JPH057970B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION BACKGROUND OF THE INVENTION This invention is directed to the treatment of solid wastes derived from citrus fruits to obtain useful products and medicaments comprising solvent extracts of citrus peels. In recent years, one of the major problems encountered in the production of citrus products such as orange juice, orange concentrate and orange sections has been the disposal of various wastes, including orange peels, pieces and pulp.
For many years these were considered to have little practical value and were therefore simply discarded without any treatment. However, in recent years it has been discovered that by further processing some of these waste products (eg pericarp), an excellent and nutritious cattle feed can be produced. Unfortunately,
Although the waste disposal problem has been partially alleviated by utilizing these treated wastes, processing the waste to produce cattle feed is not economically attractive to the extent desired. It wasn't. Therefore, efforts have recently been made to treat these wastes and produce products suitable for human and animal consumption. Furthermore, it is desirable to process these materials to obtain a wide range of products that fully advantageously utilize the raw materials contained therein. Unfortunately, it is not easy to process waste to meet such purposes. For example, US Pat. No. 2,215,944 discloses a method for treating orange peel with lime to obtain a product suitable for use as cattle feed. However, this method is not advantageous since the use of lime results in a bitter tasting product. moreover,
The pectin present in the pericarp is destroyed or decomposed during the treatment with lime, thus one of the components in the pericarp that is useful from the point of view of human and animal utilization is lost. However, the pericarp is very sticky and is therefore difficult to process without the use of lime or related substances (eg magnesium- or aluminum-containing compounds). Furthermore, it is difficult to dry the pericarp after processing, since the cell structure of the pericarp is always susceptible to deterioration due to contact with substances such as lime. Additionally, the pericarp contains substantial amounts of various sugars that are desirable to remove from the pericarp in order to reduce the caloric content of the final product. Sugars are highly hygroscopic and, if present in significant amounts, tend to make drying of the pericarp more difficult after processing.
The pericarp also contains significant amounts of essential oils (ie, natural volatile oils) that are a component of the pericarp's aroma and/or flavor. Essential oils are preferably removed from the pericarp as they impart a bitter or unpleasant taste. As an alternative to lime treatment, the waste peels have been washed with water to remove some of the sugars and unpleasant substances. However, with such water washing,
Many of the essential oils present cannot be removed.
The product also contains carotenoid pigments, which after a short time oxidize to produce an unpleasant "hay-like" odor. Water-washed products are also difficult to compress to remove excess water. Therefore,
The final product generally contains an unreasonably high amount of water (eg, 85% by weight or more) and tends to require extensive drying of the product. Additionally, additional waste is produced in the form of wash water, which is difficult to dispose of as it contains sugars and other peel-derived components extracted from the peel. It would therefore be desirable to provide improved methods for treating waste from orange processing to produce a variety of useful products and products suitable for human and animal use. Additionally, it would be desirable to provide a process that is more economically attractive and efficient than those commonly used in the orange processing industry. Furthermore, it has recently been discovered that certain pericarp components (eg pectin) have properties that can be used advantageously to control serum cholesterol. These advantages have been demonstrated in recent literature, e.g.
The Tampa Tribune Times, April 30, 1978.
Page 3-E; Food Product Development , 1978
April, pp. 81-88; Sarasota Herald
Tribune, August 6, 1977, p.9-C;
Bradenton Herald, July 19, 1978, 6-C
Page; St. Petersburg Times , October 16, 1977, 22
-Page B; The Tampa Tribune , August 6, 1977
7-B; The Chemurgic Digest , May 15, 1944, pages 119-121. Pectin is further disclosed in the patent literature in view of its various therapeutic effects. For example, US Patent No. 2139139, US Patent No. 2145016, US Patent No. 2294016,
Same No. 2333950, Same No. 2481804, Same No. 2481805,
Same No. 2865757, Same No. 3190756, and Same No.
It is disclosed in the specification of No. 3306819. [Detailed Description of the Invention] The method of the invention will be described in conjunction with the drawings.
