A multi-step method for washing dairy film.

Abstract

To provide a dairy film cleaning composition and method for cleaning dairy film. [Solution] This disclosure relates in general to the field of cleaning dairy membranes. Specifically, the method includes a stepwise treatment of dairy membranes for advantageously removing contaminants and cleaning the membranes. The method is suitable for dairy membranes, including microfiltration membranes, ultrafiltration membranes, nanofiltration membranes, and reverse osmosis membranes used in dairy production.

Description

[Technical Field]

[0001] This disclosure relates, in general terms, to the field of cleaning dairy membranes. Specifically, the method includes a stepwise treatment of dairy membranes for advantageously removing contaminants and cleaning the membranes. The method is suitable for dairy membranes, including microfiltration membranes, ultrafiltration membranes, nanofiltration membranes, and reverse osmosis membranes used in dairy production. [Background technology]

[0002] A major challenge in dairy production is fat contamination on filtration membranes. Studies of washed and unwashed in-situ membranes have shown that fat, particularly high-melting-point triglycerides, have a 10-fold higher contamination load compared to protein contamination present on dairy membranes sampled worldwide. Fat and protein contamination is difficult to remove using standard in-situ washing methods. Furthermore, because the melting point of fat is far above the in-situ washing temperature, high-melting-point fats accumulate over the lifespan of the membrane. Incomplete removal of membrane contamination affects the production performance of the membrane and is a critical factor in the overall integrity of the membrane. Triglyceride fats are difficult to remove and accumulate on the membrane over time. Triglyceride fats can be broken down via catalytic reactions with lipases. Lipase molecules separate the fatty acid portion from the glycerol portion.

[0003] Lipase can remove fat from a membrane, but it can also adhere to the membrane surface and pores depending on the size of the membrane. Lipase molecules can be about d30kDa in size, which means that, purely based on molecular size, they will pass through or permeate most microfiltration membranes but will be rejected by ultrafiltration, nanofiltration, and reverse osmosis membranes. If lipase can enter the structure of the microfiltration membrane, a larger internal pore area will interact with the lipase, causing more lipase molecules to adhere to the membrane, which also makes rinsing more difficult. In the case of porous membranes, lipase can interact with pores on the membrane surface. As the membrane surface becomes smoother (i.e., smaller pore size), lipase interaction with the membrane decreases. [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] Current washing methods do not completely remove all contaminants from all membrane types and do not address the complete fouling phenomenon. Lipase is surface-active, adhering to the membrane surface and not being able to be rinsed off with water. Lipase cannot be inactivated with acid or alkali. Similarly, oxidizing agents cannot completely inactivate lipase (stability against oxidation). Therefore, in order to overcome these shortcomings of current in-situ washing methods for dairy membranes, there is a need for dairy membrane washing compositions and methods for washing dairy membranes. [Means for solving the problem]

[0005] Methods for washing dairy membranes are disclosed herein. These methods offer various advantages over existing dairy membrane washing methodologies. For example, the methods provide a mechanism for maintaining enzyme activity during the enzymatic washing step and then inactivating lipase to avoid the degradation of the manufactured dairy product due to still-active lipase during the manufacturing process (which causes "off-flavor" in the dairy product through the production of short-chain fatty acids). Another advantage of the methods is that they are suitable for various types of dairy filtration membranes, including microfiltration membranes, ultrafiltration membranes, nanofiltration membranes, and reverse osmosis membranes. Other advantages and benefits of the disclosed methods are described herein.

[0006] A preferred embodiment is a method for washing a dairy filtration membrane, comprising: (a) contacting the dairy filtration membrane with an enzyme composition wherein the enzyme composition comprises lipase and a buffer, and the pH of the enzyme composition is about 7.5 to about 11.0; contacting the dairy filtration membrane with a surfactant composition wherein the surfactant composition comprises alkyl polyglucoside, alkyl polypentoside, amine oxide, alcohol ethoxylate, alkoxylated block copolymer, sulfonated surfactant, or a mixture thereof, and the pH of the surfactant composition is about 7.5 to about 11.0; rinsing the dairy filtration membrane; contacting the dairy filtration membrane with an acidic composition wherein the acidic composition comprises an acid, an acidic anionic surfactant, or a mixture thereof, and the pH of the acidic composition is about 2.5 or less, and the acidic composition inactivates lipase; and rinsing the dairy filtration membrane.

[0007] A preferred embodiment is a method for washing a dairy filtration membrane, comprising: (a) contacting the dairy filtration membrane with an enzyme composition comprising lipase, protease, and a buffer, wherein the pH of the enzyme composition is about 8.0 to about 10.5; contacting the dairy filtration membrane comprising a microfiltration membrane, an ultrafiltration membrane, a nanofiltration membrane, and / or a reverse osmosis membrane; and contacting the dairy filtration membrane with a surfactant composition comprising alkyl polyglucoside, alkyl polypentoside, amine oxide, alcohol ethoxylate, alkoxylated block copolymer, sulfo A method comprising contacting a dairy filtration membrane with an acidic composition comprising an ionizing surfactant or a mixture thereof, wherein the pH of the surfactant composition is about 8.0 to about 10.5, rinsing the dairy filtration membrane, and contacting the dairy filtration membrane with an acidic composition, wherein the acidic composition comprises a linear alkyl sulfonate, a branched alkyl sulfonate, a substituted aromatic sulfonate, an unsubstituted aromatic sulfonate, an organic acid, nitric acid, phosphoric acid, methanesulfonic acid, or a mixture thereof, wherein the pH of the acidic composition is about 2.5 or less, and the acidic composition inactivates lipase.

[0008] In a more preferred embodiment, the method comprises contacting the dairy product filtration membrane with an alkaline composition, wherein the alkaline composition comprises an alkali metal hydroxide, an alkali metal carbonate, an alkali metal silicate, an organic alkaline source, or a mixture thereof, and the alkaline composition has a pH of from about 10.0 to about 12.0, and further comprising rinsing the dairy product filtration membrane. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] [Figure 1] It is a flowchart of an exemplary method for washing a dairy product membrane.

[0010] [Figure 2] It shows lipase interaction in an exemplary membrane.

[0011] [Figure 3A] It shows lipase in a liquid solution.

[0012] [Figure 3B] It shows lipase in an exemplary membrane.

[0013] [Figure 3C] It shows a scanning electron microscope (SEM) image of lipase in an exemplary membrane.

[0014] [Figure 4] It is a table showing lipase inactivation by a standard cleaning method.

[0015] [Figure 5] It is a table comparing lipase inactivation by a standard cleaning method and an exemplary cleaning method.

[0016] [Figure 6] It is a table showing the lipase activity of microfiltration membranes, ultrafiltration membranes, nanofiltration membranes, and reverse osmosis membranes.

[0017] [Figure 7] This table shows lipase inactivation by exemplary washing methods on 10 different membranes.

[0018] [Figure 8] This table shows lipase inactivation by exemplary washing methods on three different membranes.

[0019] Various embodiments of the present invention will be described in detail with reference to the drawings, where similar reference numerals throughout some of the figures represent similar parts. References to various embodiments do not limit the scope of the present invention. The figures shown herein are not limited to various embodiments of the present invention, but are presented for illustrative purposes. [Modes for carrying out the invention]

[0020] This disclosure relates to a method for cleaning dairy membranes, including microfiltration membranes, ultrafiltration membranes, nanofiltration membranes, and reverse osmosis membranes used in dairy production. Advantageously, the method employs a stepwise process that can reduce and minimize contamination and optimize the cleaning agent.

[0021] Furthermore, it should be understood that all technical terms used herein are intended solely to describe specific embodiments and are not intended to limit them in any form or scope. For example, as used herein and in the appended claims, the singular forms "a," "an," and "the" may refer to multiple subjects unless otherwise clearly indicated. Moreover, all units, prefixes, and symbols may be represented in their SI-approved form.

[0022] Numerical ranges described herein include the digit defining the range and each integer within the defined range. Throughout this disclosure, various aspects of the invention are presented in range form. It should be understood that descriptions in range form are merely for convenience and brevity and should not be interpreted as rigid limitations on the scope of the invention. Therefore, a range description should be considered to specifically disclose all possible subranges, fractions, and individual digits within that range. For example, a description of a range such as 1 to 6 should be considered to specifically disclose subranges such as 1 to 3, 1 to 4, 1 to 5, 2 to 4, 2 to 6, 3 to 6, and the individual digits within those ranges (e.g., 1, 2, 3, 4, 5, 6), as well as decimals and fractions (e.g., 1.2, 3.8, 1 1 / 2, 4 3 / 4). This applies regardless of the width of the range.

[0023] definition

[0024] Certain terms are defined first so that the present invention may be more easily understood. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to whom embodiments of the present invention relate. Many methods and materials similar to, modified from, or equivalent to those described herein can be used in carrying out embodiments of the present invention without unnecessary experimentation, and preferred materials and methods are described herein. In describing embodiments of the present invention and claiming them, the following technical terms will be used according to the definitions set forth below.

[0025] As used herein, the term “approximately” refers to the variation in quantity that may occur, for example, through typical measuring techniques and equipment, with respect to any quantifiable variable, including but not limited to concentration, mass, volume, time, temperature, and pH. Furthermore, considering the handling procedures of solids and liquids used in the real world, there are certain careless errors and variations that are likely to occur due to differences in the manufacture, source, or purity of the components used to prepare a composition or to carry out a method, etc. The term “approximately” also encompasses these variations. Whether or not modified by the term “approximately,” the claims include equivalents to that quantity.

[0026] The methods and compositions of the present invention may, essentially consist of, or be composed of, the components and elements of the present invention, as with other components described herein. As used herein, “essentially consisting of” means that the methods, systems, apparatus, and compositions may include additional steps, components, or elements, but only if the additional steps, components, or elements do not substantially alter the basic and novel properties of the claimed methods, systems, apparatus, and compositions.

