Container filled with lactase solution

Abstract

The purpose of the present invention is to provide a packaged lactase solution that hardly causes clogging of a filter. The packaged lactase solution of the present invention, in which a lactase solution is present in a container, is characterized in that the head space volume in the container is controlled to 20% or less relative to the total volume of the container. Also, the packaged lactase solution is characterized in that the lactase solution has a lactase activity within the range of 10-100,000 NLU / g.

Description

Technical Field

[0001] The present invention relates to a container-packed lactase solution with improved clogging of a filtration filter.

Background Art

[0002] Lactose intolerance refers to a condition in which various symptoms such as abdominal pain and diarrhea are presented due to lactose in foods such as dairy products because lactose cannot be decomposed well innately. Lactose is a disaccharide composed of galactose and glucose. In order to cope with lactose intolerance, lactose contained in milk or the like is decomposed in advance into galactose and glucose by lactase in the food manufacturing industry.

[0003] Conventionally, a lactase solution used to decompose lactose contained in milk or the like is obtained by culturing lactase-producing microorganisms, extracting lactase from inside the cells, or secreting lactase extracellularly, removing contaminants derived from the culture and purifying it, adding additives such as stabilizers, and then filling a container with the solution that has been sterilized by filtration to produce a product.

[0004] The manufactured container-packed lactase solution is stored, sold, and transported at refrigeration (10°C or lower). Thereafter, the lactase solution is added to milk or dairy products such as milk by a user. There are mainly two methods for adding this lactase solution: a method of adding it before sterilization of milk or the like and a method of adding it after sterilization. In the former case, the filtration sterilization process is not necessarily required, whereas in the latter case, the filtration sterilization process of the lactase solution is required. After adding the lactase solution, the milk is filled and then sold.

[0005] In the manufacturing process of adding a lactase solution to milk or the like after sterilization as described above, in the filtration sterilization step, the lactase solution is likely to cause clogging of the filter, which is known to significantly reduce work efficiency. To address this problem, for example, Patent Document 1 (Japanese Patent Publication No. 6-73454) describes filtering and sterilizing the lactase solution, for example, immediately after the recovery and purification of the lactase solution, before the formation of degradation products of proteins and polysaccharides that cause clogging. This method can be carried out during the production of the lactase solution. However, it cannot be carried out once the degradation products have been formed. This is because clogging may occur when the lactase solution produced by this method is filtered after storage or transportation. For example, after transporting a container-packed lactase solution produced by this method to a user, when the user performs the filtration sterilization step of the lactase solution to add it to milk or the like, clogging may occur in the filter. When clogging occurs, the manufacturing process must be stopped to replace the filter, which poses a problem of significantly reducing work efficiency. In particular, when the individual manufacturing steps for producing milk are continuous, it is not possible to stop only the filtration sterilization step, so it becomes necessary to stop all milk manufacturing steps. As a result, the milk production efficiency is significantly reduced, and improvement has been sought. Therefore, the method described in Patent Document 1 does not solve the problem of clogging in the filtration of the lactase solution after productization.

[0006] In addition, Patent Document 2 (International Publication No. 2004-534527) describes setting the concentrations of polysaccharides and oligosaccharides contained in the lactase solution to a certain value or less, particularly removing these substances by chromatography. However, even when the concentrations of polysaccharides and oligosaccharides are set to a certain value or less, the problem of clogging in the filtration after productization may occur as described above.

[0007] To solve the above problems, Patent Document 3 (International Publication No. 2016 / 060224) has been proposed.

Prior Art Documents

Patent Document

[0008]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0009] Among the raw materials used in dairy products, lactase solution is expensive. In order to use the lactase solution without waste, users who manufacture dairy products may dilute the lactase solution and then add it to dairy products inline. The process of sterilizing the diluted lactase solution with a filtration filter and the process of adding the sterilized lactase solution to dairy products are continuously performed inline. However, when users dilute a commercially available lactase solution and add it to dairy products as described above, clogging of the filtration filter in the filtration process may occur due to the use of the diluted lactase solution. When clogging occurs, there are problems such as the cost of replacing the filtration filter and the need to stop the entire manufacturing process of dairy products, and improvement has been demanded.

