ZEIN extraction and paper coating process for sustainable packaging

Abstract

A method for extracting zein from a zein-containing material and applying it as a coating on paper material. The method involves batch or continuous extraction of zein from a zein-containing material by adding ethanol to the zein-containing material to form a zein-ethanol mixture; separating ethanol from zein in the zein-ethanol mixture by addition of water to form a separated zein-ethanol mixture; and utilizing the separated zein-ethanol mixture in a coating process with a paper material as a substrate.

Description

[0001] TITLE OF THE INVENTION

[0002] ZEIN EXTRACTION AND PAPER COATING PROCESS FOR SUSTAINABLE

[0003] PACKAGING

[0004] CROSS-REFERENCE TO RELATED APPLICATIONS

[0005] The present application claims priority to U.S. Provisional Appl. No. 63 / 678,666, filed August 2, 2024, the entire contents of which are incorporated herein by reference.

[0006] FIELD OF THE INVENTION

[0007] The present invention provides a method for extraction of zein protein from a zeincontaining material (e.g., corn or a corn-derived product), the separation of ethanol used in the extraction process, and the subsequent application of zein as a barrier coating on paper for sustainable packaging solutions.

[0008] DISCUSSION OF THE BACKGROUND

[0009] Zein, a com-derived protein, has a long history of exploration for various industrial applications. While its potential as a sustainable alternative to petroleum-based coatings in packaging is recognized, the current extraction and application processes are costly and inefficient. The expensive membrane filtration and energy-intensive spray drying methods currently used limit zein's widespread adoption.

[0010] In view of the foregoing, there remains a critical need in the art to provide cost- effective and efficient processes to create coatings based on zein. The present invention solves this need. SUMMARY OF THE INVENTION

[0011] It is an object of the present invention to address the current challenges in zein extraction and application by introducing a novel and cost-effective method.

[0012] Specifically, an object of the present invention is a method for extracting zein from a zein-containing material and applying it as a coating on paper material. The method involves batch or continuous extraction of zein from a zein-containing material by adding ethanol to the zein-containing material to form a zein-ethanol mixture; separating ethanol from zein in the zein-ethanol mixture by addition of water to form a separated zein-ethanol mixture; and utilizing the separated zein-ethanol mixture in a coating process with a paper material as a substrate.

[0013] The above objects highlight certain aspects of the invention. Additional objects, aspects and embodiments of the invention are found in the following detailed description of the invention.

[0014] BRIEF DESCRIPTION OF THE FIGURES

[0015] A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following Figures in conjunction with the detailed description below.

[0016] Figure 1 shows a set up for ethanol removal.

[0017] DETAILED DESCRIPTION OF THE INVENTION

[0018] Unless specifically defined, all technical and scientific terms used herein have the same meaning as commonly understood by a skilled artisan in in chemistry, coatings, and adhesives. All methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, with suitable methods and materials being described herein. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control. Further, the materials, methods, and examples are illustrative only and are not intended to be limiting, unless otherwise specified.

[0019] The preferred embodiments of the present invention will now be described with reference to the drawings. Identical elements in the various figures are identified with the same reference numerals.

[0020] Reference will now be made in detail to each embodiment of the present invention. Such embodiments are provided by way of explanation of the present invention, which is not intended to be limited thereto. In fact, those of ordinary skill in the art may appreciate upon reading the present specification and viewing the present drawings that various modifications and variations can be made thereto.

[0021] In an embodiment, the present invention provides a method for extracting zein from a material (e.g., corn).

[0022] In an embodiment, the method for extracting zein from com comprises adding ethanol to a material containing zein-protein to produce a zein-ethanol mixture and subsequently diluting the zein-ethanol mixture with water.

[0023] In an embodiment of the present invention, the starting material (i.e., the material containing zein protein; also referred to as a “feed material” or “zein-containing material”) is corn, a material derived from corn, or a com-based product.

[0024] In an embodiment of the present invention, the starting material may be any of the following: (i) whole, raw corn, (ii) whole, raw corn that has been subjected to dry grinding, (iii) wet-milled corn, (iv) com that is not wet-milled, (v) flaked corn treated as in any of the foregoing, (vi) corn processing by-products such as DDG or DDGS (distillers dried grains and distillers dried grains with solubles, respectively), corn gluten meal, corn germ, or com meal.