[0027] The methods and compositions of the present invention may, essentially consist of, or be composed of, the components and elements of the present invention, as with other components described herein. As used herein, “essentially consisting of” means that the methods, systems, apparatus, and compositions may include additional steps, components, or elements, but only if the additional steps, components, or elements do not substantially alter the basic and novel properties of the claimed methods, systems, apparatus, and compositions.

[0028] The terms “activity,” “percent activity,” “weight percentage activity,” or “activity concentration” are used interchangeably herein and refer to the concentration of a cleaning component expressed as a percentage after subtracting an inert component such as water or salt. For example, it may also be indicated by a percentage in parentheses, such as “chemical substance (10%).”

[0029] As used herein, the terms "alkyl" or "alkyl group" refer to saturated hydrocarbons having one or more carbon atoms (e.g., C1-C20), including linear alkyl groups (e.g., methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, etc.), cyclic alkyl groups (or "cycloalkyl," "alicyclic," or "carbocyclic" groups) (e.g., cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, etc.), branched alkyl groups (e.g., isopropyl, tert-butyl, sec-butyl, isobutyl, etc.), and alkyl-substituted alkyl groups (e.g., alkyl-substituted cycloalkyl groups and cycloalkyl-substituted alkyl groups).

[0030] Unless otherwise specified, the term "alkyl" includes both "unsubstituted alkyl" and "substituted alkyl." As used herein, the term "substituted alkyl" refers to an alkyl group having substituents that substitute one or more hydrogen atoms on one or more carbon atoms of the hydrocarbon skeleton. Examples of such substituents include alkenyl, alkynyl, halogeno, hydroxyl, alkylcarbonyloxy, arylcarbonyloxy, alkoxycarbonyloxy, aryloxy, aryloxycarbonyloxy, carboxylate, alkylcarbonyl, arylcarbonyl, alkoxycarbonyl, aminocarbonyl, alkylaminocarbonyl, dialkylaminocarbonyl, alkylthiocarbonyl, alkoxyl, phosphate, phosphonato, phosphinato, cyano, amino (including alkylamino, dialkylamino, arylamino, diarylamino, and alkylarylamino), acylamino (including alkylcarbonylamino, arylcarbonylamino, carbamoyl, and ureido), imino, sulfhydryl, alkylthio, arylthio, thiocarboxylate, sulfate, alkylsulfinyl, sulfonate, sulfamoyl, sulfonamide, nitro, trifluoromethyl, cyano, azide, heterocyclic, alkylaryl, or aromatic (including heteroaromatic) groups.

[0031] In some embodiments, the substituted alkyl group may include a heterocyclic group. As used herein, the term “heterocyclic group” includes a ring-closed structure similar to a carbocyclic group, in which one or more of the carbon atoms in the ring are elements other than carbon, such as nitrogen, sulfur, or oxygen. Heterocyclic groups may be saturated or unsaturated. Exemplary heterocyclic groups, but not limited to these, include aziridine, ethylene oxide (epoxide, oxirane), thiirane (episulfide), dioxirane, azetidine, oxetane, thiethane, dioxetane, dithiethane, dithiethone, azolidine, pyrrolidine, pyrroline, oxolane, dihydrofuran, and furan. As used herein, the term “dirt” or “stain” refers to a nonpolar oily substance which may or may not contain particulate matter such as mineral clay, sand, natural minerals, carbon black, graphite, kaolin, and environmental dust.

[0032] As used herein, the term “cleaning” refers to methods used to promote or assist in the removal of dirt, bleaching, reduction of microbial populations, and any combination thereof. As used herein, the term “microorganism” refers to any noncellular or unicellular (including colonial) organism. Microorganisms include all prokaryotes. Microorganisms include bacteria (including cyanobacteria), spores, lichens, fungi, protists, virinos, viroids, viruses, phages, and some algae. As used herein, the term “microbe” is synonymous with “microorganism.”

[0033] As used herein, the term “food processing surface” refers to the surface of tools, machinery, equipment, structures, buildings, etc., used as part of food processing, cooking, or storage activities. Examples of food processing surfaces include the surfaces of food processing or cooking equipment (e.g., slicing equipment, canning equipment, or transport equipment, including water channels), food processing vessels (e.g., the surfaces of utensils, dishes, washware, and bar glass), and the surfaces of floors, walls, or fixtures of structures where food processing takes place. Food processing surfaces are found and used in food spoilage prevention air circulation systems, aseptic packaging disinfection, cleaning and disinfecting agents for food refrigeration and coolers, warewashing disinfection, bleaching and disinfection, food packaging materials, cutting board additives, third-sink disinfection, beverage coolers and warmers, water for cooling or hot water treatment of meat, automatic dish disinfectants, disinfectant gels, cooling towers, antimicrobial clothing sprays for food processing, and non-aqueous to low-aqueous food processing lubricants, oils, and rinsing additives.

[0034] The term "hard surface" refers to solid, substantially inflexible surfaces such as countertops, tiles, floors, walls, panels, windows, sanitary fixtures, kitchen and bathroom fixtures, electrical appliances, engines, circuit boards, dishes, mirrors, monitors, touchscreens, and thermostats. Hard surfaces are not limited by material; for example, hard surfaces may be glass, metal, tiles, vinyl, linoleum, composites, wood, plastics, etc. Hard surfaces may also include, for example, healthcare surfaces and food processing surfaces.

[0035] As used herein, the term “instrument” refers to a variety of medical or dental instruments or devices that can benefit from cleaning with the compositions according to the present invention.

[0036] As used herein, the term “microorganism” refers to any noncellular or unicellular (including colonial) organism. Microorganisms include all prokaryotes. Microorganisms include bacteria (including cyanobacteria), spores, lichens, fungi, protists, virinos, viroids, viruses, phages, and some algae. As used herein, the term “microbe” is synonymous with “microorganism.”

[0037] As used herein, the term “substantially absent” means a composition that either completely lacks the component or contains such a small amount of the component that it does not affect the performance of the composition. The component may be present as an impurity or contaminant and must not exceed 0.5% by weight. In another embodiment, the amount of the component is less than 0.1% by weight, and in yet another embodiment, the amount of the component is less than 0.01% by weight.

[0038] As used herein, the terms “water-soluble” and “water-dispersible” mean that the component is soluble or dispersible in water in the composition of the present invention. Generally, the component must be soluble or dispersible at a concentration of about 0.1% to about 15% by weight, more preferably about 0.1% to about 10% by weight, in water at 25°C.

[0039] The terms "weight percent," "wt.%," "wt-%," "percent by weight," and "% by weight," and their variations, as used herein, refer to the concentration of a substance obtained by dividing its weight by the total weight of the composition and multiplying by 100.

[0040] Method for cleaning dairy film

[0041] Disclosed herein are methods for washing dairy membranes, including microfiltration membranes, ultrafiltration membranes, nanofiltration membranes, or reverse osmosis membranes, or other membranes or membrane processes, which are typically used in dairy production. Preferably, the dairy membranes may be washed in a stepwise washing manner, as shown in Figure 1, using a pre-rinse step 101, an optional pre-wash step 102, a follow-up rinse step 103, an enzyme step 104, a surfactant step 105, a rinse step 106, a lipaseic acid inactivation step 107, a rinse step 108, an optional alkaline step 109, and a follow-up rinse step 110. More preferably, the dairy membranes washed in the enzyme step 104 are washed with an enzyme composition comprising a carrier, an enzyme, and a buffer. Most preferably, the enzyme composition comprises water, lipase, protease, a buffer, and a chelating agent. More preferably, the dairy membranes washed in the lipaseic acid inactivation step 107 are washed with an acidic composition. Most preferably, the acidic composition comprises an acid, an acidic anionic surfactant, or a mixture thereof. More preferably, the dairy film to be washed in alkaline step 109 is washed with an alkaline composition. Most preferably, the alkaline composition comprises an alkali metal hydroxide, an alkali metal carbonate, or a mixture thereof. The steps of the method disclosed herein are further shown in Figure 1 and described below. The steps of the method may involve contacting the dairy film for about 1 to about 240 minutes, about 5 to about 180 minutes, about 15 to about 180 minutes, about 5 to about 180 minutes, most preferably about 15 to about 180 minutes. In a preferred embodiment, the enzyme step lasts for about 1 to about 150 minutes, more preferably about 5 to about 140 minutes, even more preferably about 10 to about 130 minutes, most preferably about 15 to about 120 minutes. In a preferred embodiment, the surfactant step lasts for about 1 to 90 minutes, more preferably about 2 to 75 minutes, and most preferably about 5 to 60 minutes.

[0042] film

[0043] A method for washing one or more dairy filtration membranes is disclosed herein. The membranes may be microfiltration membranes, ultrafiltration membranes, nanofiltration membranes, and / or reverse osmosis membranes. Examples of microfiltration membranes include, but are not limited to, Hydranautics SuPro, Synder LX, Synder FR, Alfa Laval GRM 0.1PP, Synder V0.1, Koch Dairy Pro MF-0.1, Alfa Laval FSM0.15, Alfa Laval GRM 0.2PP, Synder V0.2, and Alfa Laval FSM0.45. Examples of ultrafiltration membranes include, but are not limited to, Koch Dairy Pro 5K, Koch HFK-131, Alfa Laval GR61PP, Alfa Laval GR60PP, Synder MK, Alfa Laval GR51PP, Synder MQ, Alfa Laval FS40PP, Synder LY, Synder PY, Synder BY, Koch, and HFM-180. Preferably, the filtration membrane is Koch Dairy Pro 5K, Koch HFK-131, Alfa Laval GR61PP, or Alfa Laval GR60PP. The filtration membrane may be a polymer containing, for example, PES, PS, PVDF, PAN, PA, etc. Preferably, the polymer contains PES and PS. The filtration membrane may preferably have an approximate molecular weight cutoff of about 5 kDa to 5000 kDa. The filtration membrane can preferably have an approximate pore size of 0.0005 μm to 0.45 μm.

