The differences among several popular brewed beverages in relation to content of caffeine, theobromine, theophylline, trigonelline, nicotinic acid and amide were studied. Caffeine, the main active component of the green and roasted Arabica and Robusta coffees, was also found in Yerba mate tea and other beverages such as teas. On the other hand, it has been found that roasted grain beverages that are used as a coffee substitute contain 5000-10000 times less caffeine. In addition the effect of coffee treatment such as roasting, steaming and decaffeination processes of coffee beans was analyzed. It was shown that the steaming and/or light roasting processes have influenced the methylxantines and trigonelline content. Decaffeination process has decreased the level of theobromine and theophylline and increased the content of nicotinic acid and there was no change in nicotinamide in Vietnam Robusta coffees.

研究了几种流行的冲泡饮料在咖啡因，可可碱，茶碱，松果油碱，烟酸和酰胺含量方面的差异。咖啡因是绿色和烘焙阿拉比卡咖啡和罗布斯塔咖啡的主要活性成分，还存在于Yerba伴侣茶和其他饮料（例如茶）中。另一方面，已经发现，用作咖啡代用品的烤谷物饮料所含的咖啡因减少了5000-10000倍。此外，还分析了咖啡处理的效果，例如咖啡豆的烘焙，蒸煮和脱咖啡因过程。结果表明，蒸煮和/或轻度焙烧过程已经影响了甲基黄嘌呤和松柏油碱的含量。