Effect of high hydrostatic pressure processing of quality enzyme and sterilization in strawberry juice

The effect of high pressure treatment on polyphenol oxidase, pectinesterase and sterilization in strawberry juice were investigated. The results showed that:high pressure treatment had good effect on sterilization, microbial decreases significantly with the increase of pressure.300 MPa, 15min, total bacterial count and mold yeast count in strawberry juice were in accordance with commercial aseptic conditions. PPO and PME were resistance to pressure, on low pressure condition, the activity of PPO and PME were activated which increased with pressure and time. Well, the enzyme activity was significantly decreased (p<0.05) on high pressure. 600 MPa, 25min, PPO and PME residual enzyme activity dropped to 74.6% and 47.0% respectively.