A Comparative Study to Measure the Quantities of the Stimulant Caffeine in Some Types of Yemeni Coffee

Abstract

The research aimed to identify and reveal the history of coffee production and export in Yemen, its chemical properties, and its effect on the nervous system. The comparative-historical and experimental approach was adopted, through a sample of 17 species from different regions that were subjected to chemical analysis, then compared with similar ones or with a random sample purchased from the market. It came in two sections; The first: The Theoretical Part, the second: The experimental Part (chemical methods for extracting and measuring caffeine). The most important results are: Caffeine is present in coffee, although its percentage varies from one type to another and the quality of coffee is not measured solely by the caffeine it contains. Rather, it is determined by several factors, such as climate, soil, water and care for the coffee, including harvesting, storage, drying, etc.