Optimization of the dense phase carbon dioxide treatments on apple puree

The dense phase carbon dioxide treatment(DPCD) was applied to hold the quality of the fresh apple puree.The effect of DPCD pressures,time and temperature on sterilization efficiency and total color change of the fresh apple puree were investigated.And then the response surface methodology was used to optimize the DPCD parameters.The results showed that the optimal DPCD parameters were the DPCD pressure of 20 MPa at 40 ℃ for45 min.Under the optimal conditions,the total colony count of the fresh apple puree was 1.5 lg cfu / m L with the total color change of 1.02.The relative error of the test results was less than 5%. The regression model is true and reliable.