Application of High Pressure Treatment on Apple Slices
Abstract - The aim of this work was to evaluate the physicochemical and microbial quality of apple slices during four weeks
of storage at 4 °C. Three apple cultivars including ‘Idared’, ‘Granny Smith’ and ‘Braeburn’ were examined. Apple slices
were vacuum packed, then treated with high pressure of 450 and 600 MPa for 5 min at 20 °C. The effectiveness of treatment
on surface color, pH, soluble solid content, firmness and mesophilic aerobes were determined. Soluble solid content and pH
of treated apple slices were similar to control, whereas color change and softening were significantly affected by high
pressure treatment. Number of mesophilic aerobes on apple slices were reduced by high pressure treatment below detection
level (less than 1 log CFU/cm2) and remained below the limit of detection during 28 days of cold storage at 4 °C in case of
samples treated with 600 MPa. The counts on apple slices treated with 450 MPa after four weeks were less than on the
control 3.1, 0.5 and 4.0 log CFU/cm2 for ‘Idared’, ‘Granny Smith’ and ‘Braeburn’, respectively. The results indicated that
high pressure treatment was beneficial in controlling the growth of mesophilic aerobes on apple slices.
Keywords - High Hydrostatic Pressure.