Abstract:
The invention relates to catalytically bleaching substrates, especially laundry fabrics, with a bleaching catalyst and peroxide in the presence of an enzymatic bleach enhancing system.

Description:
FIELD OF INVENTION  
         [0001]    The present invention relates to enhancing the activity of a bleaching catalyst.  
         BACKGROUND OF INVENTION  
         [0002]    WO 93/19811 discloses the use of lipoxygenase, linoleic acid and metal complexes with ambient oxygen to degrade an environmental contaminant.  
           [0003]    DK 0352/98 discloses a process for bleaching coloured stains, comprising contacting, in an aqueous solution, the stain with a lipoxygenase enzyme, an unsaturated fatty acid and a transition metal ion.  
           [0004]    The use of bleaching catalysts for stain removal has been developed over recent years. As with any cleaning product a more economical use of active components and effective stain bleaching profile is sought.  
         SUMMARY OF INVENTION  
         [0005]    We have found that there is a synergetic interaction between a catalyst together with peroxide and an enzyme system for generating hydroperoxides.  
           [0006]    The present invention provides a bleaching composition comprising an organic ligand which forms a complex with a transition metal for bleaching a substrate with a peroxygen bleach or source thereof, and a peroxygen bleach or source thereof, together with an oxidizable precursor selected from the group consisting of:  
           [0007]    (i) an unsaturated acid or alkali metal salt thereof; and  
           [0008]    (ii) a generating system for producing an unsaturated acid in situ in an aqueous medium,  
           [0009]    together with an enzyme for oxidising the oxidizable precursor to form a hydroperoxide in situ.  
           [0010]    It is preferred that the bleaching composition comprises at least 3% of a peroxygen bleach other than an alkyl hydroperoxide.  
           [0011]    In order to permit differentiation of components, within the context of the present invention as claimed, neither the organic ligand or transition metal complex thereof nor the enzyme system for generating hydroperoxides should be construed as a peroxygen bleach or source thereof. In addition, the organic ligand which forms a complex with a transition metal is additional and distinct from other components.  
           [0012]    The bleaching composition of the present invention provides for the lipase hydrolysis of an unsaturated oil (triglyceride) to provide an unsaturated carboxylic acid (or soap formed therefrom) which is subsequently oxidized by a lipoxygenase to form a hydroperoxide which together with a catalyst serves to bleach a stain. Alternatively, the bleaching composition comprises an unsaturated carboxylic acid (or soap formed therefrom) which obviates the lipase hydrolysis step described above. In some instances unsaturated oils in a stain serve as a precursor for the lipoxygenase to provide a hydroperoxide intimate with the stain.  
           [0013]    The greatest effect is provided by a bleaching composition comprising a catalyst, a lipase and a lipoxygenase together with metabolites or precursors thereof for the enzyme system (lipase and lipoxygenase).  
           [0014]    The present invention extends to a commercial package comprising the bleaching composition according to the present invention together with instructions for its use.  
           [0015]    Any suitable textile that is susceptible to bleaching or one that one might wish to subject to bleaching may be used. Preferably the textile is a laundry fabric or garment.  
           [0016]    In a preferred embodiment, the method according to the present invention is carried out on a laundry fabric using an aqueous treatment liquor. In particular, the treatment may be effected in a wash cycle for cleaning laundry. More preferably, the treatment is carried out in an aqueous detergent bleach wash liquid, preferably in a washing machine.  
           [0017]    A unit dose as used herein is a particular amount of the bleaching composition used for a type of wash. The unit dose may be in the form of a defined volume of powder, granules or tablet or unit dose detergent liquid.  
         DETAILED DESCRIPTION OF THE INVENTION  
         [0018]    Bleach Catalyst  
           [0019]    The bleach catalyst per se may be selected from a wide range of organic molecules (ligands) and complexes thereof. Suitable organic molecules (ligands) and complexes for use with the present invention are found, for example in: GB 9906474.3; GB 9907714.1; GB 98309168.7, GB 98309169.5; GB 9027415.0 and GB 9907713.3; DE 19755493; EP 999050; WO-A-9534628; EP-A-458379; EP 0909809; U.S. Pat. No. 4,728,455; WO-A-98/39098; WO-A-98/39406, WO 9748787, WO 0029537; WO 0052124, and WO0060045 the complexes and organic molecule (ligand) precursors of which are herein incorporated by reference. The air bleaching catalysts as used herein should not be construed as an peroxyl-generating system, alone or in combination with other substrates, irrespective of how they bleaching action works.  
