Process of extracting citrus fiber from citrus vesicles

ES 2 396 974 T3

DESCRIPTION

Citrus fiber extraction process from citrus vesicles

Field of the invention

The present invention relates to citrus fiber extracted from citrus vesicles. The resulting dried citrus fiber is useful as a food additive for beverages, baked goods, meat or meat emulsions, confectionery, jams and jellies, dairy products, dressings, energy bars, and the like.

Description of Related Art

Current processes for making citrus juice use extractors to separate the inner part of the fruit that contains the juice from its outer rind. The juice extracted by the extractors contains the juice itself as well as pectinaceous and cellulosic material called citric vesicles. Sometimes this material is also called thick pulp, floating bodies, citrus cells, floating pulp, juice bags, or pulp.

Typically, citrus vesicles are separated from the juice by filtration, using instruments such as paddle finishers, screw finishers, and turbofilters. Citrus vesicles contain a significant amount of soluble solids in the juice. For economic reasons, citrus vesicles are frequently subjected to a water washing step, using, for example, blenders, screw mixers, static inclined mixers, finishers or turbofilters. The water wash step produces a secondary quality juice stream, called Water Extracted Soluble Orange Solids (WESOS) or simply "pulp wash." The washed cells from this stage, also called "washed pulp", are considered waste. Typically, the washed cells are mixed with the bark (from the extraction process mentioned above), further processed (treated, for example, with lime to help extract water) and dried for use as forage.

Some attempts have been made to recover possibly valuable components from citrus residues. For example, US Patent 6,183,806 B1 to Ficca et al. describe citrus rind extracts and flour prepared from the extracts. The citrus peel is extracted with an ethanol solvent and the solid residue is desolventized to recover orange flour. Citrus rind is provided in pieces or in crushed particles. The crushed pieces or particles can be provided in the form of a washed pulp (pomace). Ficca uses the term “washed pulp” somewhat unconventionally to refer to pomace, a component of the rind. Ficca indicates that the orange flour extracted from the pomace is similar in composition to the flour obtained from the orange peel.

The washed citrus cells contain citrus fiber, a valuable citrus component that has a relatively high total dietary fiber content and a balanced ratio of soluble to insoluble dietary fiber. The balanced dietary fiber spectrum of insoluble (primarily cellulose) and soluble (primarily pectin) fiber is advantageous in physiological functionality over cereal-based fibers. Citrus fiber, particularly orange pulp fiber, has extremely high water binding capacity, resulting in high viscosities compared to other citrus fibers such as Vitacel orange fiber (available from Rettenmaier).

It would be desirable to develop a process for recovering citrus fiber from citrus vesicles, especially a process that can recover citrus fiber in an efficient and relatively cost-effective manner. It would be especially desirable to develop a process that can recover citrus fiber without the need for possibly toxic agents. It would be particularly desirable to develop a process that provides citrus fiber that can be used as an ingredient in food and beverages.

EP 0 179 295 A1 discloses a dietary supplement for use as an insoluble, indigestible fiber source comprising a solid oral dosage form comprising a fiber-containing raw material selected from the group consisting of mushroom meat and mushroom pulp. orange and combinations thereof, said raw material having been ground to give a homogeneous paste extracted with a physiologically acceptable dehydrating agent, Filtered or centrifuged to eliminate substantially all of this agent and the water contained therein, lyophilized and dry ground to give a particulate or powder form, said supplement comprising an amount of said indigestible insoluble fiber, sufficient to satisfy the needs of fiber in the diet of a human being and a method of preparing said dietary supplement. A method for the treatment of chronic constipation comprises administering to a patient in need of such treatment an effective amount, to treat constipation, of an oral solid dosage form comprising indigestible insoluble fiber from a source selected from the group of mushrooms, bark orange and combinations thereof, said fiber having been crushed until homogeneous, dried to eliminate substantially all the water contained in its interior, extracting with a physiologically acceptable dehydrating agent, filtering with sand at

ES 2 396 974 T3 reduced pressure and lyophilizing.

Document SU 1556681 refers to a method of processing dried residues resulting from the squeezing of citrus fruits, but is not related to the extraction of citrus pulp fibers from washed vesicles. Instead, this document refers to the extraction of vitamins from dry material.

