Corn protein having decreased ethanol and method for manufacturing the same

Abstract

The disclosure relates to corn product and a method of making the same. The corn product has about or less than 1 wt% ethanol and a loss on drying in a range of about 3 – 9 wt% on a dry basis. A method of removing ethanol from a protein material is also disclosed herein.

Description

PT-1285-WO-PCTCORN PROTEIN HAVING DECREASED ETHANOL AND METHOD FOR MANUFACTURING THE SAMECROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 572,958, filed April 2, 2024, which is incorporated by reference herein in its entirety.BACKGROUND

[0002] The process for production of food-grade corn product involves treatment with ethanol (EtOH) to remove pigments and undesired compounds from the corn product. A food ingredient containing a low concentration of residual EtOH is desirable by users. Additionally, recovering EtOH from the corn product for re-use decreases not only operating costs but also environmental release of a volatile organic carbon. The removal of EtOH was originally assumed to be a minor matter and easily performed at elevated temperature combined with vacuum. In fact, it has been difficult to remove EtOH from the corn protein material under a variety of conditions.

[0003] In view of the demand for safe, economical, and environmentally benign plant proteins, there is a need for a com product having less EtOH and an improved method for producing such corn product.SUMMARY

[0004] The present disclosure provides a method of making a com product comprising the steps of providing a com protein material comprising at most about 80 wt% of ethanol on a dry basis, evaporating the corn protein material at a first temperature of 80 - 120°C to obtain a primary desolventized material, and exposing the primary desolventized material to an exposure atmosphere at 60 - 100% relative humidity and at a second temperature of 40 - 80°C to obtain the corn product. The com product has about or less than 1 wt% ethanol and a loss on drying in a range of about 3 - 9 wt% on a dry basis. Also described herein is the corn product produced by the above method. Further, a method of removing ethanol from a protein material is also disclosed herein.PT-1285-WO-PCTBRIEF DESCRIPTION OF THE FIGURES

[0005] This patent or application contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawings will be provided by the Office upon request and the payment of the necessary fee.

[0006] The drawings illustrate generally, by way of example, but not by way of limitation, various aspects discussed in the present document.

[0007] FIGS. 1A to IE show the response of loss on drying (LOD) to temperature and relative humidity at time points of 5, 10, 15, 30, and 45 minutes.

[0008] FIGS. IF to II show the response of residual ethanol (EtOH) concentration to temperature and relative humidity at time points of 5, 10, 15, 30, and 45 minutes.

[0009] FIG. 2 shows the change in LOD as a function of temperature and relative humidity at short treatment times. In the legend, Tx-RHx indicates the temperature-relative humidity treatment condition.

[0010] FIGS. 3 A to 3F show the computed desirability of conditions at 2.5-minute intervals until 15 minutes of treatment where the desired LOD being in the range of 4% and 8% and the desired residual EtOH concentration being in a range of 0.01% to 0.5%.

[0011] FIG. 4 show the removal of EtOH (expressed as % of initial EtOH concentration) over time at four temperatures (40°C, 60°C, 80°C, and 100°C) under dry condition (0% RH).

[0012] FIGS. 5A and 5B show the loss of EtOH at 40°C (FIG. 5A) and 100°C (FIG. 5B) at five relative humidities (0%, 40%, 60%, 80%, and 100%).

[0013] FIGS. 6A and 6B show the effect of the bed depths of the container holding samples of the primary desolventized materials (treated at 70°C and 70% RH on LOD and loss of EtOH.DETAILED DESCRIPTION

[0014] Described herein is a corn product and a method for making the corn product. The corn product comprises about or less than 1 weight percent (wt%) of ethanol (EtOH) and a loss on drying (LOD) in a range of about 3 - 9 wt% on a dry basis (db). The corn product is suitable for human and / or animal consumption.

[0015] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one skilled in the art to which this invention belongs. As used herein, each of the following terms has the meaning associated with it as defined below.PT-1285-WO-PCT

[0016] In one aspect, the content of EtOH in the com product (residual EtOH concentration) is about 1 wt%, about 0.9 wt%, about 0.8 wt%, about 0.7 wt%, about 0.6 wt%, about 0.5 wt%, about 0.4 wt%, about 0.3 wt%, about 0.2 wt%, about 0.1 wt%, or about 0.05 wt% on a dry basis.

