JPH0541641B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for producing pectin from apple pomace (hereinafter referred to as apple dregs) without using alcohol. (Prior Art) In general, pectin is widely contained in all plants such as fruits as a substance that maintains intercellular tissue in the plant body, and is particularly contained in large amounts in the skin of citrus fruits, apples, etc. Pectin obtained from these citrus fruits is widely used in foods and drinks as a stabilizer for soft drinks, ice cream, mayonnaise, bread, confectionery, etc., and the amount used has been increasing in recent years. Conventionally, the following method is generally known as a method for producing such pectin from citrus fruits and the like. First, the dregs of the fruit from which the juice has been squeezed is washed with water, and this dregs is boiled in a high-temperature acidic solution to hydrolyze protopectin, and then the waste peel is removed by squeezing means to obtain a pectin extract. . Next, the pectin extract is purified by filtration, neutralized, and concentrated. Ethyl alcohol is added to this concentrated pectin extract to coagulate the pectin into fibers, and then the ethyl alcohol is recovered.
Finally, the fibrous coagulum is dried and powdered to produce powdered pectin. (Problems to be Solved by the Invention) By the way, the production method of the prior art described above uses ethyl alcohol as a means for coagulating the pectin extract, and therefore has the following problems. First, since the price of ethyl alcohol in Japan is higher than in Western countries, it would be costly to produce it domestically. Second, ethyl alcohol is recovered by distillation, but pectin The manufacturing cost increases. If we calculate the production cost of pectin based on Japan's industrial alcohol prices, it is currently unprofitable. For this reason, in Aomori Prefecture, for example, the apple dregs that are pressed to extract fruit juice are completely thrown away as industrial waste, even though they are a high-quality raw material that contains a large amount of pectin. There is no demand for 100
% is dependent on imports. The present invention was made as a result of intensive research by the inventor in view of the problems of the prior art, and focused on the fact that pectin is a polymeric acid with anions, and phosphoric acid is a low-molecular acid. , provides a method for producing pectin from apple dregs without using any alcohol by utilizing ion exchange means. Note that JP-A-50-148399 discloses a technique in which a pectin extract is brought into contact with a cation exchange resin; Moreover, the purpose of cation exchange is to strengthen the gelling power of pectin and reduce its viscosity. In contrast, the purpose of ion exchange in the method of the present invention is to produce pectin without using alcohol, and the technical purpose, structure, and effect are different. (Means for Solving the Problems) The means for producing pectin according to the present invention configured to solve the above-mentioned problems includes a pretreatment step of pretreating apple dregs using a phosphoric acid solution; A pectin extraction step in which the treated apple cake is heated in an acidic solution to produce a pectin extract, a purification step in which solids are removed from the pectin extract, and the purified pectin extract is purified using an anion exchange resin. and an ion exchange step of contacting with a cation exchange resin to produce a pectin solution. (Specific Description of the Invention) The method of the present invention uses apple dregs as a raw material, and the apple dregs contains sugar, acids, some heavy metals, and pigments in addition to pectin. Therefore, pectin is produced by removing components other than pectin through the following steps. First, since apple dregs contains protopectin, which is an insoluble pectin, in the pretreatment step, a pretreatment is performed to change this protopectin into an easily soluble state. That is, apple dregs discharged during the apple juice production process is immersed in a low concentration phosphoric acid solution for a certain period of time, about 1 to 24 hours. If the soaking time is short (about 1 hour), pectin with a strong gelling power can be obtained, and if it is soaked for a long time (about 24 hours), the gelling power is weak but a large amount of pectin can be obtained. The soaking time may be determined as appropriate depending on the use of the pectin. When protopectin becomes easily soluble by soaking the apple dregs for a predetermined period of time, some pigment and sugar can be removed along with the solution by separating the phosphoric acid solution from the apple dregs using a sieve or the like and discarding it. . In the next pectin extraction step, the apple grounds are heated to 80-90°C for a certain period of time in a highly concentrated phosphoric acid solution to generate a pectin extract from the pretreated apple grounds. As a result, the apple dregs are separated into a pectin extract and a solid residue. The purification step is for removing solid substances from the pectin extract, and is carried out, for example, as follows.
