荔枝果汁贮藏过程中理化指标和营养成分的变化

摘要

To explore the changes of nutrients and physicochemical index of litchi juice during different storage temperature, the changes were measured in browning index (A420, absorbs nee at 420 nm). pH and the contents of soluble solid CSS), sucrose, ascorbic acid and free amino compounds of litchi juice by ultra-high temperature treat-merit. The results showed that during storage A420 of litchi juice did not change significantly in the 4 ℃ , A420 gradually increased in 25 ℃ ,37 ℃. 50 ℃ with prolonged storage. During different storage temperature of litchi juice, pH and the contents of soluble solid changed slowly. The change of sucrose content was not obvious at 4 ℃. But was decreased gradually at 25 ℃, 37 ℃ and 50 ℃. Ascorbic acid content is decreased slowly at 4 ℃, but it is rapidly declining in the 25 ℃ , 37 ℃ and 50 ℃. Changes in amino acid content is little at 4 ℃ and 25 ℃. However, is the rapid decline in amino acids at 37 ℃ and 50 ℃. Therefore,the storage effect of litchi in Lower temperature is more superior to that of ordinary storage, especially for the nutritional content of litchi lose less.%为探讨荔枝果汁在贮藏过程中理化指标和营养成分的变化情况,将荔枝原汁经超高温处理后,分别在4,25,37,50℃下贮藏,测定果汁的褐变度、色泽、pH值、固形物含量、蔗糖、抗坏血酸和游离氨基酸的变化.结果表明:荔枝果汁在贮藏过程中,4℃下A480变化不显著,25,37,50℃下随着贮藏时间延长,A120逐渐增大；4,25,37,50℃下pH值和可溶性固形物随着贮藏时间延长,都呈缓慢上升趋势；蔗糖含量4℃下无明显变化,25,37,50℃下蔗糖含量呈下降趋势;抗坏血酸含量4℃下缓慢下降,25,37,50℃下抗坏血酸含量下降较快;氨基酸的含量在4,25℃时变化较小,但是在37,50℃下氨基酸含量下降较快.进一步说明低温贮藏效果优于普通贮藏,尤其荔枝的营养成分损失较少.