Citrus fruits are commonly used in this invention, including oranges, grapefruit, lemons, limes, and tangerines. However, for the sake of explanation, we will consider the peel of an orange. According to the method of the invention, waste orange peels are used which consist of waste products from conventional processes such as the processing of oranges to produce orange juice.
The pericarp is fed to a suitable crusher 2, such as a hammer mill, where it is coarsely crushed. The pericarp is crushed to such an extent that it is substantially disintegrated. The crushed orange peel is then preferably passed through a steam bleaching zone 4 where it is contacted with steam for a number of minutes before being extruded and processed in a screw finisher 6. The pericarp is left in contact with steam for 5 to 15 minutes in the steam bleaching area, which softens the pericarp and renders it amenable to extrusion processing in a screw finisher. With the screw finishing machine,
The seeds, stalks, or leaves contained in the waste pericarp are removed, and the pericarp is further crushed into fine pieces. Naturally, the finer the peel, the more efficient the solvent extraction process will be. As mentioned above, the combination of steam bleaching and extrusion processing steps is not essential, but suitable for the process of treating orange peels. Advantageously, these steps render the peel amenable to extraction by various types of aqueous or non-aqueous liquids (e.g., water, lower alcohols, lower ketones, etc.), so that different types of citrus peels can be processed. (e.g., grapefruit peel, lemon peel, lime peel, etc.). The use of a screw finisher is not essential to the practice of the invention; the crushed peel from the mill 2 can also be passed directly to the mixing zone 8. The pericarp is then led to a mixing zone 8 where it is mixed with a suitable liquid, such as a non-aqueous solvent as detailed below, or with a portion of the extract 10 from the solvent extraction stage;
This generates slurry. The slurried pericarp extrudate 12 is subjected to solvent extraction in an extraction zone 14 . The pericarp extrudate is now contacted with a sufficient amount of non-aqueous solvent 16 to effect the desired degree of extraction. To be suitable for use in the process of this invention, non-aqueous solvents must be water-miscible.
The sugar must also be dissolved in the aqueous solvent solution. Preferably, the solvent has a relatively low boiling point so that it can be easily recovered from the aqueous solution.
To further facilitate recovery of the solvent, it is preferred that the solvent does not form an azeotrope with water. Non-aqueous solvents suitable for use in this invention include methanol, ethanol, propanol,
or lower alcohols such as isopropanol; lower ketones such as dimethyl ketone, methyl ethyl ketone; and monoalkyl ethers and dialkyl ethers of ethylene glycol, or esters thereof such as acetyl esters. Methanol is a preferred solvent because it does not form an azeotrope with water and has a relatively low boiling point. Methanol is also advantageous in that it dissolves oil-soluble pesticides that may be present in the pericarp. The above suitable solvents are not exhaustive, and those skilled in the art can readily determine non-aqueous solvents suitable for use in the present invention. The extruded pericarp is extracted in the extraction area 14.
Contact with the non-aqueous solvent by any method and for a sufficient time to extract all of the desired components from the pericarp. The non-aqueous solvent 16 supplied to the countercurrent extraction region 14 is
It should be noted that it is preferably substantially undiluted (ie, substantially non-aqueous or of commercial grade purity). The solvent may be introduced from an external source or may be a recycled solvent fraction from the next processing stage, as detailed below. The solvent can be diluted with small amounts of water (eg, less than about 15% by weight based on the total weight of the solution) without adversely affecting the efficiency of the extraction process. When the slurry pericarp contacts the solvent 16 in the final stage of the countercurrent extraction zone, the essential oils and oil-soluble components present in the pericarp (eg carotene, chlorophyll, flavanones, etc.) are extracted therefrom. Water is gradually removed from the pericarp while the solvent passes through successive stages in the extraction zone. As the water content of the extract increases, the water-soluble components present in the peel (e.g. various sugars, citric acid, some salts)
is also removed. Removal of the strongly aromatic essential oil from the pericarp allows the production of a product from the treated pericarp that can be used in a wide range of applications without being hampered by the presence of a strong orange odor. Solvent extracted pericarp 20 exiting extraction region 14
It contains little sugar, little essential oil (less than about 0.005% by weight on dry solids), and consists essentially of protopectin (ie, cellulose and pectin). The concentration of sugar initially present is reduced to less than about 5% by weight based on the weight of dry solids. The pectin present in the pericarp is substantially unaffected by the extraction process, and the treated and dried pericarp usually contains about 30% or more pectin by weight. It is important that the water holding capacity of the pericarp is not impaired by the extraction process. The solvent-extracted pericarp 20 is then dried by any suitable means, such as by contacting with superheated solvent vapor to remove residual solvent and moisture. Additional drying of the pericarp is performed in vacuo to ensure substantially complete removal of solvent and/or moisture. The peel product is then dried and the solvent is removed.
