PURPOSE: To form a stable coating film to the surface of a food, easily, and to prevent the secondary contamination with bacteria, by applying an aqueous solution containing alginic acid and pectin to the surface of a food in the form of a thin film, and contacting the film with a gel-forming agent composed of an aqueous solution of a calcium salt.
CONSTITUTION: Fresh or cooked meat, fish, vegetables, etc. are immersed in or sprayed with an aqueous solution containing about 0.5W5% of alginic acid and 0.2W3% of pectin to form a liquid film of about 0.5W3mm in thickness to the surface of the food. A gel-forming agent consisting of an aqueous solution containing 1W 10% of a calcium salt such as calcium chloride, calcium sulfate, calcium phosphate, etc., is sprayed uniformly to the liquid film. A considerably hard film is formed to the surface by this process. In case of coating the surface of soup, a hotchpotch, a Japanese hotchpotch, etc., the liquid part of the soup, etc. is coagulated by adding gelatin, etc. thereto, the above film-forming solution is poured to the coagulated surface to the thickness of about 1W3mm, and the gel-forming agent is sprayed to the liquid layer to obtain a considerably hard coating film.