Influence of roasting temperature on physicochemical properties of different coffees

Abstract

Arabica and robusta coffees from different origins were characterized before and after roasting at different temperatures (between 220 and 295°C). Samples were roasted (dark roast) until they attained the same colour. Colour development of the ground samples was measured throughout using CIE L*a*b* co-ordinates. The roasting temperature did not affect final weight loss and moisture content of the different coffees significantly, but slight differences were detected in the mean weight losses for the different coffees. Roasting temperature affected bulk and bean densities, grain volume increase, and soluble solids and acidity of coffee extracts. Robusta coffees were less sensitive to the bean volume increase, but showed a stronger temperature effect on the content of soluble solids and in the acidity of the aqueous extract, which can benefit its quality parameters.