[0044] Pre-rinse

[0045] Preferably, the membrane is pre-rinsed in a pre-rinse step 101. Pre-rinsing can remove some dirt, typically loose dirt, from the membrane. Rinsing is preferably carried out with water. The water may be tap water or softened water. The water may have a hardness of about 20 grains or less, preferably about 15 grains or less, more preferably about 10 grains or less, and even more preferably 5 grains or less. Most preferably, the water is distilled water or RO (reverse osmosis) water. The rinse water may be at any temperature that the membrane is suitable for. Therefore, tap water, room temperature water, or heated water can be used, as long as the temperature guidelines for a particular membrane are not exceeded. For most membranes, this is up to 50°C. For high-temperature membranes, this may be up to 60°C, or even up to 70°C. For standard membranes, preferably the rinse water temperature is 20°C to 50°C, more preferably 25°C to 50°C, and most preferably 30°C to 50°C. For high-temperature membranes, the rinse water temperature is preferably 20°C to 70°C, more preferably 25°C to 70°C, and most preferably 30°C to 70°C.

[0046] Optional pre-cleaning

[0047] Optionally, the membrane may be pre-cleaned with a membrane cleaning detergent in an optional pre-cleaning step 102. The membrane cleaning detergent can help remove some of the easier-to-clean dirt from the membrane, thereby allowing the method disclosed herein to focus more on the harder-to-clean dirt. Any suitable membrane cleaning detergent may be used.

[0048] If a pre-cleaning step is performed, a follow-up rinse 103 is performed to remove the membrane cleaning detergent. Rinsing is preferably performed with water. The water may be tap water or softened water. The water may have a hardness of about 20 grains or less, preferably about 15 grains or less, more preferably about 10 grains or less, and even more preferably 5 grains or less. Most preferably, the water is distilled water or RO (reverse osmosis) water. The rinse water may be at any temperature that the membrane is suitable for. Therefore, tap water, room temperature water, or heated water may be used, as long as the temperature guidelines for a particular membrane are not exceeded. For most membranes, this is up to 50°C. For high-temperature membranes, this may be up to 60°C, or even up to 70°C. For standard membranes, the rinse water temperature is preferably 20°C to 50°C, more preferably 25°C to 50°C, and most preferably 30°C to 50°C. For high-temperature membranes, the rinse water temperature is preferably 20°C to 70°C, more preferably 25°C to 70°C, and most preferably 30°C to 70°C.

[0049] enzyme process

[0050] The membrane comes into contact with the enzyme composition in enzyme step 104. The enzyme composition comprises a carrier, an enzyme, and a buffer. The carrier is preferably water. The water may be tap water, distilled water, or RO (reverse osmosis) water. The water may have a hardness of about 20 grains or less, preferably about 15 grains or less, more preferably about 10 grains or less, and even more preferably 5 grains or less. Tap water, room temperature water, or heated water may be used, as long as the temperature guidelines for the particular membrane are not exceeded. Preferably, the enzyme composition further comprises a chelating agent. The amount of chelating agent may be influenced by the hardness of the water.

[0051] The pH of the enzyme composition is preferably about 7.5 to about 11.0, more preferably about 8.0 to about 10.5, and most preferably about 9 to about 10.

[0052] The temperature of the enzyme composition can be any temperature to which the membrane is suitable. For most membranes, this is up to 50°C. For high-temperature membranes, this can be up to 60°C, or even up to 70°C. For standard membranes, the rinse water temperature is preferably 20°C to 50°C, more preferably 25°C to 50°C, and most preferably 30°C to 50°C. For high-temperature membranes, the rinse water temperature is preferably 20°C to 70°C, more preferably 25°C to 70°C, and most preferably 30°C to 70°C.

[0053] Lipase

[0054] The enzyme composition contains lipase. Any lipase or mixture of lipases from any source may be used in the enzyme composition, provided that the selected lipase is stable within a pH range compatible with the membrane type. For example, the lipase enzyme may be derived from plants, animals, or microorganisms such as fungi or bacteria. The lipase may be purified, a component of a microbial extract, wild-type, or a variant (either chemically or genetically modified).

[0055] Preferred lipase enzymes include, but are not limited to, enzymes derived from Pseudomonas such as Pseudomonas stutzeri ATCC 19.154, or Thermomyces such as Thermomyces lanuginosus (typically recombinantly produced in Aspergillus oryzae). Most preferably, the lipase comprises a variant of wild-type Thermomyces lanuginosus lipase, as shown in SEQ ID NO: 1: [ka] It has at least 90% sequence identity.

[0056] protease

[0057] The enzyme composition may further contain a protease. Any protease or mixture of proteases from any source may be used in the enzyme composition, provided that the selected protease is stable within a pH range compatible with the membrane type. For example, the protease enzyme may be derived from plants, animals, or microorganisms such as yeast, mold, or bacteria. Preferred protease enzymes, but not limited to these, include those derived from Bacillus subtilis, Bacillus licheniformis, and Streptomyces griseus. The protease enzyme derived from B. subtilis is most preferred. The protease may be purified, a component of a microbial extract, or either wild-type or a variant (either chemically or genetically modified).

[0058] cushioning agent

[0059] The enzyme composition includes a buffer. Preferably, the buffer is selected based on the optimal pH of the enzyme in the enzyme composition. Preferred buffers include those suitable for buffering the composition to maintain a pH of 7.5 to 11.0. Any suitable buffer that achieves this pH may be used. In preferred embodiments, the buffer includes, but is not limited to, alkali metal carbonates, sodium bicarbonate, or mixtures thereof, and includes carbonate-based buffers.

[0060] The amount of buffer included is the amount necessary to maintain the pH for optimal enzyme activity. In a preferred embodiment, the buffer is at a concentration of approximately .

[0061] Chelating agents and / or metal ion sequestering agents

[0062] The enzyme composition may optionally contain a chelating agent and / or a metal ion sequestering agent. As described herein, the chelating agent includes a compound that forms a water-soluble complex with a metal. As described herein, the metal ion sequestering agent includes a compound that forms a water-insoluble complex with a metal.

[0063] Preferred chelating agents include aminocarboxylates, sodium tripolyphosphate, and citrates (in the form of their acids or salts). Preferred aminocarboxylates include biodegradable aminocarboxylates. Examples of preferred biodegradable aminocarboxylates include ethanol diglycine, e.g., alkali metal salts of ethanol diglycine, e.g., disodium ethanol diglycine (Na2EDG), methylglycine diacetic acid (MGDA), e.g., alkali metal salts of methylglycine diacetic acid, e.g., trisodium methylglycine diacetic acid, ethylenediaminetetraacetic acid (EDTA), iminodisuccinic acid, e.g., alkali metal salts of iminodisuccinic acid, e.g., sodium iminodisuccinate, N,N-bis-(carboxylatomethyl)-L-glutamic acid (GLDA), e.g. Examples include alkali metal salts of N,N-bis-(carboxylatomethyl)-L-glutamic acid, such as sodium iminodisuccinate (GLDA-Na4); alkali metal salts of [SS]-ethylenediaminedisuccinate (EDDS), such as sodium salt of [SS]-ethylenediaminedisuccinate; and alkali metal salts of 3-hydroxy-2,2'-iminodisuccinate (HIDS), such as tetrasodium 3-hydroxy-2,2'-iminodisuccinate.

[0064] Some examples of polymer polycarboxylates suitable for use as metal ion chelating agents include those having a pendant carboxylate (--CO2) group, such as polyacrylic acid, maleic acid / olefin copolymer, acrylic / maleic acid copolymer, polymethacrylic acid, acrylic acid-methacrylic acid copolymer, hydrolyzed polyacrylamide, hydrolyzed polymethacrylamide, hydrolyzed polyamide-methacrylamide copolymer, hydrolyzed polyacrylonitrile, hydrolyzed polymethacrylonitrile, and hydrolyzed acrylonitrile-methacrylonitrile copolymer.

[0065] If present, the chelating agent and / or metal ion sequestering agent is preferably present in a concentration of about 10 ppm to about 10,000 ppm, more preferably about 25 ppm to about 5,000 ppm, and most preferably about 50 ppm to about 2,500 ppm.

[0066] Surfactant process

[0067] The membrane comes into contact with the surfactant composition in the surfactant step 105. The surfactant composition comprises a carrier and a surfactant. The carrier is preferably water. The water may be tap water, distilled water, or RO (reverse osmosis) water. The water may have a hardness of about 20 grains or less, preferably about 15 grains or less, more preferably about 10 grains or less, and even more preferably 5 grains or less. Tap water, room temperature water, or heated water may be used, as long as the temperature guidelines for the particular membrane are not exceeded. In a preferred embodiment, the surfactant composition further comprises an additional protease and / or an additional buffer. The above-mentioned protease and buffer are suitable for the surfactant composition. The protease may be the same as or different from the protease included in the enzymatic step.

[0068] surfactants

[0069] The surfactant composition contains a surfactant. Preferred surfactants include, but are not limited to, nonionic surfactants, amphoteric surfactants, sulfonated surfactants, or mixtures thereof. More preferably, the surfactant contains alkyl polyglucosides, amine oxides, alcohol ethoxylates, alkoxylated block copolymers, sulfonated surfactants, or mixtures thereof. Most preferably, the surfactant contains alkyl polyglucosides, amine oxides, sulfonated surfactants, or mixtures thereof.

[0070] Amine oxide

[0071] The amine oxide is a tertiary amine oxide corresponding to the following general formula: [Chemical formula In the formula, the arrow is the conventional representation of a semi-polar bond, and R 1 , R 2 , and R 3 can be aliphatic, aromatic, heterocyclic, alicyclic, or a combination thereof. Generally, for amine oxides for detergent purposes, R 1 is an alkyl radical having about 8 to about 18 carbon atoms, and R 2 and R 3 are alkyl or hydroxyalkyl having 1 to 3 carbon atoms, or a mixture thereof, and R 2 and R 3 can be bonded to each other through, for example, an oxygen or nitrogen atom to form a ring structure, and R 4 is an alkaline or hydroxyalkylene group containing 2 to 3 carbon atoms, and n ranges from 0 to about 20.

