Sap is not a chemistry word. Real chemists use the word
"terpenes". There are monoterpenes, diterpenes, sesquiterpenes, all based on isoprene -- C5H8 -- units linked together. When you distill conifer sap, you get an interesting assortment of various terpenes.
Since terpenes are hydrocarbons, they really aren't for human consumption. However, they are easy to oxidize molecules, and once oxidized, they become a little more digestible.
Limonene, the oil in lemon rind that gives it that particular lemony smell is a terpene, but there is little of it in the juice, which is what we consider the edible part. At the lemon juice plant, they bottle the juice for human consumption and they put the limonene in grease cutting cleaners.