[0017] In one aspect, the LOD in the corn product is in a range of about 3 - 9 wt%, about 3 - 8 wt%, about 3 - 7 wt%, about 3 - 6 wt%, about 3 - 5 wt%, about 3 - 4 wt%, about 4 - 9 wt%, about 4 - 8 wt%, about 4 - 7 wt%, about 4 - 6 wt%, about 4 - 5 wt%, about 5 - 9 wt%, about 5 - 8 wt%, about 5 - 7 wt%, about 5 - 6 wt%, about 6 - 9 wt%, about 6 - 8 wt%, about 6 - 7 wt%, about 7 - 9 wt%, about 7 - 8 wt%, or about 8 - 9 wt% on a dry basis.

[0018] In one aspect, the corn product comprises, on a dry basis, about or less than 1 wt%, about or less than 0.5 wt%, or about or less than 0.05 wt% ethanol, and LOD of about or less than 3 - 9 wt%, about or less than 4 - 8 wt%, about or less than 4 - 6 wt%, or about or less than 5 wt%.

[0019] The method described herein comprises a first step of evaporating EtOH from the corn protein materials (primary desolventization step) at a first temperature, and, in a second step, exposing the evaporated corn protein materials (or primary desolventized materials) to an exposure atmosphere at a second temperature (secondary desolventization step) to obtain the corn product.

[0020] In one aspect, during the primary desolventization step, the corn protein materials are evaporated at the first temperature of 80 - 120°C to obtain the primary desolventized material. In one aspect, the primary desolventization step is carried out at a pressure of 0.25 - 0.05 atmospheres or at the atmospheric pressure.

[0021] In one aspect, the corn protein materials comprise, on a dry basis, at most about 80 wt% EtOH, at most 75 wt% EtOH, at most about 70 wt% EtOH, at most 65 wt% EtOH, or at most 60 wt% EtOH. In another aspect, the EtOH concentration in the corn protein materials may range from about 60 to 80 wt%, about 60 to 75 wt%, about 60 to 70 wt%, about 60 to 65 wt%, about 65 to 80 wt%, about 65 to 75 wt%, about 65 to 70 wt%, about 70 to 80 wt%, or about 75 to 80 wt% on a dry basis.

[0022] In one aspect, the primary desolventization step is carried out for about 8 - 20 minutes. In another aspect, the primary desolventization step is carried out at the first temperature of 80 - 105°C, preferably at 90°C, and at the atmospheric pressure for about 45 - 60 minutes.

[0023] In one aspect, during the secondary desolventization step, the primary desolventized materials are exposed to an exposure atmosphere at 60 - 100% relative humidity (RH) and at a second temperature of 40 - 80°C to obtain the corn product. In one aspect, thePT-1285-WO-PCT exposure atmosphere is at 40% RH, 50% RH, 60% RH, 70% RH, 80% RH, 90% RH, or 100% RH. In one aspect, the exposure atmosphere is in a range of 40 - 100% RH, 50 - 100% RH, 60 - 100% RH, 70 - 100% RH, 80 - 100% RH, or 90 - 100% RH.

[0024] In one aspect, the second temperature is 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, or 100°C. In one aspect, the second temperature is in a range of 40 - 100°C, 40 - 90°C, 40 - 80°C, 40 - 70°C, 40 - 60°C, 40 - 50°C, 50 - 100°C, 50 - 90°C, 50 - 80°C, 50 - 70°C, 50 - 60°C, 60 - 100°C, 60 - 90°C, 60 - 80°C, 60 - 70°C, 70 - 100°C, 70 - 90°C, 70 - 80°C, 80 - 100°C, 80 - 90°C, or 90 - 100°C. In another aspect, the second temperature can be over 100°C; for example, it can be 105°C, 110°C, 115°C, or 120°C. The second temperature can be in a range of 40 - 105°C, 40 - 110°C, 40 - 115°C, 40 - 120°C, 60 - 105°C, 60 - 110°C, 60 - 115°C, 60 - 120°C, 70 - 105°C, 70 - 110°C, 70 - 115°C, 70 - 120°C, 80 - 105°C, 80 - 110°C, 80 - 115°C, 80 - 120°C, 100 - 105°C, 100 - 110°C, 100 - 115°C, or 100 - 120°C.

[0025] In one aspect, the secondary desolventization step is carried out at different second temperature(s) and relative humidity(s) within a single treatment. For example, the secondary desolventization step is carried out at lower temperature(s) (e.g., 40°C - 80°C) and higher relative humidity(s) (e.g., 40% - 100% RH), followed by a condition of higher temperature(s) (e.g., 100°C) and lower relative humidity(s) (e.g., 0% RH). In another aspect, the secondary desolventization step is carried out at 70°C and 70% RH.