[0010] An object of the present invention is to provide a container-packed lactase solution that is less likely to cause clogging of a filtration filter.

Means for Solving the Problems

[0011] The present invention solves the problems of the present invention by having the following technical configurations.

[0012] (1) A container-packed lactase solution in which a lactase solution is present in a container, characterized in that the headspace in the container is 20% or less of the total volume of the container. (2) The lactase solution filled in the container according to (1) above, characterized in that the lactase activity of the lactase solution is in the range of 10 to 100,000 NLU / g. (3) The lactase solution filled in the container according to (1) or (2) above, characterized in that the lactase solution is substantially transparent. (4) The lactase solution filled in the container according to any one of (1) to (3) above, characterized in that the material of the container is selected from polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyurethane, polytetrafluoroethylene, acrylonitrile butadiene styrene resin. (5) The lactase solution filled in the container according to any one of (1) to (4) above, characterized in that the temperature of the lactase solution and the temperature of the container are above 0°C and below or equal to 20°C.

Advantages of the Invention

[0013] According to the present invention, it is possible to provide a lactase solution filled in a container that is less likely to cause clogging of the filtration filter.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0015] The present invention relates to a container-packed lactase solution in which a lactase solution is present in a container, and is characterized in that the headspace in the container is 20 v / v% or less of the total volume of the container. The headspace in the container-packed lactase solution of the present invention is preferably 15% or less of the total volume of the container, and more preferably 12% or less. The lower limit of the headspace in the container-packed lactase solution of the present invention may be 0% or more, may be more than 0%, may be 1% or more, or may be 2% or more. These upper and lower limits can be combined as appropriate. Hereinafter, the lactase solution present in the container may be referred to as an internal lactase solution. It has been found that by setting it within the above range, the internal lactase solution has excellent filter permeability even when the container-packed lactase solution is transported. This mechanism is considered as follows. Hydrophobic portions of proteins have the property of adhering and binding to each other. In a normal container-packed lactase solution, since the stirring force applied to the internal lactase solution is high, the frequency of contact between proteins increases, resulting in an increase in the amount of protein aggregates generated and deterioration of the filter permeability of the internal lactase solution. On the other hand, in the container-packed lactase solution of the present invention, by setting it within the above range, the stirring force applied to the internal lactase solution is reduced, and the frequency of contact between proteins is reduced, so that the formation of protein aggregates is suppressed and the filter permeability of the internal lactase solution can be maintained.

[0016] The headspace in the container refers to the portion occupied by the gas phase in the total volume of the container. The container-packed lactase solution is such that the total volume of the container is occupied by the internal lactase solution and the headspace. The headspace in the container varies depending on the amount of the lactase solution filled. The headspace may be a gas, and examples include air, oxygen, nitrogen, noble gases, etc. From the viewpoint of manufacturing cost, air is preferable. The total volume inside the container refers to the part where liquid can be poured from the opening of the container. It does not include the part where liquid cannot be poured from the opening of the container (for example, the hollow part).

[0017] The method for calculating the total volume inside the container is as follows. (1) Measure the weight of the empty container. (2) After filling water into the empty container from its opening, measure the weight. Place the water-filled container on a horizontal table and draw a line at the interface between the water and the headspace (on the container). The water filling amount should be about 60% - 80% of the container as a guide. (3) In the container filled with water in (2), place it on a horizontal table with the top and bottom of the container reversed such that the line was drawn. Adjust the amount of water in the container so that the interface between the water and the headspace comes to the part where the line was drawn on the container. Measure the weight of the container when the interfaces match. (4) Calculate the sum of the value obtained by subtracting the weight of the container in (1) from the weight of the water-filled container in (2) and the value obtained by subtracting the weight of the container in (1) from the weight of the water-filled container in (3). Since the specific gravity of water can be regarded as 1.00, the sum is the total volume (volume) inside the container.

