JP4585913B2 - Citrus extract and production method thereof - Google Patents

Description

  The present invention relates to a citrus extract and a method for producing the same, and more specifically, it contains abundant nobiletin that exhibits physiological functions such as a carcinogenesis-inhibiting action, a cancer metastasis-inhibiting action, and a blood glucose rise-inhibiting action, The present invention relates to a citrus extract that is expected to be used and a method for producing the extract that promotes the reuse of citrus juice residue.

Nobiletin is a kind of polymethoxyflavonoid, which has a carcinogenesis-inhibiting action and a cancer metastasis-inhibiting action (Non-patent Document 1), and is considered to have a blood glucose elevation-inhibiting action.
It is known that nobiletin is contained in a large amount in citrus, particularly Citrus depressa HAYATA. Shiikuwasha has long been known as an Okinawan citrus, and its main producing area is the Yabe district, mainly in Ogimi village in the northern part of the main island of Okinawa.
However, a method for efficiently extracting nobiletin from citrus such as Shikuwasha has not been found so far.

Conventionally, citrus is often used as a raw material for processing juices and jams. Shikuwasha is also used as a raw material for processing for the purpose of vinegaring such as attaching to sashimi or for obtaining juice. Thus, in most cases, citrus remained in the use of the pulp part, and the parts such as the fruit part and the peel after squeezing were discarded as residues.
Regarding reuse of citrus juice residue, for example, use for feed for livestock and the like, soil conditioner, extraction of essential oil from fruit skin, etc. has been proposed (for example, see Non-Patent Document 2). However, efforts to develop food ingredients using squeezed residue are still not sufficient. In addition, there has been no proposal for a method of actively using a portion other than the fruit portion of citrus.

Bracke, M.M. E. (1994), Food Technology, 48, 104 “Fruit and Fruit Beverage Dictionary”, Asakura Shoten Co., Ltd., issued September 30, 1978, p. 408-412

  An object of the present invention is to provide a citrus extract containing abundant nobiletin, and to provide a method for efficiently producing the extract and to make effective use of citrus.

In order to solve the above-mentioned problems, the inventors have paid attention to synephrine, which is a polymethoxyflavonoid contained in siquasha with nobiletin in the process of intensive studies. Synephrine is best extracted with water from Shikuwasha, and is extracted to some extent even in low-concentration ethanol aqueous solutions, for example, ethanol aqueous solutions with an ethanol concentration of less than 30 (v / v)%.
The present inventors efficiently extract nobiletin from Shikuwasha by using extraction conditions that do not extract synephrine, that is, an aqueous ethanol solution having an ethanol concentration of 30 (v / v)% or more or 100 (v / v)% ethanol. It was found that it can be extracted. Moreover, this extraction condition is applicable also to citrus other than Shikuwasha, and it has been found that a citrus extract having a high nobiletin content can be efficiently obtained from various citrus, and the present invention has been completed.

That is, the present invention according to claim 1 is a plant tissue-disintegrating enzyme treatment applied to raw or dried pericarp of any one of Shikuwasha, Wenzhou mandarin orange, orange and grapefruit, and the obtained solid part is treated with 100 (v / v). ) A method for producing a citrus extract containing 1-100 mg / g of nobiletin, which is extracted with% ethanol .
In the present invention described in claim 2, the extraction condition is that extraction is performed by stirring for 10 minutes or more at a stirring speed of 10 rpm or more in a sealed container in order to prevent the solvent from decreasing due to volatilization of alcohol / acetone. It is a manufacturing method .
The present invention according to claim 3 is the production method according to claim 1 or 2, wherein the extract obtained after the extraction is concentrated .
The present invention according to claim 4 is the production method according to claim 3, wherein after the concentration, the obtained concentrate is extracted again with 100 (v / v)% ethanol .
The present invention according to claim 5 is the production method according to any one of claims 1 to 4 , wherein the plant tissue-disrupting enzyme is any one of cellulase, xylanase, mannanase and pectinase .

