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EP-4739760-A1 - WASHING METHOD FOR REMOVING PROTEINACEOUS STAINS

EP4739760A1EP 4739760 A1EP4739760 A1EP 4739760A1EP-4739760-A1

Abstract

The present invention relates to washing methods for improved removal of proteinaceous stains on textiles and to use of chelating agents for improving proteinaceous stain removal.

Inventors

  • KNÖTZEL, Jürgen, Carsten, Franz
  • BAUER, Carl, Mikael

Assignees

  • Novozymes A/S

Dates

Publication Date
20260513
Application Date
20240624

Claims (20)

  1. 1 . A method of washing a textile, comprising the steps of: a) obtaining a textile comprising a proteinaceous stain; b) treating the textile in a wash step, wherein the wash step comprises contacting the textile with a wash liquor, wherein the wash liquor is prepared by mixing a laundry detergent composition with water, and wherein the laundry detergent composition comprises a protease; and c) further treating the textile during the wash step with a chelating agent having affinity for calcium ions (Ca 2+ ), wherein the chelating agent is added to the wash liquor, and wherein the chelating agent is present in the wash liquor at a concentration of at least 1 g/L, e.g., at least 2 g/L, at least 3 g/L, at least 4 g/L, at least 5 g/L, at least 6 g/L, at least 7 g/L, at least 8 g/L, at least 9 g/L, at least 10 g/L, at least 11 g/L, at least 12 g/L, at least 13 g/L, at least 14 g/L, at least 15 g/L, at least 16 g/L, at least 17 g/L, at least 18 g/L, at least 19 g/L, at least 20 g/L, or more; wherein the proteinaceous stain is at least partially removed from the textile.
  2. 2. A method of washing a textile, comprising the steps of: a) obtaining a textile comprising a proteinaceous stain; b) treating said textile in a wash step, wherein the wash step comprises contacting the textile with a wash liquor, wherein the wash liquor is prepared by mixing a laundry detergent composition with water, and wherein the laundry detergent composition comprises a protease; and c) treating said textile in a rinse step, wherein the rinse step comprises contacting the textile with a chelating liquor comprising a chelating agent at a concentration of at least 1 g/L, e.g., at least 2 g/L, at least 3 g/L, at least 4 g/L, at least 5 g/L, at least 6 g/L, at least 7 g/L, at least 8 g/L, at least 9 g/L, at least 10 g/L, at least 11 g/L, at least 12 g/L, at least 13 g/L, at least 14 g/L, at least 15 g/L, at least 16 g/L, at least 17 g/L, at least 18 g/L, at least 19 g/L, at least 20 g/L, or more, wherein the chelating liquor is prepared by mixing the chelating agent with water, and wherein the chelating agent has affinity for calcium ions (Ca 2+ ); wherein the proteinacous stain is at least partially removed from the textile.
  3. 3. The method according to any one of the preceding claims, wherein the proteinaceous stain is a meat, dairy, egg, cocoa, grass, blood, or sebum stain.
  4. 4. The method according to any one of the preceding claims, wherein the laundry detergent composition is liquid laundry detergent composition, preferably in the form of a regular, compact, or concentrated liquid composition, or a single unit dose format.
  5. 5. The method according to any one of the preceding claims, wherein the protease is a serine endopeptidase (E.C. 3.4.21), preferably a subtilisin (E.C. 3.4.21.62).
  6. 6. The method according to claim 5, wherein the protease is selected from the group consisting of: a) a protease having a sequence identity of at least 70%, e.g., at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or even 100%, to SEQ ID NO:1 ; preferably a protease comprising, consisting essentially of, or consisting of SEQ ID NO:1; b) a protease having a sequence identity of at least 70%, e.g., at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or even 100%, to SEQ ID NO:5; preferably a protease comprising, consisting essentially of, or consisting of SEQ ID NO:5; and c) a protease having a sequence identity of at least 70%, e.g., at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or even 100%, to SEQ ID NO:6; preferably a protease comprising, consisting essentially of, or consisting of SEQ ID NO:6.
  7. 7. The method according to any of claims 1-4, wherein the protease is a metalloprotease (EC 3.4.24), preferably a thermolysin (EC 3.4.24.27) or bacillolysin (EC 3.4.24.28).
  8. 8. The method according to claim 7, wherein the protease has a sequence identity of at least 70%, e.g., at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or even 100%, to SEQ ID NO:7; preferably the protease comprises, consists essentially of, or consists of SEQ ID NO:7.
  9. 9. The method according to any one of claims 1-4, wherein the protease is a glutamyl endopeptidase (EC 3.4.21.19).
  10. 10. The method according to claim 9, wherein the protease has a sequence identity of at least 70%, e.g., at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or even 100%, to SEQ ID NO:8; preferably the protease comprises, consists essentially of, or consists of SEQ ID NO:8.
  11. 11. The method according to any one of claims 1-4, wherein the protease is a trypsin-type protease with specificity for Arg and Lys residues.
  12. 12. The method according to claim 11 , wherein the protease has a sequence identity of at least 70%, e.g., at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or even 100%, to SEQ ID NO:9; preferably the protease comprises, consists essentially of, or consists of SEQ ID NO:9.
  13. 13. The method according to any one of the preceding claims, wherein the chelating agent is present at a concentration of 0.01 g/L to 100 g/L, preferably 0.05 g/L to 50 g/L, more preferably 0.1 g/L to 25 g/L, even more preferably 0.5 g/L to 15 g/L, most preferably 1 g/L to 10 g/L.
  14. 14. The method according to any one of the preceding claims, wherein the chelating agent is selected from the group consisting of citric acid or a salt thereof (e.g., sodium citrate), gluconic acid, glutamic acid-N,N-diacetic acid (GLDA), methylglycinediacetic acid (MGDA), ethylenediaminetetraacetic acid (EDTA), and mixtures thereof.
  15. 15. The method according to claim 14, wherein the chelating agent is citric acid or a salt thereof, preferably sodium citrate, or glutamic acid-N,N-diacetic acid (GLDA).
  16. 16. The method according to claim 1 , wherein the chelating liquor further comprises a cationic surfactant.
  17. 17. The method according to claim 16, wherein the cationic surfactant is an ester of a quaternary ammonium salt (/.e., an ester quat).
  18. 18. The method according to claim 16, wherein the cationic surfactant is selected from the group consisting of cetyltrimethylammonium bromide (CTAB), diethyl ester dimethyl ammonium chloride (DEEDMAC), dimethyldioctadecylammonium chloride (DSDMAC), dimethyldistearylammonium chloride (DSDMAC), triethanolamine quat (TEAQ), alkyldimethylethanolamine quat (ADMEAQ), and 1 ,2-dioleoyl-3-trimethylammonium propane (DOTAP).
  19. 19. The method according to any one of claims 16-18, wherein the chelating liquor comprises from 0.1 % to 20% w/w of cationic surfactant, preferably from 0.5% to 15% w/w, most preferably from 1 % to 10% w/w.
  20. 20. The method according to claim 1 , wherein the chelating agent is added to the wash liquor as a single dose or as multiple doses; preferably wherein the chelating agent is added to the wash liquor as multiple, sequential doses.