[0018] The method for calculating the headspace in the container filled with lactase solution is as follows. (1) Calculate the total volume inside the container. (2) Measure the specific gravity of the lactase solution to be filled. (3) Fill a predetermined weight of lactase solution into the empty container from its opening. (4) Divide the predetermined weight filled in (3) by the specific gravity in (2) to calculate the volume (volume) of the filled lactase solution. (5) Substitute the values into the following formula to calculate the headspace (%). Headspace (%) = 100 - ((volume of the filled lactase solution in (4) ÷ total volume of the empty container in (1) × 100))

[0019] The method for calculating the headspace in the container-packed lactase solution is as detailed above. As a simple method, after calculating the total volume of the container, prepare a plurality of container-packed lactase solutions in advance so that they have a predetermined headspace (e.g., 1%, 5%, 10%, 20%, etc.), and by comparing with this, it can be used as an approximate headspace.

[0020] In the container-packed lactase solution, it is preferable to reduce the surface area at the interface between the internal lactase solution and the headspace. The greater the surface area, the more likely bubbles will occur when transporting the container-packed lactase solution, and there is a tendency for clogging of the filtration filter to occur more easily.

[0021] The activity (or protein concentration) of the internal lactase solution is preferably in the range of 10 to 100,000 NLU / g, more preferably in the range of 100 to 50,000 NLU / g, and even more preferably in the range of 1,000 to 11,000 NLU / g (FCC4 method). "NLU" is Neutral Lactase Unit. It is preferable that it is included in this range before and after transporting the container-packed lactase solution. The lower the activity of the internal lactase solution, the more likely clogging of the filtration filter will occur after transporting the container-packed lactase solution. The FCC4 method is measured by the hydrolysis of the substrate o-nitrophenyl-β-galactopyranoside (ONPG) into o-nitrophenyl and galactose. The reaction is terminated by the addition of sodium carbonate. The formed o-nitrophenyl turns yellow in an alkaline medium, and the change in absorbance is used to measure the enzyme activity (expressed in NLU / g). This procedure is published in the Food Chemicals Codex (FCC) 4th Edition, July 1, 1996, pages 801 - 802 / Lactase (Neutral) (β-Galactosidase) Activity. The lactase solution of the present invention desirably has an acidic lactase activity of 10 to 100,000 ALU / g, more desirably has an activity of 100 to 50,000 ALU / g, and even more desirably has an activity of 1,000 to 11,000 ALU / g. "ALU" is Acid Lactase Unit. The method for measuring the activity is as follows, for example. The substrate o-nitrophenyl-β-galactopyranoside (ONPG) is measured by hydrolysis to o-nitrophenyl and galactose. The reaction is terminated by the addition of sodium carbonate. The formed o-nitrophenyl turns yellow in an alkaline medium, and the change in absorbance is used to measure the enzyme activity (expressed in ALU / g). This procedure is published in the Food Chemicals Codex (FCC) 4th Edition, July 1, 1996, pages 802 - 803 / Lactase (Acidic) (β-Galactosidase) Activity. The internal lactase solution of the present invention may be a neutral lactase solution, an acidic lactase solution, or a lactase solution that acts in a neutral to acidic state with both mixed.

[0022] The internal lactase solution is preferably substantially transparent. If the internal lactase solution contains a large amount of microorganisms such as lactase-producing bacteria, turbidity will occur in the internal lactase solution, and the producing bacteria themselves will clog the filter. Substantially transparent means that the internal lactase solution should not be turbid when visually observed. The lactase solution may be colored. Specifically, it is a solution ranging from light yellow to light brown.

[0023] The temperature of the container-packed lactase solution is preferably above 0°C and below 20°C. As the temperature during storage and transportation increases, aggregates are likely to occur in the internal lactase solution.

[0024] The internal lactase solution may contain other proteins in addition to lactase protein. From the perspective of manufacturing cost, other proteins may be included. Immediately after manufacturing the container-packed lactase solution, there are no protein aggregates in the internal lactase solution. However, as the storage period increases or through transportation, the protein aggregates increase. Protein aggregates are aggregates of lactase protein molecules with each other, aggregates of lactase protein molecules and other protein molecules, and aggregates of other protein molecules with each other.