  According to the present invention, there are provided a citrus extract rich in nobiletin that exhibits physiological actions such as a carcinogenesis-inhibiting action, a cancer metastasis-inhibiting action, a blood sugar elevation-inhibiting action, and a method for efficiently producing the extract. Is done.

Hereinafter, the present invention will be described in detail.
The citrus extract of the present invention contains 1-100 mg / g of nobiletin.
Here, nobiletin is a polymethoxyflavonoid having physiological actions such as a carcinogenesis-inhibiting action, a cancer metastasis-inhibiting action, and a blood glucose rise-inhibiting action.
Citrus extract means an extract extracted from citrus. Citrus containing nobiletin includes fruit bodies belonging to the citrus genus Citrus subgenus Mikan, Tokinkan, primary citrus subfamily Daidai, lime and the like. Examples of mandarin oranges include Shiikushasha, Wenzhou mandarin orange, Sugiyama Unshu, Yatsushiro, Keraji, Oat, lobular Ponkan, Giant mandarin orange, Jimikan, Shikaikan, Clementine normal, Tachibana, Kobimi mandarin, Kishu mandarin, Sankitsu, Koji Can do. Examples of things in Toukkinkan include Karamanshi and Shikikitsu. Examples of the Daidai ward include orange, Sampoucan, and Hyuganatsu. Examples of citrus in Zabon (Buntan) include grapefruit. Among these citrus, those rich in nobiletin are preferable, and those containing both nobiletin and synephrine, specifically, sikuwasha, mandarin orange, orange and grapefruit are preferable.

  In addition, the citrus fruit may be any of the fruit bodies of citrus, that is, the pericarp, funnel membrane, flesh part, or seed, but preferably contains pericarp as described later, Use is preferred.

The citrus extract containing 1-100 mg / g of nobiletin of the present invention can be efficiently produced by extracting from citrus with a predetermined aqueous ethanol solution. The present invention also provides such a manufacturing method.
That is, in the production method of the present invention, the citrus juice residue is extracted with an ethanol aqueous solution having an ethanol concentration of 30 (v / v)% or more or 100 (v / v)% ethanol, and the extract obtained as necessary is extracted. It is characterized by concentrating.

As the citrus used as a raw material in the production method of the present invention, the above-mentioned various citrus fruits can be used. As a solvent used for extracting a target product from the raw material, an ethanol concentration of 30 (v / v )% Ethanol aqueous solution or 100 (v / v)% ethanol, preferably ethanol concentration 50 (v / v)% or more and less than 100 (v / v)% ethanol aqueous solution or 100 (v / v)% ethanol is used. .
By using this solvent, only nobiletin can be selectively extracted. Citrus used as a raw material in the present invention is as described above. Specifically, it is preferably any one of Shikuwasha, Satsuma mandarin, orange and grapefruit, and among these, Shiikuwasha is most preferred.

The citrus part may also be the whole fruit body, or any of the pericarp, persimmon membrane, pulp part, and seed. When the pulp part is used as a raw material for processed products such as juice and paste, parts other than the fruit part are usually discarded as citrus juice residue, but nobiletin is also present in parts other than the fruit part. Since it is contained abundantly, in the production method of the present invention, it is possible to preferably use a part other than the pulp part.
Citrus juice squeezed residue is composed of a residue containing fruit peels, fungi and seeds, and fine insoluble solids (pulp) discharged during fruit juice purification. The citrus juice residue may be the residue itself obtained after squeezing such citrus, or may be a dried product of the residue. The drying process can be performed by a conventional method.
Moreover, since nobiletin is abundantly contained in the pericarp among each part of citrus, pericarp can also be used selectively. When using pericarp, it may be extracted without processing after crushing it to a suitable size with a cutter, etc., but in order to increase the extraction efficiency, dry treatment is performed before extraction, It is preferable to process.

