SK20796A3 - Process for differentiating organic foodstuff residues on hard surfaces - Google Patents

Abstract

A process is disclosed for differentiating organic foodstuff residues according to their type on hard surfaces by applying a solution that contains a combination of at least two dyes, of which at least one is hydrophilic and at least one is hydrophobic, on the hard surface, then optically determining the residue type thanks to their specific colouring. Also disclosed are liquid compositions of dye mixtures and their use.

Description

Method of distinguishing organic food residues on hard surfaces

Technical field

The invention relates to a method for distinguishing organic food residues according to their type on hard surfaces by means of suitable color combinations. The invention further relates to liquid formulations of dye mixtures as well as to their use in the method of the invention.

BACKGROUND OF THE INVENTION

Any production or processing of foodstuffs or other materials containing organic constituents of animal or plant origin will result in contamination of equipment, working areas and premises. Such contamination can lead to the formation and reproduction of bacteria, fungi and microorganisms. Since this can greatly affect the quality of processed products and should be avoided, a high hygiene standard is required.

Regular cleaning and disinfection is essential to achieve a high hygiene standard in a food-processing company. In addition to inorganic salts, the food business usually also contains organic contaminants such as proteins, fats, low- and high-molecular carbohydrates, which are most commonly found together.

Various compositions are used to remove these contaminants. As a rule, the choice of suitable cleaning agents depends on the type of contaminant to be removed. If the type of contamination is known, its corresponding cleaning agent can be selected. However, different combinations of detergent ingredients cause a difference in cleaning performance against proteins, fats and carbohydrates. After the purification process, there may be small residual impurities in some circumstances which, although visually barely perceptible, present a microbiological risk.

So far, the hygiene standard has been controlled exclusively by bacteriological methods by establishing a culture. However, such hygiene standard control methods are inappropriate because they can only be used to identify living microorganisms (bacteria and fungi). Bacteriological methods do not detect organic contaminants that have given rise to bacterial reproduction. Therefore, the success of the purification cannot be immediately determined by bacteriological methods. In addition, bacteriological methods are time consuming and may take several hours, if not even days, to produce the final result.

In addition, the control of hygiene by bacteriological processes can lead to false results due to disinfection, which does not exclude the accumulation of organic impurities, which ultimately cause the reproduction of resistant micro-organisms. Furthermore, spot sampling does not guarantee that whole equipment and larger areas can be checked to the hygiene standard.

PCT Publication No. WO 90/14591 discloses a method of cleaning and at the same time controlling the success of cleaning and hygiene by applying a solution of a detergent / dye mixture or a combination of dyes to the surfaces to be cleaned. Organic contaminants that remain on the surface after cleaning are visible by coloring. According to this method, however, it is only possible to find out whether any residues remain on the surface after cleaning. With regard to the type of residues, whether fats, carbohydrates or proteins, no statement can be made under this method.

EP-A-0 347 494 discloses a method for detecting contaminants on an object by treating it with a dye solution and subsequently a developer solution. Even in this way, however, it is only possible to locate the pollutants but not to differentiate them by type.

A method for detecting leakage of organic material from containers or ducts with a suitable dye solution is described in US-A-4 745 797.

The coloring of food residues with indicators (erythrosine) is known from odontology. Here, indicators are used to make the coatings visible on the teeth. Here, too, the only statement is that there are food leftovers on the teeth. It is not possible to tell about the type of residues.

There is, however, a strong need for a method which makes it possible to determine, after cleaning, what kind of organic residues are on the surface, so that special cleaning agents can be used in a targeted cleaning or necessary cleaning agents or combinations of cleaning agents in the future. avoid refining.

It should also be possible to determine the type of organic residue before cleaning, so that a suitable detergent composition can be used immediately.

This need for a quick way to detect organic residues before or after the cleaning process concerns not only the whole food producing industry but also all areas where cleaning is necessary for hygiene and / or aesthetic reasons, such as meat, fish, delicatessen, beverage, brewing, dairy and agricultural, starch and sugar industry, kitchens, hospitals, swimming pools, cosmetics and pharmaceutical industries.

