Process of extracting citrus fiber from citrus vesicles

[0001] The present invention relates to citrus fiber.

citrus fiber] extracted from citrus vacuoles [ang. citrus vesicles]. The obtained dried citrus fiber is useful as a food additive (for beverages, bakery products, meat or meat emulsions, confectionery, jams and jellies, low-fat products , dressings, energy bars and the like).

DESCRIPTION OF THE PRIOR ART [0002] Current methods for making citrus juice use squeezers to separate the inner portion containing the juice from the outer peel. The juice extracted by the juicer contains the juice itself, as well as pectin and cellulose material, called citrus vacuoles. This material is also sometimes referred to as thick flesh, particles floating on the surface [ang. floaters], citrus cells, flesh-bearing flesh, juice bubbles, or flesh.

[0003] Citrus vacuoles are usually separated from the juice by means of filtration, using devices such as paddle-type final processing equipment, screw final-processing equipment and turbofilters. Citrus vacuoles contain a significant amount of juice-soluble solids. For economic reasons, citrus vacuoles are often subjected to a water washing step, e.g. by means of mixers, screw mixers, static mixers on the line, final processing equipment or turbofilters. In the water washing step, a stream of inferior juice is obtained, referred to as WESOS water extracted soluble orange solids, or simply as a residue after pulp wash. Washed cells, also known as washed pulp, are considered waste after this stage. Usually, the washed cells are mixed with the skin (derived from the extrusion process referred to above), further processed (for example, treated with lime to facilitate dehydration) and dried for use as cattle feed.

[0004] Some work has been undertaken to recover potentially valuable ingredients from citrus waste. For example, US Patent 6,183,806 B1 to Ficca et al. Describes a citrus peel extract and meal obtained from these extracts. The citrus peel is extracted with an ethanolic solvent, and the solvent is removed from the solid residue by recovering orange flour. Citrus peel is obtained in the form of comminuted pieces or particles. Shredded pieces or particles may be in the form of washed pulp (pomace). Ficca uses the term "washed flesh" in a somewhat unconventional way, referring to pomace - the skin ingredient. Ficca notes that orange meal extracted from pomace has a similar composition to that obtained from orange peel.

[0005] Washed citrus cells contain citrus fiber, a valuable citrus component with a relatively high total dietary fiber content and a balanced ratio of soluble to insoluble dietary fiber. The balanced nature of dietary fiber with respect to insoluble (mainly cellulose) and soluble (mainly pectin) fiber is beneficial for physiological effects compared to cereal fiber. Citrus fiber, in particular orange pulp, has an extremely high water binding capacity, which leads to high viscosity compared to other citrus fibers such as Vitacel orange fiber (available from Rettenmaier).

[0006] It would be desirable to develop a method for recovering citrus fiber from citrus vacuoles, in particular a method by which citrus fiber could be recovered efficiently and relatively economically. It would be particularly desirable to develop a method for recovering citrus fiber without the use of potentially hazardous reagents. In particular, it would be desirable to develop a method in which citrus fiber is obtained that can be used as a food and beverage ingredient.

[0007] EP 0 179 295 A1 discloses a dietary supplement for use as a source of indigestible, insoluble fiber, comprising a solid oral dosage form containing a fiber containing raw material selected from the group consisting of fungal pulp and orange pulp and combinations thereof, said raw material was crushed to form a homogeneous suspension extracted with a physiologically acceptable dehydrating reagent, filtered or centrifuged, to remove substantially all of said reagent and the water contained therein, freeze-dried and dry ground to particles or powder, so that said dietary supplement contains an amount of said indigestible, insoluble fiber sufficient to meet human fiber requirements, and a method for making such supplement diet. The method of treating chronic constipation involves administering to a patient in need of such treatment an effective amount for the treatment of constipation a solid oral dosage form containing insoluble, indigestible fiber from a source selected from the group of mushrooms, orange peel and combinations thereof, wherein said fiber has been crushed to a homogeneous, dehydrated form. to remove substantially all of the water it contains by extraction with a physiologically acceptable dehydration reagent, filtered under reduced pressure, and lyophilized.

