I have a book entitled ‘Making and Using Dehydrated Foods’, by Phyllis Hobson - I think it was recommended as a good book on the subject.
It does advise a dunk in acid, either ascorbic acid, pineapple juice, or a mixture of 1/4 C. lemon juice and 2 C. water.
I can’t find the Excalibur book right now, but I’ll check tomorrow.
-JT
/johnny