When, in the judgment of the commissioner, honest and fair dealing in the interest of consumers will be promoted, the department shall adopt regulations fixing and establishing for food or class of food a reasonable definition and standard of identity, a reasonable standard of quality, and reasonable standards of fill of container. In prescribing a definition and standard of identity for food or class of food in which optional ingredients are permitted, the department shall, for the purpose of promoting honesty and fair dealing in the interest of consumers, designate the optional ingredients which shall be named on the label. The definitions and standards adopted shall conform as far as practicable to the definitions and standards adopted under authority of the federal act. The department shall establish a mobile canned food inspection service available upon request to food packers or processors inside the state.