JPH0697954B2 - Citrus peel-derived product and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating solid waste derived from citrus fruits to produce a useful product, and the product.

[0002]

BACKGROUND OF THE INVENTION In recent years, one of the major problems encountered in the production of citrus products such as orange juice, orange concentrate and orange section has been in the treatment of various waste products including orange peel, shreds and pulp. For many years, these were considered of little practical value and were therefore simply discarded without any treatment.

However, in recent years it has been found that further processing of some of these wastes (eg pericarp) can produce a superior and nutritious cattle feed. Disadvantageously, the utilization of these treatment wastes has partially alleviated the waste treatment problem, but treating the wastes to produce cattle feed is less than desirable. It wasn't economically attractive.

[0004] Recently, therefore, efforts have 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 take full advantage of the raw materials contained therein.

Disadvantageously, it is not easy to dispose of waste to meet such purposes. For example, US Pat. No. 2,215,944 discloses a method of treating orange peel with lime to obtain a product suitable for use as cattle feed. However,
This method is not advantageous as the use of lime gives a bitter product. Furthermore, the pectin present in the peel is destroyed or degraded during the treatment with lime, thus losing one of the useful skin components from the point of view of human and animal use. However, the pericarp is so sticky that it is difficult to process without the use of lime or related substances (eg magnesium- or aluminium-containing compounds). Further, the cell structure of the pericarp is likely to be always altered by contact with a substance such as lime, so that the pericarp after treatment is also difficult to dry.

In addition, the peel contains substantial amounts of various sugars which it is desirable to remove from the peel to reduce the caloric content of the final product. Sugars are very hygroscopic and, if present in significant amounts, tend to make drying the pericarp after treatment even more difficult. The pericarp further contains a significant amount of essential oils (ie, natural volatile oils) that are a component of the perfume aroma and / or flavor. Essential oils are preferably removed from the peel because they provide a bitter or unpleasant taste.

[0007] As an alternative to the lime treatment method, the waste skins have been washed with water to remove some of the sugars and unpleasant tastants. However, most of the essential oils present cannot be removed by such washing with water. Carotenoid pigments are also present in the product, and after a short period of time they are oxidized to give an unpleasant "hay-like" odor.

[0008] Washed products are also difficult to compact to remove excess water. Therefore, the final product generally contains unreasonably high amounts of water (eg 85% by weight or more) and tends to be expensive to dry the product. In addition, additional waste is produced in the form of wash water, which is difficult to process because it contains sugars and other pericarp-derived components extracted from the pericarp.

Therefore, it is desirable to provide an improved process for treating waste from processing oranges to produce a variety of useful products and products suitable for human and animal use. Further, it is desirable to provide a method that is more economically attractive and efficient than the methods commonly used in the orange processing industry.

Furthermore, in recent years it has been found that certain pericarp components, such as pectin, have properties that can be used advantageously to control serum cholesterol. Such advantages can be seen in recent literature such as The Tampa
Tribune Times , April 30, 1978, 3-E
Page; Food Produce Devlopment , April 1978,
81-88; Sarasota Herald-Tribune , 1977.
August 6, pp. 9-C; Bradenton Herald, 1978.
July 19, pp. 6-C; St. Petersburg Times , 1
22-B, Oct. 16, 977; The Tampa T.
ribune , Aug. 6, 1977, pages 7-B; The Che Chemu
rgic Digest, May 15, 1944, 119-121
Reported on page.

Pectin is further disclosed in the patent literature in view of its various therapeutic effects. For example, US Pat. Nos. 2,139,139 and 2,145,016,
No. 2,294,016, No. 2,333,950
No. 2,481,804, No. 2,481,80
No. 5, No. 2,865,757, No. 3,190,7
56 and 3,306,819.

[0012]

DETAILED DESCRIPTION OF THE INVENTION The method of the present invention will be described in connection with the drawings. Citrus fruits are commonly used in this invention and include oranges, grapefruits, lemons, limes and tangerines. However, for convenience of explanation, consider the orange peel. According to the method of this invention, waste orange peel is used which consists of waste products from conventional processes such as processing oranges to produce orange juice. The peel is fed to a suitable crusher 2, such as a hammer mill, and is crushed here. The peel is
Crush it to the extent that it is practically dismantled.

