Temperature of soymilk reached in the high pressure valve in combination with very short time (approximately 0.7 s in this UHPH machine) at this temperature determined the quality characteristics of UHPH-treated samples. Temperature increase during UHPH treatment (Table 1) was about 20 C between 200 and 300 MPa at the different inlet temperatures used in this study. This temperature increase was close to those observed by other authors. Pereda, Ferragut, Quevedo, Guamis, and Trujillo (2007), who pressurized milk in the same UHPH equipment at inlet temperatures of 30 C and 40 C and pressures from 100 to 300 MPa, found the same temperature change. Thiebaud et al. (2003) reported a temperature increase of 18.5 C per 100 MPa, in the pressure range 100e300 MPa for milk samples. The increase of temperature during UHPH treatment is the consequence of the adiabatic heating generated in the machine in addition to the turbulence, shear, and cavitation forces that the food experiments when passing through the ultra high pressure valve (Hayes & Kelly, 2003; Thiebaud et al., 2003).