Gelled citrus fiber and method of manufacture

Abstract

The technology disclosed herein relates to a pectin-containing cellulosic material that is processed to form a strong gel when dispersed in an aqueous solution. Also disclosed is a method for processing the cellulosic material, including, at least in some embodiments, a method for monitoring changes in the infrared spectrum of the cellulosic material that occur during the processing reaction to obtain an end product that is capable of controlling the reaction and creating a gel with a desired gel strength.

Description

[Technical field]

[0001] The technology disclosed herein relates to a pectin-containing cellulosic material derived from citrus peel. The cellulosic material is processed so that it can form a strong gel when dispersed in an aqueous solution. Also disclosed is a method for processing the cellulosic material, which includes, at least in some embodiments, a method for monitoring changes in the infrared spectrum of the cellulosic material that occur during the processing reaction to control the reaction and obtain an end product that is capable of producing a gel with a desired gel strength. [Background technology]

[0002] Pectin, a heteropolysaccharide rich in galacturonic acid, is derived from protopectin (herein referred to as pectin-containing cellulosic material), a material associated with plant cell walls and the intermediate lamellar matrix. Pectin is formed from the acid hydrolysis of protopectin, which is a useful thickening agent in the presence of water, sugars, and calcium ions. The ability of some pectins to thicken aqueous solutions or form gels is limited by the methyl esters attached to the polysaccharide backbone. Thus, to extend the natural utility of pectin, protopectin is typically extracted using acid and is typically at least partially de-esterified by incubating citrus peels in an alkaline solution. Summary of the Invention

[0003] Modifications of the basic extraction and desertification reactions have been described in the art. Some modifications make pectin-containing cellulosic materials. However, there remains a need for pectin-containing cellulosic materials that form strong gels. This specification describes a pectin-containing cellulosic material, preferably obtained by processing a citrus peel to form a product that forms a strong gel. The product includes a pectin component within a cellulosic matrix. The product has a predetermined degree of esterification, a predetermined molecular weight, and can form a strong gel in aqueous solution. Although the principles described herein can be applied to pectin (or protopectin-rich cellulosic materials) in general, in a preferred embodiment, the material is made from citrus peel. In this specification, the preferred embodiment made from citrus fiber is referred to as a gelled citrus fiber material. Also disclosed herein are methods of making a gelled citrus fiber material and methods of controlling the method of making a gelled citrus fiber material.

[0004] The technology disclosed herein may be better understood with reference to the following non-limiting figures. [Brief description of the drawings]

[0005] [Figure 1] 1 is a flow diagram of an embodiment of a method for making gelled citrus fiber. [Diagram 2] 1 is a block diagram illustrating an embodiment of a method for making a gelled citrus fiber material and a method for controlling a method for making a gelled citrus fiber material. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0006] In one aspect, the present disclosure discloses a gelled citrus fibre material. In any embodiment, the gelled citrus fibre material comprises a cellulosic component and a pectin component having a percent galacturonic acid (%GA) of about 40% to about 50%, or about 40% to about 48%, or about 40% to about 46%, or about 42% to about 48%, or about 42% to about 46%, the pectin component having a degree of esterification of about 10 to about 80%, and the gelled citrus fibre material having a molecular weight of about 50 kDa to about 275 kDa. The gelled citrus fibre material is derived from the peel of a citrus fruit, and any citrus fruit may be used. In some embodiments, the citrus fruit is selected from the group consisting of lemon, lime, orange, and mixtures thereof. In a preferred embodiment, the gelled citrus fibre material is obtained from orange peel, and the orange peel may be from a single orange variety or a mixture of orange varieties.

[0007] As used herein, gelled citrus fiber comprising a cellulosic component and a pectin component refers to a material in which the cellulosic and pectin components are not simply a mixture of pectin and cellulose. Instead, the cellulosic and pectin components are associated in some manner. The manner of association is not limited, but refers to any physical association that holds at least the pectin and cellulosic components together. In at least some embodiments of the gelled citrus fiber material, the cellulosic component forms a matrix and at least a portion of the pectin component resides within the cellulosic matrix.

[0008] The present specification further provides separate embodiments of gelled citrus fiber, each embodiment having a range of degrees of esterification (% DE). In one range, the gelled citrus fiber material has a pectin component having a degree of esterification of about 30% to about 45% (% DE), or about 35% to about 45%, or about 37% to about 45%. In a second range, the gelled citrus fiber material has a pectin component having a degree of esterification of about 46% to about 55% (% DE), or about 47% to about 52%, or about 47% to about 50%. In a third range, the gelled citrus fiber material has a pectin component having a degree of esterification of about 10% to about 20% (% DE), or about 10% to about 18%, or about 10% to about 15%. In a fourth range, the gelling citrus fiber material has a pectin component with a degree of esterification of from about 60% to about 65% (% DE), or from about 60% to about 63%.

[0009] In various embodiments, the gelling citrus fiber described herein is described by a range of molecular weights. In one range, the gelling citrus fiber material has a molecular weight of about 50 to about 200 kDa, or about 50 to about 150 kDa, or about 50 to about 125 kDa, or about 50 to about 100 kDa. In a second range, the gelling citrus fiber material has a desired molecular weight of about 200 kDa to about 300 kDa, or about 210 kDa to about 275 kDa, or about 210 kDa to about 265 kDa, or about 225 kDa to about 265 kDa, or about 230 kDa to about 260 kDa. In a third range, the gelling citrus fiber material has a desired molecular weight of from about 100 kDa to about 200 kDa, or from about 100 kDa to about 150 kDa, or from about 100 kDa to about 125 kDa.

[0010] The gelling citrus fiber materials described herein are also described by a combination of degree of esterification and molecular weight. In one set of ranges, the gelling citrus fiber materials have a pectin component having a degree of esterification of about 30% to about 45% (% DE), or about 35% to about 45%, or about 37% to about 45%, and a molecular weight of the material of about 50 to about 200 kDa, or about 50 to about 150 kDa, or about 50 to about 125 kDa, or about 50 to about 100 kDa. In a second set of ranges, the gelling citrus fiber material has a pectin component having a degree of esterification of about 46% to about 55% (% DE), or about 47% to about 52%, or about 47% to about 50%, and a molecular weight of the material of about 200 kDa to about 300 kDa, or about 210 kDa to about 275 kDa, or about 210 kDa to about 265 kDa, or about 225 kDa to about 265 kDa, or about 230 kDa to about 260 kDa. In a third set of ranges, the gelling citrus fiber material has a pectin component having a degree of esterification of about 10% to about 20% (% DE), or about 10% to about 18%, or about 10% to about 15%, and a material molecular weight of 100 kDa to about 200 kDa, or about 100 kDa to about 150 kDa, or about 100 kDa to about 125 kDa. In a fourth set of ranges, the gelling citrus fiber has a pectin component having a degree of esterification of about 60% to about 65% (% DE), or about 60% to about 63%, and a material molecular weight of 100 kDa to about 200 kDa, or about 100 kDa to about 150 kDa, or about 100 kDa to about 125 kDa.

[0011] A set of degree of esterification ranges and molecular weight ranges correlate to a given range of gel strengths of gels obtainable by using the disclosed gelling citrus fiber materials. To illustrate these ranges, the present specification defines test gels using standardized aqueous solutions, standardized gelling citrus fiber materials, and standardized manufacturing methods. The test gels are useful for comparing gel strengths obtainable, but are otherwise exemplary, non-limiting embodiments of gels made from the gelling citrus fiber materials described herein. In one set of embodiments described herein, the gelling citrus fiber materials may form test gels having gel strengths of greater than about 200 g, or from about 200 g to about 500 g, or from about 225 g to about 500 g, or from about 275 g to about 500 g, or from about 300 g to about 500 g, or from about 300 g to about 400 g. In a second set of embodiments, the gelling citrus fiber materials may form test gels having a gel strength of less than about 200 g, or from about 100 g to about 200 g, or from about 110 g to about 180 g, or from about 125 g to about 175 g, or from about 130 g to about 170 g. In a third set of embodiments described herein, the gelling citrus fiber materials may form test gels having a gel strength of less than about 100 g, or from about 10 g to about 100 g, or from about 20 g to about 100 g, or from about 25 g to about 100 g, or from about 25 g to about 80 g, or from about 25 g to about 75 g.

[0012] With further reference to the specific set of embodiments described herein, a gelling citrus fiber material having a molecular weight range of about 50 to about 200 kDa, or about 50 to about 150 kDa, or about 50 to about 125 kDa, or about 50 to about 100 kDa, and having a pectin component having a degree of esterification range of about 30% to about 45% (% DE), or about 35% to about 45%, or about 37% to about 45%, may form a test gel having a gel strength of greater than about 200 g, or about 200 g to about 500 g, or about 225 g to about 500 g, or about 275 g to about 500 g, or about 300 g to about 500 g, or about 300 g to about 400 g.

[0013] In another set of embodiments described herein, gelling citrus fiber material having a molecular weight range of greater than about 200 kDa to about 300 kDa, or about 210 kDa to about 275 kDa, or about 210 kDa to about 265 kDa, or about 225 kDa to about 265 kDa, or about 230 kDa to about 260 kDa, and having a pectin component with a degree of esterification of about 46% to about 55% (% DE), or about 47% to about 52%, or about 47% to about 50%, may form test gels having gel strengths that are less than about 200 g, or about 100 g to about 200 g, or about 110 g to about 180 g, or about 125 g to about 175 g, or about 130 g to about 170 g.

