DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Status of the Application
Receipt of the Response and Amendment after Non-Final Office Action filed 10 July 2025 is acknowledged.
Applicant has overcome the following by virtue of amendment of the specification and claims: (1) the objections to claims 7, 17, and 24 have been withdrawn; (2) the 112(b) rejection of claims 4-6, 9-10, 15-19, 22, 24-25, and 28-29 have been withdrawn.
The status of the claims upon entry of the present amendment stands as follows:
Pending claims: 1-2, 4-20, 22-25, and 28-29
Withdrawn claims: None
Previously canceled claims: 21, and 26-27
Newly canceled claims: 3
Amended claims: 1-2, 4-7, 9-10, 15-19, 22, 24-25, and 28-29
New claims: None
Claims currently under consideration: 1-2, 4-20, 22-25, and 28-29
Currently rejected claims: 1-2, 4-20, 22-25, and 28-29
Allowed claims: None
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1-2, 4-8, 11-15, 17-20, 22-24, and 28-29 are rejected under 35 U.S.C. 103 as being unpatentable over Habeych Narvaez et al. (hereinafter “Habeych”) (US 2022/0240538 A1) in view of Bell et al. (US 2017/0304774 A1) and Liderfelt et al. (Liderfelt, J. and Royce, J. (2018). Chapter 23 – Filtration Methods for Use in Purification Processes (Concentration and Buffer Exchange). In G. Jagschies, E. Lindskog, K. Lacki, and P. Galliher (Eds.), Biopharmaceutical Processing (pp. 441-453) Elsevier. https://doi.org/10.1016/B978-0-08-100623-8.00023-2).
Regarding claim 1, Habeych teaches a method for the separation of potato proteins from one or more first salts and phenolic and/or glycoalkaloid compounds in potato fruit juice or a derivative thereof, said method comprising the steps of:
(i) providing a potato fruit juice or a derivative thereof comprising potato proteins, one or more first salts and phenolic and/or glycoalkaloid compounds – Tuber processing water, for example potato fruit juice as obtained after starch isolation ([0067]), was used as raw material for production of a total native (potato) protein isolate ([0137]). Salts present in the tuber processing water (i.e., first salts) are replaced by diafiltration ([0035]). The method also comprises a step of glycoalkaloid removal ([0091]) indicating the presence of glycoalkaloids in the potato fruit juice;
(ii) subjecting said potato fruit juice or the derivative thereof to a first cross-flow membrane filtration process wherein at least a portion of the first salts and at least a portion of the phenolic and/or glycoalkaloid compounds migrate across the membrane into a first permeate and the potato proteins are retained in a first retentate – “The potato processing water was ultrafiltrated using a spiral-wound membrane with a molecular weight cut-off (MWCO) of 5 kDa…” ([0143]). The diafiltration membrane may have a MWCO of 3-500 kDa ([0036]). Regarding the passage of the first salts and phenolic and/or glycoalkaloid compounds across the membrane, at least a portion of these ions and small molecules would pass through the disclosed 5 kDa molecular-weight cut-off filter;
(iii) subjecting the first retentate of step (ii) to a diafiltration step comprising adding one or more second salts and water to the first retentate, while continuing the membrane filtration process, to create a diafiltrate containing at least a portion of said phenolic and/or glycoalkaloid compounds and the added second salts and a retentate – “The retentate from the ultrafiltration [i.e., first retentate] was subjected to further treatment comprising diafiltration against a salt solution having 0.33 or 50.66 [sic, 0.66] wt. % NaCl [i.e., second salt]…This resulted in a potato protein isolate solution [i.e., retentate].” ([0144]). The salt solution is presumed to comprise water. Habeych further discloses that when the salt concentration was increased from 0.33% to 0.66%, the TGA (i.e., glycoalkaloid) content of the dried protein isolate was lower ([0148] and [0146], Table 2, Experiment 6, “Total TGA content”), indicating that at least a portion of glycoalkaloids pass through the filter during the diafiltration process. The resulting diafiltrate would also comprise the second salts since these ions would pass through the disclosed 5 kDa molecular-weight cut-off filter.