Description

WASHING METHOD FOR REMOVING PROTEINACEOUS STAINS REFERENCE TO A SEQUENCE LISTING This application contains a Sequence Listing in computer readable form, which is incorporated herein by reference. FIELD OF THE INVENTION The present invention relates to washing methods for improved removal of proteinaceous stains on textiles and to use of chelating agents for improving proteinaceous stain removal BACKGROUND OF THE INVENTION One of the primary considerations for consumers when buying laundry detergent is performance on stain removal. Proteinaceous stains are among the most common and tenacious stains with examples including food stains such as meat, dairy, egg, cocoa, and some vegetables, outdoor stains such as grass and mud, and stains arising from bodily fluids such as blood, sweat, and sebum. Proteinaceous stains are susceptible to degradation by proteases, and proteases have become the technically and commercially most important enzyme class for strain removal in laundry detergents. An increasing number of commercially available proteases used for laundry are engineered variants of naturally occurring wild type proteases. Protease variants have been described in the art with alterations relative to a parent protease resulting in improvements such as better wash performance, thermal stability, storage stability, and catalytic activity. There is a continued need in the art for further improvements of proteinaceous stain removal. In particular, there is a need for further improving proteinaceous stain removal obtained with protease variants that are already highly optimized as a result of protein engineering. SUMMARY OF THE INVENTION The present inventors have identified a method for washing a textile that provides improved removal of proteinaceous stains. The method of the invention is based on the surprising finding that chelating agents and proteases acting in concert provide dramatically improved proteinaceous stain removal, especially when high levels of chelating agents are employed. In a first aspect, the present invention relates to a method of washing a textile, comprising the steps of: a) obtaining a textile comprising a proteinaceous stain; b) treating the textile in a wash step, wherein the wash step comprises contacting the textile with a wash liquor, wherein the wash liquor is prepared by mixing a laundry detergent composition with water, and wherein the laundry detergent composition comprises a protease; and c) further treating the textile during the wash step with a chelating agent having affinity for calcium ions (Ca2+), wherein the chelating agent is added to the wash liquor, and wherein the chelating agent is present in the wash liquor at a concentration of at least 1 g/L; wherein the proteinaceous stain is at least partially removed from the textile. In a second aspect, the present invention relates to a method of washing a textile, comprising the steps of: a) obtaining a textile comprising a proteinaceous stain; b) treating said textile in a wash step, wherein the wash step comprises contacting the textile with a wash liquor, wherein the wash liquor is prepared by mixing a laundry detergent composition with water, and wherein the laundry detergent composition comprises a protease; and c) treating said textile in a rinse step, wherein the rinse step comprises contacting the textile with a chelating liquor comprising a chelating agent at a concentration of at least 1 g/L, wherein the chelating liquor is prepared by mixing the chelating agent with water, and wherein the chelating agent has affinity for calcium ions (Ca2+); wherein the proteinaceous stain is at least partially removed from the textile. DEFINITIONS In accordance with this detailed description, the following definitions apply. Note that the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Unless defined otherwise or clearly indicated by context, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Chelating agent: The term “chelating agent” means an organic compound that is capable of binding and forming a complex with a metal ion such as, e.g., Ca2+, Mg2+, Cu2+, and Fe2+. Examples of chelating agents include carbonates (e.g., sodium carbonate), silicates (e.g., sodium silicate), phosphates (e.g., sodium phosphate), polyphosphates (e.g., sodium hexametaphosphate), phosphonates (e.g., HEDP, ATMP, or EDTMP), polycarboxylates (e.g., EDTA or NTA), citrates (e.g., sodium citrate), gluconic acid, polyacrylic acid, zeolites, and aminocarboxylates (e.g., MGDA or GLDA). In an aspect, the chelating agent is capable of binding divalent metal cations. In a preferred aspect, the chelating agent is capable of binding and forming a complex with Ca2+ and/or Mg2+. In a most preferred aspect, the chelating agent is capable of binding and forming a complext with Ca2+. Chelating