Patent ID: 8399037

Claim:
A method of manufacturing grain having an increased content of γ-aminobutryic acid comprising: a humidification step humidifying grains of a raw material by applying to the grains humidifying air having a temperature of 50° C. or more and a relative humidity of 90% or more, at a humidification rate of 0.3% /hour or less such that the moisture content of the grains rises within the range of 16.0% to 18.5% with the temperature of the humidifying air being increased in stages as time advances; a stationary step of allowing the humidified grains to stand still for 2 to 6 hours with the applying of humidifying air to the grains stopped, thereby allowing γ-aminobutryic acid contained in the outer surface portion of the grains to permeate into the interior of the grains; and a dehydration step of drying the grains by applying heated air to the grains after the stationary step, wherein immediately after the start of the dehydration step the relative humidity of the heated air applied to the grains is increased by mixing the heated air with humidified air.