Habeych does not teach (iv) subjecting the first permeate and/or said diafiltrate from said first cross-flow membrane filtration process to a second cross-flow membrane filtration process wherein at least a portion of the salts present therein migrate across the membrane into a second permeate and the phenolic and/or glycoalkaloid compounds are retained in a second retentate. Instead, Habeych teaches that glycoalkaloid removal is essentially known and can be done at any point in the process ([0092]), and that the ultrafiltration and diafiltration permeate is separately processed by a step of concentration, such as by ultrafiltration or other methods as described elsewhere, to obtain tuber free amino acids ([0094]).
Habeych also does not teach that the second permeate is used, at least in part, as the source of said one or more second salts and water in step (iii).
However, Bell teaches a method for separating useable by-products from process water from processing potatoes ([0002]). The process involves a pretreatment to remove unwanted solids, a first cross-flow filtration step to remove starch ([0011]), and a second cross-flow filtration step comprising filtration membranes having increased rejection characteristics or smaller pore sizes, such as ultrafiltration, nanofiltration, or reverse osmosis membranes, than the first filtration unit to provide an essentially clear water permeate stream ([0012]). By-products isolated include polyphenols, glycoalkaloids, and nutritional products ([0012]).
Regarding the source of the second salt(s) and water in step (iii), Liderfelt teaches methods of ultrafiltration and diafiltration, including continuous-membrane filtration with partial recycling of the retentate (p. 448, Fig. 23.9, annotated below), wherein the permeate is used, at least in part, as the source of a wash solution.
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Regarding step (iv), it would have been obvious for one of ordinary skill in the art, before the effective filing date of the claimed invention, to remove the glycoalkaloids from the permeate and/or diafiltrate from the first cross-flow membrane filtration by a second membrane filtration as described by Bell by applying a known technique to a known method. See MPEP § 2143(I)(D). First, Habeych teaches that glycoalkaloids can be removed at any part of the process ([0092]), and that the ultrafiltration and diafiltration permeate is separately processed by a step of concentration ([0094]). Bell teaches that by-products, including glycoalkaloids, can be removed from potato process water by filtration, such as nanofiltration, resulting in an essentially clear water permeate ([0012]). Since Habeych teaches that the permeate is treated by filtration ([0094]), and Bell teaches that cross-flow filtration processes such as ultrafiltration, nanofiltration, and reverse osmosis can be applied to process water to extract useful by-products, such as polyphenols and glycoalkaloids ([0012]), the teachings of Bell are applicable to the method of Habeych. Therefore, one of ordinary skill in the art would have recognized that applying the technique of Bell would have yielded the predictable result of reducing the amount of glycoalkaloids in the permeate. One of ordinary skill in the art would have recognized that the pore size of the filtration unit could be selected such that at least a portion of the salts migrate across the membrane into a second permeate and the phenolic and/or glycoalkaloid compounds are retained in a second retentate.
Regarding the source of the second salt(s) and water in step (iii), it would have been obvious for one of ordinary skill in the art, before the effective filing date of the claimed invention, to improve the method of Habeych as modified by Bell by applying continuous-membrane filtration as taught by Liderfelt, such that the second permeate is used, at least in part, as the source of said one or more second salts and water in step (iii). See MPEP § 2143(I)(D). First, Habeych teaches the base method of a first cross-flow membrane filtration/diafiltration process and subjecting the first permeate to a second cross-flow membrane filtration process as described above. Liderfelt teaches that recirculating the second permeate aids in washing out all product and minimizing buffer volume (Fig. 23.9, legend), which is seen as an applicable feature and an improvement over the method of Habeych. In the present case, the recycling of the second permeate/solution of second salts and water/diafiltration solution equates to recycling a wash solution as taught by Liderfelt. Therefore, one of ordinary skill in the art would have recognized that applying the technique of Liderfelt would have yielded the predictable result and improvement of washing out all product and minimizing buffer volume. Therefore, claim 3 is rendered obvious.
Therefore, claim 1 is obvious in view of the prior art.
Regarding claim 2 and 11, Habeych, Bell, and Liderfelt teach the method according to claim 1.
