in espressos prepared from commercial blends ranged from 2.2 to 4.8 μg. Overall, tocopherol amounts in the brews corresponded to only 1% of those found in the coffee cake. However, espressos prepared from servings contained ～5-fold higher amounts of tocopherol than those prepared by the classic method. The medium-roast degree seems to be more favourable for the extraction of compounds than light or dark roasts. Compared with other coffee beverages, an arabica espresso cup contained an intermediate level of total tocopherols: 7.0 μg/30 mL, against 4.4 μg for filter (150 mL), 13.6 μg for press-pot (60 mL), 19.7 μg for moka (60 mL), 25.4 μg for Turkish, and 40.1 μg for boiled (150 mL) coffees.