To determine precisely that temperature control of food is performed properly to keep freshness, and to specify a portion where the temperature control is performed improperly in a circulation process.

In this indicator holder 31 having a structure capable of sandwiching an indicator 30 expanded and changed by gas generation in a solution caused by elapse of time and an ambient temperature, used by being added to wrapping of food, and having a function for transmitting detected freshness information toward a freshness information management server for managing the freshness information, when receiving a freshness information acquisition request at a prescribed circulation point, the gas quantity in the indicator 30 is detected as the freshness information of food, and freshness detection information including the detected freshness information and holder information capable of discriminating the indicator holder 31 is transmitted.

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