[0026] In one aspect, the corn protein material can be com protein isolate or com protein concentrate. In one aspect, the corn protein isolate is made from destarched corn gluten meal and comprises at least about 85 wt% corn protein on a dry basis. In one aspect, the com protein concentrate is made from corn gluten meal and comprises about 55 - 80 wt% corn protein on a dry basis.

[0027] In one aspect, a method for making the corn product consists of the steps of: (a) providing a com protein material comprising at most about 80 wt% of ethanol on a dry basis; (b) evaporating ethanol from the corn protein material at a first temperature of 80 - 120°C to obtain a primary desolventized material; and (c) exposing the primary desolventized material to an exposure atmosphere at 60 - 100% relative humidity and at a second temperature of 40 - 80°C to obtain the corn product. The com product has about or less than 1 wt% ethanol and a loss on drying in a range of about 3 - 9 wt% on a dry basis.

[0028] Although the method described herein is used to remove (and recover) EtOH from corn protein materials, the method, with appropriate variations in the materials and / or processPT-1285-WO-PCT parameters (e.g., temperature, pressure, etc.), can also be used to remove (and recover) volatiles other than EtOH.EXAMPLES

[0029] The invention is further described in detail by reference to the following experimental examples. These examples are provided for purposes of illustration only and are not intended to be limiting unless otherwise specified. Thus, the invention should in no way be construed as being limited to the following examples, but rather should be construed to encompass any and all variations which become evident as a result of the teaching provided herein.Materials and MethodPrimary Desolventization Step

[0030] The method described herein starts with the primary desolventization step. Samples of the corn protein materials comprising, on a dry basis, at most about 80 wt% EtOH. were prepared.

[0031] The samples were forced through a 3.36 mm screen to standardize the particle size, spread on an aluminum tray, and evaporated in an Unox Combi-oven to obtain the primary desolventized materials. Temperature of the oven was set at 90°C and relative humidity was set to zero. Beginning at 30 minutes, the primary desolventized materials were weighed every 10 minutes. The EtOH-laden primary desolventized materials had a loss on drying (LOD) of almost 75%, so the estimated residual LOD could be estimated. Multiple batches of primary desolventized materials were obtained and used with LODs ranging from 4.04 to 9.32%.Secondary Desolventization Step

[0032] Samples of the primary desolventized materials of approximately 5g were weighed into 42mL aluminum weigh boats and spread into a uniform layer for the secondary desolventization step. The samples were placed in the Unox Combi oven programmed for treatment conditions of temperature and relative humidity illustrated in Table 1 to obtain the corn product.Table 1. Treatment conditions for the secondary desolventization step.PT-1285-WO-PCT

[0033] Examples 1 - 3 were carried out to examine effects of different treatment conditions on change in LOD and EtOH concentration (in terms of weight percentage) of the com products.EtOH and LOD Analyses

[0034] Residual EtOH concentrations in the com products were measured by weighing approximately 100 mg of the corn products into a gas chromatography (GC) headspace vial. 1 mL ultrapure water including lOOpL of an Internal Standard (500ppm 1 -Propanol in water) was added to the vial. The vial was then injected onto a GC and eluted under constant temperature conditions with a flame ionization detector. A standard curve for EtOH was used to determine the residual EtOH concentrations.

[0035] LOD of the com products was measured by weighing the corn products before and after an overnight treatment at 110°C under vacuum.Example 1

[0036] Samples of primary desolventized materials were treated at treatment conditions 1 - 14 in Table 1. At each time point of 5, 10, 15, 30, and 45 minutes, a pair of treated samples werePT-1285-WO-PCT removed from the oven and immediately weighed. EtOH and LOD analyses were then carried out on the treated samples.

[0037] The changes in the treated sample weight over time reflected the gain or loss of water and the loss of EtOH. Results showed that the gains in the treated sample weight were greatest at low temperature, but relative humidity played a less obvious role in the response.Loss On Drying (LOD)

[0038] Loss on drying (LOD) can be used to reflect the volatile exchange. In one aspect, the desired final LOD of the corn product was between 4 and 8 wt%. In another aspect, the desired final LOD is preferably near 5 wt%.

[0039] The responses of LOD to treatment over time were shown in FIGS. lAto IE. White area represented desirable LOD(s) and dark area represented undesirable LOD(s) over the given temperature and RH. In general, a desired LOD value or range of values can be achieved at a lower temperature over time. This can be illustrated by focusing on specific LOD contour line(s). In one aspect, at the 5-minute time point (FIG. 1 A), when the RH was between about 60% to about 80%, a LOD value of 4 to 6 wt% (i.e., the white region between the LOD=4% and LOD=6% contour lines) can be achieved at a higher temperature range of about 70°C to about 80°C. As the treatment proceeded, the same LOD value can be obtained at lower temperatures. At the 45-minute time point (FIG. IE), the same LOD value can be achieved at a lower temperature range of about 50°C to about 60°C for RH being between about 60% to about 80%.

