Chemical Properties
Fir balsam is a tall tree with a characteristic pyramidal shape and numerous branches The tree is widespread through- out North America, particularly in Canada (Nova Scotia) and the northern United States A liquid oleoresin is contained in vesicles under the back of the trunk This resin, known as Canada balsam, is collected between May and August from incisions made in the bark The operation is repeated on the same tree every 2 to 3 years Canada balsam is in fact a turpentine consisting mainly of resin and essential oil; the resin does not contain benzoic or cinnamic acids The balsam is a viscous, pale yellow to greenish-yellow, translucent mass that slowly dries on exposure to air The needles, twigs and balsam are the parts used Fir balsam has a balsamic, pleasant, fresh odor, reminiscent of spruce or hemlock.
Composition
Reducing sugars from fir balsam account for 47% of the balsam fir bark. The leaf oil contains 17.6%
bornyl acetate and probably 1-α-pinene, Canada balsam contains approximately 20% 1-β-phellandrene and smaller quantities of
α- and β-pinene, bornyl acetate, and the alcohols androl and bupleurol. Oils are reported to contain juvabione and dehydrojuvabione.
Balsams are supposed to contain benzoic and cinnamic acids. “Turpentine” is a misnomer, implying that the oleoresin is entirely
steam volatile. Actually it contains 70 to 80% resin, but only 16 to 20% volatile oil. One analysis of the essential oils reports 14.6%
bornyl acetate, 36.1% β-pinene, 11.1% 3-carene, 11.1% limonene, 6.8% camphene and 8.4% α-pinene.
