PROBLEM TO BE SOLVED: To increase a consumption effect by imparting an additional value such as the suppression of the lowering of freshness to a frozen food by improving a freezing process of the frozen food.SOLUTION: In the freezing process, a closed pace to be cooled in freezing equipment (for example, the inside of a contact freezer chamber) is brought into a vacuum state by using a vacuum pump, a moisture is removed, next, a nitrogen gas is injected into the freezer chamber, the inside of the freezer chamber is filled with the nitrogen gas, and a portion at which the food is coated with the nitrogen gas is frozen. A temperature at freezing is set at 40°C below the freezing point, and a freezing storage temperature is set at 35°C below the freezing point. As machines for implementing the freezing process, there are employed the vacuum pump which draws out air from the closed space to be cooled of the freezing equipment, and a nitrogen injection device which injects the nitrogen gas into the closed space which is reduced in pressure by the operation of the vacuum pump.COPYRIGHT: (C)2012,JPO&INPIT【課題】冷凍食品の凍結工程を改良することにより、冷凍食品に鮮度低下抑制という付加価値を与え消費効果を増大させる。【解決手段】凍結工程において、凍結設備内の冷却されるべき閉鎖空間(例えば、コンタクトフリーザー室内)を真空ポンプにより真空状態にして水分を除去し、次に窒素ガスをフリーザー室内に注入し室内を窒素ガスで充満させ、食品が窒素ガスでコーティングされたところを凍結する。凍結の際の温度を氷点下40度とし、冷凍保管温度を氷点下35度とする。その凍結工程を実現する機械として、凍結設備の冷却されるべき閉鎖空間から空気を抜く真空ポンプと、前記真空ポンプの働きにより減圧された前記閉鎖空間に窒素ガスを注入する窒素ガス注入装置とを有する。【選択図】図2
