Effects of adding L-cysteine on the accumulation of the main compounds and their new analogs in roasting Coffea arabica beans

Hazardous substances such as acrylamide (AA) are easily produced by the Maillard reaction during coffee roasting. By adding l -cysteine ( l -Cys), the production of AA was inhibited whereas the profiles of the newly formed compounds remain unclear. To elucidate the influence of l -Cys addition on the main characteristic compounds of Yunnan Coffea arabica , investigations using LC-MSⁿ-IT-TOF, FTIR and assays of in vitro antioxidant and xanthine oxidase (XO) inhibitory activities were carried out. The result revealed that the most characteristic compounds represented by the chlorogenic acid analogs (CGAs) were critical to hazards formation during the Maillard reaction. Adding l -Cys before roasting enhanced coffee quality by reducing harmful intermediates such as 5-hydroxymethylfurfural (5-HMF) while increasing bio-potentials. New compound N6 which was formed by the addition of l -Cys and CGAs, together with the flavonoids generated through polymerization and simple phenols derived from thermal cleavage, were mainly contributed to the above potential.