[0025] In an embodiment, the starting material is a corn gluten meal or a corn meal. In an embodiment, the starting material is a corn gluten meal. Com gluten meal provides particularly advantageous benefits including decreased impurities like, for example, aggregated proteins, lipids, and high molecular weight species.

[0026] In an embodiment, the starting material is pre-treated to control the moisture content of the zein-containing material. Controlling the moisture content is particularly advantageous to ensure that the concentration of ethanol solution is not diluted beyond useful ranges.

[0027] In an embodiment, the moisture (e.g., water) content of the zein-containing material is controlled to be about 0-15% by weight. Exemplary amounts are 15 wt% or less, 12.5 wt wt% or less, 10 wt% or less, 7.5 wt% or less, 5 wt% or less, 4 wt% or less, 3 wt% or less, 2.5 wt% or less, 2 wt% or less, 1 wt% or less. It is understood that the complete absence of moisture may be difficult to obtain, as such a minimum moisture threshold that can be mentioned is 0.1 wt%, 0.25 wt%, 0.5 wt%, 0.75 wt%, 1 wt%, 1.25 wt%, 1.5 wt%, 1.75 wt%, and 2 wt%. In this embodiment, it is envisioned that the moisture content range is defined by a lower threshold value and an upper threshold value. For example, the moisture content can range from 0.1 wt% to 12.5 wt%, 0.25 wt% to 10 wt%, 0.5 wt% to 7.5wt%, or 1 wt% to 5 wt%.

[0028] Zein protein is found in four different types in com: alpha-zein, beta-zein, gammazein, and delta-zein. The difference between these zein types lies in the amino-acid profile, which impacts the properties of the respective zein types. The predominant commercially available zein is almost entirely of alpha-zein (one cysteine). However, the melt strength of this zein is low. Beta-zein and gamma-zein contain greater number of cysteine amino acid bases, at 12 and 15 cysteine respectively.

[0029] Thus, zein formulations with greater concentrations of beta- and gamma-zein may have higher melting temperatures and greater plasticity. Accordingly, it is envisioned in the present invention that the properties of the coatings obtained by the methods disclosed herein can be tuned based on the relative amounts of the respective zein types. In a particular embodiment, the zein composition may be controlled to include alpha-, beta- and gammazein. In some embodiments, the beta- and gamma-zein may comprise from about 12% to about 60% of the zein in the zein composition. In other embodiments, beta and gamma zein content (relative to all zein present) may be higher, such as at least 25%, 35% and 40% to a maximum amount of 60 %. Exemplary ranges of beta- and gamma-zein include 12 % to 60%, 15% to 55%, 20% to 50%, 25% to 45%, and 30 to 40%. Reference is made to U.S. Pat. No. 9,487,565, incorporated herein by reference, which discloses compositions and control of the relative amounts of the different zein types.

[0030] In an embodiment, the zein is extracted from the zein-containing material by extraction with ethanol. For effective zein extraction, it is advantageous to control the amount of ethanol when forming the zein-ethanol mixture. Failure to control the ethanol amount in the extraction step can lead to an increase in the zein-ethanol mixture of impurities including oils and other lipids, as well as a decrease in the amount of zein recovered.

[0031] In an embodiment, the amount of ethanol in the zein-ethanol mixture is at least 60 %, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, and at least 95%. The maximum theoretical amount of ethanol is 100%; however, due to the hydroscopic nature of ethanol, water is quickly drawn into the mixture. As such, the practical upper limit is 95% ethanol. Exemplary ranges include 60 to 95%, 65 to 90%, and 70 to 85%. Maximum extraction efficiency and purity is a function of, at least, the starting material and the ethanol concentration. Zein on its own is insoluble in water, so the more ethanol present, the better the extraction will be. Thus, coupling a selection of a dried com product (e.g., corn gluten meal or corn meal) allows for the use of the highest concentration of ethanol to be used in the extraction. Although the theoretical maximum is 100% when starting with a dry material, the practical upper limit is closer to 95% as noted above.

[0032] In an embodiment, extraction is conducted by a batch process. The type of batch reactors is not particularly limiting so long as the ethanol is substantially (i.e., at least 90% of the starting volume) is maintained within the reactor. An example of a batch reactor is a reflux reactor.

