APPLICATION OF NON-THERMAL PROCESSING FOR INACTIVATION OF YEAST (Saccharomyces cerevisae) IN ORANGE JUICE

The application of non-thermal processing for inactivation of yeast (Saccharomyces cerevisiae) in orange juice were investigated in this study and compared with conventional thermal processing. The results of this study have shown that during conventional thermal processing less than 1 log of yeast in orange juice could be inactivated at 50 0C and 15 min treated time. High pressure treatment at moderate temperature (50 °C) and 100 to 300 MPa resulted totally (up to 6 log ) inactivation ofyeast in orange juice. Supercritical CO2/CO2 treatment at ≥6 MPa and 50 °C was sufficient to inactive yeast up to 6 log after 15 min treatment time. For high electric field pulses, the field strength used in this study (15 kV/cm) was high enough to reduce the yeast count up to 3 log after240 pulses. in orange juice. Inactivation of yeast in orange juice using ultrasound is possible. Ultrasound amplitude at ≥40% (≥80 W) combined with moderate temperature (50 0C) resulted up to 6 log inactivation of yeast in orange juice after 15 min treatment

Keywords:

non-thermal processing , orange juice , yeast inactivation , High pressure , ultrasound , high electric field pulses , supercritical carbon dioxide