Method for dewaxing edible oils

Abstract

The present disclosure relates to dewaxing of edible oils, such as flavor oils and plant oils. A method for dewaxing an edible oil, the process comprising contacting the edible oil with an effective amount of a biopolymer to produce a mixture comprising the edible oil and a precipitate, and separating the precipitate from the mixture produced, is described herein.

Description

[0001] METHOD FOR DEWAXING EDIBLE OILS

[0002] Field of the Disclosure

[0003] The present disclosure relates to dewaxing of edible oils, such as flavor oils and plant oils.

[0004] Background of the Disclosure

[0005] Edible oils, such as flavor oils and plant oils, have many applications in the food and perfumery industries. Edible oils are typically extracted from natural sources and wax tends to sediment during storage, which affects the appearance of the oils. For instance, citrus oils usually contain 3-5% of wax, which is a mixture of non-volatiles mainly comprising carotenoids, flavonoids, coumarins, diterpenoids, sterols and fatty acids. The wax usually precipitates upon storage.

[0006] A process known as winterization is usually conducted to remove the undesirable wax from edible oils. A common winterization procedure includes cooling and storing the edible oil at a low temperature, for example, -10 °C, so the wax crystallizes. The crystallized wax can then be removed by a filtration or decantation process. While winterization is a well-known method for removing undesirable waxes that precipitate in the edible oils, it is a very time-consuming and inefficient process. More than a month is usually required to complete the process and further sedimentation often occurs in the de-waxed oils during storage due to the incomplete removal of the wax. Therefore, reprocessing of the oils is often needed, leading to additional processing costs.

[0007] Methods of removing wax from oils are known. For example, WO 2009 / 033306 describes a method for removing wax from citrus oils using various membranes. However, the method is limited to a filtration process, particularly on oils that have already been subjected to multiple concentration (“folding”) processes, which likely removed many materials involved in wax formation. Also known are methods used for clarifying alcoholic solutions. WO 2010 / 069028 describes purifying and polishing alcohol with natural hydrocolloids used as clarifying agents. However, the process is limited to hydro-alcoholic solutions and fails to address removing wax from undiluted edible oils.

[0008] CN 111234921 (Shandong Xiwang Food Co. Ltd.) discloses a process for refining oil rich in natural antioxidants, specifically com oil.

[0009] CN 110172372 (Jilin Baili Biotechnology Co. Ltd.) relates to vegetable oil refining, in particular to a dewaxing gel and an application thereof in a method for dewaxing evening primrose oil.

[0010] CN 103589508 (Li Ning) relates to an environment-friendly filtering process for edible oil using 0.1 % cellulose.

[0011] Therefore, there is an ongoing need for improved dewaxing methods to accelerate and enhance the efficacy of the winterization process without compromising the quality of the edible oil being dewaxed.

[0012] Summary of the Disclosure

[0013] The following aspects of the present disclosure seek to address one or more of the problems described hereinabove.

[0014] In a first aspect, the present disclosure relates to a method for dewaxing an edible oil, the process comprising:

[0015] (a) contacting the edible oil with an effective amount of a biopolymer to produce a mixture comprising the edible oil and a precipitate;

[0016] (b) separating the precipitate from the mixture produced in step (a), thereby obtaining a dewaxed edible oil.

[0017] In a second aspect, the present disclosure relates to a substantially wax-free edible oil produced by the method described herein. Brief Description of the Figures

[0018] FIG. 1 shows the amount of crystallized wax formed during storage at -10 °C under various treatment methods.

[0019] FIG. 2 shows the amount of crystallized wax collected at different filtration temperatures.

[0020] FIG. 3 shows the amount of crystallized wax formed during storage at -10 °C under other various treatment methods.

[0021] Detailed Description

[0022] As used herein, the terms “a”, “an”, or “the” means “one or more” or “at least one” unless otherwise stated.