DE 199 43 188 A1 relates to a method for increasing the water-binding capacity of dietary fibers in which plant constituents are disintegrated in an acidic or alkaline environment by providing heat and subsequently washed with alcohol. The residual matter resulting from fruit or vegetable processing can be used, for example, as a plant constituent. The invention also proposes the use of said dietary fibers

Summary of the invention

According to one aspect, the present invention refers to a process for purifying citrus fiber in citrus vesicles to obtain a food additive suitable for human consumption, as described in claim 1. The process comprises a washing step with water of citrus vesicles to remove unpleasant flavors, odors, colors, sugars, acids and the like. The vesicles are contacted with an organic solvent to obtain vesicles washed with the organic solvent. The vesicles washed with the organic solvent are desolventized and dried citrus fiber is recovered from them.

In a preferred embodiment of the invention, the extraction process employs a weight ratio of ethanol solvent to solid solvent of at least 0.25: 1, preferably at least about 0.5: 1. The solvent extraction is carried out in at least two countercurrent phases. At least a part of the solvent, preferably at least 70%, is recovered and reused.

In one embodiment, the dried citrus fiber prepared by the extraction process, as described above, has a total dietary fiber content of about 60 to about 80% by weight and a water binding capacity of about 7 to about 12 (p / p). Preferably the total dietary fiber content is at least about 70% by weight and the water binding capacity is at least about 8 (w / w).

In another aspect of the present invention, the dried citrus fiber is prepared by the extraction process, as described in claim 1. The dried citrus fiber has a total dietary fiber content of 60 to 85% by weight and a capacity of water binding of 25 (w / w). Dried citrus fiber is useful as a food additive for food products such as beverages, baked goods, meat or meat emulsions, confectionery, jams and jellies, dairy products, such as yogurt, dressings, energy bars, and the like.

Brief description of the drawings

The objects, features, and advantages of the invention will be apparent from the following more detailed description of certain embodiments of the invention and as illustrated in the accompanying drawings in which:

Figure 1 is, in accordance with a preferred embodiment of the present invention, a schematic illustration of a two-stage countercurrent solvent extraction process.

Detailed description of the invention

First, the present invention will be described with reference to the extraction of orange fiber from orange vesicles. It should be understood that the process can be used to extract citrus fiber from citrus vesicles of a wide variety of other types of citrus fruit, non-limiting examples of which include tangerines, limes, lemons, and grapefruit. Typically, citrus vesicles have a water content of at least about 80% by weight and typically from about 90 to about 97% by weight.

The term "citrus vesicles", as used herein, refers to pectinaceous and cellulosic material contained in the inner part of the citrus fruit that contains the juice. Citrus vesicles are sometimes also referred to as thick pulp, floating bodies, citrus cells, floating pulp, juice bags, or pulp.

The term "water-extracted soluble solids" as used herein refers to secondary grade juice, which is obtained by washing citrus vesicles with water. The term "water-extracted soluble solids" particularly includes water-extracted soluble orange solids (WESOS). Soluble solids extracted with water are sometimes referred to as "pulp washing."

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The term "water-washed vesicles" refers to citrus vesicles from which soluble solids extracted with water have been removed by washing with water. Vesicles washed with water are sometimes referred to as "washed cells or washed pulp."

The term "citrus fiber", as used herein, refers to a fibrous component obtained from vesicles washed with water and isolated from the residual components present therein. Citrus fiber is characterized by a high total content of dietary fiber as well as a balanced ratio of soluble to insoluble dietary fiber. Citrus fiber, particularly orange fiber, has a very high water binding capacity.

Citrus fiber, compared to citrus flour obtained from citrus rind, is lighter in color and relatively lacking in taste and odor. On the other hand, citrus flour obtained from citrus peel is characterized by an orange peel taste, smell and color, which greatly limits the uses of the product. Other advantages of citrus fiber include a high total dietary fiber content (eg, greater than about 70% vs. 58%); lower carbohydrate content (eg, about 5% vs. 15%); and a higher water binding capacity (eg, greater than about 8 grams of water per gram of fiber versus 5.5 g / g). Typically, the protein content of citrus fiber ranges from about 8 to 12% by weight.

