Fuente: WIPO Food Portada PROBLEM TO BE SOLVED: To provide a food quality-keeping agent composition, a food quality-keeping agent ink, a food quality-keeping agent containing the composition or the ink, a method of detecting a food quality-keeping agent in a food package, and a method of inspecting the food package, capable of efficiently performing both inspection of a metal foreign matter in a food package in a sealed state and inspection of omitted affixture of the food quality-keeping agent.SOLUTION: This invention relates to a method of detecting a food quality-keeping agent, etc., in a food package in which the food quality-keeping agent containing a magnetized body is sealed, the method including: a step of magnetizing the magnetized body or reinforcing the magnetic force of the magnetized body; and a step of detecting the magnetized body that has been magnetized or reinforced in its magnetic force and detecting presence or absence of the food quality-keeping agent.SELECTED DRAWING: NoneCOPYRIGHT: (C)2020,JPO&INPIT