           [0020]    Another example of a bleaching catalyst is a ligand or transition metal catalyst thereof of a ligand having the formula (I):  
                         
 
           [0021]    wherein each R is independently selected from: hydrogen, hydroxyl, and C1-C4-alkyl;  
           [0022]    R1 and R2 are independently selected from:  
           [0023]    C1-C4-alkyl,  
           [0024]    C6-C10-aryl, and,  
           [0025]    a group containing a heteroatom capable of coordinating to a transition metal, wherein at least one of R1 and R2 is the group containing the heteroatom;  
           [0026]    R3 and R4 are independently selected from hydrogen, C1-C8 alkyl, C1-C8-alkyl-O—C1-C8-alkyl, C1-C8-alkyl-O—C6-C10-aryl, C6-C10-aryl, C1-C8-hydroxyalkyl, and —(CH2) n C(O)OR5 wherein R5 is C1-C4-alkyl, n is from 0 to 4, and mixtures thereof; and,  
           [0027]    X is selected from C═O, —[C(R6) 2 ] y — wherein Y is from 0 to 3 each R6 is independently selected from hydrogen, hydroxyl, C1-C4-alkoxy and C1-C4-alkyl.  
           [0028]    It is preferred that the group containing the hetroatom is:  
           [0029]    a heterocycloalkyl: selected from the group consisting of: pyrrolinyl; pyrrolidinyl; morpholinyl; piperidinyl; piperazinyl; hexamethylene imine; 1,4-piperazinyl; tetrahydrothiophenyl; tetrahydrofuranyl; tetrahydropyranyl; and oxazolidinyl, wherein the heterocycloalkyl may be connected to the ligand via any atom in the ring of the selected heterocycloalkyl,  
           [0030]    a —C1-C6-alkyl-heterocycloalkyl, wherein the heterocycloalkyl of the —C1-C6-heterocycloalkyl is selected from the group consisting of: piperidinyl; piperidine; 1,4-piperazine, tetrahydrothiophene; tetrahydrofuran; pyrrolidine; and tetrahydropyran, wherein the heterocycloalkyl may be connected to the —C1-C6-alkyl via any atom in the ring of the selected heterocycloalkyl, a —C1-C6-alkyl-heteroaryl, wherein the heteroaryl of the —C1-C6-alkylheteroaryl is selected from the group consisting of: pyridinyl; pyrimidinyl; pyrazinyl; triazolyl; pyridazinyl; 1,3,5-triazinyl; quinolinyl; isoquinolinyl; quinoxalinyl; imidazolyl; pyrazolyl; benzimidazolyl; thiazolyl; oxazolidinyl; pyrrolyl; carbazolyl; indolyl; and isoindolyl, wherein the heteroaryl may be connected to the —C1-C6-alkyl via any atom in the ring of the selected heteroaryl and the selected heteroaryl is optionally substituted by —C1-C4-alkyl,  
           [0031]    a —C0-C6-alkyl-phenol or thiophenol,  
           [0032]    a —C2-C4-alkyl-thiol, thioether or alcohol,  
           [0033]    a —C2-C4-alkyl-amine, and  
           [0034]    a —C2-C4-alkyl-carboxylate.  
           [0035]    The ligand forms a complex with one or more transition metals, in the latter case for example as a dinuclear complex. Suitable transition metals include for example: manganese in oxidation states II-V, iron II-V, copper I-III, cobalt I-III, titanium II-IV, tungsten IV-VI, vanadium II-V and molybdenum II-VI.  