[0014] In yet another set of embodiments described herein, gelling citrus fiber material having a molecular weight of from 100 kDa to about 200 kDa, or from about 100 kDa to about 150 kDa, or from about 100 kDa to about 125 kDa and having a pectin component with a degree of esterification of from about 10% to about 20% (% DE), or from about 10% to about 18%, or from about 10% to about 15%, may form test gels having a gel strength of less than about 100 g, or from about 10 g to about 100 g, or from about 20 g to about 100 g, or from about 25 g to about 100 g, or from about 25 g to about 80 g, or from about 25 g to about 75 g.

[0015] In yet another set of embodiments described herein, gelling citrus fiber material having a molecular weight of from 100 kDa to about 200 kDa, or from about 100 kDa to about 150 kDa, or from about 100 kDa to about 125 kDa and having a pectin component with a degree of esterification of from about 60% to about 65% (% DE), or from about 60% to about 63%, may form test gels having gel strengths of less than about 100 g, or from about 10 g to about 100 g, or from about 20 g to about 100 g, or from about 25 g to about 100 g, or from about 25 g to about 80 g, or from about 25 g to about 75 g.

[0016] The gelling citrus fiber materials disclosed herein are useful for modifying the texture of a composition, including for compositions for industrial, home care, personal care, or other non-food applications, or are useful in food compositions. The use of the gelling citrus fiber materials to modify the texture of a composition or food composition includes the use of the gelling citrus fiber materials to form a gel or a composition comprising a gel. Any embodiment of the gelling citrus fiber materials disclosed herein are useful for modifying the texture of a composition or food composition. In any embodiment disclosed herein, the gelling citrus fiber is used as a gelling agent or to form a gel in a composition or food composition. The gelling citrus fiber described herein may be used in any desired amount, but is most commonly used in an amount of about 0.1% to about 10%, or 0.5% to about 5%, or about 1.5% to 4.5%, or about 2.5% to about 3.5% of the composition.

[0017] The present specification also discloses compositions and food compositions comprising the gelled citrus fiber material used in any amount. In preferred embodiments, the food compositions described herein comprise the gelled citrus fiber material in an amount of about 0.1% to about 10% (by weight of the composition), or 0.5% to about 5%, or about 1.5% to 4.5%, or about 2.5% to about 3.5%. In any embodiment disclosed herein, the composition or food composition comprises the gelled citrus fiber material as described in any embodiment herein and a second component. In any embodiment disclosed herein, the composition or food composition comprises the gelled citrus fiber and an aqueous component. In any embodiment disclosed herein, the composition or food composition comprises the gelled citrus fiber material, an aqueous component, and at least one other component. In any embodiment disclosed herein, the food composition comprises the gelled citrus fiber and an edible aqueous component. In any embodiment disclosed herein, the food composition comprises a gelling citrus fiber material, an edible aqueous component, and at least one other edible component.

[0018] Any of the embodiments of the food compositions disclosed herein include gelling citrus fiber materials and any of the second ingredients used in the food compositions. Any of the embodiments described herein include starches including, but not limited to, corn starch, tapioca starch, pea starch, broad bean starch, lentil starch, chickpea starch, tapioca starch, potato starch, and sago starch, as well as high and low amylose variants of such starches. Such starches may also be found in flours and flours, including wheat flour, tapioca flour, rice flour, and corn grits. Useful starches may be modified or unmodified. Modified starches may be crosslinked, including using phosphates or adipates, or stabilized, including hydroxypropylation and acetylation. Useful starches may be transformed or hydrolyzed using shear, enzymes, acids, chemicals, or oxidation. Starches may also be usefully modified by oxidation for purposes other than hydrolysis. Useful starches may also be physically modified, such as by thermal inhibition, annealing, or heat-moisture treatment. Modified and unmodified starches may be pregelatinized or otherwise made cold water soluble.

[0019] In any embodiment, the food composition comprising the gelled citrus fiber material described herein may further comprise a sweetener. Useful sweeteners include dextrose, allulose, tagatose, fructose, glycerol, sucrose, erythritol, rebaudiosides (A, B, J, M, etc.), and glucosylated stevia glycosides, as well as corn syrups, including high fructose corn syrup. The sweetener may be provided in the form of a solid, or powder, or liquid, or syrup.

[0020] In any embodiment, food compositions comprising a gelled citrus fiber material as described herein may further comprise a gum or gum-like material. Useful gums and gum-like materials include gelling starch, gum arabic, xanthan gum, tara gum, konjac, carrageenan, locust bean gum, gellan gum, guar gum, and mixtures thereof.

[0021] In any embodiment, food compositions comprising gelled citrus fiber materials as described herein may further comprise an oil or fat or an aqueous component. Useful oils include vegetable oils such as corn oil, olive oil, canola oil, sunflower oil, rapeseed oil, palm oil, coconut oil, etc. Useful fats (other than vegetable oils) include animal fats and dairy fats. Useful aqueous components include water, milk, syrup, or other carbohydrate-containing liquids, or acidic liquids, or basic liquids.

[0022] In any embodiment, food compositions comprising the gelled citrus fiber material as described herein may further comprise a variety of other flavors, seasonings, and colorants commonly used in food compositions.

[0023] In any embodiment, the food composition comprising the gelled citrus fiber material is any food composition. In any embodiment, the food composition comprising the gelled citrus fiber material is a gelled food composition. In any embodiment, the food composition comprising the gelled citrus fiber material is selected from the group including (but not limited to) cereals, bread and bread products, cheese and imitation cheese products, condiments, confectionery, dressings including pourable dressings and spoonable dressings, pie fillings including fruit fillings (whether or not used in pies or other similar fruit preparations) and cream fillings, sauces including dairy-based sauces such as white sauces and cheese sauces, gravies, imitation and light syrups, puddings, custards, yogurt, sour cream, pasta, beverages including dairy-based beverages, glazes, soups, and baby foods.

[0024] In another aspect, the present specification also discloses a method for making a gelled citrus fiber material conforming to any embodiment described herein. Any embodiment of the method for making a gelled citrus fiber material as described herein includes mixing ground citrus peel, including a pectin component and a cellulosic component, with an acidic solution to obtain an acid washed citrus peel, mixing the acid washed citrus peel with an alkaline solution to reduce the degree of esterification (% DE) of the pectin component thereby obtaining a de-esterified citrus peel, and recovering the de-esterified citrus peel to obtain a gelled citrus fiber material.

[0025] Another embodiment of a method for making a gelled citrus fiber material is shown as a flow diagram in FIG. 1. Citrus peels can be obtained as a raw material from dried or fresh peels, ground by any suitable method. The peels can be rehydrated before or after grinding, with rehydration before the acid step being optional. With reference to FIG. 1, the process begins with dried peels that are dry ground to a desired size in step (11). The ground citrus peels are rehydrated in step (12) using water or an aqueous solution. The rehydrated ground citrus peels are acid washed in step (13) and the acid is washed from the citrus peels in a water wash step (14). The acid washed material is subjected to an alkaline incubation in step (15) to reduce the degree of esterification in order to "de-esterify" the acid washed citrus peels. The de-esterified citrus peel (which is the gelled citrus fiber) is then washed, preferably three times, in an alcohol wash step (16) and dried in a drying step (17) to recover the final product.

[0026] Variations of the above process are possible, for example, alcohol washing is useful to reduce the ash or salt content of the gelled citrus fiber, but is not strictly necessary to obtain a gelled citrus fiber material capable of forming a gel of the desired gel strength, and thus the number of times the gelled citrus fiber material is washed can be adjusted as needed to obtain the desired ash or salt content.

[0027] In particular, in a preferred embodiment, the acid wash is carried out in an aqueous solution (not an acidic alcohol solution). Because pectin is water soluble, care must be taken to reduce the amount of pectin that is washed out of the cellulosic material during the acid wash. For example, as described below, the acid was applied at a temperature, pH, and time such that the pectin remained substantially associated with the gelled citrus fiber after the acid wash and water washing steps.

[0028] As described herein, the gelled citrus fiber material may be described with reference to its molecular weight. Both the acid wash and the alkaline incubation may contribute to reducing the molecular weight of the raw material to obtain the desired molecular weight of the gelled citrus fiber. However, preferably, the alkaline incubation is controlled so as not to substantially further change the molecular weight of the material compared to the acid washed citrus peel. In other words, preferably, the majority of the molecular weight reduction of the citrus peel that is performed to obtain the gelled citrus fiber occurs during the acid wash step. With respect to specific reaction conditions, in any embodiment described herein, the ground citrus peel is mixed with an acid solution having a pH of less than 3, or from about 1.5 to about 2.5. In any embodiment of the gelled citrus fiber material disclosed herein, the ground citrus peel is mixed with the acid solution for less than about 90 minutes, or less than about 60 minutes, or from about 10 minutes to about 90 minutes, or from about 30 minutes to about 90 minutes, or from about 10 minutes to about 60 minutes, or from about 30 minutes to about 60 minutes. A range of embodiments of gelled citrus fiber material may be obtained by subjecting the citrus peel to an acid wash for a more narrowly defined period of time. In one range of embodiments, in a method for making a gelled citrus fiber material, ground citrus peel is mixed with an acid solution for about 10 minutes to about 30 minutes. In another set of embodiments of a method for making a gelled citrus fiber material, ground citrus peel is mixed with an acid solution for about 30 minutes to about 50 minutes. In a third set of embodiments of a method for making a gelled citrus fiber material, ground citrus peel is mixed with an acid solution for about 50 minutes to about 70 minutes. Acids useful for making the acid solution include any food grade acid capable of producing a solution having a desired pH, including, but not limited to, mineral acids such as hydrochloric acid.

[0029] In any embodiment of the method for making a gelled citrus fiber material disclosed herein, an acid washed citrus peel is formed by combining ground citrus peel with an acidic solution. In any embodiment of the method for making a gelled citrus fiber material disclosed herein, after combining the ground citrus peel with the acidic solution, the method includes dehydrating the acid washed citrus peel by any suitable means including, for example, centrifugation and filtration.

