Methods for treating, and/or cooling of a target item to reduce or eliminate biological microorganisms in or on a target item. The treating agent of the invention is particularly useful for treating food products, food storage, and food transportation devices as well as treating water, or other target objects. A treating agent containing a sanitizing agent entrapped by or absorbed in or on a cooling agent is used when processing, transporting, displaying, or storing of target items. The treating agent can be used to chill and preserve target items while providing the added benefit of sanitizing the target item. The novel processes of the current invention provide for using a treating agent to process, store, or package target items using a treating agent containing a cooling agent, such as solid carbon dioxide (“dry ice”), and a sanitizing agent, such as ozone.