The crushed orange peel is then preferably passed through a steam bleaching zone 4 where it is contacted with steam for several minutes and subsequently extruded and treated in a screw finisher 6. The peels are contacted with steam for 5 to 15 minutes in the steam bleaching area, which softens them and makes them easier to adapt to the extrusion process in a screw finisher. The screw finisher removes seeds, stalks, or leaves contained in the waste skin and crushes the skin further into finer pieces. Naturally, the more finely the pericarp is crushed, the more efficient the solvent extraction process is.

As mentioned above, it is not essential to combine the steam bleaching stage with the extrusion treatment stage, but it is suitable for the process of treating orange peel. Fortunately,
These steps make the pericarp susceptible to extraction with various types of aqueous or non-aqueous liquids (e.g., water, lower alcohols, lower ketones, etc.), so that different types of citrus peel (e.g., grapefruit peel, Enhance the extraction process of lemon peels, lime peels, etc.).

The use of a screw finisher is not essential to the practice of this invention and the crushed peel from the mill 2 can be passed directly through the mixing zone 8. The pericarp is then introduced into the 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 liquid 10 from the solvent extraction step, which results in a slurry. To generate. The slurried pericarp extrudate 12 is solvent extracted in the extraction area 14. Here the pericarp extrudate is contacted with a sufficient amount of non-aqueous solvent 16 to effect the desired degree of extraction.

To be suitable for use in the method of this invention, the non-aqueous solvent must be water miscible. Sugar must also be dissolved in the aqueous solvent solution. The solvent preferably has a relatively low boiling point so that the solvent can be easily recovered from the aqueous solution. In order to further facilitate the recovery of the solvent, it is preferred that the solvent does not form an azeotrope with water.

Suitable non-aqueous solvents for use in this invention include lower alcohols such as methanol, ethanol, propanol, or isopropanol; lower ketones such as dimethyl ketone, methyl ethyl ketone; and mono- and dialkyl ethers of ethylene glycol, or These esters such as acetyl esters are included. 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 insecticides that may be present in the peel. The above-mentioned suitable solvents are not all, and those skilled in the art can easily determine a non-aqueous solvent suitable for use in the present invention.

The extruded skin is contacted in the extraction zone 14 by any method and for a time sufficient to extract all of the desired ingredients from the skin. Although a multistage 18 countercurrent extraction is shown in the figure, a batch solvent extraction operation is also suitable and in this method,
The advantages achieved by the invention are not diminished.
However, countercurrent extraction is the preferred extraction method.

Non-aqueous solvent 16 supplied to the countercurrent extraction region 14
It should be noted that is preferably substantially undiluted (ie, substantially non-aqueous or of commercial grade in purity). The solvent may be introduced from an external source, or it may be a solvent fraction that is recycled from the next process step, as will be described in more detail below. The solvent can be diluted with a small amount 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-like skin is contacted with the solvent 16 in the final stage of the countercurrent extraction zone, the essential oil and oil-soluble components present in the skin (eg carotene, chlorophyll, flavanone etc.) are extracted therefrom. Water is gradually removed from the pericarp as the solvent passes through successive stages in the extraction zone.

Water-soluble components present in the peel as the water content of the extract increases (eg various sugars, citric acid,
Some salts) are also removed. Removal of essential oils with a strong aroma from the peel allows the production of a product from the treated peel which can be used for a wide range of applications without being disturbed by the presence of a strong orange odor.

The solvent-extracted pericarp 20 exiting the extraction zone 14 contains little sugar, less essential oil (less than about 0.005% by weight on dry solids), and is substantially protopectin (ie. Cellulose and pectin). The concentration of sugar originally 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, dried pericarp usually contains about 30% or more pectin by weight. It is important that the water retention capacity of the peel is not compromised by the extraction process.

The solvent-extracted pericarp 20 is then dried by any suitable means, such as by contact with superheated solvent vapor to remove residual solvent and moisture. To ensure substantially complete removal of solvent and / or water,
Additional drying of the pericarp is performed in a vacuum. The dried, solvent-free peel product is then ground in a grinding area 24 by suitable means such as a hammer mill to a size suitable for its intended use as exemplified below. For example, the engineered skin is advantageously ground using an ultrafine grinder to an extent sufficient to pass through a 80 mesh screen, the milled skin being used for storage or shipping. Bag it.