[0040] In another aspect, a LOD of about 5% for the com product can be obtained if the primary desolventized materials were treated at a temperature range of about 50°C to about 80°C and at a RH of about 60% to about 80%.

[0041] Further, addition of water was equally important with removal of EtOH, and unsurprisingly the humidity had an impact on the product moisture.Residual EtOH Concentration [EtOH]

[0042] The residual EtOH concentrations in the corn products ([EtOH]) were also responsive to temperature and RH and the rate of EtOH removal was very fast. FIGS. IF to 1J showed the response of EtOH concentration to treatment. White area represented desirable [EtOH] and dark area represented undesirable [EtOH] over the given temperature and RH. Similar to the response of LOD, while both high temperature and RH were required to obtain the desired [EtOH] in the early stage of the treatment (e.g., at the 5-minute time point), in the later stage of thePT-1285-WO-PCT treatment (e.g., at the 30-minute time point), the desired [EtOH] can be obtained at lower temperatures and RH.

[0043] This can be illustrated by focusing on specific [EtOH] contour line(s). In one aspect, at the 10-minute time point (FIG. 1G), when the RH was between about 60% to about 80%, an [EtOH] of less than 1 wt% (i.e., the white region between the [EtOH]=l wt% and [EtOH]=0 wt% contour lines) can be achieved at a higher temperature range of about 60°C to about 100°C. As the treatment proceeded, the same [EtOH] can be obtained at lower temperatures. At the 45-minute time point (FIG 1 J), the same [EtOH] can be achieved at a lower temperature range of about 40°C to about 50°C for RH being between about 60% to about 80%.

[0044] In another aspect, [EtOH] of about 0.5 wt% for the corn product can be obtained if the primary desolventized materials were treated at a temperature range of about 50°C to about 70°C and at a RH of about 60% to about 80%.

[0045] The [EtOH] contour lines were mathematically generated from an equation describing the [EtOH] response, where the equation was derived from the treatment results. A skilled artesian would appreciate and understand that the [EtOH]=0 wt% contour line did not necessarily represent an absolute zero [EtOH] in the treated samples since such an absolute zero [EtOH] would not be feasible to achieve in reality. Thus, a skilled artesian would appreciate and understand that the [EtOH]=0 wt% contour line represented an [EtOH] value very close to zero (e.g., 0.05%, 0.01%, 0.005%, 0.001%, etc.).

[0046] The LOD data can also be examined as a simple time course (FIG. 2), showing that LOD declined with every treatment over 15 minutes, but that high temperature drove LOD down more than low temperature, and high RH maintained LOD more than low RH. This result suggested that EtOH was being lost more than water was being gained. The moisture uptake from water- saturated air might be slower than EtOH desorption.

[0047] In one aspect, though the desired [EtOH] was achieved, the corn product may not have an acceptable water concentration. FIGS. 3A to 3F was an optimization chart to show a computed desirability of conditions at 2.5-minute intervals until 15 minutes of treatment, in which the desired outcomes were LOD being in the range of 4% and 8%, and the [EtOH] being in a range of 0.01% to 0.5%. White area represented desirable LOD and [EtOH], At short times, the results were undesirable due to high EtOH concentration. But at high temperature and RH, a tiny space opened at 5 minutes then grew to a maximum between 10 and 12 minutes. The space then shrank due to low LOD at longer times. Though RH was not a significant contributor to reduction of EtOH in this time period, it was significant in maintaining LOD.PT-1285-WO-PCT

[0048] In short, the results showed that high humidity promoted loss of EtOH from the primary desolventized materials. Especially when the goal was to produce a product with both “desired” LOD and low [EtOH], using high RH was beneficial.Example 2

[0049] The aim of this example was to test whether humidity had a material effect on EtOH loss.

[0050] Samples of primary desolventized materials were treated at 40°C, 60°C, 80°C, and 100°C at zero relative humidity (treatment conditions 14 - 17 in Table 1). A pair of treated samples were removed from the oven at different time points and immediately weighed. EtOH and LOD analyses were then carried out on the treated samples.

[0051] FIG. 4 showed that EtOH removal did occur under “dry” conditions (0% RH). Higher temperature led to faster EtOH removal and resulted in lower EtOH concentrations (expressed as percentage of the initial EtOH concentration) at later times of treatment. These results showed that it was possible to remove EtOH under dry conditions and obtain an EtOH concentration below 1% (expressed as a percentage of the initial EtOH concentration) in a reasonable time frame.