           [0036]    The transition metal complex preferably is of the general formula (AI): 
           [M a L k X n ]Y m   
           [0037]    in which:  
           [0038]    M represents a metal selected from Mn(II)-(III)-(IV)-(V), Cu(I)-(II)-(III), Fe (II)-(III)-(IV)-(V), Co(I)-(II)-(III), Ti(II)-(III)-(IV), V(II)-(III)-(IV)-(V), Mo(II)-(III)-(IV)-(V)-(VI) and W(IV)-(V)-(VI), preferably from Fe(II)-(III)-(IV)-(V);  
           [0039]    L represents the ligand, or its protonated or deprotonated analogue;  
           [0040]    X represents a coordinating species selected from any mono, bi or tri charged anions and any neutral molecules able to coordinate the metal in a mono, bi or tridentate manner;  
           [0041]    Y represents any non-coordinated counter ion;  
           [0042]    a represents an integer from 1 to 10;  
           [0043]    k represents an integer from 1 to 10;  
           [0044]    n represents zero or an integer from 1 to 10;  
           [0045]    m represents zero or an integer from 1 to 20.  
           [0046]    It is preferred that the organic molecule (ligand) or transition metal complex is present in the composition such that a unit dose provides at least 0.1 μM of the organic molecule or transition metal complex thereof.  
           [0047]    The transition metal complex may be preformed or formed in situ. The organic substance (ligand) required has complexing qualities. The ligand may be present in the bleaching composition as a free ligand or the complex formed in situ, for example, in tap water used to wash cloths or stain. Ligands have different binding constants for different transition metals and tap water usually contains many different transition metal ions. A transition metal complex may be used in the method of the present invention that is not itself active in bleaching with atmospheric oxygen. However, upon addition to tap water an active atmospheric oxygen bleaching solution is formed. Common transition metals found in tap water at a relatively high concentration are iron and manganese ions. A different transition metal complex may be formed in situ than found in the bleaching composition used. The formation of a particular type of transition metal complex other than the transition metal complex found in the bleaching composition is dependent on the binding constant for a particular transition metal, transition metal ions present tap water and the concentration of transition metal ions present in the tap water. In addition, not only may the ligand complex with transition metals present in the bleaching medium but with transition metals found in a stain; for example tomato oil stains have relatively high concentrations of transition metals present, in particular iron. Alternatively, the ligand may complex with manganese as found in tea stains. However, it is preferred that the bleaching composition comprises a preformed iron transition metal catalyst.  
           [0048]    Peroxygen Bleach or Source Thereof  
           [0049]    The composition of the present invention uses a peroxyl species to bleach a substrate. The peroxy bleaching species may be a compound which is capable of yielding hydrogen peroxide in aqueous solution. Hydrogen peroxide sources are well known in the art. They include the alkali metal peroxides, organic peroxides such as urea peroxide, and inorganic persalts, such as the alkali metal perborates, percarbonates, perphosphates persilicates and persulphates. Mixtures of two or more such compounds may also be suitable.  
           [0050]    Particularly preferred are sodium perborate tetrahydrate and, especially, sodium perborate monohydrate. Sodium perborate monohydrate is preferred because of its high active oxygen content. Sodium percarbonate may also be preferred for environmental reasons. The amount thereof in the composition of the invention usually will be within the range of about 1-35% by weight, preferably from 5-25% by weight. One skilled in the art will appreciate that these amounts may be reduced in the presence of a bleach precursor e.g., N,N,N′N′-tetraacetyl ethylene diamine (TAED).  
           [0051]    Another suitable hydrogen peroxide generating system is a combination of a C1-C4 alkanol oxidase and a C1-C4 alkanol, especially a combination of methanol oxidase (MOX) and ethanol. Such combinations are disclosed in International Application PCT/EP 94/03003 (Unilever), which is incorporated herein by reference.  
           [0052]    Alkylhydroxy peroxides are another class of peroxy bleaching compounds. Examples of these materials include cumene hydroperoxide and t-butyl hydroperoxide.  