[0025] Here, conventional container-packed lactase solutions are filled with lactase solution in the headspace with a margin for the following two reasons. (1) When filling the lactase solution by machine, if the filling amount is large, the lactase solution may splash and adhere to the outside of the container, resulting in a separate wiping operation. Also, to increase the filling amount, it is necessary to lower the filling speed, leading to complication and prolongation of the manufacturing process. (2) When the user uses a container-packed lactase solution with a large filling amount, the lactase solution is likely to splash from the opening of the container, causing problems in handling. Hereinafter, the materials constituting the present invention will be described.

[0026] <Container> The container of the present invention has an opening through which a lactase solution can be filled into the container, and any container that can seal the opening is acceptable. The shape, capacity, and material of the container may be appropriately adjusted according to the purpose of use. The container can be sealed, for example, by tightening a screw cap. The shape of the container is preferably one that can stand on its own. A plastic container, a drum can, a container, etc. can be used. A rectangular parallelepiped or a plastic container or container with rounded corners at the corners of the rectangular parallelepiped is preferred because of its excellent stackability. The capacity of the container can be in the range of 10 mL to 20,000 kL. It is preferably in the range of 1 L to 10,000 kL. The material of the container can be a thermosetting resin, an ultraviolet curable resin, or a thermoplastic resin such as polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyurethane, polytetrafluoroethylene, acrylonitrile butadiene styrene resin, or a metal such as iron or stainless steel. Thermoplastic resins are preferred, especially polyethylene and polypropylene. High-density polyethylene can preferably be used as the polyethylene.

[0027] ≪Constituent components of lactase solution≫ <Lactase> (Type of raw material organism) Lactase has been isolated from a very wide range of organisms, including microorganisms. Lactase is often an intracellular or extracellular component of microorganisms such as Kluyveromyces and Bacillus. Kluyveromyces, especially K. fragilis and K. lactis, and yeasts such as Candida, Torula, and Torulopsis are common sources of yeast enzyme lactase, while B. coagulans or B. circulans are well-known sources of bacterial lactase. Lactase preparations derived from these organisms are commercially available in some cases. All of these lactases are so-called neutral lactases because their optimal pH is pH = 6 to pH = 8. In addition, Aspergillus niger, Aspergillus oryzae, and Penicillium multicolor produce extracellular lactase, and U.S. Patent No. 5,736,374 describes an example of such lactase produced by Aspergillus oryzae. The enzyme properties of lactase, such as the optimal pH and optimal temperature, vary by species. Generally, extracellular lactase is a so-called acidic lactase with a low optimal pH of pH = 3.5 to pH = 5.0. In addition, there is also lactase derived from Bifidobacterium bifidum that acts at neutral and acidic (pH 4 to pH 10). It is also possible to recombinantly produce the lactase gene derived from these microorganisms in a host. Examples of the host include Aspergillus, Kluyveromyces, Trichoderma, Escherichia coli, Pichia, Saccharomyces, Yarrowia, Neurospora, Lactococcus, or Bacillus. In the present invention, it is preferable to use neutral lactase and acidic lactase, and particularly preferable to use neutral lactase derived from the genus Kluyveromyces, acidic lactase derived from the genus Aspergillus, and lactase derived from Bifidobacterium.

[0028] The lactase solution of the present invention may contain various components as necessary. Specific examples include metal salts that contribute to the stabilization of lactase, various saccharides, ascorbic acid, glycerin, etc., starch, dextrin, which are excipients for better usability, inorganic salts having a buffering action, etc., and aggregation inhibitors that make it difficult for aggregates to form in the lactase solution.

[0029] (Stabilizer) The amount of the stabilizer to be contained in the lactase solution is preferably 10% by mass to 90% by mass, more preferably 20% by mass to 80% by mass, still more preferably 30% by mass to 70% by mass, and particularly preferably 40% by mass to 60% by mass. When the amount of the stabilizer is at least the lower limit value, it becomes easy to maintain the lactase activity of the lactase solution over a long period. When the amount of the stabilizer exceeds the upper limit value, the viscosity of the lactase solution increases, so the filtration time becomes long and the workability deteriorates. Examples of the stabilizer include glycerin and sorbitol.