The ratio of soluble to insoluble dietary fiber is an important factor in the functionality of dietary fiber Preferably, citrus fiber has a balanced ratio of soluble to insoluble dietary fiber. For example, total dietary fiber is preferably about 45-50% soluble dietary fiber and 50-55% insoluble dietary fiber. Other important considerations include the degree of grinding (grain size) and drying (drying process) conditions. Generally, a higher degree of grinding (that is, a finer grain size) offers, in foods and beverages, a greater sensation of smoothness of the fiber on the palate. Density and particle size can vary over a wide range depending on processing conditions. As an example, the density can range from about 80 to about 650 g / L, and the mean particle size can range from about 15 to about 600 microns. It should be understood that these ranges are offered as an example only. For example, in some applications it may be desirable to employ significantly larger particle sizes. In general, citrus fiber can range from a very fine structure to a coarse powder.

As shown schematically in Figure 1, the orange vesicles can be separated from the orange juice by filtration, using, for example, a conventional filtration instrument 10 such as paddle finishers, screw finishers or turbofilters. The orange vesicles can then be subjected to a water washing step using a suitable instrument 20 such as blenders, screw mixers, inclined static mixers, finishers or turbofilters. Washing with water is desirable to remove undesirable flavors, odors, and acids present in citrus vesicles. The water wash step 20 produces a stream of water extracted orange soluble solids (WESOS). The soluble orange solids extracted with water, together with the juice obtained by filtration 10, can be further processed using a conventional juice extraction instrument 15.

To extract the flavors, odors, colors, and the like, from the water-washed vesicles, an organic solvent is used. The solvent must be polar and water-miscible to facilitate removal of the desired components. Preferred solvents include lower alcohols such as methanol, ethanol, propanol, isopropanol, or butanol. The solvent can be provided (and preferably is provided) in aqueous solution. The solvent concentration in the solvent solution most often ranges from 70% by weight to about 100% by weight. In one embodiment, a 75% by weight aqueous ethanol solution is used as the solvent. In a preferred embodiment, a 90% by weight aqueous ethanol solution is used as the solvent. In general, solvents will remove water soluble components at lower concentrations and oil soluble components at higher concentrations. Optionally, to enhance the recovery of oil soluble components in citrus vesicles, a more nonpolar cosolvent may be added to the aqueous alcohol. Examples of such nonpolar solvents include ethyl acetate, methyl ethyl ketone, acetone, hexane, methyl isobutyl ketone, and toluene. Solvents that are more nonpolar can be added up to 20% of the solvent mixture. Many solvents, such as ethanol, have a lower heat of evaporation than water and therefore require less energy than is necessary to volatilize than to volatilize an equivalent body of water. Preferably the solvent is removed and recovered for reuse.

Preferably, the water-washed vesicles are contacted with organic solvent at a solids to solvent weight ratio of at least 0.25: 1, preferably at least about 0.5: 1, and frequently at least about 0 , 75: 1, from about 1: 1 to about 5: 1, or from about 1.5: 1 to about 3: 1, based on the wet weight of the solids. In one embodiment, the solids to solvent ratio is about 2: 1.

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The extraction can be achieved using a single phase but is preferably carried out using multiphase extraction, for example a two, three or four phase extraction process, and preferably using countercurrent extraction. There is no particular upper limit on the number of extraction stages that can be used. Figure 1 schematically illustrates a preferred embodiment in which a two-phase countercurrent extraction process employs a first and a second solvent extractor 25a and 25b, respectively.

The water-washed vesicles are supplied into the second extractor 25b. In the first solvent extractor 25a an aqueous ethanol solvent is supplied from a solvent tank 26. The used solvent from the first solvent extractor 25a is supplied to the second solvent extractor 25b, while the citrus vesicles extracted from the second solvent extractor 25b are supplied to the first solvent extractor 25a. The used solvent from the second solvent extractor 25b can be supplied to an evaporator 35 (optional) to separate solids (eg, sugars, colors, flavors, citrus oils, etc.) from the used solvent, which can be condensed and reincorporated into a Still 24. Distillation sludge (predominantly water) is separated and removed.

After each extraction phase, a band filter press (not shown) is preferably used to remove other liquids. A belt filter press can be constructed in a conventional manner known to those skilled in the art. Details of suitable band filter presses are found, for example, in US Patents 4,236,445, 4,297,215 and 5,022,989.