In the grinding zone 24, the material is ground by suitable means, such as a hammer mill, to a size suitable for its intended use, as exemplified below. for example,
The processed pericarp is advantageously ground using a micro-pulverizer to a degree sufficient to pass through an 80 mesh sieve, and the finely ground pericarp is bagged for storage or lead loading. Stuff it. The solvent-extracted peel products of this invention advantageously contain little sugar, low amounts of ether-extractable substances such as essential oils, lipids, fats and carotenoid pigments, and substantially less protopectin (derived from cellulose and pectin). consisting of) The amount of ether extract present in the pericarp is determined by AOAC method No.7.056
(direct method) or No. 7.057 (indirect method). More specifically, the peel product contains less than about 5% sugar and less than about 0.6% ether extractable solids by weight. The content of essential oil (one of the substances that can be extracted with ether) in the peel product is approximately 0.01
Preferably less than about 0.005% by weight
Most preferably, it is less than or equal to The pectin present in the pericarp is virtually unaffected by the extraction process and, as a result, is manufactured by Medallion Laboratories, 9000 Plimoth Ave., Minneopolis, Minnesota 55427, USA.
The pericarp generally contains about 30% or more pectin by weight, and preferably 33% or more pectin by weight, as determined by the Laboratories. The method of this invention produces solvent extracted citrus peels that have the effect of reducing and/or controlling serum cholesterol when administered orally to patients with unreasonably high levels of serum cholesterol. To achieve the intended reduction and/or control of a patient's serum cholesterol, each patient will receive no more than about 15 grams of pectin daily in the form of a pericarp product, although the amount required for each patient will vary widely. It is necessary to administer a certain amount. The pericarp products of this invention can be mixed directly into various food products by various means, such as in the form of hard or soft capsules, compressed into tablets, or in the form of particles, with inert diluents or edible carriers. It can be administered orally. Capsules and tablets generally contain about 0.5
g. Without wishing to be perverse, the pectin-containing pericarp products of this invention have minimal side effects because pectin is not administered alone, but in conjunction with a significant amount of fiber, which is also contained within the pericarp. It is believed that it can be administered alone.
It is believed that the presence of fiber strengthens the body's tolerance to the presence of pectin and reduces the incidence of intestinal disorders and the like. The extract 26 removed from the extraction zone contains some orange peel-derived compounds that are eventually separated from the extract to yield additional useful products. The majority of the extract consists of non-aqueous solvents (eg 60-65% by weight). Other ingredients present include
Alcohol-soluble components such as essential oils (of which d-limonene is predominant), bioflavanoids such as hesperidin, carotenoid pigments, and chlorophylls are included. To separate essential oils and other alcohol-soluble components from the extract, the extract is fed to a separation zone 28 where it is substantially diluted with externally supplied water 30 or recycled desolventized extract 32. .
By appropriate dilution, the alcohol-soluble essential oil present (along with chlorophyll and carotenoid pigments) becomes insoluble, resulting in the formation of an emulsion. The essential oil can be aggregated and easily removed from the extract by suitable means such as centrifugation as a separated highly colored product 34, which also contains chlorophyll and carotenoid pigments. Chlorophyl and carotenoid pigments can then be removed from the essential oil by distillation, if desired. Typically, the amount of aqueous diluent that needs to be added to the extract to provide adequate separation of soluble oils is about 15% or more by weight of the extract, and most preferably about 20% by weight of the extract.