On the other hand, it is also preferable to obtain a solid part by a plant tissue disrupting enzyme treatment and perform the following treatment on this solid part. Here, the plant tissue-degrading enzyme means an enzyme that degrades plant tissue. Specifically, it is an enzyme derived from a cellulase, xylanase, mannanase, or pectinase microorganism (filamentous fungus), such as vegetables, fruits, and cereals. It is used for softening tissues and clarification of citrus juice and apple juice.
The conditions for the treatment with the plant degrading enzyme can be appropriately set depending on the enzyme used. For example, in the case of cellulosin HC100 used in the examples, the enzyme 0.01-1.0 is used for the raw pericarp as the raw material. % Can be 2-15 hours at 25-80C. The enzyme-treated product can be appropriately dehydrated and extracted as a solid part.
Furthermore, the shiiwa washer paste obtained by the method described in the specification of Japanese Patent Application No. 2003-411618 is rich in pericarp, so that it can also be used as a raw material.

In the production method of the present invention, the citrus is mixed with an ethanol aqueous solution having an ethanol concentration of 30 (v / v)% or more or 100 (v / v)% ethanol, preferably an ethanol concentration of 50 (v / v)% to 100 (v / V) Extract with less than% ethanol aqueous solution or 100 (v / v)% ethanol.
When the ethanol concentration is less than 30 (v / v)%, synephrine is extracted at the same time, and nobiletin cannot be extracted efficiently.

  Other conditions for extraction with an aqueous ethanol solution can be appropriately determined according to the type of citrus, components, ethanol concentration, etc. In general, the ratio of ethanol aqueous solution or ethanol to citrus juice residue is 1: 2 1: 5.

The extract obtained as a result of extraction with an aqueous ethanol solution or the like can be concentrated as necessary. By concentrating, a citrus extract containing a higher concentration of nobiletin can be obtained.
Concentration can be performed by vacuum evaporation concentration or the like. That is, the concentration can be carried out by evaporating the organic solvent used for extraction and the water from the skin part under normal pressure and reduced pressure, and a large evaporator or a simple distillation apparatus is used as the equipment.
Concentration may be performed once, but can be repeated twice or more, and a citrus extract containing a higher concentration of nobiletin can be obtained.
Thus, in the citrus extract containing 1-100 mg / g of nobiletin obtained by the production method of the present invention, nobiletin exhibits physiological functions such as a carcinogenesis-inhibiting action, a cancer metastasis-inhibiting action, and a blood glucose rise-inhibiting action. Therefore, by adding to foods (particularly functional foods), feed, pharmaceuticals, etc., it can be used for the treatment and prevention of cancer, diabetes, hyperlipidemia and the like.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited only to these Examples.

Example 1 (when extracted directly from raw skin with 100% ethanol)
After using 10 g of raw skin of shiikuwasha (water content 70-80%) as a raw material and crushing to a suitable size with a cutter etc., 30 g of 100 (v / v)% ethanol at room temperature (25-30 ° C.) 30 Extraction was performed for minutes to obtain an extract. The extract was filtered and concentrated with a 300 μm mesh to obtain 874 mg of concentrate 1, and the supernatant was dissolved again by adding ethanol to obtain 269 mg of concentrate 2.
The contents of nobiletin and synephrine in raw peel, extract, concentrate 1 and concentrate 2 were examined as follows.
The content of nobiletin was measured by dissolving and stirring each sample in ethanol, filtering with a 0.45μ filter, and then using a high-performance liquid chromatograph (trade name: LC-10A, manufactured by Shimadzu Corporation). Performed by chromatography. LiChrospher 100: RP-18 (Merck, particle size 5 μm, 250 mm (length) × 4 mm (inner diameter)) was used as the reverse phase column, and methanol: 10 mM phosphoric acid aqueous solution (7: 3) was used as the mobile phase. The sample was eluted with an isocratic method under the conditions of a column temperature of 40 ° C., an injection volume of 5 μl, a flow rate of 0.6 ml / min, and a detection wavelength of 340 nm.
The synephrine content was measured by dissolving each sample in pure water. In reverse phase chromatography, 0.02M citric acid-0.02M phosphoric acid aqueous solution (7: 3, pH 3.0 or less) was used as the mobile phase, the flow rate was 1.0 ml / min, and the detection wavelength was 220 nm. Was performed in an isocratic manner as in the case of nobiletin described above.
The obtained content values are shown in Table 1.