[0033] In an embodiment, extraction is conducted by a continuous extraction process. As an example of a continuous reactor, a kneader reactor is mentioned. A kneader reactor would advantageous permit rolling out zein in sheets or film materials. Another example of a continuous reactor is a continuous-counter current extractor which would allow for a liquidliquid extraction process. Further, at higher water contents, it is advantageous to separate the zein-ethanol mixture into two layers (water and then ethanol-zein) and then utilizing the ethanol-zein layer for subsequent uses.

[0034] The extraction is conducted at an extraction temperature of 50-90° C (e.g., 55-85°C, 60-80° C, 65-75°C). Further, when a batch extraction is performed, an extraction time of 10 to 120 minutes., 15 to 100 minutes, 17.5 to 80 minutes, 20 to 60 minutes, and 30 to 45 minutes are mentioned.

[0035] The absence or presence of oils may be selected depending upon the end use and properties desired. To this end, oil extraction from corn typically uses approximately 90- 100% ethanol. Around or below 90% ethanol the efficiency drops off, but oil extraction is fairly efficient at >95% ethanol. Therefore, another possibility is to extract some (if not all) of the zein from the corn but without extracting the oils. In this situation, an embodiment would maintain the ethanol in the extraction step to be within the range of, for example, 60 to 90%, 65 to 85%, 70 to 75%.

[0036] In the foregoing methods, an embodiment includes where the extraction solvent is only a mixture of ethanol and water.

[0037] In an embodiment, the extraction solvent can include other additives including other alcohols, for example isopropyl alcohol. Other alcohol that could be used during the extraction process include 1 -hexanol or longer hydrocarbon alcohols. The benefit to using this could be to remove any strongly hydrophobic materials like oils and lipids that may not be wanted. The use of other alcohols, however, could potentially interfere with the extraction process by pulling out more unwanted materials than needed. The more hydrophobic the alcohol becomes (whether the alcohol is linear or branched), the more material is extracted which could hinder the quality of the zein-ethanol mixture. In some uses, this higher material extraction could be beneficial and desired as a neater / cleaner final material would be more predictable to work with and, thus, reduce product variance. Thus, in an embodiment, the amount of additives or additional alcohols added during extraction is no more than 10 wt%, no more than 7.5 wt%, no more than 5 wt%, no more than 2.5 wt%.

[0038] In an embodiment, following extraction of zein from a starting material, the zein-ethanol mixture is separated by water dilution.

[0039] To achieve effective separation, a sufficient amount of water is added to dilute the effective ethanol concentration to be no more than 40 wt%, no more than 35%, no more than 30 wt%, no more than 25 wt%, no more than 20 wt%, no more than 15 wt%, no more than 10 wt%. To achieve this dilution, at least 60%, at least 70%, at least 80%, at least 85%, at least 90% water is added, In an embodiment, the method of the present invention is performed without a membrane filtration and / or spray drying step.

[0040] It is known that zein is soluble in aqueous alkaline solutions of pH 11 or higher. Thus, in an embodiment, the zein-aqueous ethanol solution is diluted with water and then the aqueous ethanol with the zein precipitated out is decanted off. While the zein is still wet with ethanol, the slurry / paste is added to an aqueous alkaline solution of sodium hydroxide having a pH of 11 or more, 11.5 or more, 12 or more, or 12.5 or more. The resulting solution comprises a highly concentrated zein composition with a minimal amount of ethanol. In an embodiment, the concentration of zein in the composition is 5 to 20% w / v, 7.5 to 17.5% w / v, or 10 to 15% w / v. In an embodiment, the ethanol percentage in the zein composition is 10% or less, 7.5% or less, 5% or less, 2.5% or less, or 1% or less. While basic solutions are caustic, the skilled artisan would envision means to prevent damage to equipment. However, the far lower amount of ethanol mitigates the flammability of the resulting mixture, which is advantageous to downstream uses.

[0041] As noted above, an embodiment of the invention is where there is no membrane filtration or spray drying step. With the elimination of these steps it is possible that the resulting composition contains com solids and any co-extracted materials including oil / lipids. In an embodiment, relative to the total amount of zein, other corn solids, and co-extracted materials, the zein represents at least 55 wt%, at least 60 wt%, at least 65 wt%, at least 70 wt%, at least 75 wt%, at least 80 wt%, at least 82.5 wt%, at least 85 wt%, at least 87.5 wt%, at least 90 wt%, at least 92.5 wt%, at least 95 wt%, at least 97.5 wt% or 100 wt%.