[0008] SU 1556681 relates to a method for processing dry waste after squeezing citrus fruit, but not to squeezing fiber found in citrus flesh from washed vacuoles. Instead, the document deals with the isolation of vitamins, the raw material being dry.

[0009] DE 199 43 188 A1 relates to a method of increasing the fiber's ability to bind water, wherein the plant components are ground in an acidic or alkaline medium with simultaneous heating and then washed with alcohol. The matter left over from fruit or vegetable processing can, for example, be used as vegetable ingredients. The invention further includes proposals for using such dietary fiber.

SUMMARY OF THE INVENTION [0010] According to one aspect, the present invention relates to a method of purifying citrus fiber from citrus vacuoles to obtain a food additive suitable for human consumption according to claim 1. The method comprises the step of washing the citrus vacuoles with water to remove unwanted flavors, odors, dyes, sugars, acids and the like. Vacuoles are contacted with an organic solvent to obtain vacuoles washed with an organic solvent. The solvent vacuoles washed with organic solvent remove the solvent and recover dried citrus fiber.

[0011] In one preferred embodiment of the invention, the extraction method uses ethanol as the solvent and the weight ratio of solids to solvent is at least 0.25: 1, preferably at least about 0.5: 1. Solvent extraction is carried out countercurrently in at least two stages. At least a portion of the solvent, preferably at least 70%, is recovered and reused.

[0012] In one embodiment, the dried citrus fiber obtained in the extraction method described above has a total dietary fiber content of from about 60 wt. up to about 80 wt. and water binding capacity from about 7 to about 12 (w / w). Preferably, the total dietary fiber content is at least about 70 wt.%, And the water binding capacity is at least about 8 (w / w).

[0013] In another aspect of the present invention, dried citrus fiber is obtained by the extraction method of claim 1. The total dietary fiber content of dried citrus fiber is from 60 to

85 wt.%, And the water binding capacity is from 9 to 25 (w / w).

Such dried citrus fiber is useful as an additive to food products such as beverages, bakery products, meat or meat emulsions, confectionery, jams and jellies, dairy products, e.g. yogurt, dressings, energy bars and the like.

BRIEF DESCRIPTION OF THE DRAWINGS [0014] The objects, features and benefits of the invention will become apparent from the following more detailed description of certain embodiments of the invention and from the drawings attached thereto, wherein:

FIG. 1 schematically illustrates a two step solvent countercurrent extraction method in accordance with a preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION [0015] The present invention will be described mainly in relation to the extraction of orange fiber from orange vacuoles. It should be understood that this method can be used to extract fiber from citrus vacuoles from a wide variety of other types of citrus fruit, non-limiting examples of which are mandarins, limes, lemons and grapefruits. The water content of the citrus vacuoles is usually at least about 80 wt. and often from about 90 to about 97 wt.

[0016] The term "citrus vacuoles" as used herein means pectin and cellulose material contained within the citrus fruit containing juice. Citrus vacuoles are also sometimes referred to as coarse flesh, surface-floating particles, citrus cells, surface-floating flesh, juice bubbles, or flesh.

[0017] The term "water-extracted soluble solids" as used herein means inferior juice obtained by washing citrus vacuoles with water. The term "water-extracted soluble solids" includes in particular water-extracted soluble orange solids (WESOS). Water-soluble solids are sometimes also referred to as "flesh washing residue".

[0018] The term "water-washed vacuoles" means citrus vacuoles from which water-extracted soluble solids have been removed by washing with water. Water-washed vacuoles are also sometimes referred to as "washed cells" or "washed flesh".

[0019] The term "citrus fiber" as used herein means a fibrous component obtained from water-washed vacuoles and separated from the waste components contained therein. Citrus fiber is characterized by a high total dietary fiber content as well as a balanced ratio of soluble to insoluble dietary fiber. Citrus fiber, in particular orange fiber, has a very high water binding capacity.