           [0053]    Organic peroxyacids may also be suitable as the peroxy bleaching compound. Such materials normally have the general formula:  
                         
 
           [0054]    wherein R is an alkylene or substituted alkylene group containing from 1 to about 20 carbon atoms, optionally having an internal amide linkage; or a phenylene or substituted phenylene group; and Y is hydrogen, halogen, alkyl, aryl, an imido-aromatic or non-aromatic group, a COOH or  
                         
 
           [0055]    group or a quaternary ammonium group.  
           [0056]    Typical monoperoxy acids useful herein include, for example:  
           [0057]    (i) peroxybenzoic acid and ring-substituted peroxybenzoic acids, e.g. peroxy-.alpha.-naphthoic acid;  
           [0058]    (ii) aliphatic, substituted aliphatic and arylalkyl monoperoxyacids, e.g. peroxylauric acid, peroxystearic acid and N,N-phthaloylaminoperoxy caproic acid (PAP); and  
           [0059]    (iii) 6-octylamino-6-oxo-peroxyhexanoic acid.  
           [0060]    Typical diperoxyacids useful herein include, for example:  
           [0061]    (iv) 1,12-diperoxydodecanedioic acid (DPDA);  
           [0062]    (v) 1,9-diperoxyazelaic acid;  
           [0063]    (vi) diperoxybrassilic acid; diperoxysebasic acid and diperoxyisophthalic acid;  
           [0064]    (vii) 2-decyldiperoxybutane-1,4-diotic acid; and  
           [0065]    (viii) 4,4′-sulphonylbisperoxybenzoic acid.  
           [0066]    Also inorganic peroxyacid compounds are suitable, such as for example potassium monopersulphate (MPS). If organic or inorganic peroxyacids are used as the peroxygen compound, the amount thereof will normally be within the range of about 2-10% by weight, preferably from 4-8% by weight.  
           [0067]    Peroxyacid bleach precursors are known and amply described in literature, such as in the British Patents 836988; 864,798; 907,356; 1,003,310 and 1,519,351; German Patent 3,337,921; EP-A-0185522; EP-A-0174132; EP-A-0120591; and U.S. Pat. Nos. 1,246,339; 3,332,882; 4,128,494; 4,412,934 and 4,675,393.  
           [0068]    Another useful class of peroxyacid bleach precursors is that of the cationic i.e. quaternary ammonium substituted peroxyacid precursors as disclosed in U.S. Pat. Nos. 4,751,015 and 4,397,757, in EP-A0284292 and EP-A-331,229. Examples of peroxyacid bleach precursors of this class are:  
           [0069]    2-(N,N,N-trimethyl ammonium)ethyl sodium-4-sulphonphenyl carbonate chloride (SPCC);  
           [0070]    N-octyl-N,N-dimethyl-N10-carbophenoxy decyl ammonium chloride (ODC);  
           [0071]    3-(N,N,N-trimethyl ammonium)propyl sodium-4-sulphophenyl carboxylate; and  
           [0072]    N,N,N-trimethyl ammonium toluyloxy benzene sulphonate.  
           [0073]    A further special class of bleach precursors is formed by the cationic nitriles as disclosed in EP-A-303,520 and in European Patent Specification No.&#39;s 458,396 and 464,880.  
           [0074]    Any one of these peroxyacid bleach precursors can be used in the present invention, though some may be more preferred than others.  
           [0075]    Of the above classes of bleach precursors, the preferred classes are the esters, including acyl phenol sulphonates and acyl alkyl phenol sulphonates; the acyl-amides; and the quaternary ammonium substituted peroxyacid precursors including the cationic nitrites. Examples of said preferred peroxyacid bleach precursors or activators are sodium-4-benzoyloxy benzene sulphonate (SBOBS); N,N,N′N′-tetraacetyl ethylene diamine (TAED); sodium-1-methyl-2-benzoyloxy benzene-4-sulphonate; sodium-4-methyl-3-benzoloxy benzoate; SPCC; trimethyl ammonium toluyloxy-benzene sulphonate; sodium nonanoyloxybenzene sulphonate (SNOBS); sodium 3,5,5-trimethyl hexanoyloxybenzene sulphonate (STHOBS); and the substituted cationic nitrites.  