[0030] The acid washed citrus peel is further reacted in an alkaline solution (the resulting product is referred to herein as "de-esterified citrus peel"). As noted above, the alkaline incubation may further reduce the molecular weight of the acid washed citrus peel, but in preferred embodiments is designed to result in a smaller relative molecular weight change (citrus peel to acid incubated citrus peel compared to de-esterified citrus peel from acid washed citrus peel). In an optional embodiment, during the alkaline incubation, the acid washed citrus peel is mixed with an alkaline solution (aqueous solution) at a selected temperature and a selected pH to controllably reduce the degree of esterification of the acid washed citrus peel. In embodiments, the pH of the alkaline incubation is greater than about 8 or greater than about 8.5 so that de-esterification can occur, but less than 11 so that de-esterification can be controlled to obtain a desired degree of esterification. In a preferred embodiment, the pH of the alkaline incubation is from about 9 to about 10.

[0031] Temperature is also important to control the rate of the de-esterification reaction. In a broad embodiment range, the temperature for the de-esterification reaction is from about 1° C. to about 30° C. Within this range, the temperature is selected based on the intended target range of esterification degree for the final product. In one embodiment range, the acid washed citrus peel is mixed with an alkaline solution at a temperature of from about 1° C. to about 10° C., or from about 3° C. to about 7° C. to reduce the degree of esterification. In another embodiment range for making a gelled citrus fiber material, the acid washed citrus peel is mixed with an alkaline solution at a temperature of from about 10° C. to about 20° C., or from about 12° C. to about 17° C. to reduce the degree of esterification. In a third set of embodiments, in a method for making a gelled citrus fiber material, the acid washed citrus peel is mixed with an alkaline solution at a temperature of from about 20° C. to about 30° C., or from about 22° C. to about 27° C. In any embodiment of the method of making a gelled citrus fiber material disclosed herein, a material comprising a cellulosic component and a de-esterified pectin component is obtained by mixing acid washed citrus peel with an alkaline solution. Following alkaline incubation to reduce the degree of esterification of the pectin component, the de-esterified citrus peel is recovered using means common in the art, such as drying, filtration, centrifugation, and mixing thereof.

[0032] In at least some embodiments disclosed herein, the method for making a gelled citrus fiber material comprises washing the de-esterified citrus peel using an organic solvent, preferably an alcohol. The material may be washed more than once, for example two or three times, or more. The washing step is not strictly necessary, but it reduces the salt or ash content of the final product. After washing the material, the solvent is removed using any suitable method, including centrifugation, filtration, and evaporation, and mixtures thereof. As mentioned above, preferably the organic solvent is an alcohol, and the preferred solvent is ethanol, although any food-grade organic solvent may be used.

[0033] In another aspect, the present disclosure discloses a method for monitoring chemical reactions involving a material comprising a pectin component and a cellulosic component to obtain a gelled citrus fiber material. The reactions are monitored using infrared ("IR") spectroscopy, and preferably Fourier transform infrared ("FTIR") spectroscopy, based on changes in a significant range of wave numbers that occur during one or more steps of the method to obtain a gelled citrus fiber material. For example, in at least some embodiments described herein, one set of chemical reactions for processing the cellulosic and pectin components of the citrus peel includes an acid wash step that reduces the molecular weight of the starting material. In another example, in at least some embodiments described herein, one set of chemical reactions for processing the cellulosic and pectin components of the citrus peel includes an alkaline incubation that de-esterifies the citrus peel. In another example, the gelled citrus fiber material includes a pectin component measured by percent galacturonic acid, and the change in galacturonic acid is measured, for example, during one or more of an acid wash, an alkaline incubation, and an alcohol wash.

[0034] In a preferred embodiment, the infrared spectral changes of alkaline incubation are monitored and de-esterification can be controlled to obtain a desired degree of esterification. In one embodiment, described herein is a method for measuring a chemical reaction involving a material comprising a pectin component and a cellulosic component, comprising recording a spectrum of the material and evaluating the spectrum against a model correlating the spectrum to a second parameter of one or more of the pectin component or the cellulosic component, wherein the spectrum is at least between about 1400 and about 850 cm. -1 Wavenumber range, (A) about 1400-1050 cm -1 (B) 1050~975cm -1 , (C) 975~875cm -1 , and (D) 875 and approximately 850 cm -1 and (A) one or more wavenumber ranges selected from the group consisting of about 1095 to about 1070 cm -1 , (B) Approx. 1050~1020cm -1, (C) approx. 975~895cm -1 , and (D) about 875 to about 845 cm -1 wherein the material is gelled with citrus fibers, and preferably wherein a chemical reaction converts the material to a gelled citrus fiber.

[0035] Refers to the wavenumber range used to create the model. A model can be created by recording or measuring a wider range of wavenumbers. For example, a model can be created from 3500 to 650 cm -1 or even broader ranges of wavenumbers may be monitored. Narrower wavenumber ranges such as those listed above are selected based on how well they can be used to develop models to predict parameters of interest in gelled citrus fiber materials.

[0036] With regard to recording the spectrum of the material and evaluating the spectrum against a model correlating the spectrum to a second parameter of the pectin component, the second parameter can be any useful parameter that can be correlated to a change in the spectrum measurable using infrared spectroscopy, such parameters including the percent galacturonic acid, or the degree of esterification, or the molecular weight of the gelled citrus fiber material. In a preferred embodiment, the second parameter is the degree of esterification. The degree of esterification can be measured, for example, using the titration process described in Schultz (1965) ("Determination of the degree of esterification of pectin, determination of the ester methoxyl content of pectin by saponification and titration. Determination of the anhydro uronic acid content by decarboxylation and titration of the liberated carbon dioxide." Whistler RL, Wolfrom ML (eds) Methods in carbohydrate chemistry, vol 5. Academic Press, New York), and Lin et al. (1990) ("Quantification of methyl ester content of pectin by pectinesterase." Botanical Bulletin of Academia Sinica: Vol 31. Pages 273-278.). Modifications of these methods are possible and the method can be adapted to specific needs. As used herein, generally, the method can be divided into two parts: (1) washing of the material, and (2) double titration. The sample is washed to remove any salts, sugars, and counterions using acidic alcohol to ensure that all pectin is in an esterified form or present as the free acid.The first titration is used to determine the free acid groups, and then the neutral solution can be used in the second titration method proposed by Schultz (1965). A detailed titration process useful for measuring the degree of esterification is described in the Methods section of this specification.

[0037] The model correlating the infrared spectrum with the second parameter can be developed using any suitable process. In one embodiment, samples of the chemical reaction mixture are analyzed at predetermined times. At these time points, both the second parameter and the spectrum are measured. The samples are correlated using statistical analysis that correlates the change in the parameter with the change in the spectrum. In at least one embodiment, a wide range of de-esterification samples is obtained. Any number of samples can be used to develop the model, but more accurate models are developed with more samples. With respect to the model correlating the change in the IR spectrum with the measured degree of esterification, the degree of esterification can be measured using a titration method, and the spectrum can be correlated with the degree of esterification using statistical analysis, for example, a partial least squares regression model. Other regression algorithms can be used and / or modified by those skilled in the art to construct useful models for monitoring the reactions described herein, including principal component regression, multiple linear regression, or neural networks.

[0038] A spectrum for modeling or predicting the value of a desired parameter of the gelled citrus fiber material, e.g., degree of esterification, may be recorded using a probe in the reaction vessel. The probe may be configured to measure the spectrum and transmit the measured spectrum to a measurement means for use in modeling or predicting the desired parameter of the reaction materials, e.g., the cellulosic component or the pectin component. In various embodiments, a parameter of a monitored chemical reaction may be altered based on the predicted value of the parameter of the reaction materials. For example, in a preferred embodiment, the calculation means predicts the degree of esterification of the pectin component during alkaline de-esterification by comparing at least a portion of the measured spectrum obtained from the probe in the de-esterification reaction vessel to a de-esterification model. If the predicted degree of esterification matches the desired degree of esterification, the calculation means may signal the control means to stop the de-esterification reaction, e.g., by reducing the pH in the reaction vessel to stop the de-esterification reaction.

[0039] A block diagram of an embodiment of a process for monitoring and controlling a process for making gelled citrus fiber is shown in Figure 2. For the process (20) for making gelled citrus fiber material, a raw material is provided in step (21), the raw material is processed in a reacting step (22), and the end product is recovered in step (23). In one embodiment, the reacting step is characterized by combining one or more of an acid wash step, a de-esterification step, and an alcohol wash step. In one embodiment, the reacting step is characterized by combining one or more steps for reducing the molecular weight of the raw material and one or more steps for de-esterifying the raw material.

[0040] With further reference to FIG. 2, the process for monitoring the process for obtaining a gelled citrus fiber material includes monitoring the reaction (30) by in situ IR (infrared) monitoring steps (31), data processing steps (32), modeling steps (33), DE (degree of esterification) prediction steps (34), and process control (35). In application, these steps may be blended or overlapped or combined into fewer steps. Generally speaking, in conjunction with the steps described in FIG. 1, IR spectra are monitored and recorded. The IR data is processed to obtain at least an IR spectrum that can be correlated to a DE prediction model, making it possible to predict the degree of esterification of the reacted material at the time of measurement. Using the predicted DE, the process can be controlled by adjusting at least one parameter of the reaction, for example, by adjusting the pH of the reaction to stop the de-esterification.

[0041] In other embodiments, spectra for modeling or predicting desired parameters of the gelled citrus fiber material, such as the degree of esterification, may be recorded from samples obtained during the chemical reaction. In such embodiments, samples of the reaction fluid are extracted and the processing starting material is recovered and placed on a probe to measure its spectrum. The measured spectra are then used to develop a predictive model, or the predictive model is applied by computational means, to predict the degree of esterification using the IR spectra. Although samples collected in this manner are not in real time, the predictive model is a faster and less chemically intensive means of determining the degree of esterification of a sample, as compared to titration methods for calculating the degree of esterification.