[0023] While compositions and methods are described in terms of “comprising,” “containing,” or “including” various components or steps, the compositions and methods can also “consist essentially of” or “consist of” the various components, substances and steps. As used herein the term “consisting essentially of” shall be construed to mean including the listed components, substances or steps and such additional components, substances or steps which do not materially affect the basic and novel properties of the composition or method. In some embodiments, a composition in accordance with embodiments of the present disclosure that “consists essentially of” the recited components or substances does not include any additional components or substances that alter the basic and novel properties of the composition.

[0024] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in the art to which this specification pertains. It should be understood that any numerical range recited herein is intended to include all sub-ranges subsumed therein. For example, a range of “1 to 10” is intended to include all sub-ranges between and including the recited minimum value of 1 and the recited maximum value of 10; that is, having a minimum value equal to or greater than 1 and a maximum value of equal to or less than 10. Because the disclosed numerical ranges are continuous, they include every value between the minimum and maximum values. Unless expressly indicated otherwise, the various numerical ranges specified in this application are approximations.

[0025] As used herein, and unless otherwise indicated, the term “about” or “approximately” means an acceptable error for a particular value as determined by one of ordinary skill in the art, which depends in part on how the value is measured or determined. In certain embodiments, the term “about” or “approximately” means within 1 , 2, 3, or 4 standard deviations. In certain embodiments, the term “about” or “approximately” means within 50%, 20%, 15%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1 %, 0.5%, or 0.05% of a given value or range.

[0026] Throughout the present disclosure, various publications may be incorporated by reference. Should the meaning of any language in such publications incorporated by reference conflict with the meaning of the language of the present disclosure, the meaning of the language of the present disclosure shall take precedence, unless otherwise indicated.

[0027] In the first aspect, the present disclosure relates to a method for dewaxing an edible oil, the process comprising:

[0028] (a) contacting the edible oil with an effective amount of a biopolymer to produce a mixture comprising the edible oil and a precipitate;

[0029] (b) separating the precipitate from the mixture produced in step (a), thereby obtaining a dewaxed edible oil.

[0030] As used herein, an edible oil is any oil that is capable of being ingested and would include flavoring aromatics or oils, oleoresins and extracts derived from plants, leaves, flowers, fruits, and so forth. Edible oils are typically extracted from natural sources using known methods, such as steam distillation, expression, solvent extraction, supercritical fluid extraction (SFE), steam explosion, ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE), sfumatura, absolute oil extraction, resin tapping, wax embedding, cold pressing, and the like. Edible oils may be folded or non-folded. As understood by a person of ordinary skill in the art, a folded oil refers to an oil that has been subjected to one (i.e. , single-fold) or more (i.e., five-fold, ten-fold, 15-fold, etc.) concentration steps.

[0031] At least one advantage provided by the method of the present disclosure is the ability to remove higher amounts of wax from edible oil without subjecting the edible oil to multiple folding steps. A folding step involves further concentrating the oil by, for example, re-distillation. Such a step may remove materials involved in wax formation but may also remove components that are essential for desirable organoleptic properties. The method of the present disclosure is suitable for both folded and non-folded oils. However, in an embodiment, the edible oil is non-folded or single-folded edible oil.

[0032] In an embodiment, the edible oil is a flavor oil or a plant oil. Exemplary flavor oils include, but are not limited to, those selected from the group consisting of spearmint oil, cinnamon oil, oil of Wintergreen, peppermint oil, Japanese mint oil, clove oil, bay oil, anise oil, eucalyptus oil, thyme oil, cedar leaf oil, oil of nutmeg, allspice, oil of sage, mace, oil of bitter almonds, cassia oil, vanilla, citrus oil, and any combination thereof.

[0033] As used herein, citrus oil refers to oil derived from citrus fruits. Exemplary citrus oils include, but are not limited to, lemon oil, orange oil, lime oil, grapefruit oil, yuzu oil, sudachi oil, bergamot oil, kumquat oil, pummelo oil, and any combination thereof. In an embodiment, the flavor oil is a citrus oil selected from the group consisting of lemon oil, orange oil, lime oil, grapefruit oil, yuzu oil, sudachi oil, and any combination thereof.

