In the meantime a number of comparatively harmless aniline colours have been permitted in Austria for colouring sugar goods and liqueurs, and eventually also for cacao preparations.[160] As in the author’s opinion there is no ground for objecting to their use in other countries, a list of them is given under their commercial and scientific designations.
| Red: | Fuchsin = Rosaniline hydrochloride, soluble in water and alcohol. |
| Acid Fuchsin or Fuchsin S or Rubin = Sodium or calcium acid salt of rosaniline disulphonic acid, soluble in water. | |
| Rocellin or Roscellin (Fast Red) = Sulpho oxyazonaphtalin, soluble in water. | |
| Bordeaux and Ponceau red = product of the combination of β naphtol-disulphonic acid with diazo-compounds of Xylol and higher homologues of benzol, soluble in water. | |
| Eosin = Tetrabrom-fluoresceïn, soluble in water and alcohol. | |
| Phloxin = Tetrabromo-dichlor-fluoresceïn, soluble in water. | |
| Erythrosin = Tetra iodio-fluoresceïn, soluble in water. | |
| Blue: | Alizarin blue = Dioxyanthraquinone-quinoline, slightly soluble in alcohol. |
| Aniline blue = Triplienylrosaniline, soluble in alcohol. | |
| Water blue = Triphenylrosaniline, sulphonic acid soluble in water. | |
| Induline = Azodiphenyl blue sulphonic acid and its derivatives, soluble in alcohol. | |
| Yellow: | Acid yellow R or fast yellow R = Sodium amidoazobenzol-sulphonate, soluble in water. |
| Tropaedlin 000 or Orange I = Sulphoazobenzoll α-naphthol, soluble in water. | |
| Naphtholyellow = Sodium salt of dinitro-α-naphthol sulphonic acid, soluble in water. | |
| Violet: | Methylviolet = Hexa-and penta-methylpara-rosaniline hydrochloride, soluble in water and alcohol. |
| Green: | Malachite green = Tetramethyl-diamidotriphenyl-carbinol hydrochloride, soluble in water and alcohol. |
The above, as well as the following colours: (blue) amaranth, brilliant blue and indigosulfone, (red) erythrosin, also acid yellow S, orange L and light green S F, have in the meantime been accepted by the American Foods Act as perfectly harmless for colouring any and all articles of food.[161]
For some time past E. Merck of Darmstadt has supplied a perfectly harmless green colouring material under the name of chlorophyll, in alcoholic and in water solutions, as well as technical chlorophyll, for colouring oils and fats, which is the unaltered leaf green and is the best green colouring agent for articles of food and therefore for cacao preparations.
The chlorophyll which is soluble in fat has also been recommended like some of the aniline colours which are soluble in fat, as for example: Indulin 6 B (blue), Sudan yellow G, Sudan III (red), and Gallocyanin (violet) for colouring cacao butter; but in regard at least to the aniline colours mentioned, no authoritative sanction for their use has yet been given.
Part IV.
Examination and Analysis of Cacao Preparations.
[A. Chemical and microscopical examination of cacao and cacao preparations.]
The following observations will serve as an introduction to the chemical and microscopical examination of cacao preparations calculated to be of special value to the food chemist, corresponding as they do to the state of scientific progress at the present day and special attention being paid to the critical treatment of the methods of analysis etc. adopted.