[0030] (Aggregation inhibitor) The aggregation inhibitors to be included in the lactase solution are Aggregation Inhibitors I to III. Aggregation Inhibitor I includes (Type 1) surfactants with an HLB of 12 to 15, (Type 2) lipid-affinity surfactants, (Type 3) nonionic lipid-affinity surfactants, (Type 4) nonionic surfactants, and (Type 5) natural product-based surfactants. More preferably, it is a nonionic surfactant with an HLB of 12 to 15. The presence of such an aggregation inhibitor in the system reduces or prevents the hydrophobic interaction of proteins. As a result, it is understood that the formation of clogging substances due to aggregation can be prevented even during long-term stirring or shaking. Surfactants with an HLB of 12 to 15 are desirable in terms of high emulsification stability and high dispersion effect of hydrophobic substances in an aqueous solution. These types are classified based on physical properties, origin, etc., and a component belonging to one type may belong to another type. Also, multiple combinations of the same type of surfactant or multiple combinations of different types of surfactants may be used. As Aggregation Inhibitor II, a protective agent having an action of covering the surface of lactase and other proteins can be used. As the protective agent, polyethers and thickening polysaccharides can be used. Examples of Aggregation Inhibitor III include metal ions or salts thereof having a salting-in effect. Among metal ions, guanidium ions, calcium ions, or Mg ions or salts thereof are preferred because it is easy to obtain an appropriate ionic strength in the lactase solution. By adding metal ions or salts thereof, the ionic strength of the solution becomes appropriate, and the hydrophobic interaction between proteins such as lactase contained in the lactase solution decreases. As a result, it is understood that proteins are less likely to aggregate and have a reducing effect on the formation of clogging substances. Also, multiple combinations of the same type of metal ion or salt thereof or multiple combinations of different types of metal ions or salt thereof may be used.

[0031] These aggregation inhibitors I to III may be used alone or in combination of different types of aggregation inhibitors. For example, aggregation inhibitors I and II, aggregation inhibitors II and III, aggregation inhibitors I and III, and aggregation inhibitors I, II, and III may be used in combination. Further, since the effect of aggregation inhibitor III alone is slight, it is preferable to use aggregation inhibitors I and III, and aggregation inhibitors II and III in combination. Aggregation inhibitor I can be added to the lactase solution preferably in the range of 0.001% by mass to 5% by mass, more preferably in the range of 0.01% by mass to 1% by mass, and still more preferably in the range of 0.1% by mass to 0.5% by mass based on the total mass of the lactase solution. Aggregation inhibitor II can be added to the lactase solution preferably in the range of 0.05% by mass to 15% by mass, more preferably in the range of 0.3% by mass to 10% by mass, and still more preferably in the range of 0.5% by mass to 5% by mass based on the total mass of the lactase solution. In the lactase solution, aggregation inhibitor III is preferably at a concentration of 0.1 mM or more and 20 mM or less as a metal component, more preferably at a concentration of 0.25 mM or more and 15 mM or less, still more preferably at a concentration of 0.5 mM or more and 10 mM or less, and most preferably at a concentration of 1 mM or more and 5 mM or less. In the order of the high salt dissolution effect, they are guanidium ions, calcium ions, and magnesium ions. Although a higher concentration of magnesium ions is required, lower concentrations of guanidium ions and calcium ions are sufficient.

[0032] ≪Method for producing lactase solution≫ The method for producing a lactase solution includes, for example, (1) an extraction step of lactase involving disruption of the cell wall after culturing microorganisms such as yeast, and (2) a purification step for removing contaminants derived from the culture from the extracted lactase. It may also include (3) a step of adding an additive to the above lactase (which may be freshly prepared or a commercially available product) as necessary, and (4) a step of filtering for sterilization. By filling a predetermined amount of the filtered lactase solution into a predetermined container, a container-packed lactase solution can be obtained.