It was therefore an object of the present invention to provide a method which makes it possible to distinguish organic pollutants before or after the purification process according to their type, i.e. whether it is fat, protein or carbohydrate (low or high molecular weight). In doing so, the process should be easy to carry out and should immediately make it possible to distinguish the contaminants into fat, protein and carbohydrate on a hard surface.

SUMMARY OF THE INVENTION

This object is achieved according to the invention by a method of distinguishing organic food residues according to their type on hard surfaces by applying a solution comprising a combination of at least two dyes, at least one of which is hydrophilic and at least one of hydrophobic character, to said hard surface and subsequent visual determination the type of residues due to their specific coloring.

Where dyes of hydrophilic or hydrophobic character are referred to in the context of the present invention, reference is made, for example, to the definition of the terms hydrophilic and hydrophobic for an explanation of these keywords in Rompp Chemie Lexicon (Rompp Chemical Lexicon), 9th edition, Volume 3 (1990), Georg Thieme Verlag, pages 1892 and 1893. It states: The hydrophilic character of a substance is determined by its tendency to enter and remain in water, and the hydrophobic character of a substance is determined by its tendency not to enter and stay in water. Accordingly, dyes with a hydrophilic character will be understood as meaning those which are water-compatible and readily and readily dissolve in water (at room temperature). On the other hand, according to the invention, dyes with a hydrophobic character will be understood to mean those which are water-repellent, i.e. water-repellent. they are insoluble in water or are difficult, respectively. not soluble (at room temperature) soluble. Corresponding characteristics of the dyes that can be used in the present invention are found, for example, in the following standard works:

Kosmetische Färbemittel (Cosmetic Dyes), 3rd Edition, 1991, Publisher: Farbstoffkommision der Deutschen Forschungsgemeinschaft (DFG), VCH Verlagsgesellschaft mbH, as well as

Color Index, Third Edition, Vol. 1 to 9, published by Society of Dyers and Colorists.

Organic residues are fats, proteins and / or carbohydrates, which may occur side by side or even individually. The determination of the type of residue by the method according to the invention is possible with one solution.

In this way, the user can:

1. to recognize the type of organic contamination as well as the most polluted areas before the actual cleaning, so that the type of detergent can be chosen and more intensive site contamination can be cleaned more intensively;

2. to check the success of cleaning after cleaning,

3. Easily recognize the weaknesses of its detergent relative to the individual components of the dirt so that it can make the right choice of detergent in the future; and

4. After detecting the organic residues remaining after cleaning, remove them with special cleaning agents.

In particular, the method of the present invention provides a simple method for qualitatively evaluating the cleaning performance of detergent formulations by developing a detergent composition by first investigating the contaminant (fat / protein / starch) with the detergent under investigation and then the formulation of the present invention. standardized procedure. Depending on the different coloring of the individual components of the contamination, it is possible to recognize which component can be removed better or better by formulating the cleaning agent. Targeted improvements to the recipe can then be made.

The method according to the invention makes it possible to appropriately select a cleaning agent by detecting the type of soiling prior to cleaning. After cleaning, the cleaning success can be checked on the one hand and on the other hand a suitable special cleaning agent for the uncleaned dirt component can be selected. When cleaning large production facilities, respectively. For example, it is possible to define critical points according to. HACCP principle (Hazard Analysis of Critical Control Points). For this purpose, after purification, the critical points are sprayed with the formulation according to the invention and appropriate measures are taken according to the results.

The application of the formulation according to the invention to the hard surfaces to be investigated can be carried out according to known methods, in particular by spraying, brushing, pouring or blending the formulation according to the invention onto the surface. This can optionally also be carried out with rinsing water.

