Abstract
Food (i.e. vegetables, tofu, egg-custard gel, agar gel or kon-nyaku) was pressurized at 0.1∼686 MPa and -20°C. Texture and structure were compared with the untreated control or food frozen in freezers (-20°C, -30°C or -80°C) at 0.1 MPa. At 200∼400 MPa, food was supercooled and froze rapidly with released pressure. Therefore, the size of ice crystals was small. Thus, pressure-shift-freezing at 200∼400 MPa was effective in improving the quality of frozen food with the exception of kon-nyaku. With an increase of sugars, the appearance, texture and structure of all gels improved.
