Lower temperature and higher humidity helps preserve vitamin C

One of the ways we enjoy preserve fruit is to dehydrate it. This takes out the moisture and thus concentrates up the sugars. Yum. A study looked at vitamin C levels in kiwifruit with different drying conditions.

The lower the temperature the most vitamin C was preserved. This makes sense as vitamin C is a heat sensitive vitamin. The temperatures used were 35, 45, 55 and 65 °C. at 35 degrees I would have thought that the drying would have taken so long that more vitamin C would have been lost. However this doesn't seem the reality. I will have to get another dehydrator cause ours doesn't have a temperature control and must be quite hot as it dehydrates fast.

The other discovery was that the higher the humidity the more vitamin C is preserved. I find this very interesting as I can't explain why this would be. I will however put a saucer of water in the dehydrator after a while as the humidity starts to drop as the fruit becomes drier. 

Reference.