Weight%. However, only enough diluent needs to be added to ensure proper separation of the essential oil without excessively diluting the extract with aqueous solution. If an excessive amount of diluent is added, this will not adversely affect the separation of oil from the extract, but will result in an unnecessary load on each separation device downstream of separation zone 28. It is quite surprising that alcohol-soluble essential oils can easily become insoluble by diluting the extract with an aqueous diluent. Generally, it is very difficult to separate essential oils from such solutions by means such as fractional distillation because the solutions have azeotropic properties. However, it has been found that by diluting the extract with an aqueous diluent, the essential oil in solution is liberated from the solution, which can then be separated by suitable means such as centrifugation. The remaining solvent in the extract is then removed in a stripping region 36 by suitable means such as steam distillation. The solvent 38 recovered from the extract can be recycled to the extraction region 14 for additional processing of waste peels. After removing the non-aqueous solvent from the extract, the remaining orange peel-derived bioflavanoids become insoluble due to the decrease in the solvent concentration in the extract and precipitate out of the solution. Therefore, the bioflavanoids can be easily recovered as a separation product 42 by filtration in the filtration region 40. A portion of the solvent-free and filtered extract 44 is transferred to the centrifugation zone 2 as the aqueous diluent 32.
8 can be recycled. However, the remainder of the extract can be further processed into a refined sugar syrup product. In particular, the remainder of the extract can be passed through an ion exchange region 46 to remove any remaining impurities. Preferably, the extract is sequentially passed through a strongly acidic ion exchange resin, a weakly basic ion exchange resin, and a weakly acidic ion exchange resin. The extract can then be further purified through an activated carbon bed (not shown). As a result of this purification process, an extract 48 in the form of a sugar syrup is produced which essentially consists of an aqueous solution of sucrose, glucose, lebulose and trace impurities. Thus, the method of the invention allows the production of a variety of products with many uses. The treated pericarp has substantial water retention properties and can be used as a medicine (as described above), a thickener, an emulsifier, or a stabilizer. For example, pulverulent peel products can be used as viscosity enhancers in drilling muds, as coagulants in removing solids from cloudy solutions in sugar production, and the like. Finely ground pericarp products can be used to preserve the freshness and moisture of baked goods such as breads, doughnuts, cakes and kutskies. The treated pericarp inhibits rot by inhibiting the development of filamentous fungi. Generally, amounts ranging from about 1 to 3% by weight, based on the weight of the baked product, are sufficient to achieve the desired results. Sugar syrup products can be used as all-natural sweeteners in suitable food products such as fruit juices, baked goods, and the like. Example 1 640 pounds of orange peel is crushed in a hammer mill to a maximum particle size of approximately 2 cm x 2 cm x 3 mm. The crushed pericarp is then placed in a solvent extraction tank where it is contacted with an aqueous extraction solution containing about 95-99% methanol by weight. The extraction solution is circulated through the crushed orange peels for about 15 minutes, after which the peels are contacted with about 1250-1300 pounds of the methanol-containing solution. At the end of the 15 minute extraction time, the extraction solution contains about 67-72% methanol by weight. Repeat the above operation using 1250-1300 pounds of fresh methanol to obtain an extraction solution of 89-92% methanol. Repeat the above operation again using 1250-1300 pounds of fresh methanol,
Obtain an extract of 96-98% methanol. The orange peel is taken out from the extraction tank, drained naturally, and dried in a steam pipe dryer to obtain orange peel powder. The orange peel powder product has a pale yellowish brown color,
It consists of approximately 96 pounds of finely ground orange peel with the ability to hold 10.6 grams of water per gram of powder. Typical analytical values (dry matter basis) for the main components of orange peel powder products are shown in Table 1 below. [Table] Next, the 1250 ~
Mixing 1300 pounds of the solution (or extract) with the fully desolvented extract creates a haze in the mixture. This indicates that the essential oil present was liberated from the solution and that an emulsion was formed. Centrifuge this mixture and
Separate the oily fraction from the extract. This oily fraction is distilled under a vacuum of 5 mm Hg absolute to obtain a clear, colorless citrus oil with a pleasant odor, and a solid residue containing carotenoid pigments and chlorophyll. Methanol is separated from the remainder of the diluted extract by steam stripping. The crude hesperidin, which has become insoluble due to removal of methanol, is recovered by filtering the cooled and solvent-free extract. The extract from which the solvent has been removed is treated with strong acidic ion exchange resin IR120 [Rohm and Haas].
