不同终压对火龙果切片真空预冷效果的影响

The Effect of Different Pressures on the Vacuum Cooling Performances for Sliced Dragon Fruit

研究了不同终压(400～800Pa)下真空预冷对火龙果切片降温速率、失水率以及预冷后在4℃冷藏温度下72h内的持水性、pH值、硬度和色泽指标的影响。结果表明:终压变化对降温速率和失重率的影响都不大,然而,适当的升高终压却可以延缓持水性、pH值、硬度及色泽的变化。综合比较得知,预冷终压在700～800Pa时火龙果切片在4℃冷藏温度下产品货架期最长,为60h。

The effect of different final pressures（400～800Pa） on the vacuum cooling performances of sliced dragon fruits was studied.The cooling rate,weight loss and typical property changes（water binding capacity,pH value,hardness,colour and luster） during the storage period of 72 hours at 4℃.The results indicate that effects of final pressures on cooling rate and weight loss were not significant.However,increasing final pressure in the certain range can delay the changes of water binding capacity,pH value,hardness,colour and luster.The conclusion was drawn that 700～800Pa is considered as the best final pressure interval since the sliced dragon fruit cooled under thses pressures can be stored for 60 hours at 4℃ without significant quality change.