Method for producing peach protein-containing composition

Abstract

To provide a method for efficiently producing a peach protein-containing composition from a residue (peach fiber) of a peach fruit squeezed into juice.SOLUTION: In a method for producing a peach protein-containing composition, a residue (peach fiber) remaining when juice is harvested from peach pulp obtained by removing a seed from a peach is treated with a glycolytic enzyme selected from a cellulase, a hemicellulase, a pectinase, and a xylanase, if necessary, and the resultant is extraction-treated with an alkaline aqueous solution of a pH of 8 to 13 and then liquid from the extraction is made acidic so as to be a pH of 2 to 5, thereby precipitating a peach protein.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for efficiently producing a peach protein-containing composition from peach fruit pomace (peach fiber). [Background technology]

[0002] In recent years, from the viewpoints of environmental protection and food conservation, plant proteins have been attracting attention as an alternative protein source to animal proteins. In addition, because plant protein contains almost no fats or oils, it is an ideal protein for those trying to eat a low-fat, low-calorie diet, and the usefulness of plant protein, a natural food, is now attracting attention from the perspective of dieting.

[0003] Soybean protein (Patent Documents 1 and 2) and rice bran protein (Patent Document 3) have long been proposed as such plant proteins, and the functionality of rice bran protein has also been attracting attention (Patent Documents 4 and 5).

[0004] Incidentally, the present inventors have discovered that the residue of peach fruit juice (so-called peach dietary fiber: hereinafter sometimes referred to as "peach fiber") contains a high concentration of protein (Patent Document 6). The protein content of this peach fiber is approximately 15% by weight, which is higher than the previously known protein content of rice bran, which is 13.4% [Standard Tables of Food Composition 2015 Edition (7th revision)], making it a potential important source of protein. However, no attempt has been made to efficiently extract protein from peach fiber. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2004 / 013170 [Patent Document 2] Japanese Patent Application Publication No. 10-165106 [Patent Document 3] Japanese Patent Application Publication No. 56-1853 [Patent Document 4] International Publication No. 2013 / 0773404 [Patent Document 5] Japanese Patent Application Laid-Open No. 2013-247927 [Patent Document 6] Japanese Patent Application Publication No. 2018-7612 Summary of the Invention [Problem to be solved by the invention]

[0006] Therefore, an object of the present invention is to provide a method for efficiently producing a peach protein-containing composition from peach fruit juice residue (peach fiber). In order to solve this problem, the present inventors discovered that a peach protein-containing composition can be efficiently obtained by treating peach fiber with an alkaline aqueous solution and then subjecting the extract to an acidic treatment, thereby completing the present invention. [Means for solving the problem]

[0007] The invention for solving the above problems has the following aspects. (1) A method for producing a peach protein-containing composition, comprising extracting the residue remaining after extracting juice from peach pulp from which the seeds have been removed with an alkaline aqueous solution, and then acidifying the extract to precipitate peach protein; (2) The method according to (1), wherein the extraction with an alkaline aqueous solution is carried out with an alkaline aqueous solution having a pH of 8 to 13. (3) The method according to (1), wherein the extract is acidified to a pH of 2 to 5. (4) The method according to (1) above, wherein the residue remaining after extracting juice from peach pulp from which the seeds have been removed is subjected to an enzymatic treatment with a glycolytic enzyme before being subjected to an extraction treatment with an alkaline aqueous solution. (5) The method according to (5) above, wherein the glycolytic enzyme is selected from cellulase, hemicellulase, pectinase, and xylanase. is.

[0008] Therefore, the present invention in its most specific aspect comprises: (6) A method for producing a peach protein-containing composition, comprising: removing the seeds from peach flesh, extracting the juice from the remaining residue, optionally treating the residue with a glycolytic enzyme selected from cellulase, hemicellulase, pectinase, and xylanase; extracting the extract with an alkaline aqueous solution of pH 8 to 13; and then acidifying the extract to pH 2 to 5 to precipitate peach protein. is. [Effects of the Invention]

[0009] According to the present invention, it has become possible to produce a peach protein-containing composition containing a high concentration of protein from peach juice residue, which has previously been discarded in large quantities as waste. The protein-containing composition of the present invention is useful as a food ingredient and a food processing ingredient, and because it is a food protein obtained from plant resources, it is extremely useful from the perspectives of environmental protection and food conservation. DETAILED DESCRIPTION OF THE INVENTION

[0010] The basis of the present invention is a method for producing a peach protein-containing composition, which comprises extracting the residue (peach dietary fiber: peach fiber) remaining after extracting juice from peach pulp after removing the seeds with an alkaline aqueous solution, and then acidifying the extract to precipitate peach protein.