           [0076]    Other classes of bleach precursors for use with the present invention are found in WO0015750, for example 6-(nonanamidocaproyl)oxybenzene sulphonate.  
           [0077]    The precursors may be used in an amount of up to 12%, preferably from 2-10% by weight, of the composition.  
           [0078]    The Lipoxygenase Enzyme  
           [0079]    The enzymatic detergent compositions of the invention comprise 5,000-1,000,000 units of a lipoxygenase per gram of detergent composition, preferably 5,000-600,000 units of a lipoxygenase per gram of detergent composition and even more preferably 8,000-125,000 units op a lipoxygenase per gram of detergent composition. In which one unit will cause an increase in A234 of 0.001 per min at pH 9.0 at 25° C. when linoleic acid is the substrate in 3.0 ml volume (1 cm light path). One A234 unit is equivalent to the oxidation of 0.12 μmole of linoleic acid. The soybean enzyme will use arachidonic acid as substrate, with approximately 15% of the activity indicated using linoleic acid as substrate; the product of arachidonic acid oxidation is 12- or 15-hydroperoxyarachidonic acid (12-HETE or 15-HETE). More details are given in the following references: 1) Doderer, A., et al., Biochim. Biophys. Acta, 1120, 97 (1992). 2) van Os, C. P. A., Biochim. Biophys. Acta, 663, 177 (1981). 3) Rashbrook, L. C., et al., Biochem Soc. Trans., 13, 233 (1985).  
           [0080]    Suitable enzyme lipoxygenases for the compositions of the invention can be found in the enzyme classes of the lipoxygenases, enzyme class 1.13.11.* where * is preferably 12 or 13.  
           [0081]    Examples of suitable enzymes are: Lipoxygenase (EC 1.13.11.12), Arachidonate 5-lipoxygenase (EC 1.13.11.34), Arachidonate 12-lipoxygenase (EC 1.13.11.31), and Arachidonate 15-lipoxygenase (EC 1.13.11.33), Lipoxygenase (EC 1.13.11.12) is the preferred enzyme.  
           [0082]    The Lipolytic Enzyme  
           [0083]    As a second constituent, the enzymatic detergent compositions of the invention preferably comprise 10-20,000 LU per gram, and more preferably 50-2,000 LU per gram and even more preferably 80-500 LU per gram of the detergent composition of a lipolytic enzyme selected from the group consisting of Lipolase, Lipolase ultra, LipoPrime, Lipex, Lipomax, Liposam, and lipase from  Rhizomucor miehei  (e.g. as described in EP-A-238 023 (Novo Nordisk).  
           [0084]    In this specification LU or lipase units are defined as they are in EP-A-258 068 (Novo Nordisk). Suitable enzymes for the compositions of the invention can be found in the enzyme classes of the esterases and lipases, (EC 3.1.1.*, wherein the asterisk denotes any number).  
           [0085]    A characteristic feature of lipases is that they exhibit interfacial activation. This means that the enzyme activity is much higher on a substrate which has formed interfaces or micelles, than on fully dissolved substrate. Interface activation is reflected in a sudden increase in lipolytic activity when the substrate concentration is raised above the critical micel concentration (CMC) of the substrate, and interfaces are formed. Experimentally this phenomenon can be observed as a discontinuity in the graph of enzyme activity versus substrate concentration. Contrary to lipases, however, cutinases do not exhibit any substantial interfacial activation.  
           [0086]    Because of this characteristic feature, i.e. the absence of interfacial activation, we define for the purpose of this patent application Cutinases as lipolytic enzymes which exhibit substantially no interfacial activation. Cutinases therefor differ from classical lipases in that they do not possess a helical lid covering the catalytic binding site. Cutinases belong to a different subclass of enzymes (EC 3.1.1.50) and are regarded to be outside the scope of the present invention.  
