HPLC/diode-array applied to the thermal degradation of trigonelline, nicotinic acid and caffeine in coffee

摘要

A simultaneous determiantion of trigonelline, nicotinic acid and caffeine was performed in samples of arabica and robusta coffees, before and after roasting at either different temperatures (160-240 deg C) or different periods of time expoures, in order to study their thermal degradation. A reverse-phase HPLC/Diode-array detector method was used. The results were compared with a modl dry system roast of the compounds under study, individually and in mixture. The loss of trigonelline was strongly dependent upon the degree of roast and was assoicated with teh formation of nicotinic acid.