An exemplary list of hydrophilic and dye dyes is given below. having a hydrophobic character, useful in the present invention. As regards the C.I. color index number, DFG-name, synonyms and EG-number, reference is made to the standard works cited above:

Dyes with hydrophilic character:

Color DFG-name Synonyms index C. I.

EG number

10020 13015 14270 14700 14720 C-ext. C-Gelb C-Gelb C-Rot C-Rot Gríin 6 > 9 , 12 57 54 naphthol green B, L-ext. green 1 permanent yellow chrysol E 122 Ponceau SX, FD & C red 4 azorubine, carmoizine, L-red 1 14815 C-Rot 49 magenta GN, magenta GN E 125 15510 C-ext. Orange 8 orange II, D & C orange 4 - 15620 C-VR Rot 12 - 15980 C-Orange orange GGN E 111 15985 C-Orange yellow-orange S, Sunsett Yellow FCF. E 110 FD & C yellow 6, L-orange 2 16035 C-Rot 60 Allura red AC, FD & C red 40 - 16185 C-Rot 46 amaranth, L-red 3 E .123 16230 C-ext. Orange 11 orange GG - 16255 C-Rot 47 Ponceau 4R, L-Red 4, Chochenille-red A E 124 16290 C-Rot 48 Ponceau 6R E 126 17200 C-Rot 58 acid resistant magenta B, D & C red 33 - 18050 C-ext. Rot 63 amidonaphthol red G, red 2G, L-red 12 - 18130 C-VR Rot 3 supranol glossy red 3B -

Dyes with hydrophilic character (continued):

18690 C-VR Orange 9 zaponová was standing yellow R, Perín was standing yellow G - 18736 C-VR Orange 8 palantine stood red RN - 18820 C-VR Gelb flavazine L - 18965 - yellow 2G - 19140 C-Gelb 10 tartrazine, FD & C yellow 5, L-yellow 2, permanent yellow NCG E 102 20170 C-ext. Braun 4 resorcinol brown, D & C brown 1 - 20470 C-VR Schwarz 1 amide black 10 B - 24790 C-VR Rot supranol red BR - 27290 - glossy crocein MOD - 27755 C-Schwarz black 7984 E 152 28440 C-Schwarz glossy black BN, glossy black PN, L-black 1 E 151 40215 C-VR Orange 1 - - 42045 C-ext. Blau 13 patent blue VF - 42051 C-Blau patent blue V, patent blue V, L-blue 3 E 131 42053 C-Griin standing green FCF, FD & C green 3 - 42080 C-VR Blau patent blue A - 42090 C-Blau patent blue AE, glossy blue FCF, FD & C Blue 1, L-Blue 4 - 42100 C-VR Grun 4 - - 42170 C-ext. Grun 10 alkaline green 10 G, L-ext. green 2 - 42510 C-VR Violett 8 fuchsin magenta - 42520 - new fuchsin, new magenta - 42735 C-ext. Blau 14 glossy deep blue FFR - 44045 C-VR Blau Victoria Blue B - 44090 C-Grun 4 deep green S, shiny acid resistant green BS, L-green 3 E 142 45100 - Sulforhodamine B - 45190 C-VR Violett 5 acid resistant purple ARR, L-ext. violet 2 - 45220 C-VR Rot 16 Sulforhodamine B -

Dyes with hydrophilic character (continued):

45350 C-ext. Gelb 16 fluorescein, uranine, D & C yellow 7/8 - 45380 C-Rot eosin, eosin, D & C red 21/22 - 45430 C-Rot erythrosine, erythrosine, FD & C red- 3 L-red 11 E 127 47005 C-Gelb 11 quinoline yellow, quinoline yellow, L-yellow 3 E 104 50325 C-VR Violett deep purple stood B - 50420 - water-soluble nigrosine GF - 59040 C-ext. Gelb 24 pyranine, pyranine - 60730 C-ext. Violett anthropane violet 3B, Ext. D & C 21 violet 2 - 61570 C-Griin alizarincyanine green G, D & C Green 5 - 61585 C-VR Blau - - 73015 C-Blau indigotine, indigocarmine, FD & C blue 2, L-blue 2 E 132 74180 C-VR Blau heliogen blue SBL, turquoise- blue in light Síria GL - 75815 C-Grun Cu complex of chlorophyllin E 141 - C-Rot red, red E 162 - C-Rot anthocyanins, anthocyanins E 163

