Effect of perforated disc height and filter basket on espresso coffee carbohydrates content and composition

The instrumental equipment of an espresso coffee machine has a remarkable influence on the extraction of the espresso coffee (EC). This study aims to evaluate the effect of different perforated disc heights and filter baskets, two fundamental parts of the espresso coffee machine, on EC carbohydrates content and composition. Four different heights (4-7 mm) of perforated discs and two different filter baskets were used to prepare Italian style EC and evaluate the feasibility of lowering the amount of ground coffee while keeping the same quality of the standard Italian espresso. Arabica and Robusta coffee beans, with 12 and 14 g of roasted coffee powder, were used to prepare 40 mL of EC, split in two cups. The content of total solids, high molecular weight material (HMWM), and polysaccharides, such as galactomannans (GM) and arabinogalactans (AG), were compared. The results show that the increase of the height of perforated disc affected the extraction of the polysaccharides content in the cup, with a decrease of GM and AG. As a conclusion, the configuration of perforated disc height and the filter used was shown to modulate the chemical profile of EC brew, with impact on espresso coffee cup quality.