[0042] The machines and means for correlating spectra with measured values ​​of parameters, predicting values ​​of desired parameters from models, or controlling chemical reactions include any suitable processing devices or systems, including computers, microprocessors, and distributed computing systems. The machines and means for communicating spectra, parameter predictions, or control signals based on spectra or predictions (such communication being for any purpose) include wired and wireless communication means using any communication protocol.

[0043] Non-limiting examples and further descriptions of these means include machines with a human machine interface (HMI), which may be an integral part of the system or may generally be housed as part of any computer and / or processing device. Non-limiting examples of such devices, means, or machines, whether or not they include an HMI, may be a central processing unit alone, or a tablet, phone, handheld device, laptop, user display, or generally any other computing device capable of allowing input, providing options, and showing the output of an electronic function. A central processing unit (CPU), also referred to as a central processor or main processor, is an electronic circuit within a computer that executes the instructions of a computer program by performing basic arithmetic, logic, control, and input / output (I / O) operations specified by the instructions. Yet further examples include a microprocessor, a microcontroller, or another suitable programmable device and memory. The controller may also include other components and may be implemented partially or entirely on a semiconductor (e.g., field programmable gate array ("FPGA")) chip, such as a chip developed through a register transfer level ("RTL") design process.

[0044] An HMI may incorporate a display that may provide information or allow input, such as a user interface (UI) or graphical user interface (GUI). A user interface is how a user interacts with a machine. A user interface may be a digital interface, a command line interface, a graphical user interface ("GUI"), or any other way that a user may interact with a machine. For example, a user interface ("UI") may include a combination of digital and analog input and / or output devices, or any other type of UI input / output device needed to achieve a desired level of control and monitoring over the device. Examples of input and / or output devices include a computer mouse, keyboard, touch screen, knobs, dials, switches, buttons, etc. Inputs received from the UI may then be sent to a microcontroller to control operational aspects of the device.

[0045] The user interface module may include a display that may act as an input and / or output device. More specifically, the display may be a liquid crystal display ("LCD"), a light emitting diode ("LED") display, an organic LED ("OLED") display, an electroluminescent display ("ELD"), a surface conduction electron emission display ("SED"), a field emission display ("FED"), a thin film transistor ("TFT") LCD, a bi-stable cholesteric reflective display (i.e., e-paper), or the like. The user interface may also be configured with the microcontroller to display conditions or data related to the main device in real time or substantially real time.

[0046] According to any of the embodiments described herein, the HMI or other computing or control device, means, or machine may also include or be otherwise operably connected to a memory that may store data associated with the system. Such data may be used to operate the system in a dynamically variable manner to include historical information and tables so that the system may "look up" historical data to operate more efficiently. The memory, in some embodiments, includes a program storage area and a data storage area. The program storage area and the data storage area may include a combination of different types of memory, such as read-only memory ("ROM", an example of non-volatile memory, meaning that it does not lose data when not connected to a power source), or random access memory ("RAM", an example of volatile memory, meaning that it loses its data when not connected to a power source). Some additional examples of volatile memory include static RAM ("SRAM"), dynamic RAM ("DRAM"), synchronous DRAM ("SDRAM"), and the like. Additional examples of non-volatile memory include electrically erasable programmable read-only memory ("EEPROM"), flash memory, hard disks, SD cards, and the like. In some embodiments, a processing unit such as a processor, microprocessor, or microcontroller is connected to the memory and executes software instructions that can be stored in the RAM of the memory (e.g., during execution), in the ROM of the memory (e.g., generally permanently), or in another memory or another non-transitory computer-readable medium such as a disk.

[0047] An HMI, control, computing device, machine, or means may be powered in many ways, whether separate or integral to the system. A power supply outputs a specific voltage to a device or component or a component of a device. The power supply may be a DC power supply (e.g., a battery), an AC power supply, a linear regulator, etc. The power supply may be configured with the microcontroller to receive power from a generator or other grid-independent source such as a solar panel. With respect to the battery, a dry cell (or wet cell) may be used. In addition, the battery may be rechargeable, such as a lead acid battery, a low self-discharge nickel metal hydride battery (LSD-NiMH) battery, a nickel cadmium battery (NiCd), a lithium ion battery, or a lithium ion polymer (LiPo) battery. When using lithium ion or LiPo batteries, great care should be taken to avoid the risk of unexpected fire due to heat generated by the battery. Although such accidents are rare, through proper design, installation, procedures, and layers of safeguards, the risk may be minimized to be acceptable.

[0048] According to any of the embodiments described herein, the HMI, control or computing device, means, or machine, and any of their components may be integrated with the system or may be standalone and separate. In either sense, one or more of the components of the HMI, control or computing device, means, or machine may include network / communication components and protocols that allow the transfer of information related to the system (30) to be communicated between and outside of the components of the system. This may include the transfer of information to a central network of servers or other memory that stores certain operational information for later review and use. The information may also be transferred to one or more remote devices to allow remote monitoring of the operation of the system without the need for a physical presence. The information may also be utilized to fine-tune the operation of one or more sub-operations of the system to help increase the efficiency of the system. It is further contemplated that one or more of the remote locations may include machine learning that allows the closed loop dynamic control system to self-improve.

[0049] According to any of the embodiments described herein, the network may be, by way of example only, a wide area network ("WAN"), such as a TCP / IP-based network or a cellular network, a local area network ("LAN"), a neighborhood area network ("NAN"), a home area network ("HAN"), or a personal area network ("PAN") using any of a variety of communication protocols, such as Wi-Fi, Bluetooth, ZigBee, Near Field Communication ("NFC"), although other types of networks are possible and contemplated herein. The network typically enables communication between a communication module and a central location at moments of low quality connectivity. Communications through the network may be secured using one or more encryption techniques, such as those techniques provided in the IEEE 802.1 standard for port-based network security, pre-shared keys, Extensible Authentication Protocol ("EAP"), Wired Equivalent Privacy ("WEP"), Temporal Key Integrity Protocol ("TKIP"), Wi-Fi Protected Access ("WPA"), and the like.

[0050] According to any of the embodiments described herein, a device such as an HMI may include one or more communications ports, such as Ethernet, Serial Advanced Technology Attachment ("SATA"), Universal Serial Bus ("USB"), or Integrated Drive Electronics ("IDE"), for transferring, receiving, or storing data.

[0051] The methods and compositions herein are described by reference to preferred embodiments made from citrus peel starting materials. The methods may also be applied to other pectin-containing cellulosic materials to obtain compositions having the degree of esterification, pectin content, and / or molecular weight described herein. In the broadest sense, virtually all plants contain pectin-containing cellulosic materials, although some may not be suitable starting materials because they have a pectin content (%GA) that is outside the ranges described herein. Useful starting materials are whole or crushed fruits and vegetables, stone fruits such as apples, peaches, apricots, nectarines, berries such as blueberries, strawberries, raspberries, blackberries, root vegetables such as carrots, pomace from making purees from other similar fruits and vegetables, components other than the skin of citrus fruits such as vesicles, fibers from other plant sources such as legume husks or seeds (including peas, lentils, broad beans, chickpeas), fiber waste from starch manufacture such as potato skins, tapioca husks, corn husks, rice bran, etc. Fiber from leaves of plants harvested for other purposes or plant leaf residues such as the leaves of the stevia plant.

[0052] Embodiments of the gelled fiber materials, gelled citrus fiber materials, methods for making such materials, and methods for monitoring reactions to make such materials may be better understood with reference to the following definitions.

[0053] References herein to a "cellulosic component" refer to a component of a gelled material or gelled citrus fiber material that consists of cell walls or cell wall fragments of a plant or plant part, such as a citrus peel. Without being limited to any particular fragment of cell wall, the cellulosic component is expected to include one or more of cellulose, cellulose fragments, and hemicellulose.

[0054] References herein to a "cellulosic matrix" mean a cellulosic component that forms a structure or medium that at least in part comprises a pectin component.

[0055] References herein to a "pectin component" or "pectin" refer to one or more of protopectin, pectin, and pectic acid, a galacturonic acid-rich polysaccharide that is associated with the cellulosic component or is at least partially within the cellulosic matrix. The pectin component may be characterized by reference to the percent galacturonic acid ("% GA") of the gelled fibrous material. % GA is used as a proxy for the total pectin content of the gelled citrus fibrous material or the percentage of the gelled citrus fibrous material that is a pectin component.

[0056] References herein to "de-esterification" and grammatical variations thereof refer to a chemical reaction that removes at least a portion of the methyl ester groups from a pectin component or pectin, as compared to the raw material. Although the pectin component may be de-esterified to have essentially no methyl ester groups, preferably, as described herein, the de-esterified pectin component has a substantial degree of esterification.

[0057] Gelling citrus fibers may be evaluated by their ability to form gels having a given gel strength. For purposes of comparison, all gel strengths are measured using a "test gel" from a given aqueous solution using a given method. References herein to a "test gel" refer to gels made using the following formulations and methods:

[0058] Herein, test gels are made using the formulations in Table 1.

[0059] [Table 1]

[0060] In this specification, the test gel is made using the following method. Please note that filtered tap water 1-4 refers to the addition of filtered tap water at four different times in the process in the amounts indicated, and there is no other difference between filtered tap water 1-4. Filtration is standard drinking. Filtered tap water 1 is weighed and placed in a plastic beaker equipped with a stirring bar. Fibers are weighed and dispersed in filtered tap water 1 with stirring. The mixture is stirred for about 15 minutes. Sodium hexametaphosphate and sugar are weighed and added to the dispersion. The pH of the mixture is then adjusted to pH 4 using hydrochloric acid dropwise using a plastic pipette (if necessary). The mixture is then transferred to a pre-weighed stainless steel beaker (600 ml) and heated to 70-80°C in a water bath with stirring. After the set temperature is reached, the mixture is kept in the bath for 10 minutes.