First, the pectin extract and the solid material in a mixed state are squeezed using, for example, a press to completely squeeze out the pectin extract from the solid material. Next, the pectin extract is filtered using a sieve such as nylon mesh to remove coarse solid substances. Finally, a pectin extract is obtained by separating and removing the microsolids remaining in the pectin extract using a centrifuge. The pectin extract obtained in this way is of low purity, containing impurities such as sugars such as phosphoric acid and malic acid, trace amounts of heavy metals such as manganese, iron, copper, and zinc, and residual pigments. , these acids using anion exchange and cation exchange means,
Heavy metals are removed and a high purity pectin solution is produced. In this case, the anion exchange resin adsorbs low molecular acids such as phosphoric acid with a molecular weight of 500 or less,
By using a material such as pectin that does not adsorb polymeric acids with a molecular weight of 10,000 or more, it is possible to reliably adsorb and remove impurities such as phosphoric acid, malic acid, and other pigments. However, the ion exchange ability of anion exchange resins varies depending on the specifications, amount used, etc., and if the pH of the pectin extract is higher than 3.5, the anion exchange resin may adsorb pectin; If the pH is below, the product will have a sour taste, so always adjust the pH to 3.5. On the other hand, by bringing the pectin extract into contact with a cation exchange resin, heavy metals contained in impurities can be adsorbed and removed. Note that the order in which the anion and cation exchange resins are propagated is not particularly limited, but if the ion exchange process is performed in the order of anion exchange resin and cation exchange resin, pigments and heavy metals can be effectively removed. be able to. In this way, a highly purified pectin solution is produced through the ion exchange process, and then concentrated to obtain a concentrated pectin solution. Furthermore, it may be vacuum-dried or freeze-dried and pulverized to make powdered pectin. (Effects of the Invention) As described in detail above, the present invention makes it possible to produce a high-purity pectin solution using an ion exchange means using an anion exchange resin and a cation exchange resin. be effective. Since no alcohol is used, material costs can be reduced and pectin solutions can be produced at low cost. For the same reason as mentioned above, since the alcohol recovery device can be made unnecessary, equipment costs can be reduced. Since the anion exchange resin and the cation exchange resin can be reused many times by washing, the material cost can be significantly reduced compared to the conventional method in which alcohol is recovered and reused. (Example) Examples of the method of the present invention will be described in detail below. First, put 100g of fresh apple dregs after squeezing into a container made of synthetic resin such as polyethylene, and add 0.02N
Add 1.5 liters of phosphoric acid solution and stir, then add 1.5 liters of phosphoric acid solution at room temperature.
Leave it for a while. After 1 hour, pass the phosphoric acid solution of apple dregs through a 60-mesh stainless steel sieve to remove the phosphoric acid solution, and pour the phosphoric acid solution into the apple dregs again.
Add 1.5 liters of 0.02N phosphoric acid solution and stir. After leaving this apple dregs phosphoric acid solution at room temperature for 1 hour,
The phosphoric acid solution is removed from the apple pulp by passing it through a mesh sieve. This pretreatment makes it possible to easily solubilize protopectin contained in apple dregs, and also to remove a certain amount of pigment and sugar. Next, add 500ml of water to the pretreated apple dregs, add a few drops of phosphoric acid solution, stir well, and adjust the pH.
Obtain the phosphoric acid solution of apple dregs in Step 1.8. Pour this solution into a stainless steel container, stir it for about 30 minutes while heating it to about 90℃, and turn it into a hydrogel-like pectin extract.
