Here is a Catholic :shock: site that is very detailed in it's look at Melchizedek and the use of bread and wine.
http://www.kensmen.com/catholic/mass.html
I have not digested this lengthy work, but it does appear to provide a number of answers and clues to answers for your question.
Ephraem
~He who seeth his own sins, seeth not the sins of others.
It doesn't touch too much on sacramental substances, but this entry on Melchizedek is a wonder:
http://www.jewishencyclopedia.com/view. ... 3&letter=M
The Jewish Encyclopedia is always interesting and detailed, though it is probably good advice to be very cautious of the many hoary tangles of tales you will find there.
Shame that I don't have nice Orthodox references to share.
Ephraem
~He who seeth his own sins, seeth not the sins of others.
