Abstract: A water filter cartridge has a cylindrical shell. A conduit runs between closing end walls and is disposed within a filtration material. There are additional openings in the respective end walls for communicating the flow of water through the material. A water filtration element of a porous medium is shaped to nest within a portion of the shell encircling a corresponding portion of the filtration material and defining space between the medium and the inner side wall of the shell with that space being in the water flow path from one of the end walls and the material through the medium. A reference color is exhibited over a portion of the exterior side wall of the shell adjacent to the location of the medium inside the shell, and the medium exhibits a given color upon beginning of usage but changes color with continued usage in response to its entrapment of matter in the water. The shell is transparent over the medium to enable the user to compare the medium color to the reference color.

Abstract: A method of producing a porous pelletized food product.A mixture of finely divided, particulate edible materials, including at least one material which acquires surface stickiness when moistened and a chemical leavening system is contacted with a spray of water and formed into pellets on a pelletizing disc. The moist pellets are contacted with a stream of hot air to effect reaction of the components of the leavening system with the release of carbon dioxide gas to provide the pellets with a porous cellular structure, and to dry the pellets. The resulting dried pellets have a crisp, crunchy, friable texture, and sufficient mechanical strength to permit the pellets to be compacted at a pressure of 500-750 psi without crumbling or disintegration of the pellets. If desired, the pellets may be coated with an edible fat having a relatively high melting point to produce porous, non-hydrating food pellets.