[0033] ≪Usage and Applications of Lactase Solution≫ (Usage of Lactase Solution) As a specific form of utilization of the lactase solution, for example, it is used in the production of fermented milk. The method for producing lactose - decomposed fermented milk includes: 1. A method in which lactase is added to milk before sterilization to decompose lactose, and then lactase is inactivated simultaneously with the heat sterilization of the milk, and then the milk is fermented (Japanese Patent Laid - Open No. 5 - 501197); 2. A method in which lactase is added to sterilized milk to decompose lactose, and then lactase is inactivated by heat treatment, and then the milk is fermented; 3. A method in which lactose in milk is decomposed with immobilized lactase, and then the milk is fermented (Japanese Patent Laid - Open No. 46 - 105593, Japanese Patent Laid - Open No. 59 - 162833); 4. A method in which raw materials that have been lactose - decomposed or lactose - removed in advance are used in sterilized milk for fermentation, etc.

[0034] Furthermore, as a specific form of utilization of the lactase solution of the present invention, it is used in the production of long - life milk. Long - life milk refers to milk with long - term storage. The manufacturing process consists of a sterilization process and a continuous aseptic packaging process. Generally, it is processed by an ultra - high - temperature short - time sterilization method at 135 - 150°C for several seconds and filled in a process where a paper container pre - sterilized with hydrogen peroxide can be aseptically packaged. The lactase solution added to long - life milk is generally added after filtration sterilization when filling milk after ultra - high - temperature short - time sterilization.

[0035] (Applications of Lactase Solution) The lactase solution according to the present invention is particularly suitable for use in dairy product manufacturing. Here, dairy products refer to milk products such as ice, long - life milk, yogurt, fresh cream, sour cream, cheese, etc. In particular, the lactase solution according to the present invention is suitable for use in the production of long - life milk.

[0036] (Applications of Lactase and Its pH Profile) In addition, lactases are classified into two main categories according to their applications: neutral lactase and acid lactase. This depends on the pH profile of the application. For applications with a neutral pH, neutral lactase is usually preferred, while acid lactase is more suitable for applications in the acidic range.

[0037] The present invention will be described below with reference to examples, but the present invention is not limited thereto. EXAMPLES

[0038] In the following examples, YNL (manufactured by Godo Shusei Co., Ltd. under the trade name GODO-YNL2) was used as the lactase solution. GODO-YNL2 is a neutral lactase derived from Kluyveromyces, with an activity of 5,000 NLU / g, a specific gravity of 1.18 (g / mL), and containing 50% (v / v) glycerin.

[0039] (Filter permeability test) The detailed conditions of the filter permeability test in this embodiment are described below. (Filter Permeability Measurement Procedure) The following operations were carried out in an environment of 5 to 15°C. 1. The measuring device, lactase solution sample and distilled water were cooled to the test environment temperature. 2. The lactase solution sample was diluted with distilled water or concentrated by ultrafiltration to adjust the lactase activity to 1,400-1,600 NLU / g, and then mixed thoroughly. 3. The test was performed using a 47 mm tank-attached stainless steel holder (Advantec Toyo Co., Ltd., product name "KST-47") and a 25 mm stainless steel filter holder (PALL Co., Ltd., product number 1209 (effective membrane area 3.7 cm 2)) was used as the device. The sample permeation part in the filter holder has a configuration including an O-ring, a membrane, a support screen, and an underdrain disk from the inlet side of the measurement sample (in the test of the present invention, the parts of the filter and the filter holding part of the stainless steel holder with a tank (the support screen and its support) were not attached). As the membrane, DURAPORE (pore size 0.22 μm, φ25 mm, made of hydrophilic PVDF) manufactured by Merck Millipore was used, and as the support screen, Type 316 stainless steel attached to the above filter holder was used. Also, in order to adjust the permeation rate, about 4 circular label seals (manufactured by Ewon Co., Ltd., product name A-one color label 07010) with a diameter of 0.9 cm were symmetrically attached to the upper part of the support screen (the inlet side of the measurement sample) (effective membrane area 1.26 cm 2 ), and a membrane filter (pore size 0.22 μm) was set. The membrane was rinsed with a 50% glycerin aqueous solution and attached to a stainless steel filter holder. The lactase solution sample (sample) diluted in 4.2 was put into a stainless steel holder with a tank. 5. Using an air compressor (manufactured by Yaesaki Pneumatic Co., Ltd., product name "KAPSEL-CON YC-3R" or "PC4-15HLM"), a pressure of 0.2 MPa was applied to the stainless steel holder with a tank to pump the enzyme solution. The permeate was received in a container such as a beaker, the amount of permeate was recorded every 10 seconds, and for every 1 m of the membrane 2 conversion, (1) the permeation amount (permeate (kg / m 2 )) and (2) the permeation rate (flux (kg / min×m 2 )) were determined by the following method. Also, when (1) was plotted on the x-axis and (2) was plotted on the y-axis, the slope a of the approximate curve y = ax + b obtained was determined.