[0042] To minimize the non-zein solids content, in an embodiment, during the extraction process vacuum filtration of the zein-ethanol solution is performed.

[0043] With respect to co-extracted oils and lipids, it is desired in the present invention to minimize the content thereof. Possible negative effects of including oils and lipids in a downstream coating process includes inefficient adhesion to the substrate being coated. However, it may be advantageous to include some oil and / or lipids in the final composition. For example, oils can add to the hydrophobic character of composition and may improve water resistivity of the coating. In an embodiment, the total amount of oils and / or lipids is 40 wt% or less, 35 wt% or less, 30 wt% or less, 25 wt% or less, 20 wt% or less, 15 wt% or less, 12.5 wt% or less, 10 wt% or less, 7.5 wt% or less, 5 wt% or less, 2.5 wt% or less, or 0 wt%. As a lower limit to any of the foregoing upper limits 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt% or 5 wt% are mentioned.

[0044] The separated zein-ethanol mixture can be used directly in a coating and drying process or it may be stored for future use. If stored, in an embodiment, the separated zein- ethanol mixture is stored for up to 6 months at a temperature ranging from 15 to 45°C. With respect to storage time, mentioned are up to 6 months, up to 5 months, up to 4 months, up to 3 months, up to 2 months, up to 1 month, up to 14 days, up to 7 days, up to 3 days, up to 24 hours. Storage conditions in an embodiment are a temperature of 15 to 45°C, 20 to 40 °C, or 25 to 35°C. In an embodiment, the relative humidity of the storage vessel is 80% or lower, 75% or lower, 70% or lower, 65% or lower, 60% or lower, 55% or lower, 50% or lower, 45% or lower, 40% or lower 35% or lower, 30% or lower, or 25% or lower.

[0045] The separated zein-ethanol mixture can be loaded in and transported via a tote to a coating production line. In an embodiment, the coating production line is a paper coating production line.

[0046] Prior to use in a coating process, it is possible to add one or more additive to the separated zein-ethanol mixture. Additives include UV-resistance agents, anti-microbials, flame-retardants, filler materials beyond the active zein component like cellulose, sawdust, or other bio-mass, colorants, thickeners, etc. In an embodiment, the coating process is a paper coating process which is followed by a drying step. Although any paper coating process can be adapted for use with the separated zein-ethanol mixture, in an embodiment, the separated zein-ethanol mixture is applied to a paper material using a high-volume sprayer and then dried at 15 to 20°C. Drying may be performed in an oven. This process drives off the remaining ethanol, which can be recovered.

[0047] In an embodiment, the paper material is a woven or non-woven material. In an embodiment, the paper material is made from a wide variety of materials such as cotton, wheat straw, sugar cane waste, flax, bamboo, wood, linen rags, hemp, and recycled paper products.

[0048] In an embodiment, the residual ethanol in the coating following the coating process is less than 5%, less than 4.5%, less than 4%, less than 3.5%, less than 3%, less than 2.5%, less than 2%, less than 1.5%, less than 1%, less than 0.5%, or 0%. In an embodiment, the coating is free of any volatile organic compounds.

[0049] In an embodiment, the ethanol is removed from the coating by using a closed system, for example a vacuum oven or an ambient temperature vacuum. In this system, a sufficiently high pressure would be needed to distill off the ethanol into a solvent trap. At a sufficiently high pressure, the drying time can be limited to less than 2 hours, less than 1.5 hours, less than 1 hour, less than 45 minutes, less than 30 minutes, less than 15 minutes.

[0050] An example of a set up for ethanol removal is shown in Fig. 1. This set up utilizes a distillation column and cooling unit to condense the ethanol back into its neat form.

[0051] In a process variant, it is possible to use an elevated temperature of 25 to 30°C and, thus, the drying can be performed at a temperature ranging from 15 to 30°C. Higher temperatures lead to safety issues the flashpoint or ignition of ethanol. However, it is possible to start within a range of 15 to 50°C or 25 to 30°C and then increase the temperatures and / or pressures to decrease the drying time. An example of combining temperature and vacuum pressure is 25-30 °C with vacuum pressures of 95 mbar (boiling at 25 °C) or 123 mbar (boiling at 30 °C).