[0061] In a separate plastic beaker, mix together pre-weighed 2 parts of filtered tap water and calcium hydrogen phosphate. After shaking, add the calcium solution to the fiber mixture.

[0062] In another separate plastic beaker, pre-weigh 3 portions of filtered tap water and glucono-delta-lactone and mix together to dissolve the lactone. After mixing, add the solution to the fiber mix. Weigh 4 portions of filtered tap water and use to wash off any remaining lactone or calcium mix on the beaker. Add the wash to the fiber mix. Remove the fiber mix from the water bath and weigh. For a 100g formula, the total weight of the solution is approximately 100g. If not, rehydrate using filtered tap water and allow to cool at ambient temperature for 24 hours.

[0063] The use of "about" to modify a number is meant to include the stated number plus or minus 10%. Legally permitted recitations of values ​​in the claims mean approximately that value. The use of about in the claims or specification is not intended to limit the entire range of equivalents covered.

[0064] The indefinite article "a" or the definite article "the" is intended to mean one or more, unless the context clearly dictates otherwise.

[0065] While particular embodiments have been illustrated and described, those skilled in the art, after reading the foregoing specification, may effect modifications, substitutions of equivalents, and other types of alterations in the methods and techniques of the present invention. Each of the above aspects and embodiments may also include or incorporate such variations or aspects as disclosed with respect to any or all of the other aspects and embodiments.

[0066] The technology is also not limited with respect to the embodiments described herein, which are intended as single illustrations of individual embodiments of the technology. As will be apparent to those skilled in the art, many modifications and variations of the technology can be made without departing from its spirit and scope. Functionally equivalent methods within the scope of the technology will be apparent to those skilled in the art from the foregoing description, in addition to those recited herein. Such modifications and variations are intended to be included within the scope of the appended claims. It is to be understood that the technology is not limited to methods, complexes, reagents, compounds, compositions, labeled compounds, or biological systems, which may, of course, vary. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. It is also to be understood that the terms used herein are for the purpose of describing embodiments only, and are not intended to be limiting. Thus, it is intended that the specification be considered as illustrative only of the breadth, scope, and spirit of the technology, as indicated solely by the appended claims, definitions thereof, and any equivalents thereof. No language in the specification should be construed as indicating any non-claimed element as essential.

[0067] The embodiments illustratively described herein may be suitably practiced in the absence of any element(s), limitation(s) not specifically disclosed herein. Thus, for example, terms such as "comprising", "including", "containing" and the like are to be read expansively and without limitation. Additionally, the terms and expressions used herein are used as terms of description and are not to be limited, and there is no intention to exclude any equivalents of the features or portions thereof shown and described in the use of such terms and expressions, but it is recognized that various modifications are possible within the scope of the claimed technology. Additionally, the phrase "consisting essentially of" will be understood to include those elements specifically recited, as well as additional elements that do not materially affect the basic and novel characteristics of the claimed technology. The phrase "consisting of" excludes any elements not specified.

[0068] In addition, where features or aspects of the disclosure are described in terms of a Markush group, one of skill in the art will recognize that the disclosure is also described in terms of any individual members or subgroups of members of the Markush group. Each of the narrower species and subgroups falling within the generic disclosure also form part of the technology. This includes describing the concept of the technology with a condition or negative limitation that removes any subject matter from the genus, regardless of whether the excised material is specifically described herein.

[0069] As will be understood by those skilled in the art, for any and all purposes, in view of providing a specifically written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of those subranges. Any recited range can be easily recognized as fully describing and allowing the same range to be divided into at least one half, one third, one quarter, one fifth, one tenth, etc. As a non-limiting example, each range discussed herein can be easily divided into a lower third, a middle third, and an upper third, etc. Also, as will be understood by those skilled in the art, all words such as "up to," "at least," "greater than," "less than," etc. refer to a range that includes the recited numbers and can be divided into the subranges discussed below. Finally, as will be understood by those skilled in the art, a range includes each individual member, and each separate value is incorporated herein as if it were individually described herein.

