Effect of different freezing rates on the quality change of Carica papaya L.

The freeze features(freezing curve,freezing rate,the time through the largest ice crystals,freezing point)and the quality change of Carica papaya L. under the different freezing conditions were investigated. Results showed that the freezing point was changed with the freezing rate,it was ranges from-1.1℃ to-1.7℃. The time through the largest ice crystals were all reduced with the increase of the freeing rate. The p H of the Carica papaya L. were all reduced after freezing,and with the increase of the freezing rate,riploss,whiteness and browning degreedecreased. And the freezing rate of VC,soluble solids content of Carica papaya L. had little impact. Freeze on Carica papaya L. PPO and POD enzyme activity had certain inhibitory effect,with the increase of freezing rate both of the two enzyme activity were the trend of first increases and then decreases.According to the results of physical and chemical index and sensory evaluation,the high freezing rate was helpful for maintaining the quality of the Carica papaya L..