           [0087]    Of main interest for the present invention are fungal lipases, such as those from  Humicola lanuginosa  and  Rhizomucor miehei.  Particularly suitable for the present invention is the lipase from  Humicola lanuginosa  strain DSM 4109, which is described in EP-A-305 216 (Novo Nordisk), and which is commercially available as Lipolase (TM). Also suitable ar variants of this enzyme, such as described in WO-A-92/05249, WO-A-94/25577, WO-A-95/22615, WO-A-97/04079, WO-A-97/07202, WO-A-99/42566, WO-A-00/60063. Especially preferred is the variant D96L which is commercially available from Novozymes as Lipolase ultra, and the variant which is sold by Novozymes under the trade name LipoPrime. Another preferred variant is T231R+N233R which is commercially available from Novozymes as Lipex. The lipolytic enzyme of the present invention can usefully be added to the detergent composition in any suitable form, i.e. the form of a granular composition, a slurry of the enzyme, or with carrier material (e.g. as in EP-A-258 068 and the Savinase (TM) and Lipolase (TM) products of Novozymes). A good way of adding the enzyme to a liquid detergent product is in the form of a slurry containing 0.5 to 50% by weight of the enzyme in a ethoxylated alcohol nonionic surfactant, such as described in EP-A-450 702 (Unilever).  
           [0088]    The enzyme to be used in the detergent compositions according to the invention can be produced by cloning the gene for the enzyme into a suitable production organism, such as Bacilli, or Pseudomonaceae, yeasts, such as Saccharomyces, Kluyveromyces, Hansenula or Pichia, or fungi like Aspergillus. The preferred production organism is Aspergillus with especial preference for  Aspergillus oryzae.    
           [0089]    When both lipase and lipoxygenase are present in the bleaching composition of the present invention it is preferred that the ratio of lipase:lipoxygenase is in the weight ratio range from 1:10 to 10:1.  
           [0090]    The Detergent Composition  
           [0091]    The air bleach catalyst and unsaturated organic compound may be used in a detergent composition specifically suited for stain bleaching purposes, and this constitutes a second aspect of the invention. To that extent, the composition comprises a surfactant and optionally other conventional detergent ingredients. The invention in its second aspect provides an enzymatic detergent composition which comprises from 0.1-50% by weight, based on the total detergent composition, of one or more surfactants. This surfactant system may in turn comprise 0-95% by weight of one or more anionic surfactants and 5 to 100% by weight of one or more nonionic surfactants. The surfactant system may additionally contain amphoteric or zwitterionic detergent compounds, but this in not normally desired owing to their relatively high cost. The enzymatic detergent composition according to the invention will generally be used as a dilution in water of about 0.05 to 2%.  
           [0092]    In general, the nonionic and anionic surfactants of the surfactant system may be chosen from the surfactants described “Surface Active Agents” Vol. 1, by Schwartz &amp; Perry, Interscience 1949, Vol. 2 by Schwartz, Perry &amp; Berch, Interscience 1958, in the current edition of “McCutcheon&#39;s Emulsifiers and Detergents” published by Manufacturing Confectioners Company or in “Tenside-Taschenbuch”, H. Stache, 2nd Edn., Carl Hauser Verlag, 1981.  
           [0093]    Suitable nonionic detergent compounds which may be used include, in particular, the reaction products of compounds having a hydrophobic group and a reactive hydrogen atom, for example, aliphatic alcohols, acids, amides or alkyl phenols with alkylene oxides, especially ethylene oxide either alone or with propylene oxide. Specific nonionic detergent compounds are C 6 -C 22  alkyl phenol-ethylene oxide condensates, generally 5 to 25 EO, i.e. 5 to 25 units of ethylene oxide per molecule, and the condensation products of aliphatic C 8 -C 18  primary or secondary linear or branched alcohols with ethylene oxide, generally 5 to 40 EO.  