[0011] Specifically, this method involves immersing peach fiber in an alkaline aqueous solution to extract protein-containing components and separating the solid matter from the solution, adding an acid to the resulting aqueous solution to precipitate a peach protein-containing composition, and separating the precipitate to obtain a crude peach protein composition.The resulting crude peach protein composition can be purified as needed.

[0012] The raw peach fiber used in the present invention is the residue obtained by squeezing the edible portion of peach fruit after removing the seeds, and may be raw, dried (freeze-dried), pretreated by washing with water or aqueous ethanol, or freeze-dried. More specifically, such peach fiber can be prepared by a method already proposed by the present inventors (Patent Document 6).

[0013] Furthermore, the raw peach fiber may be pretreated by washing with water or hot water, or with a water-ethanol mixture, before the peach protein is extracted with an alkaline aqueous solution. It is also preferable to treat the pulp with a glycolytic enzyme (e.g., cellulase, hemicellulase, pectinase, xylanase, etc.). It has been found that this enzyme treatment is preferable for extraction with an alkaline aqueous solution, since this prevents the extract from becoming mushy during the extraction process. In this case, the amount of enzyme added in the enzyme treatment is preferably about 1% to 5% by weight based on the raw material peach fiber.

[0014] Generally, when extracting protein from a protein-containing raw material, protein cannot be extracted with an extracting solution on the neutral to acidic side, and an extracting solution on the alkaline side must be used. Therefore, it is essential that the extraction of peach protein from raw peach fiber in the present invention be carried out using an alkaline aqueous solution. Such an alkaline aqueous solution may include an aqueous solution of an inorganic base such as sodium hydroxide or potassium hydroxide.

[0015] The concentration (normality) and pH of the alkaline aqueous solution used are preferably about 0.02 mol / L(N) to 0.5 mol / L(N) in final concentration and about 8 to 13 in pH, respectively, and the optimum concentration and pH are about 0.05 mol / L(N) to 0.5 mol / L(N) in concentration and about 10 to 13 in pH. If the pH of the extract exceeds 11, gelation may occur during the extraction procedure, making it difficult to separate the extract, which may significantly hinder production. However, solid-liquid separation can be forcibly performed by centrifugation or other methods.

[0016] The extraction treatment with the aqueous alkaline solution produces a candy-like solid, and the solid is separated from the solution to obtain an aqueous extract. Next, an acid is added to the obtained aqueous extract solution to obtain a peach protein-containing composition (crude product) as a precipitate. The acid used in such acid precipitation treatment is not particularly limited, and examples thereof include sulfuric acid, hydrochloric acid, trichloroacetic acid, trifluoroacetic acid, etc., and by appropriately selecting and adding one of these acids, the pH of the extract is changed to the acidic side. The desirable pH on the acidic side is about 2 to 5, and more preferably about 2 to 4.

[0017] The peach protein-containing composition (crude product) obtained as described above was washed by dispersing it in an ethanol solution, and the desired peach protein-containing composition was prepared. The obtained peach protein-containing composition appeared as a coarse reddish-purple powder. In addition, gel filtration or dialysis can also be used as a means for purifying and decolorizing the crude peach protein-containing composition, and decolorization can also be achieved by oxidation treatment, for example, erythorbic acid / hydrogen peroxide treatment.

[0018] The peach protein-containing composition of the present invention obtained by the above method contains a high content of peach protein, and when the protein content was measured by the Kjeldahl method, the protein content in the composition was found to be as high as approximately 56%. Considering that the protein content of the raw material peach fiber was about 15%, the protein content of the peach protein-containing composition obtained by the method of the present invention was extremely high.

[0019] The analysis results are shown in Table 1 below.

[0020] [Table 1] [Example]

[0021] The present invention will be explained in more detail below by describing the production of a peach-containing composition investigated by the present inventors as an example.