[0072] Preferred amine oxides may include those selected from coconut or tallow alkyldi-(lower alkyl)amine oxides, and specific examples thereof are dodecyldimethylamine oxide, tridecyldimethylamine oxide, tetradecyldimethylamine oxide, pentadecyldimethylamine oxide, hexadecyldimethylamine oxide, heptadecyldimethylamine oxide, octadecyldimethylamine oxide, dodecyldipropylamine oxide, tetradecyldipropylamine oxide, hexadecyldipropylamine oxide, tetradecyldibutylamine oxide, octadecyldibutylamine oxide, bis(2-hydroxyethyl)dodecylamine oxide, bis(2-hydroxyethyl)-3-dodecoxy-1-hydroxypropylamine oxide, dimethyl-(2-hydroxydodecyl)amine oxide, 3,6,9-trioctadecyldimethylamine oxide, and 3-dodecoxy-2-hydroxypropyldi-(2-hydroxyethyl)amine oxide.

[0073] Nonionic surfactants

[0074] Preferred nonionic surfactants include, but are not limited to, block copolymers, alcohol alkoxylates, alkoxylated surfactants, reverse EO / PO copolymers, alkyl polyglucosides, alkoxylated amines, fatty acid alkoxylates, fatty acid amide alkoxylates, alkanoates, and combinations thereof.

[0075] Nonionic surfactants are generally characterized by the presence of organic hydrophobic and organic hydrophilic groups and are typically produced by condensation of organic aliphatic, alkyl aromatic, or polyoxyalkylene hydrophobic compounds with a hydrophilic alkaline oxide moiety, which in common practice is ethylene oxide or its polyhydration product, polyethylene glycol. In practice, any hydrophobic compound having a hydroxyl, carboxyl, amino, or amide group with a reactive hydrogen atom can be condensed with ethylene oxide or its polyhydration adduct, or a mixture thereof with an alkoxylene such as propylene oxide, to form a nonionic surfactant. The length of the hydrophilic polyoxyalkylene moiety that condenses with any particular hydrophobic compound can be easily adjusted to produce a water-dispersible or water-soluble compound with a desired balance between hydrophilic and hydrophobic properties.

[0076] Preferred liquid nonionic surfactants include, but are not limited to, the following.

[0077] A. Blocked polyoxypropylene-polyoxyethylene polymer compounds based on propylene glycol, ethylene glycol, glycerol, trimethylolpropane, and ethylenediamine as initiator-reactive hydrogen compounds.

[0078] B. Condensation product of 1 mole of saturated or unsaturated straight-chain or branched-chain alcohol having approximately 6 to approximately 24 carbon atoms with approximately 3 to approximately 50 moles of ethylene oxide. The alcohol portion may contain, essentially consist of, or be composed of a mixture of alcohols within the carbon range described above, or it may consist of alcohols having a specific number of carbon atoms within this range, or it may be a Guerbet alcohol ethoxylate.

[0079] In addition to ethoxylated carboxylic acids, commonly known as polyethylene glycol esters, other alkanate esters formed by reactions with glycerides, glycerol, and polyhydric (sugars or sorbitan / sorbitol) alcohols have applications in the present invention in specific embodiments. All of these ester moieties have one or more reactive hydrogen sites on their molecules that can be subjected to further acylation or ethylene oxide (alkoxide) addition to control the hydrophilicity of these substances. When adding these fatty esters or acylated carbohydrates to compositions containing lipase enzymes, caution should be exercised due to the potential for incompatibility.

[0080] C. Ethoxylation C6~C 18 Fatty alcohols and C6-C 18 Mixed ethoxylated and propoxylated fatty alcohols, particularly water-soluble ones, are suitable surfactants for use in this composition. Suitable ethoxylated fatty alcohols include C6-C6 alcohols with an ethoxylation degree of 3-50. 18 Ethoxylated fatty alcohols are one example.

[0081] D. Suitable nonionic surfactants for use with the compositions of the present invention include alkoxylated surfactants. Suitable alkoxylated surfactants include EO / PO copolymers, capped EO / PO copolymers, alcohol alkoxylates, capped alcohol alkoxylates, and mixtures thereof. Suitable alkoxylated surfactants for use as solvents include EO / PO block copolymers such as Pluronic® and reverse Pluronic® surfactants, alcohol alkoxylates, capped alcohol alkoxylates, and mixtures thereof.

[0082] E. A compound from (1) that has been modified and essentially inverted by adding ethylene oxide to ethylene glycol to provide a hydrophilic substance of a specified molecular weight, and then adding propylene oxide to obtain a hydrophobic block on the outside (end) of the molecule.

[0083] F. In particular, nonionic alkyl polysaccharide surfactants suitable for use in this composition include those disclosed in U.S. Patent No. 4,565,647, Llenado, issued on January 21, 1986. These surfactants comprise a hydrophobic group containing about 6 to about 30 carbon atoms, and a hydrophilic group containing a polysaccharide, e.g., a polyglycoside, containing about 1.3 to about 10 saccharide units. Any reduced saccharide containing 5 or 6 carbon atoms may be used, for example, the galactosyl moiety may be substituted with glucose, galactose, and glucosyl moieties. (Optionally, the hydrophobic group may be bonded to positions such as 2-, 3-, 4-, etc., producing glucose or galactose as opposed to glucoside or galactoside.) Bonding between saccharides may be, for example, between one position of an additional saccharide unit and the 2, 3, 4, and / or 6 positions on the preceding saccharide unit.

[0084] G. Suitable nonionic surfactants include alkoxylated amines, or more specifically, a class defined as alcohol alkoxylated / amination / alkoxylated surfactants. These nonionic surfactants are at least in part to have the general formula: R 20 --(PO) S N--(EO) t H, R 20 --(PO) S N--(EO) t H(EO) t H and R 20 --N(EO) t It can be expressed by H, where R 20 is an alkyl, alkenyl, or other aliphatic group, or alkyl-aryl group, having 8 to 20, preferably 12 to 14 carbon atoms; EO is oxyethylene; PO is oxypropylene; s is 1 to 20, preferably 2 to 5; t is 1 to 10, preferably 2 to 5; and u is 1 to 10, preferably 2 to 5. Other variations within the range of these compounds are shown in the alternative formula: R 20 --(PO) V --N[(EO) w H][(EO) z It may also be expressed by H, where R 20 As defined above, v is 1 to 20 (for example, 1, 2, 3, or 4 (preferably 2)), and w and z are independently 1 to 10, preferably 2 to 5.

[0085] H. Suitable nonionic surfactants include fatty acid amide alkoxylates. Preferably, such surfactants have the structural formula R2CON. R1 Examples include those having Z, where R1 is H, C1-C4 hydrocarbyl, 2-hydroxyethyl, 2-hydroxypropyl, ethoxy, propoxy group, or a mixture thereof, and R2 is a linear C5-C 31The compound is hydrocarbyl, where Z is a polyhydroxyhydrocarbyl having a linear hydrocarbyl chain with at least three hydroxyls directly bonded to the chain, or an alkoxylated derivative thereof (preferably ethoxylated or propoxylated). Z can be derived from a reducing sugar in a reductive amination reaction, such as a glycityl moiety.

[0086] Alkyl ethoxylate condensation products of aliphatic alcohols with approximately 0 to 25 moles of ethylene oxide are suitable for use in this composition. The alkyl chain of the aliphatic alcohol may be linear or branched, either primary or secondary, but generally contains 6 to 22 carbon atoms.

[0087] Suitable fatty acid amide surfactants for use in this composition include those having the formula: R6CON(R7)2, where R6 is an alkyl group containing 7 to 21 carbon atoms, and each R7 is independently hydrogen, C1-C4 alkyl, C1-C4 hydroxyalkyl, or --(C2H4O) X H is such that x is in the range of 1 to 3.

[0088] I. Suitable nonionic surfactants include nonionic alkanoates. Suitable alkanoates are nonionic esters or salts thereof formed from the reaction of alkanic acid and alkanol.

[0089] J. Suitable alkyl polyglucosides include surfactants derived from quaternary sugars, such as quaternary alkyl polyglucosides or polyquaternary alkyl polyglucosides. Quaternary functionalized alkyl polyglucosides are cationic surfactants naturally derived from alkyl polyglucosides and have a sugar backbone. Quaternary functionalized alkyl polyglucosides have the following typical formula: [ka] In the formula, R1 is an alkyl group having approximately 1 to approximately 22 carbon atoms, and R2 is CH3(CH2) n’The formula is such that n' is an integer in the range of 0 to 21. Examples of suitable quaternary functionalized alkyl polyglucoside components that can be used in the cleaning composition according to the present invention include those in which the alkyl portion of R1 mainly contains about 10 to 12 carbon atoms, the R2 group is CH3, and n has a degree of polymerization of 1 to 2.

[0090] Polyquaternary alkyl polyglucosides are naturally derived from alkyl polyglucosides and possess a sugar skeleton. Polyquaternary alkyl polyglucosides have the following representative formulas: [ka] In the formula, R is an alkyl group having about 6 to about 22 carbon atoms, and n is an integer in the range of 4 to 6. Examples of suitable polyquaternary functionalized alkyl polyglucosides that can be used in the composition include those in which the alkyl portion of R contains about 8 to about 12 carbon atoms. In preferred embodiments, the quaternary functionalized alkyl polyglucoside mainly contains about 10 to 12 carbon atoms.

[0091] Sulfonated surfactants

[0092] The surfactant composition may contain a sulfonated surfactant. Preferred sulfonated surfactants include sodium caprylsulfonate, sodium lauryl sulfate, linear alkylbenzene sulfonate, sodium dodecylbenzenesulfonate, or mixtures thereof.

[0093] The pH of the enzyme composition is preferably about 7.5 to about 11.0, more preferably about 8.0 to about 10.5, and most preferably about 8.5 to about 9.5.