The solvent-extracted peel products of this invention are conveniently free of sugars, low in ether-extracted substances such as essential oils, lipids, fats and carotenoid pigments, and substantially protopectin (cellulose). And pectin)). The amount of ether extract present in the peel is AOAC method No. 7.056 (direct method) or N
o. It is measured by 7.057 (indirect method). More specifically, the peel product contains less than about 5% by weight sugar and about 0.6%.
Contain less than wt% solids that can be extracted with ether.

The essential oil (which is one of the substances that can be ether extracted) content in the peel product is preferably less than about 0.01% by weight, and most preferably less than about 0.005% by weight. The pectin present in the pericarp was virtually unaffected by the extraction process, and as a result, US, Minnesota 5
5427, Minneopolis, Primos Ave
9000, Medallion Laboratories (Medallion
Pericarp, as measured by Laboratories), generally has greater than about 30% by weight pectin, and preferably 33%.
It contains more than wt% pectin.

According to the method of the present invention, a solvent-extracted citrus peel is produced which has the effect of reducing and / or controlling serum cholesterol when administered orally to patients with unduly high levels of serum cholesterol. In order to achieve the intended reduction and / or control of the patient's serum cholesterol, the amount of pectin in the form of the peel product of this invention of about 15 g or less daily, although the amount required for each patient may vary significantly. It is necessary to administer a dose.

The peel products of this invention can be applied directly to various food products by various means, for example in the form of hard or soft capsules, compressed into tablets, or in the form of particles, together with an inert diluent or an edible carrier. By mixing, it can be administered orally. Capsules and tablets will generally contain about 0.5 g.

Although not intended to be adhered to, the pectin-containing peel product of the present invention provides a minimum because pectin is not administered by itself, but with a significant amount of fiber also contained in the peel. It is believed that it can be administered only with the side effects of. It is believed that the presence of fibers enhances the body's resistance to the presence of pectin and reduces the incidence of bowel upset and the like.

The liquor 26 withdrawn from the brewing zone contains some orange peel-derived compounds, which are eventually separated from the liquor to give additional useful products. Most of the extract consists of non-aqueous solvents (eg 60-
65% by weight). Other components present include alcohol-soluble components such as essential oils, of which d-limonene is predominant, bioflavanoids such as hesperidin, carotenoid pigments, and chlorophyll.

In order to separate the essential oils and other alcohol soluble components from the extract, the extract is fed to a separation zone 28 where it is substantially provided by externally supplied water 30 or recycled solvent removal extract 32. Top dilute. Appropriate dilution makes the alcohol-soluble essential oil present (along with chlorophyll and carotenoid pigments) insoluble, resulting in the formation of an emulsion. The essential oil is allowed to flocculate and can be easily removed from the extract as a separated highly colored product 34 by suitable means such as centrifugation, which highly colored product 34 also contains chlorophyll and carotenoid pigments. The chlorophyll and carotenoid pigments can then be removed from the essential oil by distillation, if desired.

Generally, the amount of aqueous diluent that needs to be added to the extract to effect proper separation of the soluble oil is about 15% by weight or more based on the extract and most preferably about 20% by weight. . However, it is only necessary to add sufficient diluent to ensure the proper separation of the essential oil without over-diluting the extract with the aqueous solution. The addition of excess diluent does not adversely affect the separation of oil from the extract, but results in unnecessary loading of each separation device downstream of the separation zone 28.

It is quite surprising that the alcohol-soluble essential oil is easily insoluble by diluting the extract with an aqueous diluent. In general, separating essential oils from such solutions by such means as fractional distillation is very difficult due to the azeotropic nature of the solution. However, it has been found that by diluting the extract with an aqueous diluent, the essential oil in solution is released from the solution, which can then be separated by suitable means such as centrifugation.

Next, the solvent remaining in the extract is removed in the stripping zone 36 by a suitable means such as steam distillation. Solvent recovered from the extract 38
Can be recycled to the extraction area 14 for separate treatment of the waste skin. After removing the non-aqueous solvent from the extract,
Due to the decrease in the solvent concentration in the extract, the residual orange peel-derived bioflavanoids become insoluble and precipitate from the solution. Therefore, the bioflavanoid can be easily recovered as the separated product 42 by filtration in the filtration region 40.

