Title : The influence of technological processes of coffee beans on the phenolic compounds, trigonelline, methylxanthines, nicotinic acid, and amide determined in the coffee brews by LC-MS/MS
Abstract:
Coffee is probably the most popular beverage in the world. Coffee, a complex of above 1000 compounds, contains caffeine and other alkaloids, chlorogenic acids among many other bioactive compounds. It is well known that the content of phenolic and other compounds in coffee is affected by coffee variety and cultivar, climatic conditions (altitude, soil, fertilization, sun exposure, temperature, rainfall), and post-harvest conditions (washing, drying, and storage). The technology of coffee beans starts from a green bean and then the coffee bean can be decaffeinated, steamed and/or roasted mainly on the three various grades (first crack, city/full city, second crack). In the case of Kopi Luwak coffee, the green coffee beans are fermented in the gut of the Asian palm civet (Paradoxurus hermaphroditus), excreted, collected, cleaned, and roasted. The aim of the study was to determine 18 bioactive compounds in Arabica and Robusta coffee brews analyzed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). 5 Arabica coffees of various origins (green and roasted on 3 grades), 7 Robusta coffees (green and roasted on 3 grades, steamed and decaffeinated), and Kopi Luwak coffee (full city grade) were used as the samples. The dominating compounds of all analyzed coffees were caffeine and trigonelline. From chlorogenic acids’ groups of compounds: 5-caffeoylquinic acid, 4-caffeoylquinic acid, 3-caffeoylquinic acid as well as 3,5-caffeoylquinic acid, 3,4-caffeoylquinic acid, and 4,5-caffeoylquinic acid were determined and it was found that the technological processes significantly influenced the quantity of these compounds. Nicotinic amide and acid were determined in all analyzed coffee brews. Kopi Luwak coffee possessed one of the highest levels of bioactive compounds among Vietnam (Robusta), Brazil, and Uganda Bugishu (Arabica) coffees.
