JP4142008B2 - Zein stable ethanol aqueous solution and method for producing the same - Google Patents

Description

  The present invention relates to a long-term stable aqueous ethanol solution of zein, which is a highly functional plant protein obtained from corn. More specifically, it is used as a coating agent or binder that protects the surface of health foods, chocolates and other confectionery, pharmaceutical preparations, etc., and is uniform without thickening and gelling over a long period of time. The present invention relates to an aqueous ethanol solution of zein maintained in a transparent state and a method for producing the same.

  Zein is a kind of seed protein, and belongs to a prolamin system soluble in 70% by mass of ethanol according to the difference in solubility. Among the three types of zeins of α, β, and γ-types, those having α-zein, which is a polypeptide having a molecular weight of 21,000 to 25000, as the main component are currently commercially available.

  Zein is a protein having the ability to form or adhere to films and fibers with excellent water resistance, etc., and is generally dissolved in alcohol and adhered to the surface of an object to be treated by means such as spraying, coating, or dipping. It can be dried to form a coating. Corn-derived zein is a material useful as a coating agent, as is the case with shellac currently used as a coating agent for foods (chocolate etc.) and tablets. "Zein DP" (trade name, manufactured by Showa Sangyo Co., Ltd.)

  When zein is used as a coating agent for foods, ethanol is often used because of its high safety as a solvent and its relatively low boiling point that allows the solvent to be dried in a short time. For example, Japanese Patent Application Laid-Open No. 10-108630 (Patent Document 1) discloses workability of suppressing binding between particles in a coating by dissolving zein or shellac and lipid as a coating component in an ethanol and / or isopropanol solvent. A good food glaze coating is disclosed.

  On the other hand, a zein solution, particularly a water-containing organic solvent solution, has a thickening property, and a zein ethanol solution eventually forms a gel. The thickening is more remarkable as the zein concentration is higher and the water content of the solvent is higher. For example, in the case of a commercially available zein powder (“Showa Zein DP”, manufactured by Showa Sangyo Co., Ltd.), a 70% by mass ethanol aqueous solution is initially well dissolved and a uniform transparent solution is obtained. For example, zein is contained by 9% by mass. In the case of a 70 mass% ethanol aqueous solution, if it is allowed to stand at room temperature, it will gel after about one month (see Reference Example 1). Further, in the case of an ethanol aqueous solution having an ethanol content of about 82% by mass and containing about 9% by mass of zein, which is currently used in food coating agents, it partially contains starch (hereinafter referred to as “Ori”) and becomes cloudy. In this state, a solution that can be used without any problem as a coating agent is obtained immediately after dissolution. However, with the passage of time, the orientation increases and the viscosity increases, and it solidifies after 2 to 3 months.

  When using an aqueous ethanol solution of zein as a coating agent, etc., a spray device is generally used. However, there is a problem that expensive zein is wasted as industrial waste.

JP-A-10-108630

  Accordingly, an object of the present invention is to provide a stable aqueous ethanol solution of zein that can be maintained in a uniform and transparent state without gelation for a long period of time as a raw material solution for a coating agent.

  In order to solve the above-mentioned problems, the present inventors have conducted extensive research to obtain a stable aqueous ethanol solution that does not gel for a long period of time on a commercially available high-purity zein powder (“Showa Zein DP”). A homogeneous transparent solution obtained by separating and removing floating oliate as an insoluble material immediately after dissolving zein powder in a constant concentration of ethanol aqueous solution is surprisingly stable and commercially expected for at least 3 months It has been found that the above period can be stably stored without thickening and gelling, and the present invention has been completed.