Dyes with hydrophobic character:

Color DFG-name index C. I. Synonyms EG number 11920 C-Orange 1 Sudan orange G - 12150 C-Rot 2 solvent red 1 food red 16 12700 - Sudanese yellow 3G - 21230 C-ext. Gelb 21 Sudanese Yellow 3G GRN L- ext. yellow 1 26100 C-ext. Rot 56 Sudan Red BK, D & C Red 17 40800 C-Orange β-carotine, L-orange 8 E 160a

Dyes with hydrophobic character (continued):

40820 C-Orange 16 apokarotinal, L-orange 8 E 160e 40825 C-Orange 17 apocarotinic acid ethyl ester L-orange 9 E 160f 40850 C-Orange 15 canthaxanthin E 161g 45370 C-Rot D & C Orange 5 4700 C-ext. Gelb 23 Alcohol soluble quinoline yellow A D & C yellow 11 - 56238 C-VR Gelb 16 hostasol yellow 3G - 61554 - solvent blue 35, greasy blue B, Sudan blue II - 61565 C-Grtin alizarin cyanine soluble in fats, D & C green 6 - 60725 C-ext. Violett alcohol soluble irizole, 18 D & C violet 2 - 69800 C-Blau indantrene blue RS, indantrone E 130 7300 C-Blau indigo, D & C blue 6 - 75120 C-Orange 12 Annatto, Orlean, bixin, norbixin, L-orange 4 E 160b 75125 C-Orange 14 lycophin, L-orange 6 E 160d 75130 C-Orange 11 carotine, carotene, L-orange 3 E 160a 75135 C-Orange 15d xanthophylls, L-orange 7d, rubixanthin E 161d 75170 - guanine - 75300 C-Gelb curcumin, turmeric, Turmeric, L-yellow 7 E 100 75810 C-Grun 8 Cu-chlorophyll complex, L-green 2 E 140 - C-Gelb riboflavin, lactoflavin, vitamin B ₂ , L-yellow 6 E 101 - C-VR Grun 3 bromocresol green, bromocresol green, - - C-VR Blau 3 bromothymol blue, bromothymol blue - C-Orange 13 Capsantine, Capsorubin, L-Orange 5 E 160c - - solvent blue 97, Ceres Blau RR -

According to one preferred embodiment of the invention, erythrosine (C.I. 45 430; E 127) and Ponceau 4 R (C.I. 16255; E 124) are used as dyes of hydrophilic character. Curcumin (C.I. 75300; E 100), β-carotine (C.I. 40800; E 160a), riboflavin (E 101) and Ceres Blau RR are preferably used as dyes with a hydrophobic character according to the invention.

According to a further preferred embodiment of the invention, combinations of dyes of two different dyes (binary system) are used, one of which is hydrophilic and the other of hydrophobic character. In this sense, it is preferred that one component of the binary dye combination is erythrosine and the other component is curcumin or β-carotine.

In addition, the present invention encompasses combinations of dyes of three different dyes (ternary system), at least one of which is hydrophilic in nature and at least one other is hydrophobic in nature. In principle, it is irrelevant to systems of this kind whether the third additional dye is hydrophilic or hydrophobic in nature. For the purposes of the present invention, however, the aforementioned combinations of dyes for binary systems and the third component Ceres Blau RR are used for such ternary systems.

By analogy with the above teachings, the present invention also includes combinations of dyes from four different dyes (quaternary system) or from several different dyes.