[0052] Odors in the coating or off-gassing during the coating process can be eliminated by using deodorizers or activated carbon filters.

[0053] The process of the present invention offers several advantages over existing methods:

[0054] 1. Reduced Costs: By eliminating expensive membrane filtration and spray drying, the cost of zein extraction and application is significantly reduced.

[0055] 2. Enhanced Efficiency: The batch extraction and water separation steps streamline the process and improve overall efficiency. An extruder process might be even more streamlined.

[0056] 3. Sustainable: The potential for ethanol recovery aligns with sustainable practices.

[0057] 4. Scalability: The method is adaptable to large-scale production.

[0058] The present invention is exemplified by the following embodiments:

[0059] [1] A method for extracting zein from a zein-containing material and applying it as a coating on paper material, comprising: a) Batch or continuous extraction of zein from a zein-containing material by adding ethanol to said zein-containing material to form a zein-ethanol mixture; b) Separating ethanol from zein in said zein-ethanol mixture by addition of water to form a separated zein-ethanol mixture; and c) Utilizing the separated zein-ethanol mixture in a coating process with a paper material as a substrate.

[0060] [2] The method of [1], wherein said zein-containing material is corn. [3] The method of [1] or [2], wherein said zein-containing material is selected from the group consisting of (i) whole, raw corn, (ii) whole, raw com that has been subjected to dry grinding, (iii) wet-milled com, (iv) corn that is not wet-milled, (v) flaked com treated as in any of the foregoing, and (vi) a com processing by-product.

[0061] [4] The method of any of [1] - [3], wherein said zein-containing material is a corn process by-product selected from the group consisting of distillers dried grains, distillers dried grains with solubles, corn gluten meal, corn germ, and corn meal.

[0062] [5] The method of any of [1] - [4], wherein said zein-containing material is a corn gluten meal or a corn meal.

[0063] [6] The method of any of [1] - [5], wherein the moisture content in the zeincontaining material is 15 wt% or less.

[0064] [7] The method of any of [1] - [6], wherein 12 to 60 wt% of all zein present is beta- and / or gamma-zein.

[0065] [8] The method of any of [1] - [7], the amount of ethanol in step (a) is at least 60%.

[0066] [9] The method of any of [1] - [8], wherein said extraction is a batch extraction process.

[0067]

[0010] The method of [9], wherein said extraction is at an extraction temperature of from 50 to 90°C and for an extraction time of 10 to 120 minutes.

[0068]

[0011] The method of any of [1] - [8], wherein said extraction is a continuous extraction process.

[0069]

[0012] The method of

[0011] , wherein said continuous extraction process utilizes a kneader reactor or a continuous-counter current extractor.

[0070]

[0013] The method of

[0011] or

[0012] , wherein said extraction is at an extraction temperature of from 50 to 90°C.

[0014] The method of any of [1] -

[0013] , wherein said extraction further comprises one or more additional alcohols selected from the group consisting of isopropyl alcohol and 1- hexanol.

[0071]

[0015] The method of any of [1] -

[0014] , wherein said separating is by adding sufficient water to dilute the effective ethanol concentration to be no more than 40 wt%.

[0072]

[0016] The method of any of [1] -

[0015] , wherein said separating is by adding sufficient water to dilute the effective ethanol concentration to be no more than 20 wt%.

[0073]

[0017] The method of any of [1] -

[0016] , further comprising between (b) and (c) decanting a fraction of the separated zein-ethanol mixture which contains aqueous ethanol with the zein precipitated out; adding an aqueous alkaline solution of sodium hydroxide having a pH of 11 or more; and recovering a highly concentrated zein composition.

[0074]

[0018] The method of any of [1] -

[0017] , wherein said method does not utilize a membrane filtration or spray drying step.

[0075]

[0019] The method of any of [1] -

[0018] , wherein between (b) and (c) the ethanol / zein is transported via a tote.

[0076]

[0020] The method of any of [1] -

[0019] , wherein before (c) one or more additives are added to the separated zein-ethanol mixture.

[0077]

[0021] The method of

[0020] , wherein the additive is selected from the group consisting of a UV-resistance agent, an anti-microbial, a flame-retardant, a filler material, a colorant, and a thickener.