That is, this invention relates to the zein ethanol aqueous solution which can be stored for a long time with the following uniform transparent solution, and its manufacturing method.
1. An aqueous ethanol solution of zein that does not gel for a period of 3 months or more at room temperature, comprising 5 to 20 mass% zein in an ethanol aqueous solution having an ethanol concentration of 75 mass% or more and less than 90 mass%.
2. An ethanol aqueous solution of zein that has an ethanol concentration of 80% by mass or more and less than 86% by mass and contains 7 to 15% by mass of zein and is kept in a transparent state for 3 months or more at room temperature and does not gel.
3. An aqueous ethanol solution of zein that has an ethanol concentration of 81% by mass or more and less than 83% by mass and contains zein in an amount of 8 to 12% by mass and maintains a uniform transparent state for 6 months or more at room temperature and does not gel.
4). The aqueous ethanol solution of zein according to any one of 1 to 3 above, which is used for a coating agent or a binder for foods, health foods or pharmaceuticals.
5. An aqueous ethanol solution of zein containing ori obtained by adding zein fine powder to an ethanol aqueous solution having an ethanol concentration of 75% by mass or more and less than 90% by mass so as to have a content of 5 to 20% by mass and stirring and mixing at room temperature- A method for producing an aqueous ethanol solution of zein that does not gel for a period of 3 months or longer at room temperature, wherein the supernatant is allowed to stand at a temperature of 4 ° C to 9 ° C and the supernatant liquid is separated.
6). A solution of zein containing ethanol obtained by adding zein fine powder to an ethanol aqueous solution having an ethanol concentration of 80% by mass or more and less than 86% by mass so as to have a content of 7 to 15% by mass and stirring and mixing at room temperature- A method for producing an aqueous ethanol solution of zein that is kept in a transparent state for 3 months or more at room temperature and does not gel, wherein the supernatant liquid is allowed to stand at a temperature of 4 ° C to 9 ° C and the sediment is separated.
7). An aqueous ethanol solution of zein containing ori obtained by adding zein fine powder to an ethanol aqueous solution having an ethanol concentration of 81 mass% or more and less than 83 mass% so as to have a content of 8 to 12 mass% and stirring and mixing at room temperature. A method for producing an aqueous ethanol solution of zein that is kept at a room temperature of 6 ° C. to 7 ° C. and is kept in a uniform transparent state for 6 months or more at room temperature and does not gel.
8). The method for producing an aqueous ethanol solution of zein according to any one of 5 to 7 above, wherein the supernatant is extracted through a mesh of 50 to 400.

  Since the zein ethanol aqueous solution of the present invention can be stored for a long period of time in a state of being uniform and transparent and not thickening, it can be supplied as a stable raw material liquid for coating agents or binder agents. Products that can be used for various applications such as food (chocolate etc.), health foods, coatings for pharmaceutical preparations, biodegradable films, etc., and products that require quality preservation for a certain period of time, such as nail polish coatings and cosmetics Can also be used.

  Zein is a vegetable protein made from corn. For example, zein is produced by extraction and purification from corn gluten meal, which is a protein fraction separated from the starch production process (Japanese Patent Laid-Open Nos. 6-189687 and 5-95). No. 92998), usually supplied as a powder. Zein powder usually has a yellowish color and has a unique odor, but currently available products ("Showa Zein DP", manufactured by Showa Sangyo Co., Ltd.) are sufficiently refined, yellow The taste is light and almost odorless.

  The inventors of the present invention have found that a supernatant obtained by precipitating olivine in an initial stage in which zein is dissolved in an ethanol aqueous solution having an ethanol content of 75% by mass or more is about 3 months or more at room temperature as required on a commercial basis. It has been found that it can be stably stored without increasing the viscosity for a long time that far exceeds the standard of stable storage.

  The ethanol concentration of the aqueous ethanol solution used in the present invention is 75% by mass or more and less than 90% by mass, preferably 80% by mass or more and less than 86% by mass, and more preferably 81% by mass or more and less than 83% by mass. If it is lower than 75% by mass, oli, which is considered to be one of the factors that inhibit the stability of zein aqueous ethanol solution, may not be generated. On the other hand, if the ethanol content is higher than 90% by mass, the amount of ori produced in the initial stage increases, so that the concentration of the active ingredient zein after removing ori is reduced.

  The amount of zein powder added to the ethanol aqueous solution is 5 to 20% by mass, preferably 7 to 15% by mass, and more preferably 8 to 12% by mass. If it is lower than 5% by mass, a coating agent solution having a low concentration of the active ingredient is formed, and the working efficiency of coating deteriorates. On the other hand, when the addition amount is higher than 20% by mass, the initial orientation amount increases and the solution viscosity increases, so that the working efficiency of the coating is deteriorated.