As is clear from Table 1, the amount of transfer of synephrine to the extract was significantly reduced as the amount of transfer of nobiletin was reduced, as compared to a significant decrease with each extraction or concentration operation.
From this, it is possible to obtain a citrus extract containing nobiletin at a high concentration from raw skin with 100 (v / v)% ethanol, and further concentration to further increase the concentration of nobiletin. It became clear that things could be obtained.

Example 2
Using 10 g of raw pericarp skin (70 to 80% water content) as a raw material, after crushing to a suitable size with a cutter, etc., and then drying under normal temperature hot air conditions to obtain a dry pericarp (water content 10% or less) It was. The dried pericarp was extracted with 20 g of 100 (v / v)% ethanol at room temperature (25 ° C. to 30 ° C.) for 30 minutes to obtain an extract. The extract was filtered through a 300 μ mesh and concentrated to obtain 246 mg of concentrate.
The contents of nobiletin and synephrine in the raw peel, dried peel, extract, and concentrate were examined in the same manner as in Example 1. The numerical values of the obtained contents are shown in Table 2.

As is clear from Table 2, the amount of nobiletin transferred was hardly reduced as compared with the case where the amount of synephrine transferred to the extract decreased significantly each time the extraction operation and the concentration operation were performed.
From this, it was clarified that a citrus extract containing nobiletin at a high concentration can be obtained even when dry peel is used as a raw material, as in the case of raw peel.

Example 3
Using 10 g of raw pericarp skin (70 to 80% water content) as a raw material, after crushing to an appropriate size with a cutter or the like, plant tissue-disintegrating enzyme, cellulosin HC100 (trade name, manufactured by HBI Co., Ltd.) 05% was added and reacted at 40 ° C. for 15 hours. After the reaction, dehydration was performed to obtain a solid part (water content 60 to 70%). This solid part was extracted with 20 g of 100 (v / v) ethanol under conditions of 30 minutes at room temperature to obtain an extract.
This extract was filtered through a 300 μ mesh and concentrated to obtain 271 mg of concentrate 1. Further, the concentrate 1 was redissolved with ethanol, filtered and concentrated to obtain 134 mg of the concentrate 2.
The contents of nobiletin and synephrine in the raw pericarp, solid part, extract, concentrate 1 and concentrate 2 were examined in the same manner as in Example 1. The numerical values of the obtained contents are shown in Table 3.

As is apparent from Table 3, the amount of nobiletin transferred was hardly reduced as compared with the case where the amount of transfer of synephrine to the extract decreased significantly each time the extraction operation and the concentration operation were performed. Moreover, when the nobiletin content of the concentrate 2 finally obtained is compared with the final content of Example 1 and 2 as a density | concentration (ratio) with respect to the weight of a concentrate, it turns out that it is very high density | concentration.
From this, it was clarified that when the solid part of the plant tissue-disrupting enzyme is used as a raw material, a citrus extract containing a higher concentration of nobiletin can be obtained than in the case of raw peel or dried peel.

  According to the present invention, there are provided a citrus extract rich in nobiletin that exhibits physiological actions such as a carcinogenesis-inhibiting action, a cancer metastasis-inhibiting action, a blood sugar elevation-inhibiting action, and a method for efficiently producing the extract. Is done.

Claims (5)

Shiikuwasha performs plant tissue-disruptive enzymes processing to Citrus unshiu, either fresh pericarp or dry pericarp of orange and grapefruit, the obtained solid part and extracting with 100 (v / v)% ethanol the method of citrus extract to 1 to 100 mg / g containing nobiletin. Extraction conditions, for preventing the reduction of the solvent due to volatilization of alcohol acetone process according to claim 1 wherein the extract by stirring at a stirring rate of 10rpm or more than 10 minutes in a sealed container. The manufacturing method of Claim 1 or 2 which concentrates the extract obtained after extraction. The method according to claim 3, wherein after the concentration, the obtained concentrate is extracted again with 100 (v / v)% ethanol. The production method according to any one of claims 1 to 4, wherein the plant tissue-disrupting enzyme is any of cellulase, xylanase, mannanase and pectinase.