[0094] The temperature of the enzyme composition can be any temperature to which the membrane is suitable. For most membranes, this is up to 50°C. For high-temperature membranes, this can be up to 60°C, or even up to 70°C. For standard membranes, the rinse water temperature is preferably 20°C to 50°C, more preferably 25°C to 50°C, and most preferably 30°C to 50°C. For high-temperature membranes, the rinse water temperature is preferably 20°C to 70°C, more preferably 25°C to 70°C, and most preferably 30°C to 70°C.

[0095] The pH of the surfactant composition is preferably about 7.5 to about 11.5, more preferably about 8.0 to about 11.0, and most preferably about 8.5 to about 10.5.

[0096] The temperature of the surfactant composition can be any temperature to which the membrane is suitable. Therefore, tap water, room temperature water, or heated water can be used, as long as the temperature guidelines for a particular membrane are not exceeded. For most membranes, this is up to 50°C. For high-temperature membranes, this can be up to 60°C, or even up to 70°C. For standard membranes, the rinse water temperature is preferably 20°C to 50°C, more preferably 25°C to 50°C, and most preferably 30°C to 50°C. For high-temperature membranes, the rinse water temperature is preferably 20°C to 70°C, more preferably 25°C to 70°C, and most preferably 30°C to 70°C.

[0097] Rinsing process

[0098] After the surfactant washing step, in the rinsing step 106, the membrane is rinsed to remove excess enzymes, surfactants, buffers, and chelating agents. Specifically, it is important to remove lipase because residual lipase can react to form fatty acid salts, which can impart an unpleasant taste to dairy products subsequently processed through the dairy filtration membrane. Rinsing is preferably carried out with water. The water may be tap water or softened water. The water may have a hardness of about 20 grains or less, preferably about 15 grains or less, more preferably about 10 grains or less, and even more preferably 5 grains or less. Most preferably, the water is distilled water or RO (reverse osmosis) water. The rinse water may be at any temperature that the membrane is suitable for. Therefore, tap water, room temperature water, or heated water can be used, as long as the temperature guidelines for a particular membrane are not exceeded. For most membranes, this is up to 50°C. For high-temperature membranes, this may be up to 60°C, or even up to 70°C. For standard membranes, the rinse water temperature is preferably 20°C to 50°C, more preferably 25°C to 50°C, and most preferably 30°C to 50°C. For high-temperature membranes, the rinse water temperature is preferably 20°C to 70°C, more preferably 25°C to 70°C, and most preferably 30°C to 70°C.

[0099] Lipase acid inactivation process

[0100] We found that in lipase inactivation step 107, it is important to inactivate the lipase by unfolding the enzyme protein. This provides a technical benefit in the formation of fatty acid salts that cause an unpleasant taste in dairy products. Any residual lipase on the membrane can be inactivated by contacting the membrane with an acidic composition. The acidic composition preferably comprises an acid, an acidic anionic surfactant, or a mixture thereof. The pH of the acidic composition is preferably about 2.5 or less, more preferably about 2.4 or less, even more preferably about 2.3 or less, even more preferably about 2.2 or less, even more preferably about 2.1 or less, and most preferably about 2.0 or less or less.

[0101] Acidic anionic surfactants

[0102] Acidic compositions may contain acidic anionic surfactants. Anionic surfactants are surfactants classified by the negative charge on a hydrophilic substance, or surfactants in which the hydrophobic compartment of the molecule does not carry a charge unless the pH rises above a pKa (e.g., carboxylic acid). Some anionic surfactants have an acidic pH in solution. Carboxylates, sulfonates, sulfates, and phosphates are polar (hydrophilic) solubilizing groups found in anionic surfactants. Of the cations (counterions) associated with these polar groups, sodium, lithium, and potassium confer water solubility, ammonium and substituted ammonium ions provide both water and oil solubility, and calcium, barium, and magnesium promote oil solubility.

[0103] Preferred acidic anionic surfactants include, but are not limited to, sulfonated surfactants, and include alkyl sulfonates, linear and branched primary and secondary alkyl sulfonates, and aromatic sulfonates with or without substituents. In one embodiment, the sulfonate includes sulfonated carboxylic acid esters. In one embodiment, suitable alkyl sulfonate surfactants include C8-C22 alkylbenzene sulfonates or C10-C22 alkyl sulfonates. In exemplary embodiments, the acidic anionic surfactant includes alkyl sulfonate surfactants, most preferably linear alkyl benzene sulfonic acid (LAS). In further embodiments, the acidic anionic surfactant may alternatively or additionally include diphenylated sulfonates and / or sulfonated oleic acid. Most preferred acidic anionic surfactants include, but are not limited to, C8-C22 alkylbenzene sulfonates, sulfonated oleic acid, sulfosuccinates, secondary alkane sulfonates, or mixtures thereof.

[0104] acid

[0105] The acidic composition may contain an acid. Preferred acids include organic acids, nitric acid, phosphoric acid, methanesulfonic acid, and mixtures thereof. Preferred organic acids include, but are not limited to, formic acid, acetic acid, glycolic acid, glyoxylic acid, oxalic acid, propionic acid, lactic acid, glyceric acid, malonic acid, tartonic acid, glycisic acid, butanoic acid, 2-methylpropanoic acid, citric acid, and mixtures thereof. Strong acids, such as sulfuric acid, hydrochloric acid, and hydrofluoric acid, are not preferred. More preferred acids include nitric acid, phosphoric acid, methanesulfonic acid, lactic acid, citric acid, and mixtures thereof. Most preferred acids include citric acid, lactic acid, and mixtures thereof.

[0106] The temperature of the acidic composition can be any temperature to which the membrane is suitable. Therefore, tap water, room temperature water, or heated water can be used, as long as the temperature guidelines for a particular membrane are not exceeded. For most membranes, this is up to 50°C. For high-temperature membranes, this can be up to 60°C, or even up to 70°C. For standard membranes, the rinse water temperature is preferably 20°C to 50°C, more preferably 25°C to 50°C, and most preferably 30°C to 50°C. For high-temperature membranes, the rinse water temperature is preferably 20°C to 70°C, more preferably 25°C to 70°C, and most preferably 30°C to 70°C.

[0107] Rinsing process

[0108] After the lipase inactivation step, in rinsing step 108, the membrane is rinsed to remove excess acid and / or surfactant. Rinsing is preferably carried out with water. The water may be tap water or softened water. The water may have a hardness of about 20 grains or less, preferably about 15 grains or less, more preferably about 10 grains or less, and even more preferably 5 grains or less. Most preferably, the water is distilled water or RO (reverse osmosis) water. The rinse water may be at any temperature that the membrane is suitable for. Therefore, tap water, room temperature water, or heated water may be used as long as the temperature guidelines for a particular membrane are not exceeded. For most membranes, this is up to 50°C. For high-temperature membranes, this may be up to 60°C, or even up to 70°C. For standard membranes, the rinse water temperature is preferably 20°C to 50°C, more preferably 25°C to 50°C, and most preferably 30°C to 50°C. For high-temperature membranes, the rinse water temperature is preferably 20°C to 70°C, more preferably 25°C to 70°C, and most preferably 30°C to 70°C.

[0109] Optional alkaline process

[0110] Optionally, the membrane may be washed in alkaline step 109. Alkaline step 109 can help further inactivate the lipase by charging a portion of the unfolding protein so that it remains unfolded. Step 109 is not required, but in some situations it can aid inactivation. In alkaline step 109, the membrane comes into contact with an alkaline composition. The alkaline composition preferably comprises an alkali metal hydroxide, an alkali metal carbonate, or a mixture thereof. Preferred alkali metal hydroxides include sodium hydroxide, potassium hydroxide, or a mixture thereof. Preferred alkali metal carbonates include sodium carbonate, potassium carbonate, or a mixture thereof. In addition to alkali metal hydroxides and / or alkali metal carbonates, the alkaline composition may optionally further comprise an alkali metal silicate, a metasilicate, a sesquicarbonate, an organic alkali source, or a mixture thereof.

[0111] Organic alkali sources are often strong nitrogen bases, including, for example, ammonia (ammonium hydroxide), amines, alkanolamines, and amino alcohols. Typical examples of amines include primary, secondary, or tertiary amines and diamines that support at least one nitrogen-bonded hydrocarbon group, which represent saturated or unsaturated linear or branched alkyl groups having at least 10 carbon atoms, preferably 16 to 24 carbon atoms, or aryl, aralkyl, or alkaryl groups containing up to 24 carbon atoms, with an optional other nitrogen-bonded group formed by optionally substituted alkyl, aryl, or aralkyl or polyalkoxy groups. Typical examples of alkanolamines include monoethanolamine, monopropanolamine, diethanolamine, dipropanolamine, triethanolamine, and tripropanolamine. Typical examples of amino alcohols include 2-amino-2-methyl-1-propanol, 2-amino-1-butanol, 2-amino-2-methyl-1,3-propanediol, 2-amino-2-ethyl-1,3-propanediol, and hydroxymethylaminomethane.

[0112] The pH of the alkaline composition used in the optional alkaline step is preferably about 9.5 to about 12.0, more preferably about 9.7 to about 11.8, and most preferably about 10.0 to about 11.5.

[0113] If an alkaline process is performed, a follow-up rinse process 110 is then performed to remove the alkaline composition. Rinsing is preferably performed with water. The water may be tap water or softened water. The water may have a hardness of about 20 grains or less, preferably about 15 grains or less, more preferably about 10 grains or less, and even more preferably 5 grains or less. Most preferably, the water is distilled water or RO (reverse osmosis) water. The rinse water may be at any temperature to which the membrane is suitable. Therefore, tap water, room temperature water, or heated water may be used, as long as the temperature guidelines for a particular membrane are not exceeded. For most membranes, this is up to 50°C. For high-temperature membranes, this may be up to 60°C, or even up to 70°C. For standard membranes, the rinse water temperature is preferably 20°C to 50°C, more preferably 25°C to 50°C, and most preferably 30°C to 50°C. For high-temperature membranes, the rinse water temperature is preferably 20°C to 70°C, more preferably 25°C to 70°C, and most preferably 30°C to 70°C.