  When the ethanol concentration and the amount of zein powder to be added affect the uniform transparent state retention period of the zein ethanol aqueous solution, the ethanol concentration is 75% by mass or more and less than 90% by mass, and the zein powder content is 5 to 20% by mass When the ethanol concentration is 80% by mass or more and less than 86% by mass and the zein powder content is 7 to 15% by mass at room temperature for 3 months or more, the ethanol concentration is 81% by mass or more and 83% by mass When the zein powder content is 8 to 12% by mass, the transparent state is maintained for 6 months or longer at room temperature.

  When a predetermined amount of zein powder is added to an aqueous ethanol solution having a predetermined ethanol concentration, fine powdery zein floats on the liquid surface in the form of mama powder, and is stirred and mixed at room temperature to promote dissolution. The intensity of stirring is set to a minimum so that the zein protein is not denatured. The stirring and mixing time is about 30 minutes to 2 hours depending on the concentration of addition, and a uniform solution containing oli can be obtained.

  Next, the olith produced by allowing the zein ethanol aqueous solution containing lye to stand in a refrigerator is allowed to settle. The temperature of refrigeration is -4-9 degreeC, and 0-7 degreeC is preferable. If the temperature is lower than −4 ° C., the protein zein is denatured and coagulated. If the temperature is higher than 9 ° C., sedimentation of the soil is insufficient and separation of the supernatant liquid performed in the next step becomes difficult. The refrigeration standing time is usually 3 to 5 hours although it depends on the temperature.

  Subsequently, the supernatant liquid in which the sediment is settled as a lower layer is collected. Separation may be performed only by removing the supernatant, but it is preferable to perform filtration through a filter of 50 to 400 mesh, preferably 100 to 200 mesh. If it is coarser than 50 mesh, it will not be possible to remove the scum mixed during the separation and collection, and if it is finer than 400 mesh, clogging is likely to occur and the filtration efficiency is poor. The material of the filter is not particularly limited as long as it does not affect the ethanol aqueous solution of zein, but is preferably made of stainless steel that can withstand repeated use. The filtration is preferably gravity filtration, but may be performed under pressure or reduced pressure as necessary.

  The zein ethanol aqueous solution of the present invention obtained by the above method is kept in a state where it does not gel for a period of 3 months or more at room temperature, depending on the ethanol concentration of the ethanol aqueous solution used and the amount of zein to be dissolved. In a preferred embodiment of the present invention, it can be stored in a uniform transparent state for a period of 1 year or longer at room temperature.

  The aqueous zein ethanol solution of the present invention can be used as it is as a coating agent or a binder, but various additives can be blended before the coating operation or the formulation operation as required. Examples of the additive include a plasticizer, a colorant, and a sweetener. Examples of the plasticizer include oleic acid, vegetable fatty acid, shellac, propylene glycol, distilled acetic acid monoglyceride, glycerin, sorbitan monolaurate, and cooking oil (MCT).

  Hereinafter, the present invention will be described in detail with reference to Reference Examples, Examples, and Comparative Examples, but the present invention is not limited thereto.

Reference example 1:
Add 100 ml of 70% ethanol aqueous solution into a beaker, and gradually add 9% by mass of zein powder (“Showa Zein DP”, Showa Sangyo Co., Ltd.) while stirring using a magnetic stirrer at room temperature. Stir for 30 minutes. When 10 to 15 minutes had passed, the solution was cloudy, but when stirring was continued for 30 minutes, a transparent solution was obtained (see the photograph in FIG. 1A). When this solution was kept at room temperature, the viscosity increased markedly from around the 18th day and gelled completely in about one month.

Reference Examples 2 to 4:
Using 100 ml of 80 wt%, 82 wt% and 86 wt% ethanol aqueous solution instead of 70 wt% ethanol aqueous solution, each zein powder (“Showa Zein DP”, Showa Sangyo Co., Ltd.) as in Reference Example 1 9% by mass was dissolved to obtain solutions containing oli (Reference Examples 2, 3 and 4). When these solutions were transferred to a sealed container and allowed to stand at 6 ° C. for 5 hours, the sediment settled and separated into a supernatant, and the sediment sediment was more as the alcohol concentration was higher (FIGS. 1B and 1C). ) And (D) see photo).