[0040] Calculation formula (concept formula) (1) permeate (kg / m 2 ) = weight of the permeated product (g) at n points / (membrane radius (mm)) × membrane radius (mm) × pi) (m2 )×1000 (2)Flux (kg / min×m 2 ) = (Permeate at nth point - Permeate at (n - 1)th point) / (Permeation time at nth point (min) - Permeation time at (n - 1)th point (min)) ※ n indicates the measurement point. To record the permeation amount every 10 seconds, for example, when the permeation amount or permeate at the nth point is the permeation amount at 10 seconds, the (n - 1)th point is the permeation amount or permeate at 0 seconds.

[0041] (Reference Example 1) A 250 mL I - boy (wide - mouth, manufactured by AS ONE Corporation, product number 5 - 002 - 03) was filled with 170 g of a lactase solution at 5,000 NLU / g to obtain a container - filled lactase solution (headspace 60%). As shown in Figure 4, the container - filled lactase was shaken in (a) the horizontal position or (b) the vertical position. The shaking conditions were carried out at 20 °C, amplitude 30 mm, 100 spm, for 2 hours. The container - filled lactase solution after shaking was allowed to stand for 5 hours and a filter permeability test was conducted. Those without shaking were used as controls. The results are shown in Figure 1(a). By shaking the container - filled lactase solution, the filter permeability of the internal lactase solution deteriorated. The deterioration of the filter permeability was more suppressed in the vertical position than in the horizontal position. From this, it was suggested that by reducing the surface area of the interface between the internal lactase solution and the headspace, the deterioration of the filter permeability is suppressed.

[0042] (Reference Example 2) The following test was conducted in parallel with Reference Example 1. A filter permeability test was conducted in the same manner as in Reference Example 1 except that the container - filled lactase solution after shaking was allowed to stand until the next day. The results are shown in Figure 1(b). The filter permeability deteriorated depending on the standing time after shaking. From the results of Reference Examples 1 and 2, it was suggested that when aggregates are formed in the internal lactase solution by shaking the container - filled lactase solution, as the storage time of the lactase solution increases, the aggregates grow and the filter permeability deteriorates.

[0043] (Example 1) When the lactase activity value of the internal lactase solution is high, it is less affected by the filter permeability test by shaking (aggregates are less likely to occur in the internal lactase solution), so the lactase activity value of the internal lactase solution was diluted and tested. A 100 mL Iwaki (wide mouth (manufactured by AS ONE Corporation, product number 5-002-02), total volume 128.5 mL) was filled with 40 mL to 130 mL of a lactase solution (YNL 2 diluted 3.42 times (weight ratio) with distilled water) having a lactase activity of 1,460 NLU / g to obtain a lactase solution filled in each container. Each container-filled lactase solution was shaken at 20°C, 100 spm, amplitude 30 mm for 1 hour and allowed to stand overnight at 10°C. Those that were not shaken were used as controls, and a filter permeability test was performed. Part of the results is shown in Figure 2. Figure 2 shows the results from permeate 4.9 to 286.8 after the start of the filter permeability test. However, those with a flux of less than 7 show the results up to that point. The slope of the graph shown in Figure 2 was calculated from the linear approximation in Excel and used as an index for the filter permeability test. The larger the value of the slope (negative value), the worse the filter permeability. The obtained results are shown in Table 1.