[0034] In an embodiment, the edible oil is a plant oil. As used herein, a plant oil is any oil that is derived from plant sources. Exemplary plant oils include, but are not limited to, those selected from the group consisting of sunflower oil, coconut oil, soya oil, castor oil, canola oil, peanut oil, sesame oil, olive oil, rapeseed oil, palm oil, peanut oil, camellia seed oil, cottonseed oil, rice bran oil, com oil, and any combination thereof.

[0035] In some instances, certain edible oils are not contemplated. Therefore, in some embodiments, the edible oil is not a plant oil. In some particular embodiments, the edible oil is not primrose oil or corn oil.

[0036] As used herein, the term “biopolymer” refers to biomacromolecules produced by living organisms. Biopolymers are characterized by molecular weight distributions ranging from 1 ,000 (1 thousand) to 1 ,000,000,000 (1 billion) Daltons. These macromolecules may be polysaccharides or carbohydrates (sugar-based) or proteins (amino-acid based) or a combination of both (gums) and can be linear or branched. Biopolymers may be unmodified or modified by known means, for example, by means of chemical derivatization to chemically graft on different functional groups to provide certain properties.

[0037] Exemplary biopolymers are those selected from the group consisting of alginates, xanthans, carrageenans, chitosans, pectins, such as high methoxyl pectin and low methoxyl pectin; gellans, agar-agar, hydroxycellulose, hydroxymethylcellulose, hydroxypropylcellulose, hydroxyethylcellulose, dextrin, maltodextrin, edible fiber, and any combination thereof.

[0038] In an embodiment, the biopolymer is an edible fiber. As used herein, the term “edible fiber” is any fiber that can be ingested, such as dietary fiber. As understood by a person of ordinary skill in the art, dietary fiber consists of non-starch polysaccharides and other plant components such as cellulose, resistant starch, resistant dextrin, inulin, lignin, chitin, pectin, beta-glucan, and oligosaccharides. Dietary fibers can act by changing the nature of the contents of the gastrointestinal tract and by changing how other nutrients and chemicals are absorbed. Dietary fibers include soluble fibers, insoluble fibers, and partially soluble dietary fibers. The term “partially soluble dietary fibers” refers to fibers, which are partially soluble in water. Soluble fibers are generally known as fibers that completely dissolve in solvent, typically water, or can exist within the solvent such as water in high amounts. Partially soluble dietary fibers dissolve if a small but still perceptible amount of the fiber is added to a solvent, but they do not dissolve if too much is added. Insoluble fibers do not dissolve in a perceptible way in solvent such as water. Partially soluble fiber is known to provide an advantageous effect on the absorption and balance of calcium, magnesium, iron, and zinc in a diet rich in this kind of fiber.

[0039] In an embodiment, the edible fiber is a dietary fiber selected from the group consisting of sugar beet fiber, pea fiber, soybean dietary fiber, oat dietary fiber, wheat dietary fiber, citrus fiber, and any combination thereof.

[0040] In an embodiment, the edible fiber is citrus fiber. Citrus fiber can be obtained from from commercial sources or from processing citrus peel and / or pulp using known methods. In an exemplary process, the process comprises treating citrus peel and / or pulp to obtain homogenized citrus peel and / or pulp; washing the homogenized citrus peel and / or pulp with an organic solvent to obtain organic solvent washed citrus peel and / or pulp; drying the organic solvent washed citrus peel and / or pulp; and recovering citrus fiber therefrom. Commercially available citrus fiber, such as Citri-Fi 100M40 marketed by Fiberstar Inc., are also suitable.