Example 1:
Using 100 ml of 82% by weight ethanol aqueous solution instead of 70% by weight ethanol aqueous solution, 9% by weight of zein powder (“Showa Zein DP”, Showa Sangyo Co., Ltd.) is dissolved in the same manner as in Reference Example 1 and contains oli. A solution was obtained. When this solution was transferred to a sealed container and allowed to stand at 6 ° C. for 5 hours, the sediment settled and separated into a supernatant (see the photograph in FIG. 1C). The supernatant was gently extracted through a 100 mesh stainless steel filter to obtain 95 ml of a transparent and uniform zein ethanol aqueous solution. When this zein ethanol aqueous solution was allowed to stand at room temperature, it did not thicken or gel for one year or more and was kept in a transparent and uniform state (see the photograph in FIG. 2).

Comparative Example 1:
In Example 1, when the solution containing the orientation (see the photograph in FIG. 3 (A)) was allowed to stand at room temperature, the viscosity increased at the third month (see the photograph in FIG. 3 (B)), It completely gelled and solidified at the seventh month (see the photograph in FIG. 3C).

(A) It is the photograph of the zein ethanol aqueous solution which melt | dissolved zein powder in 70 mass% ethanol aqueous solution in the reference example 1, (B) The zein ethanol aqueous solution which melt | dissolved zein powder in 80 mass% ethanol aqueous solution in the reference example 2 is refrigerated. (C) is a photograph of a zein ethanol aqueous solution obtained by dissolving zein powder in an 82 mass% ethanol aqueous solution in Reference Example 3 and Example 1, and (D) Reference Example 4 It is the photograph of the state which left refrigerated the zein ethanol aqueous solution which melt | dissolved zein powder in 86 mass% ethanol aqueous solution. It is the photograph of the state which stored the supernatant liquid separated from the sediment settled in Example 1 at room temperature for 1 year. (A) It is the photograph of the zein ethanol aqueous solution which melt | dissolved zein powder in 82 mass% ethanol aqueous solution in the comparative example 1, (B) The zein ethanol aqueous solution which melt | dissolved zein powder in 82 mass% ethanol aqueous solution in the comparative example 1 at room temperature (C) is a photograph of a zein ethanol aqueous solution obtained by dissolving zein powder in an 82% by mass ethanol aqueous solution in Comparative Example 1 for 7 months at room temperature.

Claims (4)

  An aqueous ethanol solution of zein containing ori obtained by adding zein fine powder to an ethanol aqueous solution having an ethanol concentration of 75% by mass or more and less than 90% by mass so as to have a content of 5 to 20% by mass and stirring and mixing at room temperature- A method for producing an aqueous ethanol solution of zein that does not gel for a period of 3 months or longer at room temperature, wherein the supernatant is allowed to stand at a temperature of 4 ° C to 9 ° C and the supernatant liquid is separated.   A solution of zein containing ethanol obtained by adding zein fine powder to an ethanol aqueous solution having an ethanol concentration of 80% by mass or more and less than 86% by mass so as to have a content of 7 to 15% by mass and stirring and mixing at room temperature- A method for producing an aqueous ethanol solution of zein that is kept in a transparent state for 3 months or more at room temperature and does not gel, wherein the supernatant liquid is allowed to stand at a temperature of 4 ° C to 9 ° C and the sediment is separated.   An aqueous ethanol solution of zein containing ori obtained by adding zein fine powder to an ethanol aqueous solution having an ethanol concentration of 81 mass% or more and less than 83 mass% so as to have a content of 8 to 12 mass% and stirring and mixing at room temperature. A method for producing an aqueous ethanol solution of zein that is kept at a room temperature of 6 ° C. to 7 ° C. and is kept in a uniform transparent state for 6 months or more at room temperature and does not gel. The method for producing an aqueous ethanol solution of zein according to any one of claims 1 to 3 , wherein the supernatant is extracted through a 50 to 400 mesh.

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