Obtain 586g. Furthermore, the hydrogel-like pectin extract is rotated at about 5000 rpm using a centrifuge to separate solid matter from the pectin extract and discarded. As a result, 386 g of pectin extract having a pH of 1.8, an EC of 7.6 mS, and a sugar content of 1.0% is obtained. Next, this pectin extract is brought into contact with an anion exchange resin. Namely, anion exchange resin XT5028
(Made by Organo) Filled with 200ml, diameter 65mm, length
Pass the pectin extract through a 380 mm column to adsorb and remove the pigment. This anion exchange resulted in the pectin extract having a pH of 2.0, an EC of 5.4 mS, and a sugar content of 0.4%. Therefore, we filled it again with 100 ml of anion exchange resin IRA67 (manufactured by Organo) with a diameter of 65 mm and a length of 380 mm.
The pectin extract is passed through a mm column, and the initially added phosphoric acid, acids such as malic acid in the apple dregs, and the remaining pigment are adsorbed and removed. By contacting this anion exchange resin, the pectin extract has a pH of 3.5.
EC0.5mS, sugar content 0.2%. If the pH is below 3.5, the product will remain sour, so either fill the column with a small amount of anion exchange resin (IRA67) or repeatedly contact the pectin extract until the pH reaches 3.5. Adjust so that On the other hand, if the pH exceeds 3.5, the gelling power of pectin decreases, so add phosphoric acid solution to the pectin extract immediately to lower the pH.
Adjust it to be 3.5. Now, as mentioned above, after removing the remaining pigments and acids by contacting with an anion exchange resin, the pectin extract was placed in a column with a diameter of 65 mm and a length of 380 mm filled with 200 ml of cation exchange resin IRC718 (manufactured by Organo). is passed through the fruit to adsorb and remove trace amounts of heavy metal ions such as manganese, copper, iron, and zinc contained within the fruit. By contacting this cation exchange resin, the pectin extract has a heavy metal content as shown in Table 1, and also has a pH of 3.4,
EC0.3mS, sugar content becomes 0%. In this way, approximately 526 g of a high-purity pectin solution from which pigments, acids, heavy metals, and sugars have been removed is obtained. After concentrating this solution under reduced pressure on a water bath at 60°C to obtain approximately 383 g of pectin concentrate, about
Freeze-dry powdered pectin under 0.1 TORR vacuum
Obtain 1.3g. The composition of the powdered pectin thus obtained is shown in Table 2, and the quality (jelly strength and viscosity) is shown in Table 3. The pectin used in the comparative examples shown in Tables 1 to 3 is an imported product, but as can be understood from each table, according to the method of the example, high-grade pectin that is comparable to imported pectin can be prepared using alcohol. It is possible to manufacture the product without using it at all. Further, the jelly strength and viscosity of each pectin of Examples and Comparative Examples shown in Table 3 were determined by the following method. (b) Jelly strength: 10g of pectin, 20g of white sugar, 1 citric acid in a mortar
g, and while mixing thoroughly with a pestle, gradually add 50 ml of water and mix well.The mixture is packed into a column (diameter 30 mm, length 30 mm) and left at 0°C for 48 hours. Thereafter, the jelly-like sample taken out from the column was subjected to an indentation test to measure its breaking strength and the size of the dent. For measurement, NRM-2010J-CW manufactured by Fudo Kogyo Co., Ltd.
Measurements were made using a mold rheometer with a 5 mm spherical plunger at a table speed of 6 cm/min. In addition, comparative pectin (imported pectin)
3450NH95J (manufactured by Unipectin) was also tested in the same manner as above. (b) Viscosity 300 ml of water was added to 6 g of powdered pectin to completely dissolve it, and the solution was measured using a viscometer (manufactured by Rion Co., Ltd.) at a temperature of 5°C. Similar tests were conducted on pectin as a comparative example.

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Claims (1)

[Claims] 1 A pretreatment step in which apple dregs is pretreated with a phosphoric acid solution, a pectin extraction step in which a pectin extract is produced by heating the pretreated apple dregs in an acidic solution, and a solid is extracted from the pectin extract. A method for producing pectin comprising a purification step for removing molds, and an ion exchange step for bringing a purified pectin extract into contact with an anion exchange resin and a cation exchange resin to produce a pectin solution.