[0041] According to the method of the present disclosure, contacting the edible oil with an effective amount of a biopolymer produces a mixture comprising the edible oil and a precipitate. Without wishing to be bound by theory, the biopolymer provides nucleation sites, or seeds, at which wax crystals can readily form, thereby precipitating the wax contained in the edible oil. The effective amount of the biopolymer is the minimum amount required to cause the precipitation of the wax crystals contained in the edible oil and can be determined using known methods, such as adding the biopolymer and observing the formation of precipitate. In an embodiment, the effective amount of the biopolymer is from 0.01 % to 1 %, typically from 0.025 % to 0.5 %, by weight relative to the weight of the edible oil. Step (b) of separating the precipitate from the mixture produced in step (a) may be conducted using any suitable method known to those of ordinary skill in the art. For instance, the mixture comprising the edible oil and precipitate may be spun on a centrifuge to create a pellet containing the precipitate and a supernatant containing the edible oil. The edible oil is then recovered by decanting the supernatant. Alternatively, the mixture created in step (a) can be filtered.

[0042] In an embodiment, separating the precipitate from the mixture produced in step (a) comprises filtering the mixture. The type of membrane suitable for use in the filtration step is not particularly limited. Suitable membranes include, but are not limited to, ceramic, metal, graphite, or polymer membranes. In an embodiment, the mixture is filtered through a hydrophilic membrane, typically PVDF hydrophilic membrane (such as Durapore® marketed by Merck Millipore). The pore size of the filtration membrane is not particularly limited. However, in some embodiments, the mixture is filtered through a membrane having a pore size of from 0.05 to 5 pm, typically from 0.05 to 0.5 pm.

[0043] The temperature at which step (b) is conducted is not particularly limited. However, in some embodiments, step (b) is conducted at a temperature of from -10 °C to 15 °C, typically from 0 °C to 10 °C.

[0044] The method described herein may optionally comprise additional steps to increase the amount of precipitate to be removed from the edible oil, thereby reducing the need to re-process an oil that has already undergone a winterization process.

[0045] In an embodiment, the edible oil is subjected to a cooling step prior to step (a) or after step (a). The temperature at which the edible oil is cooled is not particularly limited and may be optimized based on the nature of the edible oil. However, in an embodiment, the edible oil is cooled at a temperature of from -20 °C to 0 °C, typically from -15 °C to -5 °C.

[0046] In an embodiment, the edible oil is subjected to a cooling step prior to step (a). Therefore, in such an embodiment, the method comprises: (a1 ) cooling the edible oil;

[0047] (a2) contacting the edible oil with an effective amount of a biopolymer to produce a mixture comprising the edible oil and a precipitate;

[0048] (b) separating the precipitate from the mixture produced in step (a), thereby obtaining a dewaxed edible oil.

[0049] The present disclosure provides a method in which the rate of formation of precipitate or the amount of precipitate formed is increased compared to the rate of formation of precipitate and / or amount of precipitate formed in the same method in which biopolymer is replaced with pre-crystallized wax. Mention is made of the use of a biopolymer to produce a mixture comprising the edible oil and a precipitate in a dewaxing method, such as the method described herein.

[0050] In the second aspect, the present disclosure relates to a substantially wax-free edible oil produced by the method described herein. The substantially wax-free edible oil produced by the method described herein may be used in areas of perfumery and flavors and incorporated into fragrance compositions, perfumed consumer products, or comestible products.

[0051] The method according to the present disclosure is further illustrated by the following non-limiting examples.

[0052] Example 1

[0053] 15 g single folded orange oil (available from Firmenich) was placed in a 20 mL of glass vial and heated at 40°C for 2 hrs. After heat treatment, the sample was stored at -10°C. Crystallized wax was collected by filtration at 4 °C using a 0.1 pm of PVDF hydrophilic membrane (Durapore® available from Merck Millipore) and dried in a vacuum oven at 35 °C for 24 hrs. The crystallized wax adhered on the glass wall of the vials was also collected using the same drying method. The amount of crystallized wax formed during storage at -10°C was determined (filtration at 4 °C) every 24 hours afterwards and illustrated in FIG. 1 and designated as “Treatment A”.

