The Changes of Kahweol and Cafestol of Arabica Coffee from Bean to Consumption: A Systematic Literature Review

The main diterpenes found in coffee, kahweol and cafestol, possess anti-inflammatory, anti-diabetic, and anticancer properties but are also reported to cause hypercholesterolemic effects. Their concentrations are known to be variable in coffee. This review aimed to discuss the concentrations of kahweol and cafestol from green coffee beans to brewed coffee. The results showed that the average concentrations of kahweol and cafestol in Arabica green beans were higher than in roasted and brewed coffee. The decrease in kahweol from green beans to roasted beans was 14.83%. In brewed coffee, kahweol was reduced by 90.26% and cafestol by 88.28%, compared to green beans. The changes in kahweol and cafestol levels were found to be influenced by various factors, including roasting methods and brewing techniques. The ratio of kahweol to cafestol in Arabica green beans was 1.7; in green coffee oil and roasted coffee oil, 1.2; in roasted beans, 1.3; and in brewed coffee, 1.1. In addition to their health-related functional properties, kahweol and cafestol concentrations and their ratio are suggested to be relevant markers in distinguishing between coffee species at various processing stages.