*2.2.2 Carbohydrates*

Arabica coffee is more preferred by most consumers than Robusta because it is less bitterness and has good flavour [49, 50]. These characteristics are contributed by the carbohydrates that account for more than 50% of the coffee bean dry weight [8]. During roasting, sucrose is degraded to form the anhydro-sugars and glyypxal that determine flavour and aroma [29]. These compounds react with amino acids through the Maillard reaction to form aliphatic acids, hydroxymethylfurfural, pyrazine and other furans. Furan derivatives are the principal products of decomposition of monosaccharides and higher sugars [51]. The composite roasting is regarded as essential in contributing to the final coffee flavour either being volatile or non-volatile [52]. Sucrose levels in Arabica coffee range from 5.1% to 9.4% in the dry matter of coffee beans which is higher than that of Robusta that range between 4–7% [53, 54].
