本文模拟了公路运输草莓的汽车在运输过程中的机械振动情况,研究了机械振动对草莓后期贮藏品质的影响。通过扫频振动实验,测得了所选草莓包装件的固有频率为20.5 Hz。在17 Hz、19 Hz、20.5 Hz、22 Hz以及24 Hz 5种频率下,分别进行了草莓的定频振动实验。以硬度、可溶性固形物含量、可滴定酸含量、维生素C含量以及丙二醛(MDA)含量为评价指标,研究了经机械振动后的草莓在0℃、5℃以及10℃贮藏时的品质变化情况。研究发现:经过机械振动后贮藏的草莓,品质的变化是机械振动频率与贮藏温度相互耦合的结果;贮藏温度相同时,经历了固有频率振动的草莓最不易保存,在0℃下贮藏9天后,硬度降低了15.5%,而MDA含量增加了30%;在相同的振动频率下,0℃保存效果最佳。
The road transport process was simulated in the vibration bench, the natural frequency of selected strawberry package was found to be 20.5 Hz by scanning frequency experiment. Fifteen same strawberry packages have been tested in the fixed frequency experiment under 17 Hz, 19 Hz, 20.51 Hz, 22 Hz and 24 Hz, respectively. After the fixed frequency experiment, strawberries in the fifteen packages were divided into three groups to be stored at 0 ~C, 5 ~C and 10 ℃ respectively. The effects of mechanical vibration on the hard- ness and SSC, titratable acid, vitamin C and MDA contents of each group of strawberries have been analyzed. The results showed that the storage qualities of strawberry were determined by both mechanical vibration frequencies in the transport process and storage temperature. At the same storage temperature, the qualities of the strawberries suffered natural frequency vibration test are the worst. After 9 days of 0 ℃ storage, the strawberry's hardness has been reduced by 15.5%, while the strawberry MDA content has been increased by 30%. 0 ℃ is the best storage temperature for strawberries suffered same frequency vibration test.