The cited prior art does not specifically teach that the method further comprises the step (v) of: subjecting the retentate obtained in step (iii) to a microfiltration membrane filtration process wherein at least a portion of the potato proteins soluble in said first retentate migrate across the membrane into a microfiltration permeate with a lower turbidity than the turbidity of said first retentate (re: claim 2) or wherein the microfiltration permeate obtained in step (v) is further treated with a third cross-flow membrane filtration process whereby the potato protein is concentrated in a third retentate and the salts migrate through the membrane to create a third permeate (re: claim 11).
However, Habeych teaches microfiltration as a preferred way to remove solids in pre-treatment of the potato fruit juice ([0087]) and that solids removal may also be performed at another point in the method ([0085]). Habeych further discloses that “…the main protein fractions in…potato protein, are oppositely charged at many pH values. Patatin has a pI of 4.8-5.2, whereas protease inhibitor has a pI of from 5.8 up to 9. Even pH values optimized for solubility cannot prevent aggregation, precipitation and clogging, in particular during diafiltration. It has been found that the conductivity of a solution has great influence on protein solubility, and that low solubility can be offset by increasing conductivity. This is important in particular during diafiltration.” ([0039]). The preferred protein isolate is a tuber protein isolate comprising native protease inhibitor and native patatin with or without any other native tuber proteins ([0030]-[0032]).
Regarding claim 2, It would have been obvious for one of ordinary skill in the art, before the effective filing date of the claimed invention, to add to the method of Habeych a step of microfiltration of the first retentate after ultrafiltration and diafiltration to retain any aggregated proteins and allow soluble potato proteins to migrate into the microfiltration permeate, thereby reducing the turbidity. First, Habeych teaches that the preferred protein isolate comprises native potato proteins ([0030]-[0032]), and that the pI of proteins of interest (e.g., patatin and protease inhibitors) differs such that aggregation cannot be prevented ([0039]). While maintaining high conductivity through diafiltration helps offset low protein solubility ([0039]), it is reasonably expected that not all of the protein remains completely soluble. Since Habeych also discloses microfiltration as a preferred means of solids removal ([0087]), and that multiple microfiltration steps can be employed throughout the method ([0085]), one of ordinary skill in the art would have been motivated to remove aggregated protein from the first retentate via microfiltration to allow native proteins to selectively pass into the permeate and, for the same reasons, would have been met with a reasonable expectation of success for doing so. Therefore, claim 2 is rendered obvious.
Regarding claim 11, it would have been obvious for one of ordinary skill in the art to implement a subsequent cross-flow ultrafiltration step to concentrate the native protein permeate from the microfiltration step of claim 2 such that the native proteins are retained and the salts pass through. To arrive at the claimed invention, one of ordinary skill in the art would have simply applied known filtration techniques as taught by Habeych regarding a series of filtration steps as disclosed in Example 3 ([0143]-[0144]), and also regarding concentrating permeates as disclosed in paragraph [0094], to the method of claim 2. Since these techniques were both known and applicable, one of ordinary skill in the art would have recognized that applying the techniques would have yielded predictable results and resulted in an improved system wherein the purity of native proteins in the protein isolate is increased. See MPEP § 2143(I)(D). Therefore, claim 11 is rendered obvious.
Regarding claim 4, Habeych, Bell, and Liderfelt teach the method according to claim 1.
Habeych also teaches that the method further comprises the step of adjusting the pH of said potato fruit juice or the derivative thereof to a pH in the range of 4.5 to 8.5 prior to said first cross-flow membrane filtration process – “The pretreatment may include one or more pH adjustments.” ([0080]). “For example, a pH adjustment to 4.0-5.5 can be used to precipitate at least part of the patatin fraction…” ([0082]). The claimed range overlaps the disclosed range. In a case where the claimed ranges overlap or lie inside ranges disclosed by the prior art, a prima facie case of obviousness exists, MPEP § 2144.05(I). Therefore, claim 4 is rendered obvious.
Regarding claim 5, Habeych, Bell, and Liderfelt teach the method according to claim 1.