A portion of the solvent-free and filtered extract 44 is used as the aqueous diluent 32 in the centrifuge zone 28.
Can be recycled. However, the balance of the extract can be further processed into a refined sugar syrup product.

Particularly, the rest of the extract is the ion exchange region 46.
Through, residual impurities can be removed. Preferably, the extract is passed through a strong acidic ion exchange resin, a weak basic ion exchange resin, and a weak acidic ion exchange resin one after another. And the extract is an activated carbon bed (not shown)
Can be further purified through. As a result of this purification process, an extract 48 in the form of a sugar syrup is produced, which basically consists of an aqueous solution of sucrose, glucose, lebroth and trace impurities.

Thus, the method of the present invention allows the production of various products having many uses. The treated pericarp has a substantial water retention capacity,
It can be used as a thickener, emulsifier or stabilizer. For example, a finely powdered peel product can be used as a viscosity enhancer for drilling mud, a coagulant for removing solids from a cloudy solution in sugar production, and the like.

Finely powdered peel products include bread, doughnut,
It can be used to preserve the freshness and moisture of baked products such as cakes and cookies. The treated pericarp suppresses spoilage by inhibiting the development of filamentous fungi. Generally, an amount in the range of about 1 to 3% by weight, based on the weight of the baked product, is sufficient to obtain the desired results. The sugar syrup products can be used as totally natural sweeteners in suitable foodstuffs such as fruit juices, baked goods and the like.

Example 1 640 pounds of orange peel is crushed with a hammer mill to a maximum particle size of about 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% by weight methanol. The extraction solution is circulated between the crushed orange peels for about 15 minutes, after which the peels are removed for about 1250 to 1
Contact with 300 pounds of a solution containing methanol. 1
At the end of the 5 minute extraction time, the extraction solution is approximately 67-7.
It contains 2% by weight of methanol.

The above procedure was repeated using 1250-1300 lbs of fresh methanol to give 89-92%
An extraction solution of methanol is obtained. The above procedure is repeated again using 1250-1300 lbs of fresh methanol to obtain an extract of 96-98% methanol. The orange peel is taken out from the extraction tank, naturally drained, and dried by a steam tube dryer to obtain orange peel powder. The orange peel powder product has a light yellowish brown color, and is 1 per 1 g of the powder.
It consists of about 96 pounds of finely ground orange peel which has the ability to hold 0.6 g of water. Representative analytical values (dry matter basis) of the main components of the orange peel powder product are shown in Table 1 below.

Table 1 Composition of orange peel powder of Example 1 (% by weight) Crude fiber 18.20 Acid washed fiber 26.6 Protein 5.92 Neutral washed fiber 27.7 Water 5.12 Pectin 32.0 Fat (Acid decomposition) 2.15 Pentosean 26.4 Ash 3.48 Fructose 0.87 Sucrose 1.79 Glucose 0.84

Next, 12 used for extraction of orange peel
The mixing of 50-1300 lbs of solution (i.e., the extract) with the fully solvent-extracted extract causes clouding of the mixture. This indicates that the essential oil present was released from the solution and that an emulsion was formed. This mixture is centrifuged to separate the oily fraction from the extract. This oily fraction is distilled under a vacuum of absolute 5 mmHg to obtain a colorless and transparent citrus oil having a pleasant odor, and a solid residue containing carotenoid pigment and chlorophyll.

Methanol is separated from the rest of the diluted extract by steam stripping. The crude hesperidin, which is insoluble due to the removal of methanol, is recovered by cooling and filtering the extract from which the solvent has been removed.

The solvent-removed extract was treated with a strongly acidic ion exchange resin IR120 [Rohm and Haas (Rohm an
d Hass)], weakly basic ion exchange resin A-37 [Diamond Alkali (Dia
mond Alkali)], an ion exchange column containing a weakly acidic ion exchange resin IR84 (made by Rohm and Haas), and an activated carbon bed. The concentration of the liquid thus obtained is adjusted to Brix 65 to obtain sugar syrup.