           [0094]    Suitable anionic detergent compounds which may be used are usually water-soluble alkali metal salts of organic sulphates and sulphonates having alkyl radicals containing from about 8 to about 22 carbon atoms, the term alkyl being used to include the alkyl portion of higher acyl radicals. Examples of suitable synthetic anionic detergent compounds are sodium and potassium alkyl sulphates, especially those obtained by sulphating higher C 8 -C 18  alcohols, produced for example from tallow or coconut oil, sodium and potassium alkyl C 9 -C 20  benzene sulphonates, particularly sodium linear secondary alkyl C 10 -C 15  benzene sulphonates; and sodium alkyl glyceryl ether sulphates, especially those ethers of the higher alcohols derived from tallow or coconut oil and synthetic alcohols derived from petroleum. The preferred anionic detergent compounds are sodium C 11 -C 15  alkyl benzene sulphonates and sodium C 12 -C 18  alkyl sulphates. Also applicable are surfactants such as those described in EP-A-328 177 (Unilever), which show resistance to salting-out, the alkyl polyglycoside surfactants described in EP-A-070 074, and alkyl monoglycosides.  
           [0095]    Preferred surfactant systems are mixtures of anionic with nonionic detergent active materials, in particular the groups and examples of anionic and nonionic surfactants pointed out in EP-A-346 995 (Unilever). Especially preferred is surfactant system that is a mixture of an alkali metal salt of a C 16 -C 18  primary alcohol sulphate together with a C 12 -C 15  primary alcohol 3-7 EO ethoxylate.  
           [0096]    The nonionic detergent is preferably present in amounts greater than 10%, e.g. 25-90% by weight of the surfactant system. Anionic surfactants can be present for example in amounts in the range from about 5% to about 40% by weight of the surfactant system. It is preferred that the bleaching composition comprises at least 1% an unsaturated surfactant, preferably an anionic surfactant having an HLB of at least 10.  
           [0097]    The detergent composition may take any suitable physical form, such as a powder, granular composition, tablets, a paste or an anhydrous gel.  
           [0098]    Enzymes  
           [0099]    The detergent compositions of the present invention may additionally comprise one or more other enzymes, which provide cleaning performance, fabric care and/or sanitation benefits.  
           [0100]    Said enzymes include oxidoreductases, transferases, hydrolases, lyases, isomerases and ligases. Suitable members of these enzyme classes are described in Enzyme nomenclature 1992: recommendations of the Nomenclature Committee of the International Union of Biochemistry and Molecular Biology on the nomenclature and classification of enzymes, 1992, ISBN 0-12-227165-3, Academic Press.  
           [0101]    The composition may contain additional enzymes as found in WO 01/00768 A1 page 15, line 25 to page 19, line 29, the contents of which are herein incorporated by reference.  
           [0102]    The composition may also contain antioxidants or reductants as taught in WO 00/521124.  
           [0103]    Builders, polymers and other enzymes as optional ingredients may also be present as found in WO0060045. Suitable detergency builders as optional ingredients may also be present as found in WO0034427.  
           [0104]    The composition of the present invention may be used for laundry cleaning, hard surface cleaning (including cleaning of lavatories, kitchen work surfaces, floors, mechanical ware washing etc.). As is generally known in the art, bleaching compositions are also employed in waste-water treatment, pulp bleaching during the manufacture of paper, leather manufacture, dye transfer inhibition, food processing, starch bleaching, sterilisation, whitening in oral hygiene preparations and/or contact lens disinfection.  
           [0105]    In the context of the present invention, bleaching should be understood as relating generally to the decolourisation of stains or of other materials attached to or associated with a substrate. However, it is envisaged that the present invention can be applied where a requirement is the removal and/or neutralisation by an oxidative bleaching reaction of malodours or other undesirable components attached to or otherwise associated with a substrate. Furthermore, in the context of the present invention bleaching is to be understood as being restricted to any bleaching mechanism or process that does not require the presence of light or activation by light.  
           [0106]    In a preferred aspect of the present invention the bleaching composition is substantially devoid of fat other than a fat which participates as a precursor for a lipase or a lipoxogenase. By having a low concentration of fat which does not participate in the enzymatic process permits fat which participates in enzymic reactions to be selectively partitioned into an oily stain of a textile, thus aiding the bleaching process by targeting a stain.  