[0054] Example 2 The same treatment described in Example 1 was applied to the orange oil, except that 0.5% of pre-crystallized wax was added to the orange oil before the heat treatment. The amount of crystallized wax formed during storage at -10°C was determined (filtration at 4 °C) every 24 hours afterwards and illustrated in FIG. 1 and designated as “Treatment B”.

[0055] Example 3

[0056] The same treatment described in Example 1 was applied to the orange oil, except that 0.5% of pre-crystallized wax was added to the orange oil after the sample was stored at -10°C for 24 hrs. The amount of crystallized wax formed during storage at - 10°C was determined (filtration at 4 °C) every 24 hours afterwards and illustrated in FIG. 1 and designated as “Treatment C”.

[0057] Example 4

[0058] The same treatment described in Example 1 was applied to the orange oil, except that 0.1 % of citrus fiber (Citri-Fi 100M40 available from Fiberstar Inc.) was added to the orange oil before the heat treatment. The amount of crystallized wax formed during storage at -10°C was determined (filtration at 4 °C) every 24 hours afterwards and illustrated in FIG. 1 and designated as “Treatment D”.

[0059] Example 5

[0060] The same treatment described in Example 1 was applied to the orange oil, except that 0.1 % of citrus fiber (Citri-Fi 100M40 available from Fiberstar Inc.) was added to the orange oil after the sample was stored at -10°C for 24 hrs. The amount of crystallized wax formed during storage at -10°C was determined (filtration at 4 °C) every 24 hours afterwards and illustrated in FIG. 1 and designated as “Treatment E”.

[0061] As can be see in FIG. 1 , the crystallization rate of wax was significantly accelerated by the addition of 0.1% citrus fiber, especially when added after the orange oil was cooled at -10°C for 24 hrs (Treatment E). The amount of crystallized wax reached a plateau following an 8-day and 22-day storage at -10°C in treatment E and treatment D, respectively. The amount of crystallized wax in Treatment A reached a plateau after 23 days, while Treatments B and C did not reach plateaus within 29 days. Example 6

[0062] The procedures described in Examples 1 to 6 were repeated, except that on day 24, the filtration was conducted at room temperature (ca. 25 °C), different from the 4°C on day 23. The amount of crystallized wax formed during storage at -10°C was recorded and illustrated in FIG. 2.

[0063] As shown in FIG. 2, the amount of crystallized wax was much higher when filtrated at 4 °C.

[0064] Example 7

[0065] Orange oils were subjected to the treatment described in Example 5 (Treatment E), except that the amount of citrus fiber that is added to the orange oil was varied. The de-waxed oils were collected 24 hrs after the initial treatment (Day 1 ) and at later times (Day 4, 8, and 11 ). The quality of the de-waxed oils was checked by storing the oils again at -10°C for 24 hrs to see if there was any precipitate, and the appearances are summarized in Table 1 below.

[0066] Table 1. x; Precipitated o: Clear

[0067] As shown in Table 1 , the addition of citrus fiber increased the de-waxing efficacy.

[0068] Example 8

[0069] The same treatment described in Example 1 was applied to the orange oil, except that 0.1 % of high methoxyl pectin (“Treatment F”), low methoxyl pectin (“Treatment G”), dextrin (“Treatment H”) or maltodextrin (“Treatment I”) was added in the orange oil before the heat treatment. The amount of crystallized wax formed during storage at -10 °C for 33 days was determined and illustrated in FIG. 3 and designated as Treatments F-l.

[0070] As can be seen in the figure, all the biopolymers added to the orange oil can facilitate the formation of wax, thereby increasing dewaxing efficiency.

