An appliance system including a module (12) removably mounted to an appliance, one or more removable gas canisters operably connected to the module (12), and a food retaining enclosed space operably connected to the module (12). The one or more gas canisters supply a modified atmosphere in the food retaining enclosed space to produce a modified atmosphere that enhances preservation of the food contained in the food retaining enclosed space. A method of modifying the atmosphere in a food storage space for food includes the steps of: providing a module (12) capable of being removably engaged to an appliance (10) and typically receiving power from the appliance (10) and at least one removable gas canister; operatively connecting or otherwise engaging the module (12) with the appliance (10); operatively connecting or otherwise engaging the module (12) to a food storage area having an existing atmosphere; and removing at least a portion of the existing atmosphere from the food storage space and replacing it with a modified food storage atmosphere using at least one of the at least one removable gas canisters to supply the modified atmosphere to the food storage area.