[0070] The technology disclosed herein is further described with reference to the following non-limiting embodiments. 1. A gelled citrus fiber material comprising: a) a cellulosic component; and b) an associated pectin component in an amount of 40%-50% (% galacturonic acid (% GA)), or about 40% to about 48%, or about 40% to about 46%, or about 42% to about 48%, or about 42% to about 46%, wherein the pectin component has a degree of esterification (% DE) of about 10% to about 80%, and wherein the gelled citrus fiber material has a molecular weight of about 50 kDa to about 275 kDa, and optionally, the gelled citrus fiber material is obtained from citrus peel. 2. The gelled citrus fiber material of claim 1, wherein the pectin component has a degree of esterification selected from the group consisting of: about 30% to about 45% (% DE), or about 35% to about 45%, or about 37% to about 45%; about 46% to about 55% (% DE), or about 47% to about 52%, or about 47% to about 50%; about 10% to about 20% (% DE), or about 10% to about 18%, or about 10% to about 15%; and about 60% to about 65% (% DE), or about 60% to about 63%. 3. The gelled citrus fiber material of claim 1 or 2, wherein the material has a molecular weight selected from the group consisting of about 50 to about 200 kDa, or about 50 to about 150 kDa, or about 50 to about 125 kDa, or about 50 to about 100 kDa; about 200 kDa to about 300 kDa, or about 210 kDa to about 275 kDa, or about 210 kDa to about 265 kDa, or about 225 kDa to about 265 kDa, or about 230 kDa to about 260 kDa; and 100 kDa to about 200 kDa, or about 100 kDa to about 150 kDa, or about 100 kDa to about 125 kDa. 4. The gelled citrus fiber material of any one of claims 1 to 3, wherein the degree of esterification of the pectin component is from about 30% to about 45% (% DE), or from about 35% to about 45%, or from about 37% to about 45%, and the molecular weight of the material is from about 50 to about 200 kDa, or from about 50 to about 150 kDa, or from about 50 to about 125 kDa, or from about 50 to about 100 kDa. 5. The gelled citrus fiber material of any one of claims 1 to 4, wherein the degree of esterification in the pectin component is from about 46% to about 55% (% DE), or from about 47% to about 52%, or from about 47% to about 50%, and the molecular weight of the material is from about 200 kDa to about 300 kDa, or from about 210 kDa to about 275 kDa, or from about 210 kDa to about 265 kDa, or from about 225 kDa to about 265 kDa, or from about 230 kDa to about 260 kDa. 6. The gelled citrus fiber material of any one of claims 1 to 5, wherein the degree of esterification is from about 10% to about 20% (% DE), or from about 10% to about 18%, or from about 10% to about 15%, and the molecular weight of the material is from 100 kDa to about 200 kDa, or from about 100 kDa to about 150 kDa, or from about 100 kDa to about 125 kDa. 7. The gelled citrus fiber material of any one of claims 1 to 6, wherein the degree of esterification of the pectin component is from about 60% to about 65% (% DE), or from about 60% to about 63%, and the molecular weight of the material is from about 100 kDa to about 200 kDa, or from about 100 kDa to about 150 kDa, or from about 100 kDa to about 125 kDa. 8. The gelled citrus fiber material of any one of claims 1 to 7, which is capable of forming a gel in aqueous solution when used in an amount of about 0.5% to about 5% (wt % of the gel), or when used in an amount of about 1.5% to 4.5%, or about 2.5% to about 3.5%. 9. The gelled citrus fiber material of any one of claims 1 to 8, capable of forming a test gel having a gel strength selected from the group consisting of: greater than about 200 g, or from about 200 g to about 500 g, or from about 225 g to about 500 g, or from about 275 g to about 500 g, or from about 300 g to about 500 g, or from about 300 g to about 400 g; less than about 200 g, or from about 100 g to about 200 g, or from about 110 g to about 180 g, or from about 125 g to about 175 g, or from about 130 g to about 170 g; and less than about 100 g, or from about 10 g to about 100 g, or from about 20 g to about 100 g, or from about 25 g to about 100 g, or from about 25 g to about 80 g, 25 g to about 75 g. 10. The gelling citrus fiber material of any one of claims 1-9, wherein the degree of esterification of the pectin component is from about 30% to about 45% (% DE), or from about 35% to about 45%, or from about 37% to about 45%, and the molecular weight of the gelling citrus fiber material is from about 50 to about 200 kDa, or from about 50 to about 150 kDa, or from about 50 to about 125 kDa, or from about 50 to about 100 kDa, and the material is capable of forming a test gel having a gel strength of greater than about 200 g, or from about 200 g to about 500 g, or from about 225 g to about 500 g, or from about 275 g to about 500 g, or from about 300 g to about 500 g, or from about 300 g to about 400 g. 11. The gelling citrus fiber of any one of claims 1 to 10, wherein the degree of esterification in the pectin component is from about 46% to about 55% (% DE), or from about 47% to about 52%, or from about 47% to about 50%, and the molecular weight of the gelling citrus fiber material is from about 200 kDa to about 300 kDa, or from about 210 kDa to about 275 kDa, or from about 210 kDa to about 265 kDa, or from about 225 kDa to about 265 kDa, or from about 230 kDa to about 260 kDa, and capable of forming a test gel having a gel strength of less than about 200 g, or from about 100 g to about 200 g, or from about 110 g to about 180 g, or from about 125 g to about 175 g, or from about 130 g to about 170 g. 12. The gelling citrus fiber of any one of claims 1 to 11, wherein the degree of esterification is from about 10% to about 20% (% DE), or from about 10% to about 18%, or from about 10% to about 15%, the molecular weight of the material is from 100 kDa to about 200 kDa, or from about 100 kDa to about 150 kDa, or from about 100 kDa to about 125 kDa, and the fiber is capable of forming a test gel of less than about 100 g, or from about 10 g to about 100 g, or from about 20 g to about 100 g, or from about 25 g to about 100 g, or from about 25 g to about 80 g, or 25 g to about 75 g. 13. The gelled citrus fiber material of any one of claims 1 to 12, wherein the degree of esterification of the pectin component is from about 60% to about 65% (% DE), or from about 60% to about 63%, the molecular weight of the material is from 100 kDa to about 200 kDa, or from about 100 kDa to about 150 kDa, or from about 100 kDa to about 125 kDa, and the gel strength of the test gel is less than about 100 g, or from about 10 g to about 100 g, or from about 20 g to about 100 g, or from about 25 g to about 100 g, or from about 25 g to about 80 g, or from 25 g to about 75 g. 14. A gelled citrus fiber material according to any one of claims 1 to 13, wherein the gel strength of the test gel is measured at a temperature of about 20°C. 15. The gelled citrus fiber material of any one of claims 1-14, wherein the cellulosic component forms a matrix and at least a portion of the pectin component is present within the matrix. 16. A method for making the gelled citrus fiber material of any one of claims 1-15, comprising mixing ground citrus peel, comprising a pectin component and a cellulosic component, with an acidic solution to obtain acid washed citrus peel; mixing the acid washed citrus peel with an alkaline solution to reduce the degree of esterification (% DE) of the pectin component, thereby obtaining a de-esterified citrus peel; and recovering the de-esterified citrus peel to obtain a gelled citrus fiber material. 17. The method of claim 16, further comprising mixing the de-esterified citrus peel with a solution comprising an organic solvent to wash the de-esterified citrus peel, optionally the organic solvent being an alcohol, thereby obtaining a gelled citrus fiber material, and optionally the de-esterified citrus peel is washed with the organic solvent two or more times, preferably three times. 18. The method of claim 16 or 17, further comprising, prior to step a), obtaining a citrus peel material and grinding the citrus peel material to obtain ground citrus peel, optionally wherein the ground citrus peel is rehydrated prior to mixing with the acidic solution. 19. The method of any one of claims 16 to 18, wherein the acidic solution has a pH of less than 3, or from about 1.5 to about 2.5. 20. The method of any one of claims 16 to 19, wherein the crushed citrus peel is mixed with the acidic solution for about 10 minutes to about 90 minutes. 21. The method of any one of claims 16 to 20, wherein the crushed citrus peel is mixed with the acidic solution for a time period selected from the group consisting of about 10 minutes to about 30 minutes, about 30 minutes to about 50 minutes, and about 50 minutes to about 70 minutes. 22. The method of any one of claims 16 to 21, wherein the alkaline solution has a pH of greater than about 8, or greater than about 8.5, or from 8.5 to about 11, or from about 9 to about 10. 23. The method of any one of claims 16 to 22, wherein the acid washed citrus peel is mixed with the alkaline solution at a temperature of about 1°C to about 30°C. 24. The method according to any one of claims 16 to 23, wherein the acid-washed citrus peel is mixed with the alkaline solution at a temperature selected from the group consisting of about 1°C to about 10°C or about 3°C ​​to about 7°C, about 10°C to about 20°C or about 12°C to about 17°C, and about 20°C to about 30°C or about 22°C to about 27°C. 25. A method for monitoring a chemical reaction involving a material containing a pectin component and a cellulosic component, comprising recording a spectrum of the material and evaluating the spectrum against a model that correlates the spectrum to one or more second parameters of the pectin component or the cellulosic material containing the cellulosic component, wherein the spectrum is at least between about 1400 and about 845 cm. -1 Wavenumber range, (A) about 1400 to about 1050 cm -1 , (B) Approximately 1050~975cm -1 , (C) approx. 975~875cm -1 , and (D) about 875 and about 845 cm -1 and (A) one or more wavenumber ranges selected from the group consisting of about 1095 to about 1070 cm -1 , (B) Approx. 1050~1020cm -1 , (C) approx. 975~895cm -1 , and (D) about 875 to about 845 cm -1 wherein the chemical reaction converts the material to a gelled citrus fiber, preferably within one or more wavenumber ranges selected from the group consisting of: 26. The method of claim 25, wherein the spectrum is measured using infrared spectroscopy, preferably using Fourier transform infrared spectroscopy. 27. The method of claim 25 or 26, wherein the second parameter is selected from the group consisting of degree of esterification, total pectin component content, and molecular weight. 28. A method according to any one of claims 25 to 27, wherein the spectrum is recorded in a reaction vessel during a chemical reaction that alters the pectin component-containing cellulosic material, and optionally the chemical reaction alters one or more of the degree of esterification, the total pectin component content, or the molecular weight of the pectin component-containing cellulosic material. 29. The method according to any one of claims 25 to 28, wherein a spectrum is measured during the process according to any one of claims 28, preferably a spectrum is measured at least during the deesterification step. 30. The method of any one of claims 25 to 29, wherein a spectrum is recorded by measuring a sample collected from the reaction vessel, and optionally the chemical reaction changes one or more of the degree of esterification, total pectin component content, or molecular weight of the pectin component-containing cellulosic material. 31. A method according to any one of claims 25 to 30, wherein a spectrum is recorded from a sample obtained during the reaction according to any one of claims 25 to 30, preferably the spectrum is measured from a sample taken during the deesterification step. 32. The method of any one of claims 25 to 31, further comprising adjusting a parameter of a chemical reaction based on evaluation of the spectrum, optionally the parameter being associated with de-esterification of the material. 33. The method of any one of claims 25-32, further comprising recovering the gelled citrus fiber from the chemical reaction, wherein the gelled citrus fiber is as described in claims 1-15. 34. Use of a gelled citrus fiber material according to any one of claims 1 to 33 to modify the texture of a composition, optionally wherein the composition is a food composition. 35. Use of the gelling citrus fiber material according to claim 34, wherein the gelling citrus fiber is used as a gelling agent. 36. Use of a gelling citrus fiber material according to claim 34 or 35, wherein the gelling citrus fiber material is used in an amount of about 0.1% to about 10%, or about 0.5% to about 5% (by weight of the composition), or in an amount of about 1.5% to 4.5%, or about 2.5% to about 3.5%. 37. A composition comprising the gelled citrus fiber material of any one of claims 1-36 and a second component, optionally a food composition. 38. The composition of claim 37, wherein the second component is an aqueous component and the gelling citrus fiber material is used in an amount of about 0.1% to about 10%, or about 0.5% to about 5% (by weight of the composition), or in an amount of about 1.5% to 4.5%, or about 2.5% to about 3.5%. 39. A gelling fiber material comprising: a) a cellulosic component; and b) an associated pectin component in an amount of 40%-50% (% galacturonic acid (% GA)), or about 40% to about 48%, or about 40% to about 46%, or about 42% to about 48%, or about 42% to about 46%, wherein the pectin component has a degree of esterification (% DE) of about 10% to about 80%, and the gelling fiber material has a molecular weight of about 50 kDa to about 275 kDa.

[0071] The technology disclosed herein is further described with reference to the following non-limiting examples.

[0072] Example 1 - Method Gelled citrus fiber materials were prepared and measured for percent galacturonic acid ("%GA"), degree of esterification ("%DE"), and molecular weight measured in Daltons ("Da"). Solutions were also made using the prepared gelled citrus fiber materials and tested for gel strength measured in grams ("g"). As described above herein, %GA is used as a proxy for the pectin content of the gelled citrus fiber material, and thus is a proxy for the percentage of the gelled citrus fiber material that is a pectin component.

[0073] The degree of esterification (%DE) of pectin-containing cellulosic materials and the pectin content (%GA) of pectin-containing cellulosic materials were measured using a titration method. The method can be divided into two parts: (1) washing of the material, and (2) double titration. By washing the sample, any salts, sugars, and counterions are removed using acidic alcohol to ensure that all pectin is in esterified form or present as free acid. The first titration is used to determine the free acid groups, and then a neutral solution can be used in the second titration method proposed by Schultz (1965).

[0074] The process for washing the material follows. The dry powder sample is first tested for moisture content before washing. An acidic alcohol solution is prepared by mixing isopropanol (600m) with water (350ml) and concentrated hydrochloric acid (50ml). Approximately 10 grams of the sample is suspended in 150ml of acidic alcohol and stirred with a magnetic stirrer for 15 minutes. The slurry is then filtered through a Büchner funnel and resuspended in another 150ml aliquot of the acidic alcohol solution. This process was repeated until all of the acidic alcohol was used. The powder was then resuspended in 150ml of a 60 / 40 isopropanol / water mixture, allowed to soak for 5 minutes, and then the liquid was removed using a vacuum. This process was repeated three times. The sample was then resuspended again in 150ml of a high purity isopropanol mixture, allowed to soak for 5 minutes, and then the liquid was removed using a vacuum. This process was repeated three times. Using filter paper on a funnel, a vacuum was used to suck out the liquid and air until the sample no longer smelled of alcohol. The powder was then dried overnight at 45°C.

[0075] A double titration process followed. For the first titration, a 1.0 gram sample of dry material was weighed. The sample was then suspended in 10 ml of isopropanol and then dispersed in 150 ml of distilled water. If the sample became too viscous, more water was added. The dispersion was stirred for 1 hour using a magnetic stirrer and the pH was measured. The sample was titrated against sodium hydroxide solution (0.1 M) to pH 7. This measured the free acid groups. This was recorded as the first titer. For the second titration, about 40 ml of sodium hydroxide (0.1 M) was pipetted into a plastic beaker and stirred for 30 minutes. This removes the ester groups. The sample was then titrated with hydrochloric acid (0.1 M) to pH 7 and recorded as titer 2. The degree of esterification (%DE) is the molar ratio of esters to total GA.

