BEVERAGE EXTRACTION SYSTEM

The invention concerns a system comprising an extraction device of a beverage preparation machine and a capsule, wherein - the capsule comprises a capsule body and a delivery wall forming a chamber, and - the extraction device comprises upstream and downstream capsule enclosing parts relatively movable between an open position for inserting and/or ejecting the capsule and a closed position for forming an extraction chamber enclosing the capsule during extraction, the downstream part comprising a extraction plate with engaging means in the form of pyramidal elements for opening the delivery wall of the capsule, wherein the delivery wall of the capsule is made of biodegradable materials and comprises in a layered manner at least a carrier layer adapted to be opened under the effect of rising pressure of the fluid being injected into the capsule, and an adhesive layer provided on the side of the carrier layer that is oriented towards the chamber for joining the delivery wall and the capsule body, and wherein pyramidal elements of the downstream part and the delivery wall of the capsule are designed so that - in a first step, the delivery wall interacts with the pyramidal elements and assumes an imprint of the pyramidal elements on its surface facing the pyramidal elements without visible piercing of the delivery wall, - in a second step, upon contact of the fluid injected in the capsule with the surface of the delivery wall facing the chamber of the capsule, permeable openings appear in the structure of the delivery wall through cavities in the structure of one or more of the layers of the delivery wall, and - during a third step, the formed beverage is drained from the capsule and contacts the extraction plate. Preferably, the capsule of the system of the invention is compostable and made of cellulose- based material, preferably molded-pulp cellulose-based material. The invention also relates to the use of a capsule in the system of the invention. L'invention concerne un système comprenant un dispositif d'extraction d'une machine de préparation de boisson et une capsule ; la capsule comprend un corps de capsule et une paroi de distribution formant une chambre ; le dispositif d'extraction comprend des parties amont et aval de confinement de capsule relativement mobiles entre une position ouverte pour insérer et/ou éjecter la capsule et une position fermée pour former une chambre d'extraction confinant la capsule pendant l'extraction ; la partie aval comprend