[0020] Citrus fiber, compared to citrus flour obtained from citrus peel, has a lighter color and relatively no taste or smell. In contrast, citrus flour obtained from citrus peel is characterized by the taste, smell and color of the orange peel, which significantly limits the use of the product. Additional benefits of citrus fiber include a higher total dietary fiber content (e.g., above about gastrointestinal properties

70% against 58%); lower carbohydrate content (e.g. around 5% versus 15%); and higher water binding capacity (e.g., above about 8 grams of water per gram versus 5.5 g / g). The protein content of citrus fiber is usually in the range of about 8 to 12 wt.

[0021] The ratio of soluble to insoluble dietary fiber is an important factor for the possibility of using citrus fiber. Preferably, the ratio of soluble to insoluble dietary fiber in citrus fiber is balanced. For example, total dietary fiber consists of about 45-50% soluble dietary fiber and 50 to 55% insoluble dietary fiber. Other important ones include the degree of milling (granulometric test) and the drying conditions (drying process). Generally, a higher degree of milling (i.e. greater fiber fineness in a granulometric test) results in greater mildness in the mouth when fiber is found in foods and drinks. The density and particle size can vary widely depending on the processing conditions. For example, the density may be in the range of about 80 to about 650 g / L, and the average particle size may be in the range of about 15 to about 600 microns. It should be understood that these ranges are illustrative only. For some applications, for example, it may be beneficial to use significantly larger particle sizes. Generally, citrus fiber can have a structure from very finely divided to coarse-grained powder.

[0022] As shown schematically in Fig. 1, the orange vacuoles can be separated from the orange juice by means of filtration, e.g. using conventional filtration devices 10, for example paddle-type final processing equipment, screw-type final processing equipment and turbofilters. The orange vacuoles can then be subjected to a water washing step using appropriate devices, e.g. mixers, screw mixers, static mixers on-line, final processing equipment or turbofilters. Water washing is desirable to remove unwanted aromas, odors and acids in citrus vacuoles. In the water washing step, a stream of water-extracted soluble orange solids (WESOS) is obtained. Water-extracted soluble orange solids, along with the juice obtained by filtration 10, can be further processed using conventional juice-making devices 15.

[0023] The extraction of aromas, fragrances, dyes and the like from vacuoles washed with water is used

The solvent should be water, which facilitates the removal of organic solvent. polar and mix the right ingredients. Preferred solvents include lower alcohols, for example methanol, ethanol, propanol, isopropanol or butanol. The solvent may be (and preferably is) in an aqueous solution. The solvent concentration in the solvent solution usually remains in the range of 70 wt. up to about 100 wt. In one embodiment, 75 wt. aqueous ethanol solution. In a preferred embodiment, the solvent is used

90 wt. aqueous ethanol solution. In general, solvents remove water-soluble components at lower concentration and oil-soluble components at higher concentration. Optionally, a more non-polar co-solvent can be added to the aqueous alcohol solution, which increases the recovery of the oil-soluble components contained in the citrus vacuoles. Examples of such non-polar solvents include ethyl acetate, methyl ethyl ketone, acetone, hexane, methyl isobutyl ketone and toluene. More nonpolar solvents can be added in an amount of up to 20% of the solvent mixture. Many solvents, such as ethanol, have a lower heat of vaporization than water, so less energy is needed to evaporate them than if an equivalent mass of water needs to be evaporated. Preferably, the solvent is removed and reused.

[0024] Preferably, the contact of the water washed vacuoles with the organic solvent occurs at a solids / solvent weight ratio of at least 0.25: 1, preferably at least about 0.5: 1 and often 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 weight of wet solids. In one embodiment, the solids to solvent ratio is about 2: 1.

[0025] The extraction may be carried out in one stage, but preferably a multi-stage extraction is carried out, e.g. a two-, three- or four-stage extraction process, preferably using countercurrent extraction. There is no specific upper limit to the number of extraction steps that can be used. FIG. 1 schematically shows a preferred embodiment in which the two-stage countercurrent extraction process uses the first and second solvent extraction devices 25a and 25b, respectively.