[0022] Example 1: Preparation of peach protein-containing composition 200g of raw peach fiber (manufactured by Okayasu Co., Ltd.) was taken and washed with 2.5L of water. stomach Got a bar. The washed peach fiber was subjected to alkaline extraction by stirring with an alkaline solution consisting of 2 L of a 0.1 N aqueous sodium hydroxide solution and 1 L of water. In this case, the sodium hydroxide concentration in the alkaline extraction treatment was 0.07N, and the pH of the extract was 10.4. After the extraction treatment, the mixture was filtered to remove solids and obtain an extract. Approximately 7 g of 60% sulfuric acid was added to the extract, the pH was adjusted to 3.0, and a precipitate was obtained by acid precipitation. The precipitate was washed twice with 1 L of 90% ethanol and finally with 99.5% ethanol, and then dried to obtain the desired peach protein-containing composition in a yield of 3.3%. The protein content of the obtained peach protein-containing composition was 55.9% as a result of analysis by the Kjeldahl method.

[0023] In the alkaline aqueous solution extraction procedure, the following sodium hydroxide concentrations were used: hand The results of the same treatment as above are also shown in Table 2 below.

[0024] [Table 2]

[0025] No difference in the protein content of the resulting peach protein-containing composition was observed depending on the concentration of the alkaline aqueous solution. Although not shown in the table, when the concentration (normality) of the base added to the alkaline aqueous extract was 0.01 or less, the pH of the extract itself shifted toward the neutral to acidic side, and protein extraction was not possible.

[0026] Example 2: Preparation of peach protein-containing composition using enzyme-treated peach fiber The preparation of peach protein-containing compositions was investigated by treating raw peach fiber with cellulase, hemicellulase, pectinase, and xylanase as glycolytic enzymes. 3 g of peach fiber (manufactured by Okayasu Co., Ltd.) was taken, and 30 mL of water was added using the enzymes cellulase, hemicellulase, pectinase, and xylanase at 1% or 5% by weight of the raw peach fiber.The mixture was then left overnight in an incubator set to 50°C for enzyme treatment. Pectinase and xylanase were only added at 5% by weight.

[0027] The enzyme-treated reaction solution was filtered under suction to separate the solid matter (enzyme-treated peach fiber) from the liquid, and 30 mL of 0.1 N aqueous sodium hydroxide solution was added to the solid matter to carry out an alkali extraction treatment. After the alkaline extraction treatment, the extract was filtered to remove solids and obtain an extract. Approximately 7 g of 60% sulfuric acid was added to the extract, the pH was adjusted to 3.0, and a precipitate was obtained by acid precipitation. The precipitate was washed twice with 1 L of 90% ethanol, and finally with 99.5% ethanol, and then dried to obtain the desired peach protein-containing composition. The yield and protein content of the obtained peach protein-containing composition are shown in Table 3 below.

[0028] [Table 3]

[0029] The results in Table 2 demonstrate that even when enzyme treatment is used, a peach protein-containing composition containing a high amount of protein can be produced. Furthermore, the enzyme treatment reduced the viscosity of the extract during the alkaline extraction procedure, making the mixture easier to extract. [Industrial Applicability]

[0030] The present invention makes it possible to produce a peach protein-containing composition containing a high concentration of protein from peach fruit juice residue (peach fiber), which has previously been discarded in large quantities as waste.The resulting peach protein-containing composition is useful as a food ingredient and food processing ingredient, and therefore has great industrial applicability.

Claims

1. This method for producing a peach protein-containing composition comprises extracting the residue remaining after extracting juice from peach pulp from which the seeds have been removed with an alkaline aqueous solution, removing solids, and acidifying the resulting extract to precipitate peach protein.

2. The method according to claim 1, wherein the extraction with an alkaline aqueous solution is carried out with an alkaline aqueous solution having a pH of 8 to 13.

3. The method according to claim 1, wherein the extract is acidified to a pH of 2 to 5.

4. 2. The method according to claim 1, wherein the residue remaining after extracting juice from peach pulp from which the seeds have been removed is subjected to an enzymatic treatment with a glycolytic enzyme before being subjected to an extraction treatment with an alkaline aqueous solution.

5. The method according to claim 4, wherein the glycolytic enzyme is selected from the group consisting of cellulase, hemicellulase, pectinase, and xylanase.

6. This method for producing a peach protein-containing composition comprises the steps of: removing the seeds from peach flesh, extracting juice from the remaining residue, optionally treating the residue with a glycolytic enzyme selected from cellulase, hemicellulase, pectinase, and xylanase; extracting the residue with an alkaline aqueous solution of pH 8 to 13; removing solids; and acidifying the resulting extract to pH 2 to 5 to precipitate peach protein.

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