According to a further preferred embodiment of the invention, the colorant combination of at least two colorants is present in a solution with a proportion of 0.05 to 3% by weight, preferably 0.05 to 2% by weight. % and particularly preferably 0.05 to 1 wt.%.

The ratio of dyes in binary systems is 1: 10 to 10: 1, preferably 1: 5 to 5: 1 and particularly preferably 1: 2 to 2: 1. However, as a rule, 1: 1 mixtures lead to good results.

For ternary, respectively. For quaternary systems, the content of one dye does not exceed a 10-fold, preferably a 5-fold excess, based on the dye with the lowest proportion. This also applies to combinations with more than four different dyes. Generally, however, combinations in which the dyes are present in equal proportions are generally preferred.

The invention further relates to liquid formulations comprising, in addition to a suitable solvent, a combination of at least two dyes, at least one of which is hydrophilic in nature and at least one hydrophobic in nature. Such a combination of dyes makes it possible to optically distinguish organic food residues on hard surfaces according to their type.

Particularly good results with respect to differentiation of the type of contamination according to its specific coloring are achieved according to the invention in particular by one component of the colorant combination being erythrosine and the other component being curcumin or β-carotine. For ternary dye systems according to the present invention, it is preferable to use the above dyes as well as an additional third component of the Ceres Blau RR dye combination.

As a suitable solvent for the liquid formulation of the colorant combination, water having a pH of ≥ 8 can be used. The pH value suitable for dissolving the colorant combination, which must always be determined individually, is adjusted with suitable bases, especially alkali metal hydroxides (NaOH, KOH) metals (sodium carbonate, potassium carbonate). In this way, the water adjusted to the pH values in the basic region is also capable of dissolving the above-mentioned dyes with a hydrophobic character.

However, a mixture of water and a water-miscible solvent such as a solubilizer is particularly suitable as another suitable solvent for the colorant combination. The water-miscible organic solvent is preferably used in a ratio by weight of water to water-miscible organic solvent in the range from 20: 1 to 1:20, preferably 10: 1 to 1: 10 and in particular 2: 1 to 1: 2. in this case, there is no need to add bases to the solution.

Suitable water-miscible organic solvents are, in particular, mono- and dibasic, water-miscible alcohols, in particular ethanol, propanol, isopropanol, butanol, ethylene glycol, propylene glycol, butyl glycol, methyldiglycol, ethylene diglycol, butyldiglycol or dipropylene glycol monoethyl ether. These water-miscible organic solvents act as solubilizers. In this connection, a 1: 1 mixture of triethanolamine and caprylic acid or sodium cumolsulfonate, optionally in the form of their aqueous solutions, should be mentioned as a solubilizer.

The dye combination may also be dissolved in a suitable pure organic solvent. In this connection, mention may be made in particular of the above, as solubilizers, of water-miscible organic solvents or mixtures thereof. Furthermore, a 1: 1 mixture of triethanolamine and caprylic acid or sodium cumolsulfonate, in each case as an aqueous solution, can also serve as a solvent for the colorant combination.

The dye combination solution may further comprise conventional, otherwise non-ionic, cationic, anionic or amphoteric surfactants, or mixtures thereof, in the detergent compositions, to permeate any fat or protein layers for the colorant combination present to provide the underlying carbohydrates and to color them . Surfactants in a proportion of 0.05 to 2% by weight, preferably 0.05 to 0.5% by weight, may be added to such formulations. % and particularly preferably 0.05 to 0.15% by weight.

As anionic surfactants, for example, sulphonate or sulphate-type surfactants, in particular alkene and hydroxyalkanesulphonates or mixtures thereof, alkanesulphonates, ester sulphonates, sulphonated fatty acid esters of glycerol / sulphotriglycerides, alkyl sulphates or alcohol sulphates or alkyl (sulphate) sulphate sulphates / ether, , isothionates, taurates, phosphate esters or mixtures thereof.