[0026] Water-washed vacuoles are introduced into a second extraction device 25b. From the solvent tank 26, a solvent - aqueous ethanol solution is introduced into the first solvent extraction device 25a. The spent solvent from the first solvent extraction device 25a is fed to the second solvent extraction device 25b, and the citrus vacuoles after extraction are fed from the second solvent extraction device 25b to the first solvent extraction device 25a. The spent solvent from the second solvent extraction device 25b can be fed to the evaporator 35 (optional) to separate solids (e.g. sugars, dyes, aromas, citrus oils, etc.) from the used solvent, which can be condensed and recycled to the distillation apparatus 24. Remains from distillation (mainly water) are separated and removed.

[0027] After each extraction step, a belt filter press (not shown) is preferably used to further remove the liquid. A belt filter press may have a conventional construction known to those skilled in the art. Detailed information on suitable press with belt filter is provided, for example, in US patents

4,236,445, 4,297,215 and 5,022,989.

[0028] Solvent vacuoles from the first solvent extraction device 25a are introduced into the solvent removal device 30. In the solvent removal device 30 the solvent and water are removed from the remaining solids after extraction so that the solvent can be reused, which also ensures that the product can be safely ground and used commercially. Indirect heating may be applied to the solvent removal device to remove a significant amount of solvent from the solid residue. Alternatively, direct heating may be used for drying, e.g. with hot air from pneumatic dryers or fluidized bed dryers. If necessary, steam can be used directly to remove any traces remaining in solids. Vapors from the solvent removal device 30 are preferably recovered and introduced into the distillation apparatus 24 to recover at least part of the solvent.

[0029] The retention time for each extraction step is 5 minutes or less and is preferably about 3 minutes or less. The temperature in the solvent extraction device or devices depends on factors such as the type of solvent used, but most often it ranges from about 4.44 ° C (40 ° F) to about 82.2 ° C (180 ° F) at atmospheric pressure . The temperature can be appropriately increased or decreased so that the process runs under greater or less than atmospheric pressure. Alternatively, methods such as ultrasound can be used to increase the efficiency of the extraction process. If the system is kept closed, solvent losses during extraction, solvent removal and distillation can be minimized. Preferably at least 70 wt. the solvent is recovered and reused. The solvent make-up stream supplies the solvent tank 26 with fresh solvent that replenishes the solvent that has not been recovered.

[0030] The dried orange fiber product is generally a coarse meal. The flour can be ground if powder is needed for the application. Optionally, citrus fiber is subjected to one or more processing steps necessary or desirable for the given end use. For example, inactivation of natural enzymes can be performed prior to the solvent extraction or drying process. Enzymes can be inactivated, e.g. ultrasound or conventional thermal method.

[0031] Unlike many commercially available forms of fiber, the orange fiber of the present invention has the ability to thicken, forms a fleshy structure (coarse fraction), and has good stability. For example, citrus fiber can be used to replace 1% sucrose in a standard baking cream recipe with improved baking stability and good freezing and thawing stability. This means that the fiber's orange water binding capacity is extremely high, resulting in relatively high viscosity.

[0032] The high water binding capacity may be beneficial for many applications (e.g., processed meat). In other applications, for example in bakery products, high water binding capacity may not be desirable. Very finely ground fiber (e.g.

20 to 30 pm particle size) usually exhibits excellent organoleptic properties (high smoothness).

[0033] In addition to being able to be used as a food additive, e.g. for beverages, bakery products, meat or meat emulsions (e.g. sausages, mortadella, hot dogs), confectionery, jams and jellies, dairy products, dressings, energy bars and similar, citrus fiber can also potentially be used as a natural thickener for food products, e.g. yogurt, or as a carrier for other ingredients in beverages. Those skilled in the art will determine the appropriate amounts of citrus fiber for a variety of foods, depending on factors such as user preferences, using routine experiments at most.

