A capsule comprises a casing (202) that includes: a base wall (203) and a side wall (204) defining a cavity (205) that is suitable for containing a food preparation (P); a flange-shaped edge (206) extending from the side wall (204), the side wall (204) being deformable along preset lines of pliability (219, 220) to enable the casing (202) to be compressed along a direction (A) that is transverse to the base wall (202). The capsule (201) further comprises: a cover element (208) fixed to the flange edge (206) to close the cavity (205) hermetically and a nozzle (210; 310), fixed to the cover element (208), which is housed in the cavity (205). The nozzle (210; 310) comprises: a first end (211; 311) and a second end (212; 312) that are opposite; a first portion (213; 313) that includes the first end (211; 311), is arranged for receiving injection means of fluid (F) and comprises a plurality of openings (213a; 313a) for supplying the fluid (F) from the injection means to the cavity (205); a second portion (214; 314) that includes the second end (212; 312), extends through the outlet opening (207) and comprises a first tubular part (214a; 314a) with a constant section, and a second part (214b; 314b) that is shaped with respect to the first part (214a; 314a), in which the second portion (214; 314) further comprises an outer flange (215; 315) that peripherally surrounds the second end (212; 312) and closes the outlet opening (207) when the capsule (201) is in a first, undeformed, configuration (K). The outer flange (214; 314) of the nozzle (210; 310) is configured for pushing the closing element (209) outwards to open the capsule (201), when the capsule (201) is compressed to pass from the first configuration (K) to a second, deformed, configuration (J). Moreover, the second part (214b; 314b) of the nozzle (210; 310) is configured for projecting beyond the base wall (203) of the capsule (201) when the capsule (201) is further compressed passing from the second configuration (J) to a third′ configuration (E), which is deformed further. In addition, the second part (214b; 314b) of the nozzle (210; 310) is shaped into a divergent form so as to guide outwards the food preparation (P) that exits the outlet opening (207) pushed by the pressurised fluid (F) when the capsule (201) is in the second configuration (J) or in the third configuration (E).