Preferred nonionic surfactants are ethoxylated and / or propoxylated alcohols which are derived from primary alcohols preferably having from 9 to 18 carbon atoms and an average of from 1 to 12 moles of ethylene oxide and / or propylene oxide. Furthermore, alkyl glucosides can be used.

Suitable cationic surfactants are, in particular, quaternary ammonium compounds (QAV), quaternary phosphonium compounds (QPV) and amine oxides. In addition, amphoteric compounds, in particular betaines, should be mentioned.

In addition to dyes, surfactants or solubilizers, conventional preservatives may also be present in the solution.

After treatment with a solution containing a combination of dyes, the fat, protein and carbohydrate (starch) can be immediately differentiated according to their different coloration. The different colors of these food residues can be determined visually by the naked eye, usually already in daylight. Optionally, however, the dyeings can be partially intensified or even at all visible by UV-light on the surfaces to be treated. In the presence of a mixture of fat, proteins and carbohydrates, mixed discoloration may occur, depending on the ratio of the amount of food residue present one or the other color is dominant.

The solutions are storage stable and can be stored for a longer period of time without losing their properties.

The following examples describe the present invention without being limited thereto.

DETAILED DESCRIPTION OF THE INVENTION

Example 1

Demineralized water, butyldiglycol as solubilizer, C8-C18-fatty alcohol-1,6-glucoside (Triton BG 10, a commercial product of Union Carbide), as well as the respective formulations were used in the following formulations (percentages =% by weight). a dye or a combination of dyes. The dye combination was then sprayed onto the surface to be examined (white ceramic tiles) and the staining was examined by the corresponding specific staining of previously applied contaminants in visible and UV light (366 nm).

Beef tallow, fat starch (10% by weight in water) was used as fat, and a mixture of whole milk with proteins or casein was used as protein.

formulations 1 2 3 4 Water 47,33% 47,18% 47,18% 47,18% solubilizer 52,59% 52,59% 52,59% 52,59% surfactant 0,10% 0,10% 0,10% 0,10% curcumin 0,10% - 0,10% 0.15% erytrozín - 0.20% 0.20% 0.15%

Note: Formulations 1 and 2 are comparative examples Experiments A) Colors below daily light formulations 1 2 3 4 grease Red yellow yellow light yellow protein Red yellow Orange Red starch Red yellow Red pink B) Colors below UV-light (366 nm) - formulations 1 2 3 4 grease - green / yellow Lena / yellow green / yellow protein orange green / yellow red / orange Orange starch green / yellow Orange svetlooranž

The same result is obtained for the combination of dyes erythrosine and curcumin (2: 1) when a single solvent (butyldiglycol, butylglycol, methyldiglycol, ethylene glycol, dipropylene glycol monoethyl ether, ethanol, aqueous solution of 40% by weight Na-kraft) is used instead of water / solubilizer. 66% triethanolamine / caprylic acid solution (1: D) ·

In a mixture with water, butyldiglycol can be replaced by butyl glycol, ethylene glycol, methyldiglycol, ethanol or an aqueous 1: 1 solution of triethanolamine: caprylic acid (67% by weight) without affecting the result.

Example 2

For the following formulations, 47.1 wt. % fully demineralized water, 52.5 wt. % butyldiglycol as solubilizer, 0.1 wt. % Of Triton BG 10 as a surfactant and a total of 0.3 wt. of the respective dye combination.

These formulations were then sprayed onto the surface to be examined (white ceramic tiles) and the staining of previously applied contaminants (as described above) was determined under visible light and under UV light (366 nm).

The results are shown in Table 1 below.