[0114] Preferred Embodiment

[0115] This disclosure is further defined by embodiments numbered below.

[0116] 1. A method for washing a dairy product filtration membrane, (a) Contacting a dairy product filtration membrane with an enzyme composition, wherein the enzyme composition contains lipase and a buffer, and the pH of the enzyme composition is approximately 7.5 to approximately 11.0. (b) Contacting a dairy filtration membrane with a surfactant composition, wherein the surfactant composition comprises alkyl polyglucoside, alkyl polypentoside, amine oxide, alcohol ethoxylate, alkoxylated block copolymer, sulfonated surfactant, or a mixture thereof, and the pH of the surfactant composition is about 7.5 to about 11.0. (c) Rinsing the dairy filtration membrane, (d) Contacting a dairy filtration membrane with an acidic composition, wherein the acidic composition comprises an acid, an acidic anionic surfactant, or a mixture thereof, the pH of the acidic composition is about 2.5 or less, and the acidic composition inactivates lipase. (e) A method comprising rinsing a dairy filtration membrane.

[0117] 2. The method according to paragraph 1, wherein the lipase comprises a lipase derived from Pseudomonas or Humicola.

[0118] 3. The method according to paragraph 1 or 2, wherein the enzyme composition further comprises a protease.

[0119] 4. The method according to any one of paragraphs 1 to 3, wherein the surfactant composition further comprises a protease.

[0120] 5. The method according to paragraph 3 or 4, wherein the protease comprises proteases derived from Bacillus subtilis, Bacillus licheniformis, and Streptomyces griseus.

[0121] 6. The method according to any one of paragraphs 1 to 5, wherein the buffer comprises an alkali metal hydroxide, an alkali metal carbonate, sodium bicarbonate, or a mixture thereof.

[0122] 7. The method according to any one of paragraphs 1 to 6, wherein the enzyme composition comprises a chelating agent.

[0123] 8. The method according to paragraph 7, wherein the chelating agent comprises an aminocarboxylic acid or a salt thereof, sodium tripolyphosphate, citric acid or a salt thereof, or a mixture thereof.

[0124] 9. The method according to any one of paragraphs 1 to 8, wherein the acidic composition comprises a linear alkyl sulfonate, a linear alkyl sulfate, a branched alkyl sulfonate, a branched alkyl sulfate, a substituted aromatic sulfonate, an unsubstituted aromatic sulfonate, an organic acid, nitric acid, phosphoric acid, methanesulfonic acid, or a mixture thereof.

[0125] 10. The surfactant composition contains C5, C 12 ~C 14 Alkyl polypentoside, C8~C 16 Alkyl polyglycoside, EO PO block copolymer, nonylphenol ethoxylate, lauryl dimethylamine oxide, linear alkylbenzene sulfonate, 2-ethyl-hexyl alkoxylate, C6 alkyl polyglycoside, secondary n-alkyl sulfonate, sodium lauryl sulfonate, C 12~14 The method according to any one of paragraphs 1 to 9, comprising one or more of sodium alcohol sulfate or mixtures thereof.

[0126] 11. (f) Contacting a dairy product filtration membrane with an alkaline composition, wherein the alkaline composition has a pH of about 9.5 to about 12.0. (g) The method according to any one of paragraphs 1 to 10, further comprising rinsing the dairy filtration membrane.

[0127] 12. The method according to paragraph 11, wherein the alkaline composition comprises an alkali metal hydroxide, alkali metal carbonate, alkali metal silicate, organic alkali source, or a mixture thereof.

[0128] 13. The method according to any one of paragraphs 1 to 12, further comprising the step of pre-rinsing the dairy filtration membrane before step (a).

[0129] 14. The method according to any one of paragraphs 1 to 13, further comprising the step of contacting a dairy filtration membrane with a membrane detergent composition prior to step (a), and then rinsing the dairy filtration membrane.

[0130] 15. The method according to any one of paragraphs 1 to 14, wherein the dairy filtration membrane includes a microfiltration membrane, an ultrafiltration membrane, a nanofiltration membrane, and / or a reverse osmosis membrane.

[0131] 16. A method for washing a dairy product filtration membrane, (a) Contacting a dairy filtration membrane with an enzyme composition, wherein the enzyme composition comprises lipase, protease, and a buffer, the pH of the enzyme composition is about 8.0 to about 10.5, and the dairy filtration membrane includes a microfiltration membrane, an ultrafiltration membrane, a nanofiltration membrane, and / or a reverse osmosis membrane. (b) Contacting a dairy filtration membrane with a surfactant composition, wherein the surfactant composition comprises alkyl polyglucoside, alkyl polypentoside, amine oxide, alcohol ethoxylate, alkoxylated block copolymer, sulfonated surfactant, or a mixture thereof, and the pH of the surfactant composition is about 8.0 to about 10.5. (c) Rinsing the dairy filtration membrane, (d) Contacting a dairy filtration membrane with an acidic composition, wherein the acidic composition comprises a linear alkyl sulfonate, a branched alkyl sulfonate, a substituted aromatic sulfonate, an unsubstituted aromatic sulfonate, an organic acid, nitric acid, phosphoric acid, methanesulfonic acid, or a mixture thereof, and the pH of the acidic composition is about 2.5 or less, and the acidic composition inactivates the lipase. (e) A method comprising rinsing a dairy filtration membrane.

[0132] 17. (f) Contacting a dairy filtration membrane with an alkaline composition, wherein the alkaline composition comprises an alkali metal hydroxide, alkali metal carbonate, alkali metal silicate, organic alkali source, or a mixture thereof, and the alkaline composition has a pH of about 10.0 to about 12.0. (g) The method according to paragraph 16, further comprising rinsing the dairy filtration membrane.

[0133] 18. The method according to paragraph 17, wherein the alkaline composition comprises an alkali metal hydroxide, an alkali metal carbonate, or a mixture thereof.

[0134] 19. The method according to any one of paragraphs 16 to 18, wherein the lipase comprises a lipase derived from Pseudomonas or Humicola, the protease comprises a protease derived from Bacillus subtilis, Bacillus licheniformis, and Streptomyces griseus, and the buffer comprises an alkali metal carbonate, sodium bicarbonate, or a mixture thereof.

[0135] 20. The method according to any one of paragraphs 16 to 19, wherein the enzyme composition further comprises a chelating agent, the chelating agent comprising an aminocarboxylic acid or a salt thereof, sodium tripolyphosphate, citric acid or a salt thereof, or a mixture thereof.

[0136] 21. The method according to any one of paragraphs 16 to 20, wherein the surfactant composition further comprises a protease, the protease comprising a protease derived from Bacillus subtilis, Bacillus licheniformis, and Streptomyces griseus.

[0137] 22. The surfactant composition contains C5, C 12 ~C 14 Alkyl polypentoside, C8~C 16 Alkyl polyglycoside, EO PO block copolymer, nonylphenol ethoxylate, lauryl dimethylamine oxide, linear alkylbenzene sulfonate, 2-ethyl-hexyl alkoxylate, C6 alkyl polyglycoside, secondary n-alkyl sulfonate, sodium lauryl sulfonate, C 12~14 The method according to any one of paragraphs 16 to 21, comprising one or more of sodium alcohol sulfate or mixtures thereof.

[0138] 23. The method according to any one of paragraphs 1 to 22, wherein the lipase comprises a variant of wild-type Thermomyces lanuginosus lipase.

[0139] 24. The method according to any one of paragraphs 1 to 23, wherein the lipase has at least 90% sequence identity with respect to sequence number 1. [Examples]

[0140] Examples

[0141] Embodiments of the present disclosure are further defined in the following non-limiting examples. These examples illustrate certain embodiments of the present disclosure, but should be understood to be given merely as illustrations. From the above considerations and these examples, those skilled in the art can identify the essential features of the present disclosure and make various changes and modifications to the embodiments of the present disclosure to suit various uses and conditions without departing from the spirit and scope thereof. Accordingly, various modifications to the embodiments of the present disclosure will be apparent to those skilled in the art from the foregoing description, in addition to those shown and described herein. Such modifications are also intended to be within the scope of the appended claims. Several commercially available lipase compositions were used. Specific lipase information is unknown because it is a proprietary formula from Novozymes. Three are identified herein as lipase A, lipase B, and lipase C. Each of lipase A, lipase B, and lipase C is a variant of wild-type Thermomyces lanuginosus lipase and has at least 90% sequence identity with SEQ ID NO: 1.

[0142] Example 1

[0143] Fats are a significant challenge in dairy production. Studies of washed and unwashed in-situ membranes have shown that fats, particularly high-melting-point triglycerides, carry a 10-fold higher contamination load compared to protein deposits present on the membrane. Fats and protein deposits are difficult to remove during in-situ washing, and high-melting-point fats accumulate over the membrane's lifespan because their melting points far exceed the in-situ washing temperature. Incomplete removal of membrane deposits affects the membrane's production performance and is a critical factor in the overall integrity of the membrane. Triglyceride fats are difficult to remove and accumulate on the membrane over time. Triglyceride fats can be broken down via catalytic reactions with lipases. Lipase molecules unfold the three-dimensional structure of triglyceride fats, resulting in the loss of active sites, as can be seen in the following diagram. [ka]

[0144] Figure 2 demonstrates that lipase can remove fat from the membrane, but also adheres to the membrane surface and within the pores. Figure 3C shows an SEM surface image of a microfiltration membrane. Inactivation of lipase is more difficult in membrane filtration systems (Figure 3B) compared to liquid solution scenarios (Figure 3A). On the upper membrane surface, lipase interacts with the membrane pores. Lipid-degrading enzymes are designed to be stable in highly alkaline formulations, for example, for laundry applications. These formulations contain chelators and oxidizing agents (e.g., NaOCl), and are therefore very difficult to inactivate. Current washing methods do not completely remove all dirt components from all membrane types and do not address the complete fouling phenomenon. Lipase is surface-active, adheres to the membrane surface, and cannot be rinsed off with water. Lipase cannot be inactivated with acid or alkali. Similarly, oxidizing agents cannot completely inactivate lipase (stability against oxidation).

