Kletzinsky published years ago formulas for 15 fruit essences, which, in 1867, were republished by several journals. Some of these formulas were again produced in the Confectioners' Journal without any alterations, except that in the essence of apple the quantity of oxalic acid was reduced from 1 to 1/4 part, and glycerine from 4 to 2 parts; in essence of raspberry, the succinic acid was entirely omitted, and essence of peach was directed to be made of 2 oz. oil of bitter almonds, 1 oz. acetic ether, and 2 pints alcohol; but the latter product has evidently the flavour of peach kernels accompanied by a slight fruit odour. The flavour of peach fruit may be imitated by using 5 parts each acetic-butyric and amylacetic ethers, 1/2 (or less) of methyl-salicylic ether (oil of wintergreen), 2 or 3 parts oil of bitter almonds, and 80 or 100 of alcohol.
Kletzinsky's formulas for the extracts of strawberry and raspberry are much improved by adding 10 to 20 per cent, of tincture of orris root. If desired, the rather acrid taste of this tincture may be removed by precipitating the resin, and if solution of lead acetate is used for this purpose, the filtrate should be carefully freed from any excess of lead by sulphuretted hydrogen, or by agitation with solution of sodium sulphate, which salt, being insoluble in the alcoholic liquid, will not impart its peculiar saline taste. The tincture of orris may probably be conveniently replaced by an alcoholic solution of the oil of orris, which has been an article of commerce for some years past.
Since several very important errors had crept into the formulas of Kletzinsky as published in 1867, some of which are, however, readily corrected, it has been thought best to republish all the formulas from Wittstein's Vierteljahresschrift,' xvi. p. 268. These formulas are given in parts by measure for 100 parts alcohol, and whenever acids are used, they are to be previously dissolved in alcohol.
Aldehyde, 2 parts; chloroform, acetic ether, nitrous ether, and oxalic acid, each 1; glycerine, 4; amyl-valerianic ether, 10.
Butyric ether, 10; valerianic ether, 5; glycerine, 4; amy lie alcohol, 2; amyl-butyric ether, chloroform, oenanthic ether, and tartaric acid, each 1.
Consists usually of butyric ether and amyl-acetic ether, equal parts, dissolved in about 5 parts alcohol.
Tincture of orris root (1 to 8), 1 pint; acetic ether, 30 drops; butyric ether, 60 drops.
Benzoic ether, 5; acetic ether, 10; oil of persico (peach kernels) and benzoic acid, each 2; oxalic acid, 1.
Benzoic ether, acetic ether, each 5; glycerine, 3; oenanthic ether and benzoic acid, each 1.
Acetic ether, tartaric acid, each 5; benzoic acid, succinic acid, benzoic ether, aldehyde, and oenanthic acid, each 1.
(Enanthic ether, glycerine, each 10; tartaric acid, 5; succinic acid, 3; aldehyde, chloroform, and formic ether, each 2, and methyl - salicylic ether, 1.
Oil of lemon, acetic ether, and tartaric acid, each 10; glycerine, 5; aldehyde, 2; chloroform, nitrous ether, and succinic ether, each 1.
Sebacylic ether, 10; valerianic ether, 5; glycerine, 3; butyric ether, 4; aldehyde, 2; formic ether, 1.
Oil of orange and glycerine, each 10; aldehyde and chloroform, each 2; acetic ether, 5; benzoic ether, formic ether, butyric ether, amyl-acetic ether, methyl-salicylic ether, and tartaric acid, each 1.
Formic ether, valerianic ether, butyric ether, acetic ether, glyferine, and oil of persico, each 5; aldehyde and amylic alcohol, each 2; seba-cylic ether, 1.
Acetic ether, 5; amyl-acetic ether and glycerine, each 2.
Amyl-butyric ether, 10; butyric ether, 5; glycerine, 3; aldehyde and chloroform, each 1.
Glycerine, 8; acetic ether and aldehyde, each 5; oil of persico, 4; butyric ether, 2; formic ether, 1.
Acetic ether and tartaric acid, each 5; glycerine, 4; aldehyde, formic ether, benzoic ether, butyric ether, amyl-butyric ether, acetic ether, eenanthic ether, methyl-salicylic ether, nitrous ether, sebacylic ether, and succinic acid, each 1.
Butyric ether and acetic ether, each 5; amyl-acetic ether, 3; amyl-butyric ether, and glycerine, each 2; formic ether, nitrous ether, and methyl-salicylic ether, each 1.
The different manufacturers of artificial fruit essences doubtless prepare them by formulas of their own, and this explains the difference in the flavour, which is particularly noticeable on largely diluting them with water. If the essences have been prepared with a dilute alcohol, their odour is more prominent, and they are apparently stronger; but on mixing a small quantity with a large amount of water in given proportions, the true flavouring strength maybe better discerned.
The red colour of strawberry and raspberry essences is produced by aniline red (fuchsine), the bluish tint of which is conveniently neutralized by a little caramel. If caramel alone is used for colouring essence, a yellow or brown colour is obtained, according to the quantity used. (Maisch, Amer, J I. Pharm.)