"D) E "D) E "D) E Ό E C C they they they they they they 0 t-1 H Rti Rti Rti Q) within 0 VO □ within υ within P P within P within P VO P within (D • H cn • H P> • H m H m > T> Ό Ό Ό what • H > • H • H > • H > > □ > > □ > ABOUT 'honors 'honors 'honors > P 'honors 'honors honor > 0 r- < > > they 'they 0 'honors > N > N 0 'honors 0 • H > > N > they > N > > N > 0 C 0 honor 'honors they 0 they 0 > N honor > N they > honor > N honor 44 D H they 0 0 they they they R-1 D 0 honor 0 > N 0 honor 0 (D P 0 H > they 0 they 0 • H 0 P 0 honor honor P 0 P ffl P E they R-1 ! p > N P 0 > N > N >. >. >> C they C whether P they they • H > > > 'honors C 44 44 > (U > tfl > cfl 0 P • > N 'honors 'd > N 'honors > N 'honors > N they > H x> > C > C > they honor 0 > 0 0 0 honor 0 honor 0 honor they > N at H > N H > N they > N they 0 C C X 0 they 0 they 0 0 honor N > CN H 0 they 0 they 0 | P they H P H P 0 Λ P P P <u C 0 0 d) > H > > > Λ Q (Λ (Λ M 'honors P Rti 'd 'honors 'honors 'honors > N 'honors 'honors 'honors λ: P P P P 0 P P P ú Rti R-1 R-C Rti Rti r- < rp R-1 H > N > N 'N > N P »N > N > N 0 > IN)

Table 1 (ternary mixtures

they they they they C G C C 'they 'they 'they 'they Ή Ή 'they 'they E E E E E E E E they they they they they they they they 44 44 44 44 44 44 44 44 they they they they they they they they they they they they they they they they 44 44 > 44 44 44 44 44 44 Ή P P X) P P P rh P P they honor • · • ·  · they ♦, they P <A at 'they Ή honor honor they p · they p · C > they > they they they they p · they p · they honor 'they 'they 'they honor 'they honor 'they 'they 'they 'they 'they 'they • they N they N they N 1-1 N r-i N P N P they P they P 0 0 honor 0 honor 0 P 0 p 0 0 0 0 honor 0 honor 0 'honors they (D they d) they 0 they about they they they they at they U they they P 0 P U P P P P P honor P honor Q honor 0 honor • they > 1 they they 44 >> 44 > the 44 >> 44 C 44 C 44 x> they 0 they 0 they honor they honor they 1 they 1 0 1 0 1 E o d) honor d) honor 0 P d) R-4 d) WHAT. d) honor honor GTI honor CQ. class- P P P P P P t < rh P P rh P P P P P

Example 3

Further experiments were performed with the following formulations (binary and ternary dye combinations):

binary comb. ternárna komb. dyes (1: D dyes (1: 1: D dye combination 0.4% weight. 0.6% weight. surfactant (Triton BG 10) 0.1% weight. 0.1% weight. solubilizer 5.0% weight. 5.0% weight. (Metyldiglykol) water (totally 94.5% weight. 94.3% weight. demineralized)

The formulations were sprayed onto the investigated surface (white ceramic tiles) to which the above contaminants had previously been applied - individually as well as a ternary mixture - and the colorings were observed and determined under visible light (daylight).

The results are shown in Table 2 below.