Example 2 An aliquot of orange peel is collected on a drum and contacted with steam for about 10 minutes until softened. Next, the softened pericarp is passed through a screw finisher equipped with a 0.040 inch sieve. Then, the extruded skin is pulped to form puree. 8.8 lbs of this puree was subjected to an alternating extraction and the extracted pericarp dried and
A peel product consisting of 23 pounds of dry solids is obtained. The extract is treated in the same manner as described in Example 1, from which the essential oil and bioflavanoids are recovered and a sugar syrup product is obtained.

Example 3 A raw fruit peel prepared according to the method of Example 1
The AC solvent extraction is applied by feeding to the AC solvent extraction zone at a rate of minutes. Substantially undiluted methanol (> 95%) is fed to the extraction zone at a rate of 15 lbs / min. Extracted orange peel is removed from the extraction area at a rate of 4.5 pounds / minute (compressed weight) and spent methanol is removed from the extraction area at a rate of 20.5 pounds / minute. The composition of each of these streams is as follows.

Table 2 Composition of feed and product streams during AC extraction Raw material Orange peel water 7.5 lbs Insoluble solids 1.5 lbs Soluble solids 1.0 lbs total 10.0 lbs Orange peeled water after extraction 0.2 lbs insoluble solids 1.5 lbs soluble solids traces 2.8 lbs total methanol 4.5 lbs Spent alcoholic water 7.3 lbs soluble solids 1.0 lbs methanol 12.2 lbs total 20. Five pounds of the extracted orange peel is treated in the same manner as described in Example 1 to obtain orange peel powder having a composition corresponding to that shown in Table 1.

[Brief description of drawings]

FIG. 1 is a schematic representation of the method of the present invention for treating citrus peel-derived waste to produce various products.

[Explanation of symbols]

 2 ... Mill 4 ... Bleaching area 6 ... Screw finishing machine 8 ... Mixing area 14 ... Extraction area 22 ... Drying area 24 ... Grinding area 28 ... Separation area 36 ... Stripping area 40 ... Filtration area 46 ... Ion exchange area

Claims (8)

[Claims] 1. A citrus peel containing a solution containing a lower alcohol, a lower ketone, and a water-miscible non-aqueous solvent selected from the group consisting of mono- and dialkyl esters of ethylene glycol in a citrus peel. Is obtained by countercurrent solvent extraction of the pericarp with the solution such that the pericarp is contacted with the solution for a sufficient time to obtain an aqueous extract containing substantially all sugars, essential oils and bioflavanoids present in The essential oil contained in the extract is insolubilized by diluting the extract with an aqueous diluent, the essential oil is separated from the extract, and the nonaqueous solvent is removed from the extract to remove the non-aqueous solvent. The bioflavanoids present in the insolubles, separating the insolubilized bioflavanoids from the extract,
A sugar syrup product is obtained by purifying this extract, which is a method for producing a citrus peel product. 2. The method according to claim 1, wherein the water-miscible non-aqueous solvent is methanol. 3. A solution comprising a water-miscible non-aqueous solvent,
The method of claim 1 comprising less than about 15% by weight water, based on the weight of the solution. 4. The citrus fruit is orange, grapefruit,
The method of claim 1 selected from the group consisting of lemon, lime and tangerine. 5. The method according to claim 1, wherein the essential oil is separated from the extract by centrifugation. 6. The method according to claim 1, wherein the bioflavonoid is separated from the extract by filtration. 7. The method of claim 1 wherein said peel comprises orange peel. 8. A solution containing a lower alcohol, a lower ketone, and a water-miscible non-aqueous solvent selected from the group consisting of mono-alkyl esters and di-alkyl esters of ethylene glycol is supplied to the solvent extraction zone to produce citrus peels. Is obtained by countercurrent solvent extraction of the pericarp with the solution such that the pericarp is contacted with the solution for a sufficient time to obtain an aqueous extract containing substantially all sugars, essential oils and bioflavanoids present in The essential oil contained in the extract is insolubilized by diluting the extract with an aqueous diluent, the essential oil is separated from the extract, and the nonaqueous solvent is removed from the extract to remove the non-aqueous solvent. Bioflavanoids present in water are insolubilized and insoluble bioflavanoids are separated from the extract,
And sugar syrup product manufactured by purifying this extract.