Patent GB-462170-A (GB)
Title: Improvements in colouring foodstuffs
IPC: A23L1/275
Filed: 1935-08-24
Abstract: Fruit and vegetables which are subsequently sterilized by heating and stored are coloured by means of derivatives of 4.4<1>-diaminotriphenyl-carbinol corresponding to the general formula <FORM:0462170/IV/1> where the R1 is an ethyl or hydroxyethyl group, R2 is ethyl, Z is hydrogen or halogen, alkyl, hydroxyalkyl or alkoxy, X is hydrogen or halogen, hydroxy, alkoxy or sulphonic, and one Y is hydrogen, an amino group or the radicle of a primary or secondary amine, the other Y being hydrogen.  The sulphonic acid derivatives of the dyestuffs may be used.  Dyestuffs suitable for colouring beans are derived from 2-6-dichlorbenzaldehyde, o-chlorbenzaldehyde or o-chlor-m-nitrobenzaldehyde and two molecular proportions of diethylaniline; from 2-6-dichlorbenzaldehyde or o-methylbenzaldehyde and two molecular proportions of N-ethyl-N-benzylaniline sulphonic acid; from tetraethyldiaminobenzhydrol and a molecular proportion of 2-naphthol-3-6-disulphonic acid; by condensing two molecular proportions of diethylaniline in the presence of sulphuric acid with a molecular proportion of m-nitrobenzaldehyde, reducing the leuco-compound obtained in sulphuric acid solution with zinc dust to form the amino compound which is treated with about a molecular proportion of benzyl chloride in alkaline solution, the resulting di-p-diethylaminophenyl-m-benzylamino-phenyl methane being sulphonated and the disulphonic acid of the leuco-compound oxidized with lead dioxide to give the dyestuff; by reducing the leuco-compound obtained from two molecular proportions of diethylaniline and one of m-nitrobenzaldehyde and treating it with an excess of benzyl chloride in alkaline solution to form di-p-diethylamino-m-dibenzylaminophenylmethane, which is sulphonated and the disulphonic acid of the leuco-compound oxidized with lead dioxide to form the dyestuff.  For colouring spinach there may be used the dyestuff prepared by reducing the leuco-compound obtained from two molecular proportions of diethylaniline and one of m-nitrobenzaldehyde, and condensing it in soda-alkaline solution with 2.4-dinitro-1-chlorbenzene, the di-p-diethylaminophenyl-m-2<1>.4<1>-dinitro - phenylaminophenylmethane obtained being sulphonated and the disulphonic acid of the leuco-compound oxidized with lead dioxide to give the dyestuff.  For colouring peas there may be used the dyestuffs obtained by condensing a molecular proportion of p-chlorbenzaldehyde with two molecular proportions of N-dihydroxy-m-toluidine, N-dihydroxyethyl-m-chlor- (or brom-) aniline or N-dihydroxyethyl-m-methoxyaniline, oxidizing the leuco-compound and exchanging the chlorine atom in the p-position by the radicle of p-phenetidine, aniline, toluidine, chlortoluidine or cresidine.  The Provisional Specification describes the use for colouring beans of a dyestuff derived from tetraethyldiaminobenzyhydrol and a molecular proportion of m-xylyl disulphonic acid.ALSO:Fruit and vegetables which are subsequently sterilized by heating and stored are coloured by means of derivatives of 4.41-diamino-triphenyl-carbinol corresponding to the general formula <FORM:0462170/VI/1> where the R1 is an ethyl or hydroxyethyl group, R2 is ethyl, Z is hydrogen or halogen, alkyl, hydroxyalkyl or alkoxy, X is hydrogen or halogen, hydroxy, alkoxy or sulphonic, and one Y is hydrogen, an amino group or the radicle of a primary or secondary amine, the other Y being hydrogen.  The sulphonic acid derivatives of the dyestuffs may be used.  Dyestuffs suitable for colouring beans are derived from 2-6-dichlorbenzaldehyde, o-chlorbenzaldehyde or o-chlor-m-nitrobenzaldehyde and two molecular proportions of diethylaniline; from 2-6-dichlorbenzaldehyde or o-methylbenzaldehyde and two molecular proportions of N-ethyl-N-benzylaniline sulphonic acid; from tetraethyl-diaminobenzhydrol and a molecular proportion of 2-naphthol-3-6-disulphonic acid; by condensing two molecular proportions of diethylaniline in the presence of sulphuric acid with a molecular proportion of m-nitrobenzaldehyde, reducing the leuco-compound obtained in sulphuric acid solution with zinc dust to form the amino compound which is treated with about a molecular proportion of benzylchloride in alkaline solution, the resulting di-p-diethyl-aminophenyl-m-benzylamino-phenyl methane being sulphonated and the disulphonic acid of the leuco-compound oxidized with lead dioxide to give the dyestuff; by reducing the leuco-compound obtained from two molecular proportions of diethylaniline and one of m-nitrobenzaldehyde and treating it with an excess of benzyl chloride in alkaline solution to form di - p - diethylamino - m - dibenzylaminophenylmethane, which is sulphonated and the disulphonic acid of the leuco-compound oxidized with lead dioxide to form the dyestuff.  For colouring spinach there may be used the dyestuff prepared by reducing the leuco-compound obtained from two molecular proportions of diethylaniline and one of m-nitrobenzaldehyde, and condensing it in soda-alkaline solution with 2.4-dinitro-1-chlorbenzene, the di-p-diethyl-aminophenyl - m - 21.41 - dinitro - phenylamino-phenylmethane obtained being sulphonated and the disulphonic acid of the leuco-compound oxidized with lead dioxide to give the dyestuff.  For colouring peas there may be used the dyestuffs obtained by condensing a molecular proportion of p-chlorbenzaldehyde with two molecular proportions of N - dihydroxy - m - toluidine, N-dihydroxyethyl-m-chlor- (or brom-) aniline or N-dihydroxyethyl-m-methoxyaniline, oxidizing the leuco-compound and exchanging the chlorine atom in the p-position by the radicle of p-phenetidine, aniline, toluidine, chlortoluidine or cresidine.  The Provisional Specification describes the use for colouring beans of a dyestuff derived from tetraethyl-diaminobenzhydrol and a molecular proportion of m-xylyl disulphonic acid.