The solvent-washed vesicles from the first solvent extractor 25a are delivered to a desolventizer 30. The desolventizer 30 removes solvent and water from the solids remaining after extraction, allowing recovery of the solvent for future use and also ensuring that the product be safe for grinding and commercial use. Desolventizer 30 can employ indirect heat to remove significant amounts of solvent from solid waste. Alternatively, direct heat can be provided for drying, for example by providing hot air from ultra dryers or fluid bed dryers. If desired, direct current can be employed to remove any trace solvent remaining in the solids. Preferably, to recover at least a portion of the solvent, the vapors from desolventizer 30 are recovered and delivered to still 24.

The retention time in each extraction stage is less than or equal to 5 minutes and is preferably approximately less than or equal to 3 minutes. The temperature in the solvent extractor (s) depends on factors such as the type of solvent used but more frequently ranges from about 4.44 ° C (40 ° F) to about 82.2 ° C (180 ° F) to atmospheric pressure. Temperatures can be raised or lowered appropriately to perform operations at super or sub atmospheric pressures. Optionally, techniques such as ultrasound are used to enhance the efficiency of the extraction process. By maintaining a closed system, solvent losses during extraction, desolventization and distillation can be minimized. Preferably, at least 70% by weight of the solvent is recovered and reused. A solvent stream delivers fresh solvent to solvent tank 26 to replenish any solvent that has not been recovered.

The dried orange fiber product is generally a coarse flour. The flour can be ground if a powder is required for a particular application. Optionally, the citrus fiber is subjected to one or more additional treatments necessary or desired for a particular end use. For example, prior to performing the solvent extraction or drying process, natural enzymes can be inactivated. The enzymes can be inactivated, for example, by ultrasound or by conventional heat inactivation.

Unlike many typical commercial fibers, the orange fiber of the present invention has a coarser powder, creates pulpy textures (coarse fraction), and has good stability. For example, citrus fiber can be used for a 1% sucrose replacement in a conventional bakery cream recipe with improved cooking stability and good freeze / thaw stability. This indicates an extremely high water binding capacity of the orange fiber, resulting in relatively high viscosities.

The high water binding capacity can be beneficial for many applications (eg, processed meat applications). In other applications, such as bakery, a high water-binding capacity may not be desirable. Extremely fine milled fibers (eg, 20-30 pm particle size) will generally show superior sensitivity characteristics (greater softness).

In addition to being useful as a food additive in beverages, baked goods, meat or meat emulsions (for example, sausage, mortadella, hot dogs), confectionery, jams and jellies, dairy products, dressings, energy bars and the like, citrus fiber also it can possibly be used as a natural thickening agent for food products, such as yogurt or as a vehicle for other components in beverage systems. Adequate amounts of citrus fiber for various food products can be determined by an expert in

ES 2 396 974 T3 technique according to factors such as consumer preferences and only with the aid of routine experimentation.

Example 1

This example illustrates the extraction of citrus fiber from water-washed vesicles using a 75% by weight aqueous ethanol solvent solution in a two-stage countercurrent extraction process as described above. The resulting orange fiber was analyzed for dietary fiber content using the AOAC 991.43 method (Prosky). It was observed that the citrus fiber had the composition and properties shown in Table 1:

TABLE 1

<td>Total dietary fiber (TDF)</td><td> 72,3%</td>

<td>Soluble dietary fiber (SDF)</td><td> 37,1%</td>

<td>Insoluble dietary fiber (IDF)</td><td> 34,4%</td>

<td>Carbohydrates</td><td> 5%</td>

<td>Proteins (dry)</td><td>1.6% N (9.7% protein)</td>

<td>Fatty acids (dry)</td><td> 0,16%</td>

<td>Ashes</td><td> 2,14%</td>

<td>Sodium</td><td>102 mg / kg</td>

<td>Potassium</td><td>4960 mg / kg</td>

<td>Magnesium</td><td>648 mg / kg</td>

<td>Calcium</td><td>1850 mg / kg</td>

<td>Phytic acid</td><td>479 ppm</td>

<td>Humidity</td><td> 11%</td>

Example 2

This example illustrates the preparation of bread that contains orange fiber. Table 2 lists the ingredients used to prepare the bread:

TABLE 2

<td>Ingredient</td><td>Amount (g)</td>

<td>Duo flour (Ceres)</td><td> 950</td>

<td>Orange pulp fiber</td><td> 30</td>

<td>Bread enhancer</td><td> 100</td>

<td>Salt</td><td> 17</td>

<td>Margarine</td><td> 20</td>

<td>Water</td><td> 551</td>

All ingredients were dry blended in a spiral mixer (Veema type). Then water was added, and the resulting mass was mixed for 20 minutes. The dough was divided into 700 gram portions. Consolidation and fermentation were carried out for 1.5 hours at 32 ° C and a relative humidity of 82%. The bread was baked in a platform oven at 220 ° C for 35 minutes.