[0044]

Table 1

[0045] The headspace and slope shown in Table 1 were plotted to create Figure 3. It was confirmed that the smaller the headspace of the container-filled lactase solution, the more excellent the filter permeability tends to be.

[0046] (Example 2) Domestic transportation test of container-filled lactase solution A 10 L plastic container (manufactured by Kodama Resin Industry Co., Ltd., Tamakan, product number KM-349, total volume 11.7 L in terms of lactase volume) was filled with YNL so that the headspace was 10% or 28%, and each container-filled lactase solution was obtained. While storing this container-filled lactase solution at 10°C or lower, it was transported by truck over 22 hours to a location approximately 600 km away. The container-filled lactase solution after transportation was diluted in the same manner as in Example 1 to obtain a lactase solution of 1,460 NLU / g, and then a filter permeability test was conducted. The results are shown in Table 2. Note that the container-filled lactase solution with a filling amount of 10 kg is commercially available. The lot of the internal lactase solution used in Example 2 is the same, and the lots of the internal lactase solutions used in Example 1 and Example 2 are different.

[0047] [Table 2]

[0048] As shown in Table 2, it was shown that the filter permeability was improved by reducing the headspace of the container-filled lactase solution. The results shown in Table 2 are tests under conditions where aggregate substances are less likely to occur because the internal lactase solution was transported without dilution. In the lot used here, the 10 kg one also showed satisfactory results in the filter permeability test. However, since the internal lactase solution is a substance produced by microorganisms, lot differences are likely to occur in the filter permeability test. It was shown that it is preferable to reduce the headspace of the container-filled lactase solution to prevent unexpected deterioration of the filter permeability.

[0049] (Example 3) Foreign transportation test of container-filled lactase solution A 10-L plastic container (manufactured by Kodama Resin Industry Co., Ltd., Tamakan, product number KM-349, with a total volume of 11.7 L in terms of lactase volume) was filled with YNL so that the headspace was 1.4 to 56% to obtain a lactase solution filled in each container. While storing the lactase solution filled in this container at 10°C or lower, it was transported by truck and ship for land transportation and sea transportation to a place about 10,000 km away. The lactase solution filled in the container after transportation was diluted in the same manner as in Example 1 to obtain a lactase solution of 1,460 NLU / g, and then a filter permeability test was conducted. The results are shown in Table 3. The lactase solution filled in a container with a filling amount of 10 kg is a commercially available product of contract alcohol. The lots of the internal lactase solution used in Example 3 are the same, and the lots of the internal lactase solution used in Example 1, Example 2, and Example 3 are all different.

[0050]

Table 3

[0051] As shown in Table 3, it was shown that the filter permeability was improved by reducing the headspace of the lactase solution filled in the container.

Claims

**Claim 1** A lactase solution packed in a container, wherein a lactase solution is present in the container, the container has a closable opening, and the headspace in the container is 20% or less of the total volume of the container. A lactase solution packed in a container, characterized in that. **Claim 2** The lactase solution-packed container according to claim 1, characterized in that the lactase activity of the lactase solution is in the range of 10 to 100,000 NLU / g. **Claim 3** The lactase solution-packed container according to claim 1 or 2, characterized in that the lactase solution is substantially transparent. **Claim 4** The lactase solution-packed container according to any one of claims 1 to 3, characterized in that the material of the container is selected from polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyurethane, polytetrafluoroethylene, acrylonitrile-butadiene-styrene resin. **Claim 5** The lactase solution-packed container according to any one of claims 1 to 4, characterized in that the temperature of the lactase solution and the temperature of the container are above 0°C and below or equal to 20°C. **Claim 6** The lactase solution-packed container according to any one of claims 1 to 5, characterized in that the headspace in the container is 14% or less of the total volume of the container. **Claim 7** The lactase solution-packed container according to any one of claims 1 to 6, characterized in that the headspace in the container is 7% or less of the total volume of the container.

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