[0052] FIGS. 5 A and 5B showed the impact of humidity on EtOH removal. While EtOH was removed under dry conditions at 40°C, the removal was much faster and more complete as humidity increased. Removal of EtOH at 100°C was more effective than that at 40°C, but relative humidity still had a visible effect. Taking the results together, humidity had a beneficial effect on EtOH removal.Example 3

[0053] The effect of the bed depths of the containers holding samples of the primary desolventized materials on LOD and loss of EtOH was studied. Containers with different bed depths (6.7mm, 14mm, and 20mm) were filled with 5, 10, and 15 g of the primary desolventized materials, respectively. The containers were then placed in the Unox Combi oven at 70% RH and 70°C for 5, 10, and 15 minutes. At each time point, a pair of treated samples were removed from the oven and immediately weighed. EtOH and LOD analyses were then carried out on the treated samples.

[0054] FIGS. 6A and 6B showed that there was a clear effect of bed depth on the changes in LOD and [EtOH], LOD initially dropped more rapidly in the thin bed and appeared to bePT-1285-WO-PCT reaching a steady state value while the LOD drops at thicker beds were changing. In contrast, the [EtOH] dropped very quickly in the two thinner beds and a deeper bed resulted in a slower EtOH loss. Under all conditions, EtOH was shown to decrease faster than water was being absorbed, which demonstrated that EtOH loss preceded water gain.Conclusion

[0055] The above results showed that humid air was much more effective than dry air for removing EtOH from com protein materials after the primary desolventizing step. Hot dry air will remove EtOH but will not result in an acceptable moisture (where loss on drying was overwhelmingly water). There were combinations of time, temperature and relative humidity that resulted in essentially no change in loss on drying while simultaneously decreasing the [EtOH] to well under 1 wt%.

[0056] Given a good contact between the corn protein materials and humid air, EtOH removal can be very fast. A thick static bed of material may retard the EtOH removal.

[0057] Most of the studies in these examples were performed using a fixed particle size. In an aspect, particle size may influence the primary desolventizing step and / or the secondary desolventizing step.

Claims

PT-1285-WO-PCTCLAIMSWhat is claimed is:

1. A method of making a com product, comprising the steps of: a. providing a corn protein material comprising at most about 80 wt% of ethanol on a dry basis; b. evaporating ethanol from the corn protein material at a first temperature of 80 - 120°C to obtain a primary desolventized material; and c. exposing the primary desolventized material to an exposure atmosphere at 60 - 100% relative humidity and at a second temperature of 40 - 80°C to obtain the corn product; wherein the corn product has about or less than 1 wt% ethanol and a loss on drying in a range of about 3 - 9 wt% on a dry basis.

2. The method of claim 1, wherein the content of ethanol in the corn product is about or less than 0.5 wt% on a dry basis.

3. The method of claim 1, wherein the content of ethanol in the corn product is about or less than 0.05 wt% on a dry basis.

4. The method of claim 1, wherein the loss on drying in the corn product is about 3 - 9 wt% on a dry basis.

5. The method of claim 1, wherein the loss on drying in the corn product is about 4 - 8 wt% on a dry basis.

6. The method of claim 1, wherein the loss on drying in the corn product is about 5 wt% on a dry basis.

7. A method of removing ethanol from a protein material, comprising the steps of: a. providing the protein material comprising at most about 80 wt% of ethanol on a dry basis;PT-1285-WO-PCT b. evaporating ethanol from the protein material at a first temperature of 80 - 120°C to obtain a primary desolventized material; and c. exposing the primary desolventized material to an exposure atmosphere at 60 - 100% relative humidity and at a second temperature of 40 - 80°C to obtain a protein product; wherein the protein product has about or less than 1 wt% of ethanol and a loss on drying in a range of about 3 - 9 wt% on a dry basis.

8. The method of claim 7, wherein the protein material is selected from a group consisting of a plant derived protein material, an egg derived protein material, a dairy product derived protein material, and an animal derived protein material.

9. The method of claim 7, wherein the protein material is a com protein material.

10. A com product made by the method of any of claims 1 - 6.

11. A com product, comprising: about or less than 1 wt% ethanol and a loss on drying in a range of about 3 - 9 wt% on a dry basis.

12. The corn product of claim 11, wherein the content of ethanol is about or less than 0.5 wt% ethanol on a dry basis.

13. The com product of claim 11, wherein the loss on drying is about 5 wt% on a dry basis.

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