[0076] The weight percent of galacturonic acid (%GA) is the combined weight of pectic acid and pectin (esters) divided by the dry weight of the sample:

[0077]

number

[0078]

number

[0079] Method for measuring molecular weight using gel permeation chromatography (GPC). A variety of instruments can be used. Reported samples were measured using a WATERS Alliance GPCV2000 equipped with a refractive index detector or an AGILENT 1260 Infinity II high temperature GPC equipped with a refractive index detector. Reported molecular weights are the average of the weight fractions over the observed distribution and are weight average molecular weights relative to pullulan standards.

[0080] Method for measuring gel strength - After curing, gel strength was measured using a texture analyzer (Texture Technologies) using an AOAC probe (T10) advanced at 0.5 mm / sec for a distance of 20 mm with a trigger force of 1 g (trigger force is the minimum force required to start recording data). Gel strength values ​​were measured from the first break (break force in grams). The trigger force is the force point that the instrument must detect / reach before the measurement begins.

[0081] Example 2 - Exemplary Process for Making Gelled Citrus Fiber Materials Whole dried citrus peels (519.3 g) were dry milled through a 1.5 mm screen using a Fitzmill followed by a kitchen mill to obtain a fine particle size. The peels were then mixed into tap water (25° C., 6266 g) with stirring using an overhead mixer. The mixture (7% solids) was rehydrated by stirring at 25° C. for 1 hour. The mixture was dehydrated using a Buchner funnel, flask, and grade 113 wet strength filter paper to obtain wet peels (2331 g) and filtrate (4390 g). The wet peels were reslurried to 7% solids by adding tap water (25° C., 4454 g). The acidity of the slurry was adjusted to pH 1.7 (170.7 g of 3N HCl). The slurry was held at 25° C. for 1 hour. The mixture was dewatered again to give wet acidified peels (4320 g) and filtrate (2190.4 g). The wet acidified peels were reslurried to 7% solids by adding tap water (25° C., 2465 g). The mixture was stirred for 30 minutes during the water wash.

[0082] The mixture was dehydrated again to obtain clean washed citrus peels (2426 g) and filtrate (2190.4 g). The clean peels were reslurried to 7% solids by adding pre-chilled tap water (4595 g) and the mixture was cooled to 5° C. The reaction mixture was monitored using an infrared spectroscopy ("IR") probe inserted into the reaction vessel. Sodium carbonate monohydrate (27 g) was added to the mixture to adjust the pH to 9. The mixture was maintained at pH 9 for approximately 18 hours at 4° C. using a pH controller and peristaltic pump and 25% sodium carbonate solution (25.12 g). The mixture was then collected and neutralized to pH 4-5 by adding citric acid monohydrate (1 hour: 14.52 g, 18 hours: 84.06 g).

[0083] The collected samples were washed with alcohol. An equal volume of alcohol was stirred into the samples for 20 minutes. The mixture was dehydrated using a Buchner funnel and a solvent rated vacuum pump. The wash was repeated two more times for a total of three times. The dried orange peel raw materials and products were then placed in an oven and dried overnight at 40°C.

[0084] The sample made by the exemplary method is referred to herein as Sample 1. It had a total pectin content of 45.49±0.28 (%GA), a percent degree of esterification (%DE) of 62.56±0.60, and a molecular weight of 142,000 (Da).

[0085] Example 3 - Exemplary Process for Making Gels from Gelled Citrus Fiber Materials Test gels were prepared as specified, but for convenience the formulations (listed in Table 1) and methods are repeated below.

[0086] [Table 2]

[0087] Please note in the formula that filtered tap water 1-4 refers to the addition of filtered tap water at four different times in the process in the amounts indicated, but otherwise there is no difference between filtered tap water 1-4. The filter used was a standard drinking water filter. The gel was made as follows: Filtered tap water 1 was weighed and placed in a plastic beaker equipped with a stirring bar. Fibers were weighed and dispersed in filtered tap water 1 with stirring. The mixture was stirred for about 15 minutes. Sodium hexametaphosphate and sugar were weighed and added to the dispersion. The pH of the mixture was then adjusted to pH 4 using hydrochloric acid dropwise using a plastic pipette (if necessary). The mixture was then transferred to a pre-weighed stainless steel beaker (600 ml) and heated to 70-80°C in a water bath with stirring. After reaching the set temperature, the mixture was kept in the bath for 10 minutes.

[0088] In a separate plastic beaker, pre-weighed 2 parts of filtered tap water and calcium hydrogen phosphate were mixed together. After shaking, the calcium solution was added to the fiber mixture.

[0089] In another separate plastic beaker, 3 portions of filtered tap water and glucono-delta-lactone were pre-weighed and mixed together to dissolve the lactone. After mixing, the solution was added to the fiber mix. 4 portions of filtered tap water were weighed and used to wash off any remaining lactone or calcium mixture on the beaker. The wash solution was added to the fiber mix. The fiber mix was removed from the water bath and weighed. For a 100g formulation, the total weight of the solution was approximately 100g. If not, filtered tap water was used to rehydrate. The fiber mix was then divided into 4 equal portions and allowed to cool at ambient temperature for 24 hours.

[0090] Example 4 - Comparison of gelled citrus fiber materials By varying the process of Example 3, various gelled citrus fiber materials were made. The resulting samples were tested for pectin content (%GA), degree of esterification (%DE), and molecular weight (Da) (weight average Mw). The resulting gelled citrus fiber was used to form solutions as described in Example 1 and observed to determine whether the solutions formed gels and, if so, what the gel strength (g) was. The properties of the resulting gelled citrus fiber and the gel strength of the gels obtained from the gelled citrus fiber are shown in Table 3.

[0091] [Table 3] * Raw crushed orange peel.

[0092] Samples 0-15 were prepared by varying the temperature of the deesterification reaction, the pH of the deesterification reaction, the length of the acid wash, and the pH of the acid wash. The relevant conditions used to prepare samples 0-15 are reported in Table 4.

[0093] [Table 4]

[0094] To highlight the relationships between the parameters, Table 5 below repeats the data from Table 3 but sorted from high to low degree of esterification. Cohorts are generated to group similar gel strengths.

[0095] [Table 5] * Raw crushed orange peel.

[0096] Cohort 4 had the gelling citrus fiber material that formed the strongest gels, greater than about 200 g. The gelling citrus fiber material in Cohort 4 generally had a moderate degree of esterification, between about 35% and 45%, and had a medium to low molecular weight of between 50,000 and 200,000 Da.

[0097] Cohort 2 had gelled citrus fiber material that formed moderately strong gels at 100-200 g of Cohort 2. The gelled fiber material of Cohort 2 generally had a higher degree of esterification of 45%-55% than the gelled citrus fiber material of Cohort 4. The gelled fiber material of Cohort 3 also generally had a higher molecular weight, greater than about 200,000 Da, compared to Cohort 4.

[0098] The gelled citrus fiber materials that formed the weakest gels were present in Cohort 1 and Cohort 5. The gelled citrus fiber materials of Cohort 5 had a low degree of esterification, less than about 20%. The gelled citrus fiber materials of Cohort 1 had a high degree of esterification, greater than about 60%.

[0099] The amount of pectin (%GA) was similar between samples compared to the differences in degree of esterification and molecular weight.

[0100] Example 5 - Functional Effects of Acid Washing Acid washing was found to be important to obtain gelled citrus fibres that formed strong gels. The effect of acid is seen by preparing samples as follows: Samples were prepared by taking whole dried citrus peels and dry grinding followed by kitchen grinding to obtain a fine particle size. The peels were then mixed in tap water with stirring using an overhead mixer. The mixture was rehydrated by stirring for 6 minutes at 25°C. The mixture was dehydrated using a Buchner funnel, flask and grade 113 wet strength filter paper to obtain wet peels and the filtrate was collected and weighed. The rehydrated peels were reslurried by adding tap water (25°C).

[0101] In this experiment, sample E146 was not acid washed, whereas sample E145 was acid washed. For the acid wash, the acidity of the slurry was adjusted to pH 2.5 and held at 25°C for 20 minutes. The mixture was dewatered again to obtain wet acidified peels and a filtrate. The wet acidified peels were reslurried by adding unfiltered tap water (25°C). After the acid wash, samples E145 and E146 were processed using the same reaction conditions. Sodium carbonate monohydrate was added to the mixture to raise the pH to pH 10. The mixture was maintained at pH 10 for 2 hours at 25°C using a pH controller and peristaltic pump and a 25% sodium carbonate solution. The reaction mixture was then pH adjusted to pH 4-5 by adding citric acid monohydrate. The mixture was then alcohol washed. An equal amount of alcohol was stirred in the sample for 20 minutes. The mixture was dewatered using a Buchner funnel and a solvent rated vacuum pump. Washing was repeated two more times for a total of three times. The dried orange peel raw material and product were then placed in an oven and dried overnight at 40° C. The dried product was tested for total pectin, degree of esterification (DE), and gel strength. The recovered material was used to form gels as described in Example 2. The gels were measured for gel strength using the method described in Example 1.

[0102] The results are reported in Table 6 and show that samples E145 and E146 had similar total pectin and degree of esterification, but the acid washed sample (E145) formed a much stronger gel. Samples E145 and E146 were also compared with untreated dried orange peel.