ion exchange column containing a weakly basic ion exchange resin A-37 (manufactured by Diamond Alkali), an ion exchange column containing a weakly acidic ion exchange resin IR84 (manufactured by Rohm & Haas) The sample is passed through an ion-exchange column containing an active carbonaceous substance (manufactured by J.D. Co., Ltd.) and an activated carbon bed. The concentration of the solution thus obtained is adjusted to a Brix of 65 to obtain a sugar syrup. Example 2 A quantity of orange peel is collected in a drum and left in contact with steam for approximately 10 minutes until softened. The softened pericarp is then passed through a screw finisher equipped with a 0.040 inch sieve. The extruded pericarp is then pulped to form piure. 8.8 pounds of this piure is subjected to AC extraction and the extracted peel is dried to yield a peel product consisting of 1.23 pounds of dry solids. The extract is treated similarly to the method described in Example 1, from which essential oils and bioflavanoids are recovered and a sugar syrup product is obtained. Example 3 Raw pericarp prepared according to the method of Example 1 is subjected to alternating current solvent extraction by feeding it into an alternating current solvent extraction zone at a rate of 10 pounds per minute. 15 lbs/substantially undiluted methanol (>95%)
Feeding the extraction area at a rate of 1 minute. The extracted orange peel is removed from the extraction area at a rate of 4.5 lb/min (compressed weight) and the spent methanol is
Remove from extraction area at a rate of 20.5 lb/min.
The composition of each of these streams is as follows. [Table] The orange peel after extraction is treated in a manner similar to that described in Example 1 to obtain an orange peel powder having a composition corresponding to that shown in Table 1.

[Brief explanation of drawings]

The figure schematically illustrates the method of the invention for processing citrus fruit waste to produce various products. In the figure, 2 is a mill, 4 is a bleaching area, 6 is a screw finishing machine, 8 is a mixing area, 14 is an extraction area, 22 is a drying area, 24 is a grinding area, 28 is a separation area, 36 is a stripping area, and 40 is a stripping area. and 46 indicates an ion exchange region.

Claims (1)

[Scope of Claims] 1. A solution comprising a water-miscible non-aqueous solution selected from the group consisting of lower alcohols, lower ketones, and monoalkyl esters and dialkyl esters of ethylene glycol is supplied to a solvent extraction region to extract citrus peels. countercurrent solvent extraction of the pericarp with the solution such that the pericarp is in contact with the solution for a sufficient period of time to obtain an aqueous extract containing substantially all the sugars, essential oils and bioflavanoids present in the pericarp; A method for recovering useful products from citrus peels, characterized by separating the solvent-extracted peels from a solution and drying the solvent-extracted peels to obtain a solid product with a high content of cellulose and pectin. 2. The method according to claim 1, wherein the water-miscible non-aqueous solvent is methanol. 3. The method of claim 1, wherein the solution comprising a water-miscible non-aqueous solvent contains less than about 15% water by weight, based on the weight of the solution. 4. The method according to claim 1, wherein the citrus fruit is selected from the group consisting of oranges, grapefruits, lemons, limes and tangerines. 5. The method of claim 1, wherein the peel comprises orange peel. 6. Supplying a solution comprising a water-miscible non-aqueous solvent selected from the group consisting of lower alcohols, lower ketones, and monoalkyl esters and dialkyl esters of ethylene glycol to the solvent extraction zone to extract the substances present in the citrus peel. countercurrent solvent extraction of the pericarp with the solution such that the pericarp is in contact with the solution for a sufficient period of time to obtain an aqueous extract containing all the sugars, essential oils and bioflavanoids; A pericarp solid product rich in cellulose and pectin, produced by separating the pericarp and drying the solvent-extracted pericarp.