table

erythrosine / riboflavin / Ceres Blau RR 1: 1: 1 blue Red Red M C w 3 0 ' Ό £ Ctf rH > tí 'they 'those' those - those 0 Ή Ή · • H Ό they > c 'they 43 N Pffl rl rd 0 4) 0 4) tí Ό 0 O P E > > N> 4) P > N t M M t H 0 \ they C tí > rd they P tí 4) tí 'tí 4) 4) t> N they >> 44 people n p > 0 t> 0 4) they Ô i (D Pi H) rd 0 > 0 0 0 c £ L (J p4 • r-j'N >> w tí (Λ C Ή P 'they 'they - those 'they Ή Ή í> they > 'they ph N P tí ·· 'they 0 ABOUT tí Ό • 0 0 H P > > N 4) P > N tí tí Ή H rd they they > rd they P tí 0 > N 4) they those ’N they >> 44 .o ·· > 0 they 4) they t 1 -H 0 cq. tí P 0 > 0 0 \ t C C t H 'they 'they 'they M rd 'they C C C N CQ ·· they 4) about 4) 0 Ό > > > tí Λ P 0 they they they P 4) E 4) 4) 4) ery Cer RR > 0 > 0 > 0 \ tí tí Ή 'they 'they R> rd they C N tí 4) 4) M 0 rd · · 1 > > t <P they they they POP 4) 4) > 0 > 0 tí p 4) tí >> \ Ί3 C c 'they - those 0 'id Ή rH 'they > 'they 43 N P C ABOUT 4) 0 0 ·· 'they 4) > N 4) P > N tí tí P > they > rd they P tí P rd they they t> N they >> 44 > N 4) they 4) they 4) CQ. > 0 0 > 0 0 they z-a Ή • r) 4> 0 N rd they 44 (Λ Ή Z-X 'with-' 4) N they E Ό they N ^: tí '3 they > E • H they ABOUT > C n about they 44 'they 0 rd they and they 4) they they 44 • rd 4) H > EN) CQ H

not measured)

Claims (19)

PATENT CLAIMS 1. A method of distinguishing organic food residues according to their type on hard surfaces, comprising applying to said surface a solution comprising a combination of at least two colorants, at least one of which is hydrophilic and at least one of which is hydrophobic, and the type of residues is then optically determined according to their specific coloring. Method according to claim 1, characterized in that the type of organic residues is fats, proteins and / or carbohydrates. Method according to claim 1 or 2, characterized in that the dyes with hydrophilic character are selected from erythrosine and Ponceau 4 R and the dyes with hydrophobic character are selected from curcumin, β-carotine, riboflavin and Ceres Blau RR. Method according to one or more of Claims 1 to 3, characterized in that one component of the colorant combination is erythrosine and the other component is curcumin or β-carotine. Method according to claim 4, characterized in that the additional component of the colorant combination is Ceres Blau RR. Method according to one or more of Claims 1 to 5, characterized in that said combination of at least two dyes is present in a solution with a proportion of 0.05 to 3% by weight. Method according to one or more of Claims 1 to 6, characterized in that water having a pH of ≥ 8 is used as the solvent for the said combination of at least two dyes. Process according to one or more of Claims 1 to 6, characterized in that a mixture of water and a water-miscible organic solvent is used as the solvent for said combination of at least two dyes. The method of claim 8 wherein the weight ratio of water to water miscible organic solvent is in the range of from 20: 1 to 1:20, preferably in the range from 10: 1 to 1: 10, and in particular from 1:20 to 1:10 2: 1 to 1: 2. Process according to one or more of Claims 1 to 6, characterized in that a water-miscible organic solvent is used as solvent for said combination of at least two dyes. The method according to one or more of claims 1 to 10, characterized in that said solution additionally comprises at least one nonionic, anionic, cationic or amphoteric surfactant. The method of claim 11, wherein said surfactant is present in solution in an amount of 0.05 to 2% by weight. 13. A liquid formulation comprising, in addition to a suitable solvent, a combination of at least two dyes, at least one of which is hydrophilic and at least one of which is hydrophobic. The liquid formulation according to claim 13, wherein one component of the colorant combination is erythrosine and the other component is curcumin or β-carotine. 15. A liquid formulation according to claim 14, wherein the additional component of the colorant combination is Ceres Blau RR. Liquid formulation according to one or more of claims 13 to 15, characterized in that water with a pH of 8 8, a water-miscible organic solvent or a mixture of water and a water-miscible organic solvent is used as solvent. I » 17. The liquid formulation as claimed in claims 13 to _R 16, characterized in that the proportion of the dye combination of 0.05 to 3% by weight .. Liquid formulation according to one or more of claims 13 to 17, characterized in that it additionally contains 0.05 to 2% by weight of a liquid formulation. surfactant. Use of a liquid formulation according to one or more of claims 13 to 18 for distinguishing organic food residues according to their type on hard surfaces.