EXAMPLE 1 [0034] In this example, extraction of citrus fiber from vacuoles washed with water using 75 wt. aqueous solution of ethanol as a solvent in the two-step method of countercurrent extraction described above. In the obtained fiber from orange, the content of dietary fiber was determined based on the AOAC 991.43 (Prosky) method. Citrus fiber has been found to have the composition and properties given 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 (on a dry weight basis)</td><td>1.6% N (9.7% protein)</td>

<td>Fatty acids (calculated on the dry matter)</td><td> 0,16%</td>

<td>Ash</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 [0035] This example shows the production of bread containing fiber from oranges. Table 2 lists the ingredients for making bread:

TABLE 2

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

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

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

<td>Bread improver</td><td> 100</td>

<td>salt</td><td> 17</td>

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

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

[0036] All dry ingredients were mixed in a spiral mixer (Veema type). Then water was added and the resulting dough was mixed for 20 minutes. The dough was divided into portions of 700 grams. Rolling and rising of the dough was carried out for 1.5 hours at 32 ° C and a relative humidity of 82%. Bread was baked in an oven floor oven] at 220 ° C for 35 minutes.

EXAMPLE 3 [0037] This example illustrates the preparation of a dressing (in a form containing 30% oil) containing orange fiber. Table 3 lists the ingredients for obtaining dressing:

TABLE 3

<td>Ingredient</td><td>Quantity (wt.%)</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>Egg yolk powder</td><td> 1,5</td>

<td>Xanthan gum + guar</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>

[0038] The aqueous and acidic phases were introduced into the Fryma colloid mill. The dispersion phase was then added and homogenized for 30 seconds. The oil phase was added over the next minute and the mixture emulsified for an additional 30 seconds. Then the dressing was poured into jars.

EXAMPLE 4 [0039] This example shows the production of beef burgers containing orange fiber. Table 4 lists the ingredients for making beef burgers:

TABLE 4

<td>Ingredient</td><td>Quantity (wt.%)</td>

<td>Beef (ground)</td><td> 90</td>

<td>Spices</td><td> 1,5</td>

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

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

[0040] All ingredients (except spices) were mixed in a Hobart N50CE mixer at a speed of 1. After 30 seconds, spices were added. The mixture was stirred for a maximum of 5 minutes, after 2.5 minutes it was turned over manually. The mass was cooled in the fridge for 2 hours. Burgers with a diameter of 80 mm were formed in portions of 90 g. Hamburgers can be fried in a pan until the temperature inside is reached

74-75 ° C.

EXAMPLE 5 [0041] This example shows the production of a jam containing fiber from oranges. Table 5 lists the ingredients that can be used to make jam:

TABLE 5

<td>Ingredient</td><td>Quantity (wt.%)</td>

<td>Mixture of fruit (red, frozen fruit) 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>until pH 3.4 is reached</td>

[0042] Fruit, sweeteners and water can be mixed and cooked together. Then you can add orange fiber and cook until you get the desired dry matter content. Citric acid solution can then be added until the mixture reaches pH 3.4. You can fill glass jars with hot jam.

EXAMPLE 6 [0043] This example shows the production of energy bars. Table 6 lists the ingredients for obtaining energy bars:

TABLE 6

<td>Ingredient</td><td>Quantity (wt.%)</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 fat</td><td> 7</td>

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

<td>Shredded red fruits</td><td> 15</td>

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

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

<td>Ground soybeans</td><td> 11</td>

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

[0044] The sweeteners and water were heated in a pot to 88 ° C. The melted fat and lecithin were mixed in a Hobart mixer for 1 minute at a speed of 1. Sweetener was added to the fat and mixed for 1 minute at a speed of 1. The dry ingredients were added and mixed for 30 seconds at a speed of 1. The mixture was poured as a sheet and cut into pieces of the right size. Then the bars were cooled and packaged.

[0045] Although specific embodiments of the present invention have been described and shown, it should be understood that the invention is not limited thereto and that those skilled in the art can make modifications. The present invention includes any modifications that fall within the scope of the disclosed and claimed in the basic document of the invention.