[0145] Exemplary washing methods were tested against current conventional enzymatic washing methods for their effectiveness in lipase inactivation in microfiltration and ultrafiltration membranes. Figures 4 and 5 show the effectiveness of the washing methods. Figure 4 compares five standard inactivation procedures (enzyme, enzymatic rinse, enzymatic method 1, and enzymatic method 2). As can be seen from the figure, the enzymatic washing methods still show a significant amount of lipase enzyme activity in both microfiltration and ultrafiltration membranes compared to commercial enzymatic washing methods. Nevertheless, the described washing methods still have residual lipase after washing. Figure 5 compares the enzymatic washing methods with the exemplary washing methods (commercial washing methods 1 and 2). As shown by the graph in Figure 5, the exemplary washing methods show little to no residual lipase enzyme activity. Detection was only observed in microfiltration membranes using the exemplary washing methods without an optional alkaline washing step. This test demonstrates that the anionic surfactant in the exemplary washing methods can unfold lipase in an acidic environment. The addition of an alkaline step helps reduce surfactant residue and positively contributes to the inactivation process.

[0146] As shown in the diagram, the type of membrane affects the activity of lipase on the membrane. Lipase molecules are approximately 30 kDa. Therefore, purely based on size, they pass through or permeate most microfiltration membranes but are rejected by ultrafiltration, nanofiltration, and reverse osmosis membranes. If lipase can enter the structure of the microfiltration membrane, a larger internal pore area allows the lipase to interact with it, causing more lipase molecules to adhere to the membrane, which also makes rinsing more difficult. In the case of ultrafiltration membranes, lipase can interact with pores on the membrane surface. As the membrane surface becomes smoother (i.e., smaller pore size), lipase interaction with the membrane decreases. Figure 6 illustrates these differences between microfiltration, ultrafiltration, nanofiltration, and reverse osmosis membranes.

[0147] Example 2

[0148] Exemplary surfactants used in exemplary cleaning methods were tested over time for their cleaning performance on butter fat. Polysulfone test pieces were washed with the exemplary surfactants at 50°C for 10 minutes and 20 minutes. Table 3 compares the cleaning performance of the exemplary surfactants at pH 9.5 and 11 for 10 minutes at 50°C. Table 4 further compares the cleaning performance of the exemplary surfactants at pH 9.5 and 11 for 20 minutes. As can be seen from Table 3, nonylphenol ethoxylate (NPE) at 600 ppm at either pH 9.5 or 11 is the best performing surfactant for removing butter fat in 10 minutes. Furthermore, as can be seen from Table 4, NPE at 600 ppm and pH 11 for 20 minutes removed approximately 100% of the dirt.

[0149] [Table 1]

[0150] [Table 2]

[0151] Example 3

[0152] The cleaning performance of ghee was tested with exemplary surfactants applied either all at once (one-pot) or in small amounts (replenishment). Polysulfone test specimens measuring 1 inch x 3 inches and 0.06 inches thick were prepared by immersion in methyl alcohol for 30 seconds, then placed in a 60°C oven for 30 minutes, and weighed on an analytical balance. The test specimens were contaminated with ghee in amounts of 0.0250–0.0300 g in a "c" pattern (seven "c"s were created on each test specimen using a 1-inch foam paintbrush). The test specimens were then dried overnight.

[0153] The exemplary surfactant used in the replenishment procedure begins with DI water heated to 50°C, mixed at 240 RPM using a 1.5-inch stirring rod in a 1000 mL beaker. Upon reaching that temperature, 7500 ppm buffer solution is added and mixed for approximately 1 minute to achieve a pH of 9.5. 600 mL of surfactant solution and 150 ppm lipase are added to the solution. The test specimen is then placed in the pot using a metal hanger. After 10 minutes, the exemplary product is added to the solution using approximately 1 g of DI water. After another 10 minutes, the metal hanger holding the test specimen is removed, and the specimen is immersed once in DI water at room temperature and allowed to dry overnight.

[0154] The exemplary surfactant applied in the one-pot procedure begins with DI water heated to 50°C, mixed at 240 RPM using a 1.5-inch stirring rod in a 1000 mL beaker. Upon reaching that temperature, 7500 ppm buffer solution is added and mixed for approximately 1 minute to achieve a pH of 9.5. The total volume of the surfactant solution is 600 mL, to which 150 ppm lipase is added. The test specimen is then placed in the pot using a metal hanger. After 20 minutes, the metal hanger containing the test specimen is removed, and the test specimen is immersed once in DI water at room temperature and allowed to dry overnight.

[0155] Table 5 shows exemplary ghee removal % results (%SR) of surfactants using both procedures. In the absence of the enzyme, the procedures are equivalent, or the one-pot procedure performs better. This is not surprising, as the one-pot procedure has the surfactant for 20 minutes compared to 10 minutes with the supplement.

[0156] [Table 3]

[0157] Table 6 shows the % ghee removal results (%SR) for the same exemplary surfactant using both procedures, including the enzyme. The enzyme was first added with DI water in a 1000 mL beaker, heated to 50°C, and stirred at 240 RPM using a 1.5-inch stirring rod. The procedure was the same as described above. When the enzyme is included in the exemplary procedure, there is no synergistic effect affecting the removal results for alkoxylate or short-chain alkyl polyglycoside surfactants.

[0158] [Table 4]

[0159] Example 4

[0160] The exemplary procedure of Example 3 is tested below. Tables 7-11 show how the percentage of dirt removed (%SR) is affected by enzyme concentration (Table 7), temperature (Table 8), water type (Table 9), enzyme type (Table 10), and surfactant concentration (Table 11).

[0161] Table 7 shows the use of one enzyme (lipase A) at four concentrations (0, 25, 50, and 150 ppm) using the supplementation and one-pot procedure described in Example 3. Table 7 shows that the supplementation procedure using any concentration of enzyme is better at removing ghee than the one-pot procedure with or without the enzyme.

[0162] [Table 5]

[0163] Table 8 shows the same surfactant, surfactant concentration, enzyme, and enzyme concentration used in the replenishment and one-pot procedures described in Example 2 at different temperatures (30, 40, and 50°C). The enzyme used in Table 8 is lipase A. Table 8 shows that temperature equally affects the performance of the surfactant / enzyme in either the replenishment or one-pot procedure, with the best performance observed in the replenishment procedure at 50°C.

[0164] [Table 6]

[0165] Table 9 shows the same surfactant, surfactant concentration, and enzyme, but using different enzyme concentrations and different grains per gallon (GPG) of water, utilizing the replenishment and one-pot procedures described in Example 2. The enzyme used in Table 9 is lipase A. When the enzyme concentration is the same but the water grains are different, Table 9 shows that the change in ghee removal is minimal for the replenishment procedure (replenishment: 62.6-66.7=4.1), but more substantial for the one-pot procedure (one-pot: 32.8-43.4=10.6).

[0166] [Table 7]

[0167] Table 10 shows four different surfactants (alkyl polypentosides, C8-C) at the same concentration in two different procedures as described in Example 2. 16 Alkyl polyglycosides, lauryldimethylamine oxide, and EO PO block copolymers are used. Table 10 shows the use of three different lipase enzymes at the same concentration.

[0168] [Table 8]

[0169] As can be seen from Table 10, all of the lipases performed better using the supplementation procedure compared to the standard one-pot procedure. Furthermore, it should be noted that lipases A and C tended to perform better than lipase B when combined with alkyl polyglycosides and alkyl polypentosides, respectively, while lipase B performed even better when combined with EO / PO block copolymers. Therefore, regardless of the lipase used, the use of the supplementation procedure provides synergistic results compared to the one-pot procedure.

[0170] Table 11 shows two different surfactants (C) at four different concentrations (600, 300, 150, and 75 ppm) in two different procedures as described in Example 2. 12 ~C 14 Alkyl polypentosides and C8-C 16 The same alkyl polyglycoside, enzyme, and enzyme concentration were used. Table 11 shows that the surfactant worked best at higher concentrations than the enzyme in each of the procedures.

[0171] [Table 9]

[0172] Example 5

[0173] The exemplary products and procedures of the above examples were tested with 10 different microfiltration and ultrafiltration membranes (Dairy Pro MF, Synder MQ, Synder LY, Synder FR, Synder MK, Synder PY, Synder BY, Synder V3, GR60PP, and FS40PP). The membranes were further washed with an optional alkaline treatment. Lipase adsorption of the membranes was then detected and plotted on a chart for comparison, as shown in Figure 7. Most of the tested membranes were microfiltration membranes and, with the exception of GR60PP, had molecular weight cutoffs above the lipase size (approximately 30 kDa). As shown in Figure 7, after both the inactivation step and the optional alkaline washing, the lipase activity was substantially below the detection limit. One outlier, Synder V3, is a cationic membrane. The cationic membrane surface increases surface interaction with lipase, which makes lipase inactivation more difficult than with non-cationic membranes. These membranes are generally not used in food applications. Therefore, the exemplary washing methods and procedures of the above examples are highly effective in lipase inactivation and membrane washing. The combination of an additional alkaline step helps reduce surfactant residue and positively contributes to the inactivation procedure.

[0174] Three microfiltration membranes (Synder FR, SuPro, and Synder LX) were further tested for lipase absorbance after exemplary washing methods at 30, 45, and 60 minutes, with or without alkaline rinsing. Figure 8 shows the results of these tests. As can be seen from the chart in Figure 8, all exemplary washing methods resulted in lipase inactivation, and any remaining lipase was below the detection limit.

[0175] Example 6

[0176] Exemplary washing methods were tested in various dairy membrane facilities. Three different embodiments were tested in filtration systems to evaluate the methods applied to different systems.

