PROBLEM TO BE SOLVED: To provide a drying method of food materials weak in heat denaturation, and a simple drying device suitably used for the drying method, capable of performing efficient drying without denaturing the food materials weak in heat denaturation, and achieving desired moisture content.SOLUTION: In this drying method of the food materials weak in heat denaturation, a lower limit pressure and a lower limit temperature at that time are determined, and an upper limit pressure and an upper limit temperature at that time are determined, in drying the food materials weak in heat denaturation under a reduced pressure in a state of placing the same in a drying chamber 11. The moisture of the food materials is evaporated by reducing a pressure in the drying chamber 11 to the lower limit pressure, to reach a saturation temperature under the lower limit pressure, and then low-temperature steam of 100°C or less is injected to heat the food materials to the upper limit temperature to reach the upper limit pressure. This operation is repeated, for example, some dozen times to lower the moisture content of the food materials, for example, to 20% or less.COPYRIGHT: (C)2011,JPO&INPIT【課題】熱変性に弱い食品材料を変性させることなく、効率良く乾燥させることができ、所望とする含水率を得ることができる熱変性に弱い食品材料の乾燥方法及びその乾燥方法に適した簡易な乾燥装置を提供する。【解決手段】熱変性に弱い食品材料の乾燥方法は、熱変性に弱い食品材料を乾燥庫11内に収容して減圧下で乾燥するに際し、下限圧力とそのときの下限温度を設定すると共に、上限圧力とそのときの上限温度を設定する。そして、乾燥庫11内の圧力を下限圧力まで下げて前記食品材料の水分を蒸発させ、下限圧力での飽和温度に到らしめた後、100℃以下の低温水蒸気を注入して食品材料を上限温度まで加熱し、上限圧力まで到らしめる。この操作を例えば数十回繰り返すことにより、食品材料の含水率を例えば20%以下に低下させる。【選択図】図1