[0071] The disclosed subject matter has been described with reference to specific details of particular embodiments thereof. It is not intended that such details be regarded as limitations upon the scope of the disclosed subject matter except insofar as and to the extent that they are included in the accompanying claims. Therefore, the exemplary embodiments described herein are well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the exemplary embodiments described herein may be modified and practiced in different but equivalent manners apparent to those of ordinary skill in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered, combined, or modified and all such variations are considered within the scope and spirit of the exemplary embodiments described herein. The exemplary embodiments described herein illustratively disclosed herein suitably may be practiced in the absence of any element that is not specifically disclosed herein and / or any optional element disclosed herein.

Claims

CLAIMS1 . A method for dewaxing an edible oil, the process comprising:(a) contacting the edible oil with an effective amount of a biopolymer to produce a mixture comprising the edible oil and a precipitate;(b) separating the precipitate from the mixture produced in step (a), thereby obtaining a dewaxed edible oil.

2. The method according to claim 1 , wherein the edible oil is a flavor oil or a plant oil.

3. The method according to claim 2, wherein the edible oil is a flavor oil, typically selected from the group consisting of spearmint oil, cinnamon oil, oil of Wintergreen, peppermint oil, Japanese mint oil, clove oil, bay oil, anise oil, eucalyptus oil, thyme oil, cedar leaf oil, oil of nutmeg, allspice, oil of sage, mace, oil of bitter almonds, cassia oil, vanilla, citrus oil, typically lemon oil, orange oil, lime oil, grapefruit oil, yuzu oil, sudachi oil, and any combination thereof.

4. The method according to claim 2, wherein the edible oil is a plant oil, typically selected from the group consisting of sunflower oil, coconut oil, soya oil, castor oil, canola oil, peanut oil, sesame oil, olive oil, rapeseed oil, palm oil, peanut oil, camellia seed oil, cottonseed oil, rice bran oil, corn oil, and any combination thereof.

5. The method according to any one of claims 1 to 4, wherein the biopolymer is selected from the group consisting of alginates, xanthans, carrageenans, chitosans, pectins, such as high methoxyl pectin and low methoxyl pectin; gellans, agar-agar, hydroxycellulose, hydroxymethylcellulose, hydroxypropylcellulose, hydroxyethylcellulose, dextrin, maltodextrin, edible fiber, and any combination thereof.

6. The method according to claim 5, wherein the biopolymer is an edible fiber, typically citrus fiber, high methoxyl pectin, low methoxyl pectin, dextrin, maltodextrin, or a combination thereof.

7. The method according to any one of claims 1 to 6, wherein the effective amount of the biopolymer is from 0.01 % to 1 %, typically from 0.025 % to 0.5 %, by weight relative to the weight of the edible oil.

8. The method according to any one of claims 1 to 7, wherein separating the precipitate from the mixture produced in step (a) comprises filtering the mixture.

9. The method according to claim 8, wherein the mixture is filtered through a membrane having a pore size of from 0.05 to 5 pm, typically from 0.05 to 0.5 pm.

10. The method according to any one of claims 1 to 9, wherein step (b) is conducted at a temperature of from -10 °C to 15 °C, typically from 0 °C to 10 °C.11 . The method according to any one of claims 1 to 10, wherein the edible oil is subjected to a cooling step prior to step (a) or after step (a).

12. The method according to claim 11 , wherein the edible oil is cooled at a temperature of from -20 °C to 0 °C, typically from -15 °C to -5 °C.

13. The method according to any one of claims 1 to 12, wherein the method comprises:(a1 ) cooling the edible oil;(a2) contacting the edible oil with an effective amount of a biopolymer to produce a mixture comprising the edible oil and a precipitate;(b) separating the precipitate from the mixture produced in step (a), thereby obtaining a dewaxed edible oil.

14. The method according to any one of claims 1 to 13, wherein the rate of formation of precipitate or the amount of precipitate formed is increased compared to the rate of formation of precipitate and / or amount of precipitate formed in the same method in which biopolymer is replaced with pre-crystallized wax.

15. A substantially wax-free edible oil produced by the method according to any one of claims 1 to 14.

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