Co2 hydrate for oral ingestion or complex for oral ingestion containing said co2 hydrate, and methods respectively for producing those products

The present invention addresses the problem of providing: a CO 2 hydrate for oral ingestion which is reduced in the risk of carbon dioxide intoxication when added to a food or beverage and then orally ingested through the food or beverage or orally ingested directly, and has a sufficient sensation of carbonated water and higher safety, and others; and methods for producing the CO 2 hydrate and others. The present invention also addresses the problem of providing: a CO 2 hydrate for oral ingestion, of which the sustained CO 2 release is controlled so that the maximum CO 2 generation rate upon the melting of the CO 2 hydrate under an environment similar to human oral cavity can become less than 8 mL/sec., and others; and methods for producing the CO 2 hydrate and others. The CO 2 hydrate is characterized by being so adjusted that the maximum CO 2 generation rate can become less than 8 mL/sec. (Definition of maximum CO 2 generation rate (mL/sec)) The following test is repeated three times: the CO 2 hydrate is sampled in such an amount that 0.3 to 0.36 g of CO 2 is contained in the CO 2 hydrate, then the sampled CO 2 hydrate is added to 10 mL of water having a liquid temperature of 37oC under an atmosphere having an atmospheric pressure at room temperature (37oC) and at a humidity of 70%, then the change in weight of the solution is measured at intervals of 5 seconds for a total period of at least 30 seconds after the addition of the CO 2 hydrate to calculate the amount (mL) of CO 2 generated during every 5 seconds, and then a CO 2 generation rate (mL/sec) during every 5 seconds is calculated from the generated amount (mL). The largest value, among the values for the CO 2 generation rates (mL/sec) during every 5 seconds which are obtained by the repeated test, is employed as a maximum CO 2 generation rate (mL/sec) for the CO 2 hydrate.