Example 3

This example illustrates the preparation of a dressing (30% oilseed type) containing orange fiber. Table 3 lists the ingredients used to prepare the dressing:

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TABLE 3

<td>Ingredient</td><td>Amount (% by weight)</td>

<td>Sugar</td><td> 3</td>

<td>Salt</td><td> 2</td>

<td>Potassium sorbate</td><td> 0,12</td>

<td>Water</td><td> 49,8</td>

<td>Oil</td><td> 12</td>

<td>Orange fiber</td><td> 3</td>

<td>Powdered egg yolk</td><td> 1,5</td>

<td>Xanthan gum + guar gum</td><td> 0,2</td>

<td>Sunflower oil</td><td> 18</td>

<td>Vinegar</td><td> 7,2</td>

<td>Mustard</td><td> 3</td>

The water and the acid phase were added in a Fryma colloid mill. The dispersion phase was then added and homogenized for 30 seconds. The oil phase was added after one minute and the mixture was emulsified for a further 30 seconds. The dressing was then poured into jars.

Example 4

This example illustrates the preparation of a beef patty that contains orange fiber. Table 4 lists the ingredients used to prepare the beef patty:

TABLE 4

<td>Ingredient</td><td>Amount (% by weight)</td>

<td>Veal (minced)</td><td> 90</td>

<td>Spice</td><td> 1,5</td>

<td>Orange fiber</td><td> 1,5</td>

<td>Water</td><td> 7</td>

All ingredients (except spices) were mixed in a Hobart type N50CE mixer at speed 1. The 10 spices were added 30 seconds later. The mixture was mixed up to 5 minutes by turning the dough manually after 2.5 minutes. The dough was chilled in a refrigerator for 2 hours. The hamburgers were molded into 90 g portions with a diameter of 80 mm. The hamburgers were fried in a frying pan to a core temperature of 74-75 ° C.

Example 5

This example illustrates the preparation of a marmalade containing orange fiber. Table 5 lists the ingredients that can be used to prepare the jam:

TABLE 5

<td>Ingredient</td><td>Amount (% by weight)</td>

<td>Mixed berries (berries, frozen) or strawberries</td><td> 43</td>

<td>Saccharose</td><td> 25</td>

<td>Fructose syrup</td><td> 25</td>

<td>Orange fiber</td><td> 2</td>

<td>Water</td><td> 5</td>

<td>Citric acid solution (50%)</td><td>up to a pH of 3.4</td>

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Fruit, sweeteners, and water can be mixed and cooked together. The orange fiber can then be added and boiled to provide the desired dry substance. The citric acid solution can then be added until the mixture reaches a pH of 3.4. The jam can be placed hot in glass jars.

Example 6

This example illustrates the preparation of energy bars. Table 6 lists the ingredients used to prepare the energy bars:

TABLE 6

<td>Ingredient</td><td>Amount (% by weight)</td>

<td>Fructose syrup</td><td> 14</td>

<td>Saccharose</td><td> 8</td>

<td>Isomaltulose (Cerestar Cargill)</td><td> 15</td>

<td>Water</td><td> 3</td>

<td>Glycerol</td><td> 3</td>

<td>palm butter</td><td> 7</td>

<td>Orange fiber</td><td> 3</td>

<td>Red fruit nuggets</td><td> 15</td>

<td>Lecithin</td><td> 1</td>

<td>Oatmeal</td><td> 13</td>

<td>Soya nuggets</td><td> 11</td>

<td>Whey powder</td><td> 7</td>

The sweeteners and water were heated in a frying pan to 88 ° C. The melted fat and lecithin were mixed in a Hobart mixer for 1 minute at speed 1. The sweetener was added to the fat and mixed on speed 10 for 1 minute. The ingredients were added dry and mixed at speed 1 for 30 seconds. The mixture was deposited on a sheet and cut to the desired size. The bars were then cooled and packaged.

Although particular embodiments of the present invention have been described and illustrated, it should be understood that the invention is not limited thereto as modifications may be made by those skilled in the art. The present application contemplates any and all modifications that are within the scope of the underlying invention described and claimed herein.