       
    
    
       [0107]    The invention will now be further illustrated by way of the following non-limiting examples:  
       COMPLEX 1  
     Synthesis of [(MeN4Py)FeCl]Cl  
       [0108]    The ligand N,N-bis(pyridin-2-yl-methyl)-1,1-bis(pyridin-2-yl)-1-aminoethane (MeN4py) was prepared as described in EP 0 909 809 A2. The synthesis of the iron complex, [(MeN4Py)FeCl]Cl, has been described elsewhere (WO 0116271).  
                                                 Detergent formulation A                                    STP:   0.756   g           Na2CO3:   0.301   g           Sodium Sulphate   0.518           Disilicate:   0.245   g           LAS:   0.420   g           NI 7EO:   0.182   g           Sodium Percarbonate:   200   mg           TAED:   30   mg           Dequest 2047:   50   mg           Savinase 12TB:   8   mg                      
 
         [0109]    Detergent formulation A was added to one litre of water.  
         [0110]    Test cotton cloth samples were treated according to procedure 1 described below. After the wash, the cloths were rinsed with water and subsequently dried at 30° C. and the change in colour was measured 2 hours after drying with a Linotype-Hell scanner (ex Linotype). The change in colour (including bleaching) is expressed as the ΔE value. The measured colour difference (ΔE) between the washed cloth and the unwashed cloth is defined as follows: 
         Δ E =[(Δ L ) 2 +(Δ a ) 2 +(Δ b ) 2 ] 1/2   
         [0111]    wherein ΔL is a measure for the difference in darkness between the washed and unwashed test cloth; Δa and Δb are measures for the difference in redness and yellowness respectively between both cloths. With regard to this colour measurement technique, reference is made to Commission International de l&#39;Eclairage (CIE); Recommendation on Uniform Colour Spaces, colour difference equations, psychometric colour terms, supplement no 2 to CIE Publication, no 15, Colorometry, Bureau Central de la CIE, Paris 1978. The results are shown in the tables below. A higheer value indicates a better performance. The values as given as statistically significant for values of 1 ΔE or greater.  
         [0112]    Procedure 1  
         [0113]    A cloth stained with one of curry oil, tomato oil or tomato extract were stirred (cloth to liquor ratio of 1:40 wt/wt) in an aqueous solution of 10 mM Tris-Cl buffer pH 8, 4° FH at a temperature of 25° C. for 30 minutes. After the 30 minutes had passed the aqueous phase was discarded and replaced by, an aqueous solution of detergent A described above, providing an aqueous solution of pH 9, 8° FH, after which the mixture was stirred for a further 30 minutes at 25° C.  
         [0114]    Lipolase was added as mg/l of Lipolase 100T granules with an activity of 111 LU/mg granules. Lipoxygenase was added as mg/l solids of Sigma enzyme L7395, which is a soybean lipoxygenase with an activity of 127,000 units/mg solids. The iron complex was added to the wash liquor using a stock solution of 1 mM in water.  
         [0115]    Two levels of enzyme and catalyst were employed, as disclosed in the table below. The same amount of enzyme and catalyst was present in the Tris-Cl buffer described in procedure 1.  
         [0116]    Results of Experiment with Combination of Lipolase, Lipoxygenase and [(MeN4Py)FeCl]Cl in the Presence of a Peroxyl Species  
                                                                                                                                     Concentration   Results (delta E vs                Lipo-           blank)                lase   Lipoxygenase   Complex 1   Curry   Tomato   Tomato       Expt.   (mg/l)   (mg/l)   (μM)   oil   oil   extract                    1    10   10   1.7   18.0   7.8   27.1       2    10   10       3.4   0.4   3.1       3    10       1.7   16.0   6.8   26.1       4        10   1.7   8.9   0.6   27.1       5    10           2.0   −0.3   2.4       6        10       1.3   0.0   7.3       7            1.7   8.4   0.7   26.3       1a   2   2   0.33   11.8   0.9   23.5       2a   2   2       4.6   0.0   2.4       3a   2       0.33   4.2   0.6   10.9       4a       2   0.33   4.2   0.0   23.2       5a   2           2.3   −0.2   1.3       6a       2       2.2   −0.2   8.7       7a           0.33   2.5   −0.2   12.7