[0078]

[0022] The method of any of [1] -

[0021] , wherein the paper material is a woven or nonwoven material.

[0079]

[0023] The method of any of [1] -

[0022] , wherein the paper material is made from a material selected from the group consisting of cotton, wheat straw, sugar cane waste, flax, bamboo, wood, linen rags, hemp, and a recycled paper product.

[0024] The method of any of [1] -

[0023] , wherein the coating process comprises coating the paper material with the separated zein-ethanol mixture and drying the coated paper material.

[0080]

[0025] The method of

[0024] , wherein said coating is by a high-volume sprayer.

[0081]

[0026] The method of

[0024] or

[0025] , wherein said drying is at 15 to 30°C.

[0082]

[0027] The method of any of

[0024] -

[0026] , wherein the ethanol released during drying is recovered.

[0083] In the context of the present description, all publications, patent applications, patents and other references mentioned herein, if not otherwise indicated, are explicitly incorporated by reference herein in their entirety for all purposes as if fully set forth, and shall be considered part of the present disclosure in their entirety.

[0084] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. In case of conflict, the present specification, including definitions, will control.

[0085] The descriptions of the various embodiments of the present invention have been presented for purposes of illustration, but are not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein was chosen to best explain the principles of the embodiments, the practical application or technical improvement over technologies found in the marketplace, or to enable others or ordinary skill in the art to understand the embodiments disclosed herein.

[0086] Except where expressly noted, trademarks are shown in upper case.

[0087] Unless stated otherwise, all percentages, parts, ratios, etc., are by weight. When an amount, concentration, or other value or parameter is given as a range, or a list of upper and lower values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper and lower range limits, regardless of whether ranges are separately disclosed. Where a range of numerical values is recited herein, unless otherwise stated, the range is intended to include the endpoints thereof, and all integers and fractions within the range. It is not intended that the scope of the present disclosure be limited to the specific values recited when defining a range. Further, where a numerical limit or range is stated herein, the endpoints are included. Also, all values and subranges within a numerical limit or range are specifically included as if explicitly written out.

[0088] Further, unless otherwise explicitly stated to the contrary, when one or multiple ranges or lists of items are provided, this is to be understood as explicitly disclosing any single stated value or item in such range or list, and any combination thereof with any other individual value or item in the same or any other list.

[0089] When the term “about” is used, it is used to mean a certain effect or result can be obtained within a certain tolerance, and the skilled person knows how to obtain the tolerance. When the term "about" is used in describing a value or an end-point of a range, the disclosure should be understood to include the specific value or end-point referred to.

[0090] As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having" or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0091] The transitional phrase "consisting of' excludes any element, step, or ingredient not specified in the claim, closing the claim to the inclusion of materials other than those recited except for impurities ordinarily associated therewith. When the phrase "consists of appears in a clause of the body of a claim, rather than immediately following the preamble, it limits only the element set forth in that clause; other elements are not excluded from the claim as a whole.

[0092] The transitional phrase "consisting essentially of limits the scope of a claim to the specified materials or steps and those that do not materially affect the basic and novel character! stic(s) of the claimed invention. A “consisting essentially of’ claim occupies a middle ground between closed claims that are written in a “consisting of’ format and fully open claims that are drafted in a “comprising” format. Optional additives as defined herein, at a level that is appropriate for such additives, and minor impurities are not excluded from a composition by the term “consisting essentially of’.

[0093] As used herein, an "embodiment" means that a particular feature, structure or characteristic is included in at least one or more manifestations, examples, or implementations of this invention. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to a person skilled in the art. Combinations of features of different embodiments are all meant to be within the scope of the invention, without the need for explicitly describing every possible permutation by example. Thus, any of the claimed embodiments can be used in any combination.

[0094] Further, unless expressly stated to the contrary, “and / or” refers to an inclusive and not to an exclusive. Thus, “and / or” should be understood to mean “either or both” of the elements so conjoined, e.g., elements that are conjunctively present in some cases and disjunctively present in other cases. For example, a condition A and / or B, is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present). The use of "a" or "an" to describe the various elements and components herein is merely for convenience and to give a general sense of the disclosure. This description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise. Similarly, the adjective “another,” when used to introduce an element, is intended to mean one or more elements. The terms “including” and “having” are intended to be inclusive such that there may be additional elements other than the listed elements.