[0103] [Table 6]

[0104] Example 6 - Modeling and process control of the deesterification reaction With reference to the reaction described in Example 1. In particular, as described above, the reaction mixture was monitored using an IR probe inserted into the reaction vessel. IR spectra were measured using Fourier transform infrared spectroscopy ("FTIR"). An FTIR spectrometer (Bruker Optics, Matrix MF) coupled with a diamond attenuated total reflectance (ATR) fiber probe (Bruker Optics, IN356-EX) was placed next to the reaction tank to collect spectra every 30 seconds during the material processing and deesterification reaction steps. Spectra were measured using a 4 cm -1 With a resolution of 3500 to 650 cm -1 Spectral spectra were collected from a wavenumber range of 100 nm to 100 nm. A probe (with a diameter of 12 mm and a total fiber length of 2 m) was inserted and fixed securely in the vessel for the length of the reaction (up to 18 h). The instrument and spectral collection were controlled by OPUS software (Bruker Optics).

[0105] To develop an IR model for real-time process monitoring, the in-line system was first used (to collect IR spectra) in a series of reactions (referred to as training reactions) that produced a wide range of de-esterification products. The in-process and final products of these training reactions were tested by the titration method described herein to determine the actual degree of esterification. To develop a model that predicts the degree of esterification from the comparison, a partial least squares ("PLS") regression was formulated (using OPUS software) to correlate the collected in-line spectra with the degree of esterification measured using the titration method.

[0106] Once the model was developed, it was tested in a new reaction to verify the predictive performance of the model. To test / implement the developed model for in-line process monitoring, IR spectra were collected during the deesterification reaction and the IR model was immediately applied to each spectrum (in real time by the OPUS software) to predict the degree of esterification value at the time of collection. Samples were collected at the time the IR model was applied and titration was used to measure the degree of esterification to determine the measurement error of the predictive model. The IR model predictions and titration measurements of the degree of esterification are reported in Table 7 below.

[0107] [Table 7]

[0108] A second model was developed for rapid "off-line" IR measurements, meaning that the IR spectral model can be applied to samples withdrawn from the reaction vessel instead of being measured within the reaction vessel, allowing faster degree of esterification calculations than is possible using titration measurements.

[0109] Training samples were acquired and run on IR spectra using a ThermoFisher Nicolet iS10 spectroscopy equipped with an attenuated total reflectance (ATR) accessory (PIKE Technologies). System suitability (i.e., system boot and internal calibration) was measured using the built-in software and background spectra were acquired. The benchtop FTIR was acquired as follows: Approximately 0.025 g of powdered sample was placed on the diamond crystal probe. All scans were run from 4000 to 650 cm. -1 From the wavenumber range, 32 scans, 4 cm -1 Resolution, collected in triplicate. Spectral models were developed from training runs using spectra generated from in-line and final product reaction samples that correlated to the degree of esterification for such samples obtained using titration. To develop a model to predict the degree of esterification from the comparison, a partial least squares (PLS) regression was formulated to correlate the collected spectra with the degree of esterification measured using the titration method.

[0110] Once the model was developed, it was tested in new reactions to verify the predictive performance of the model. To test / implement the developed model for offline process monitoring, samples were collected during and at the end of each reaction, scanned with an IR instrument, and the IR model was applied to predict the degree of esterification. The same samples were also tested by titration, and the predicted IR degree of esterification values ​​were compared with the degree of esterification measured by titration to evaluate the validity of the IR model.

[0111] The IR model predictions and titration measurements of the degree of esterification are reported in Table 8 below.

[0112] [Table 8] * The value is rounded to the nearest integer.

[0113] With respect to Tables 7 and 8, the model developed as described accurately predicted the degree of esterification based on the FTIR spectra of pectin-containing cellulosic materials, as shown when validated against the titration method.

Claims

1. 1. A gelled citrus fiber material comprising: a) a cellulosic component; b) associated de-esterified pectin components in an amount of 40%-50% (% galacturonic acid (% GA)), or 40%-48%, or 40%-46%, or 42%-48%, or 42%-46%, the pectin component has a degree of esterification (% DE) of 10% to 80%; the gelled citrus fiber material has a weight average molecular weight of 50 kDa to 275 kDa; Optionally, said gelled citrus fiber material is obtained from citrus peel.

2. The pectin component is a. 30% to 45% (% DE), or 35% to 45%, or 37% to 45%, b. 46% to 55% (% DE), or 47% to 52%, or 47% to 50%, c. 10% to 20% (% DE), or 10% to 18%, or 10% to 15%, and d. The gelled citrus fiber material of claim 1 having a degree of esterification selected from the group consisting of: 60% to 65% (% DE); or 60% to 63%.

3. The material is a. 50-200 kDa, or 50-150 kDa, or 50-125 kDa, or 50-100 kDa; b. 200 kDa to 300 kDa, or 210 kDa to 275 kDa, or 210 kDa to 265 kDa, or 225 kDa to 265 kDa, or 230 kDa to 260 kDa, and c. The gelled citrus fiber material of claim 1 or 2, having a weight average molecular weight selected from the group consisting of: 100 kDa to 200 kDa, or 100 kDa to 150 kDa, or 100 kDa to 125 kDa.

4. the degree of esterification of the pectin component is between 30% and 45% (% DE), or between 35% and 45%, or between 37% and 45%; 3. A gelled citrus fibre material according to claim 1 or 2, wherein the molecular weight of the material is from 50 to 200 kDa, or from 50 to 150 kDa, or from 50 to 125 kDa, or from 50 to 100 kDa.

5. the degree of esterification in the pectin component is between 46% and 55% (% DE), or between 47% and 52%, or between 47% and 50%; 3. A gelled citrus fibre material according to claim 1 or 2, wherein the molecular weight of the material is from 200 kDa to 300 kDa, or from 210 kDa to 275 kDa, or from 210 kDa to 265 kDa, or from 225 kDa to 265 kDa, or from 230 kDa to 260 kDa.

6. the degree of esterification is from 10% to 20% (% DE), or from 10% to 18%, or from 10% to 15%, 3. A gelled citrus fibre material according to claim 1 or 2, wherein the molecular weight of the material is from 100 kDa to 200 kDa, or from 100 kDa to 150 kDa, or from 100 kDa to 125 kDa.

7. 3. The gelled citrus fiber material of claim 1 or 2, wherein the cellulosic component forms a matrix and at least a portion of the pectin component is present within the matrix.

8. A method for making the gelled citrus fiber material of claim 1, comprising: a. mixing comminuted citrus peel, including a pectin component and a cellulosic component, with an acidic solution to obtain an acid washed citrus peel; b. mixing the acid washed citrus peel with an alkaline solution to reduce the degree of esterification (% DE) of the pectin component, thereby obtaining a de-esterified citrus peel; c) recovering said de-esterified citrus peel to obtain said gelled citrus fiber material.

9. 9. The method of claim 8, further comprising mixing the de-esterified citrus peel with a solution comprising an organic solvent to wash the de-esterified citrus peel, optionally the organic solvent being an alcohol, thereby obtaining a gelled citrus fiber material, and optionally the de-esterified citrus peel is washed with the organic solvent two or more times, preferably three times.

10. The method according to claim 8 or 9, wherein the acidic solution has a pH of less than 3, or between 1.5 and 2.

5.

11. The ground citrus peel is mixed with the acidic solution for 10 minutes to 90 minutes; Optionally, the crushed citrus peel is mixed with the acidic solution; a. 10 to 30 minutes, b. 30 minutes to 50 minutes, and c. The method of claim 8 or 9, wherein the mixing is performed for a period of time selected from the group consisting of: 50 minutes to 70 minutes.

12. 10. The method of claim 8 or 9, wherein the alkaline solution has a pH of greater than 8 or greater than 8.5, or from 8.5 to 11, or from 9 to 10.

13. The acid-washed citrus peel is mixed with the alkaline solution at a temperature between 1° C. and 30° C.; Optionally, the acid washed citrus peel is treated with the alkaline solution and a. 1°C to 10°C, or 3°C to 7°C; b. 10°C to 20°C, or 12°C to 17°C, and The method of claim 8 or 9, wherein mixing is performed at a temperature selected from the group consisting of 20°C to 30°C, or 22°C to 27°C.

14. 1. A method for monitoring a chemical reaction involving a material comprising a pectin component and a cellulosic component, comprising: a. recording a spectrum of the material; b. evaluating the spectrum against a model that correlates the spectrum to a second parameter of one or more of the pectin component or the cellulosic component-containing cellulosic material, wherein the spectrum comprises at least: i. 1400-845cm －１ The wavenumber range of ii. (A) 1400-1050cm －１ , (B) 1050-975cm －１ , (C) 975-875cm －１ , and (D) 875 and 845 cm －１ One or more wavenumber ranges selected from the group consisting of: iii. (A) 1095-1070cm －１ , (B) 1050-1020cm －１ , (C) 975-895cm －１ , and (D) 875 to 845 cm －１ one or more wavenumber ranges selected from the group consisting of: Preferably, the chemical reaction converts the material into gelling citrus fiber.

15. 15. The method of claim 14, wherein the second parameter is selected from the group consisting of degree of esterification, total pectin component content, and molecular weight.

16. 16. The method of claim 14 or 15, wherein the spectrum is recorded in a reaction vessel during a chemical reaction that changes the pectin component-containing cellulosic material, and optionally the chemical reaction changes one or more of the degree of esterification, total pectin component content, or molecular weight of the pectin component-containing cellulosic material.

17. 3. A composition comprising the gelled citrus fiber material of claim 1 or 2 and an edible aqueous component, the composition being a food composition.

18. The composition of claim 17, wherein the gelling citrus fiber material is used in an amount of 0.1% to 10% or 0.5% to 5% (by weight of the composition), or in an amount of 1.5% to 4.5% or 2.5% to 3.5%.

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