Comparison of extraction methods for kahweol and cafestol analysis in roasted coffee

Abstract

Caveol e cafestol, diterpenos da fração lipídica do café, têm efeitos conhecidos na saúde humana, como atividade anticarcinogênica e hipercolesterolêmica. Existem divergências quanto às concentrações desses compostos reportadas para café torrado, provavelmente devido aos processos de extração empregados. Assim, quatro métodos de preparo de amostra foram estudados: saponificação direta a quente (SDQ), saponificação direta a frio (SDF); e extração por Bligh e Dyer (BD) ou soxhlet (SO) seguida de saponificação. Teores dos diterpenos e seus dehidroderivados obtidos por cromatografia líquida de alta eficiência acoplada a detector de arranjo de diodos e espectrometria de massa (HPLC-DAD-MS/MS) e perfis cromatográficos de café torrado, obtidos pelos quatro métodos, foram comparados. SDQ foi mais eficiente quanto à extração, mostrando melhor separação dos picos cromatográficos e teores de 930,2 (± 36,8), 113,2 (± 4,7), 568,6 (± 16,6) e 87,1 (± 3,7) mg 100 g -1 para caveol, dehidrocaveol, cafestol e dehidrocafestol, respectivamente. O extrato SDQ apresentou teores de diterpenos (caveol e cafestol) 15% superiores àqueles obtidos por SDF e até 88% maiores que pelos métodos SO e BD.Kahweol and cafestol, diterpenes from the unsaponifiable fraction of coffee, present known effects on human health such as anticarcinogenic and hipercholesterolemic activities. There are discrepancies regarding the levels reported for these compounds in roasted coffee, probably due to the extraction processes. Therefore, four sample preparation methods were studied: direct hot saponification (DHS), direct cold saponification (DCS); and Bligh and Dyer (BD) or Soxhlet (SO) extraction followed by saponification. The levels of diterpenes and their dehydro derivatives obtained by high performance liquid chromatography with diode array and mass spectrometry detectors (HPLC-DAD-MS/MS) and the chromatographic profiles of roasted coffee, obtained by these four methods, were compared. DHS was more efficient for extraction, showing better separation of chromatographic peaks and levels of 930.2 (± 36.8), 113.2 (± 4.7), 568.6 (± 16.6) and 87.1 (± 3.7) mg 100 g -1 for kahweol, dehydrokahweol, cafestol and dehydrocafestol, respectively. The DHS extract presented a diterpene content (kahweol and cafestol) 15% superior to that of DCS and up to 88% superior than using SO and BD methods.

Discrimination between Arabica and Robusta Coffees Using Hydrosoluble Compounds: Is the Efficiency of the Parameters Dependent on the Roast Degree?

“…Kitzberger et al [17] reported values of 28.7 (L*) and 40.6 (h°) for various arabica coffees at a medium roast degree. For dark roasting, a range from 19 to 37 L* and from 35 to 55 h° in arabica coffee were reported [12,[34][35][36] and, for robusta, values from 14 to 41 L* and from 50 to 57 h° were found [36,37].…”

Chemometric Analysis of UV Characteristic Profile and Infrared Fingerprint Variations ofCoffea arabicaGreen Beans under Different Space Management Treatments

“…Values for these pentacyclic alcohols were reported at 225 nm for cafestol and 288 nm, for kahweol. 40 The S 10 treatment showed higher contents of cafestol and kahweol in the dichloromethane extract. In the hexane extract, the R 6 treatment showed a slightly higher kahweol content compared with other treatments.…”

Saponificação Assistida Por Micro-Ondas Na Extração De Diterpenos Em Café Arábica Torrado

“…[16][17][18][19][20][21][22] Dias et al, 18 estudando extração de diterpenos de café, reportaram uma maior eficiência da saponificação à quente (em banho à 80 ºC, 1 h) comparativamente a saponificação à frio e a extração (Soxhlet ou Bligh & Dyer) seguida de saponificação à quente.…”