[0177] System A

[0178] The first filtration system included a four-loop ultrafiltration membrane for producing WPC30. The membrane was approximately 1.5 years old at the time of the CIP test, and the system was compromised by denatured proteins and fatty deposits. Data were accessed using integrated key performance indicators during the production phase. The in-situ washing concepts tested were based on lipases, proteases, and APG surfactants.

[0179] Potential fouling was observed before the filtration system was initially washed using a lipase-based CIP concept. The baseline enzymatic in-situ washing method showed a significant fouling tendency, with increasing pressure rise over the membrane lifetime. Lipase washing resulted in a lower fouling tendency slope of approximately 200% in pressure-normalized permeate flow rate. Furthermore, with a lipolytic in-situ washing replenishment process, we observed a 275% increase in the average fluid retention capacity of the membrane. In-situ lipase washing can positively influence fouling behavior, increased membrane lifetime, and lower pressure input, resulting in an overall higher pressure-normalized permeate flow rate. Special washing with lipase confirmed that a single in-situ washing increased overall filtration capacity by approximately 275%. The effect on productivity stabilized for at least two weeks after a single lipase washing event.

[0180] System B

[0181] The second dairy filtration system included a composite reverse osmosis / nanofiltration membrane system that treated WPC30 to WPC80. After the CIP (Clean-in-Place) stage, the washing performance of the replenishment accessed by a clean water flux was measured. The concept of stationary washing was based on lipase, protease, and APG surfactant.

[0182] In the acidic phase, a validated inactivation concept for lipase inactivation was implemented. Product generation, water flux data, and in-situ wash analysis were investigated. The in-situ wash solution resulted in a high chemical oxygen demand in the lipase recirculation phase and showed an increase in decomposed fatty acids, indicating fat removal. Furthermore, the solution resulted in complete lipase inactivation, without off-flavor issues in the product and without the presence of incompatible substances in the membrane.

[0183] The dairy filtration system showed a significant increase in flux (approximately 10%), particularly on the nanofiltration loop. The dairy filtration system also showed a significantly increased production capacity.

[0184] System C

[0185] The third dairy filtration system included a 4-loop RO / ROP membrane system for wastewater treatment. Washing performance of the refresh accessed by cleanwater flux was measured after the CIP stage. Washing resulted in significant fouling removal compared to baseline and pre-washing steps, and a significant increase in flux with each additional wash.

[0186] After switching back to the baseline method, the dairy filtration system showed a significant decrease in flux. A further increase in flux was observed after additional lipase washing. The dairy filtration system demonstrated improved washing efficiency while also exhibiting increased productivity.

[0187] Although the present invention has been described in this manner, it will be apparent that it can be modified in many ways. Such modifications should not be considered departures from the spirit and scope of this disclosure, and all such modifications are intended to fall within the scope of the following claims. The above specification provides a description of the manufacture and use of the disclosed compositions and methods. Since many embodiments can be made without departing from the spirit and scope of this disclosure, the present invention falls within the scope of the claims.

Claims

1. A method for washing a dairy product filtration membrane, wherein the method is: (a) Contacting the dairy product filtration membrane with an enzyme composition, wherein the enzyme composition comprises lipase and a buffer, and the pH of the enzyme composition is approximately 7.5 to approximately 11.

0. (b) Contacting the dairy product filtration membrane with a surfactant composition, wherein the surfactant composition comprises an alkyl polyglucoside, alkyl polypentoside, amine oxide, alcohol ethoxylate, alkoxylated block copolymer, sulfonated surfactant, or a mixture thereof, and the pH of the surfactant composition is about 7.5 to about 11.

0. (c) Rinsing the dairy product filtration membrane, (d) Contacting the dairy product filtration membrane with an acidic composition, wherein the acidic composition comprises an acid, an acidic anionic surfactant, or a mixture thereof, the pH of the acidic composition is about 2.5 or less, and the acidic composition inactivates the lipase. (e) A method comprising rinsing the dairy product filtration membrane.

2. The method according to claim 1, wherein the lipase comprises a lipase derived from Pseudomonas or Humicola.

3. The method according to claim 1 or 2, wherein the enzyme composition further comprises a protease.

4. The method according to any one of claims 1 to 3, wherein the surfactant composition further comprises a protease.

5. The method according to claim 3 or 4, wherein the protease comprises proteases derived from Bacillus subtilis, Bacillus licheniformis, and Streptomyces griseus.

6. The method according to any one of claims 1 to 5, wherein the buffering agent comprises an alkali metal hydroxide, an alkali metal carbonate, sodium bicarbonate, or a mixture thereof.

7. The method according to any one of claims 1 to 6, wherein the enzyme composition comprises a chelating agent.

8. The method according to claim 7, wherein the chelating agent comprises an aminocarboxylic acid or a salt thereof, sodium tripolyphosphate, citric acid or a salt thereof, or a mixture thereof.

9. The method according to any one of claims 1 to 8, wherein the acidic composition comprises a linear alkyl sulfonate, a linear alkyl sulfate, a branched alkyl sulfonate, a branched alkyl sulfate, a substituted aromatic sulfonate, an unsubstituted aromatic sulfonate, an organic acid, nitric acid, phosphoric acid, methanesulfonic acid, or a mixture thereof.

10. The surfactant composition is C ５ , C １２ ~C １４ Alkyl polypentoside, C ８ ~C １６ Alkyl polyglycoside, EO PO block copolymer, nonylphenol ethoxylate, lauryl dimethylamine oxide, linear alkylbenzene sulfonate, 2-ethyl-hexyl alkoxylate, C ６ Alkyl polyglycosides, secondary n-alkyl sulfonates, sodium lauryl sulfonate, C １２～１４ The method according to any one of claims 1 to 9, comprising one or more of sodium alcohol sulfate or mixtures thereof.

11. (f) Contacting the dairy product filtration membrane with an alkaline composition, wherein the alkaline composition has a pH of about 9.5 to about 12.

0. (g) The method according to any one of claims 1 to 10, further comprising rinsing the dairy product filtration membrane.

12. The method according to claim 11, wherein the alkaline composition comprises an alkali metal hydroxide, an alkali metal carbonate, an alkali metal silicate, an organic alkali source, or a mixture thereof.

13. The method according to any one of claims 1 to 12, further comprising the step of pre-rinsing the dairy product filtration membrane before step (a).

14. The method according to any one of claims 1 to 13, further comprising the step of contacting the dairy filtration membrane with a membrane detergent composition before step (a), and then rinsing the dairy filtration membrane.

15. The method according to any one of claims 1 to 14, wherein the dairy product filtration membrane includes a microfiltration membrane, an ultrafiltration membrane, a nanofiltration membrane, and / or a reverse osmosis membrane.

16. A method for washing a dairy product filtration membrane, wherein the method is: (a) Contacting the dairy product filtration membrane with an enzyme composition, wherein the enzyme composition comprises lipase, protease, and a buffer, the pH of the enzyme composition is about 8.0 to about 10.5, and the dairy product filtration membrane includes a microfiltration membrane, an ultrafiltration membrane, a nanofiltration membrane, and / or a reverse osmosis membrane. (b) Contacting the dairy product filtration membrane with a surfactant composition, wherein the surfactant composition comprises an alkyl polyglucoside, alkyl polypentoside, amine oxide, alcohol ethoxylate, alkoxylated block copolymer, sulfonated surfactant, or a mixture thereof, and the pH of the surfactant composition is about 8.0 to about 10.

5. (c) Rinsing the dairy product filtration membrane, (d) Contacting the dairy filtration membrane with an acidic composition, wherein the acidic composition comprises a linear alkyl sulfonate, a branched alkyl sulfonate, a substituted aromatic sulfonate, an unsubstituted aromatic sulfonate, an organic acid, nitric acid, phosphoric acid, methanesulfonic acid, or a mixture thereof, and the pH of the acidic composition is about 2.5 or less, and the acidic composition inactivates the lipase. (e) A method comprising rinsing the dairy product filtration membrane.

17. (f) Contacting the dairy product filtration membrane with an alkaline composition, wherein the alkaline composition comprises an alkali metal hydroxide, alkali metal carbonate, alkali metal silicate, organic alkali source, or a mixture thereof, and the alkaline composition has a pH of about 10.0 to about 12.

0. (g) The method according to claim 16, further comprising rinsing the dairy product filtration membrane.

18. The method according to claim 17, wherein the alkaline composition comprises an alkali metal hydroxide, an alkali metal carbonate, or a mixture thereof.

19. The method according to any one of claims 16 to 18, wherein the lipase comprises a lipase derived from Pseudomonas or Humicola, the protease comprises a protease derived from Bacillus subtilis, Bacillus licheniformis, and Streptomyces griseus, and the buffer comprises an alkali metal carbonate, sodium bicarbonate, or a mixture thereof.

20. The method according to any one of claims 16 to 19, wherein the enzyme composition further comprises a chelating agent, the chelating agent comprising an aminocarboxylic acid or a salt thereof, sodium tripolyphosphate, citric acid or a salt thereof, or a mixture thereof.

21. The method according to any one of claims 16 to 20, wherein the surfactant composition further comprises a protease, the protease comprising a protease derived from Bacillus subtilis, Bacillus licheniformis, and Streptomyces griseus.

22. where the surfactant composition is C ５ , C １２ -C １４ alkyl poly pentoside, C ８ -C １６ alkyl polyglycoside, EO PO block copolymer, nonylphenol ethoxylate, lauryldimethylamine oxide, linear alkylbenzene sulfonate, 2-ethyl-hexyl alkoxylate, C ６ alkyl polyglycoside, secondary n-alkyl sulfonate, sodium lauryl sulfonate, C １２～１４ sodium alcohol sulfate, or one or more of mixtures thereof, the method according to any one of claims 16 to 21.

23. The method according to any one of claims 1 to 22, wherein the lipase comprises a variant of wild-type Thermomyces lanuginosus lipase.

24. The method according to any one of claims 1 to 23, wherein the lipase has at least 90% sequence identity with respect to SEQ ID NO: 1.

Images