不同冻结速率对冻后番木瓜品质的影响

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

研究木瓜在不同冻结方式下的冻结特性(冻结曲线、冻结速率、通过最大冰晶带时间、冻结点等)和品质变化。研究表明木瓜的冻结点随着速冻速率的改变而有所变化,但整体变化幅度不大,在-1.1^-1.7℃之间。提高冻结速率可减少通过最大冰晶带的时间。冻结后木瓜的p H均降低,且随着冻结速率的增大,干耗率、汁液损失率、褐变度逐渐减小,但冻结速率对木瓜中的VC、可溶性固形物含量影响很小。冻结对木瓜的PPO和POD酶活性有一定的抑制作用,随着速冻速率的增大,两种酶活性均呈先增大后减小的趋势。综合理化指标和感官评价结果,冻结速率快有利于保持木瓜的品质。

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 pH 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..