[0095] The above written description of the invention provides a manner and process of making and using it such that any person skilled in this art is enabled to make and use the same, this enablement being provided in particular for the subject matter of the appended claims, which make up a part of the original description.

[0096] As used herein, the phrases “selected from the group consisting of,” “chosen from,” and the like include mixtures of the specified materials.

[0097] The above written description of the invention provides a manner and process of making and using it such that any person skilled in this art is enabled to make and use the same, this enablement being provided in particular for the subject matter of the appended claims, which make up a part of the original description.

[0098] Although this invention has been described with a certain degree of particularity, it is to be understood that the present disclosure has been made only by way of illustration and that numerous changes in the details of construction and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention.

[0099] The above description is presented to enable a person skilled in the art to make and use the invention, and is provided in the context of a particular application and its requirements. Various modifications to the preferred embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Thus, this invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein. It is, therefore, to be understood that within the scope of the accompanying claims, the invention may be practiced otherwise than as specifically described herein.

[0100] Numerous modifications and variations on the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the accompanying claims, the invention may be practiced otherwise than as specifically described herein.

Claims

CLAIMSWhat we claim is1. A method for extracting zein from a zein-containing material and applying it as a coating on paper material, comprising: a) Batch or continuous extraction of zein from a zein-containing material by adding ethanol to said zein-containing material to form a zein-ethanol mixture; b) Separating ethanol from zein in said zein-ethanol mixture by addition of water to form a separated zein-ethanol mixture; and c) Utilizing the separated zein-ethanol mixture in a coating process with a paper material as a substrate.

2. The method of claim 1, wherein said zein-containing material is selected from the group consisting of (i) whole, raw corn, (ii) whole, raw corn that has been subjected to dry grinding, (iii) wet-milled com, (iv) corn that is not wet-milled, (v) flaked com treated as in any of the foregoing, and (vi) a corn processing by-product.

3. The method of claim 1, wherein said zein-containing material is a com process byproduct selected from the group consisting of distillers dried grains, distillers dried grains with solubles, com gluten meal, com germ, and corn meal.

4. The method of claim 1, wherein said zein-containing material is a com gluten meal or a corn meal.

5. The method of claim 1, wherein the moisture content in the zein-containing material is 15 wt% or less.

6. The method of claim 1, wherein 12 to 60 wt% of all zein present is beta- and / or gamma-zein.

7. The method of claim 1, the amount of ethanol in step (a) is at least 60%.

8. The method of claim 1, wherein said extraction is a batch extraction process at an extraction temperature of from 50 to 90°C and for an extraction time of 10 to 120 minutes.

9. The method of claim 1, wherein said extraction is a continuous extraction process utilizing a kneader reactor or a continuous-counter current extractor and said extraction is at an extraction temperature of from 50 to 90°C.

10. The method of claim 1, wherein said separating is by adding sufficient water to dilute the effective ethanol concentration to be no more than 40 wt%.

11. The method of claim 1, further comprising between (b) and (c) decanting a fraction of the separated zein-ethanol mixture which contains aqueous ethanol with the zein precipitated out; adding an aqueous alkaline solution of sodium hydroxide having a pH of 11 or more; and recovering a highly concentrated zein composition.

12. The method of claim 1, wherein said method does not utilize a membrane filtration or spray drying step.

13. The method of claim 1, wherein between (b) and (c) the ethanol / zein is transported via a tote.

14. The method of claim 1, wherein before (c) one or more additives are added to the separated zein-ethanol mixture and said additive is selected from the group consisting of a UV-resistance agent, an anti-microbial, a flame-retardant, a filler material, a colorant, and a thickener.

15. The method of claim 1, wherein the paper material is a woven or non-woven material.

16. The method of claim 1, wherein the paper material is made from a material selected from the group consisting of cotton, wheat straw, sugar cane waste, flax, bamboo, wood, linen rags, hemp, and a recycled paper product.

17. The method of claim 1, wherein the coating process comprises coating the paper material with the separated zein-ethanol mixture and drying the coated paper material.

18. The method of claim 17, wherein said coating is by a high-volume sprayer.

19. The method of claim 17, wherein said drying is at 15 to 30°C.

20. The method of claim 17, wherein ethanol released during drying is recovered.

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