Habeych also teaches that the method further comprises the step of adjusting the conductivity of said potato fruit juice or the derivative thereof to a conductivity in the range of 1 to 50 mS/cm – “pretreatment results in a pretreated tuber processing water having a conductivity of 2-20 mS/cm…” ([0020]). The disclosed range lies within the claimed range. Therefore, claim 5 is rendered obvious.
Regarding claim 6, Habeych, Bell, and Liderfelt teach the method according to claim 1.
Habeych also teaches that the potato proteins are selected from the group consisting of patatin and protease inhibitors – “the tuber protein isolate is isolate comprising native protease inhibitor and native patatin. In further much preferred embodiments, the tuber protein isolate is a total native tuber protein isolate.” ([0030]). Therefore claim 6 is rendered obvious.
Regarding claim 7, Habeych, Bell, and Liderfelt teach the method according to claim 1.
Habeych also teaches that the potato fruit juice or the derivative thereof is pretreated by centrifugation and/or filtration to remove insoluble material of a particle size larger than 10 microns prior to said first cross-flow membrane filtration process – Habeych discloses solids removal as a pretreatment step ([0085]), which can be filtration, centrifugation, cycloning, decanting, nanofiltration or microfiltration ([0086]). Microfiltration is preferably performed over membranes having a pore size of 0.1-10 μm ([0087]). As such, insoluble material of a particle size larger than 10 microns is removed. Therefore, claim 7 is rendered obvious.
Regarding claim 8, Habeych, Bell, and Liderfelt teach the method according to claim 1.
Habeych and Bell also teach that said potato proteins, first salts and said phenolic compounds are in solution in said potato fruit juice – As mentioned above, Habeych discloses tuber processing water, for example potato fruit juice as obtained after starch isolation ([0067]), was used as raw material for production of a total native protein isolate ([0137]). Salts present in the tuber processing water are replaced by diafiltration ([0035]). Habeych is silent regarding phenolic compounds. However, Bell discloses that process water from potatoes comprises polyphenols ([0012]). The claimed components are in solution as claimed, particularly since the proteins are isolated in native form ([0032]). Therefore, claim 8 is rendered obvious.
Regarding claim 12, Habeych, Bell, and Liderfelt teach the method according to claim 11.
Habeych and Bell do not teach that the third permeate is used as a diafiltration liquid to be added during the microfiltration process in step (v) to wash out further potato proteins from the first retentate into the microfiltration permeate.
However, Liderfelt teaches methods of ultrafiltration and diafiltration, including continuous-membrane filtration with partial recycling of the retentate (p. 448, Fig. 23.9, annotated below), wherein the permeate is used, at least in part, as the source of the diafiltration solution.
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It would have been obvious for one of ordinary skill in the art, before the effective filing date of the claimed invention, to improve the method of Habeych as modified by Bell and Lederfelt as described regarding claim 11 by again applying continuous-membrane filtration as taught by Liderfelt, such that the third permeate is used as a diafiltration liquid to be added during the microfiltration process in step (v) to wash out further potato proteins from the first retentate into the microfiltration permeate. See MPEP § 2143(I)(D). First, Habeych teaches the base method of a microfiltration process and subjecting the microfiltration permeate to a third cross-flow membrane filtration process as described regarding claim 11. Liderfelt teaches that recirculating the permeate from the second stage aids in washing out all product and minimizing buffer volume (Fig. 23.9, legend), which is an applicable feature and an improvement over the method of Habeych. Therefore, one of ordinary skill in the art would have recognized that applying the technique of Liderfelt would have yielded the predictable result and improvement of washing out all product and minimizing buffer volume. Therefore, claim 12 is rendered obvious.
Regarding claim 13, Habeych, Bell, and Liderfelt teach the method according to claim 1.
Habeych also teaches that the one or more second salts and water added to the first retentate in step (iii) is an aqueous solution of said second salt(s) in said water – “The retentate from the ultrafiltration [i.e., first retentate] was subjected to further treatment comprising diafiltration against a salt solution having 0.33 or 50.66 [sic, 0.66] wt. % NaCl [i.e., second salt]” ([0144]). The salt solution is presumed to comprise water and, with no indication of any substantial proportion of non-water liquid components, would be an aqueous solution. Therefore, claim 13 is rendered obvious.
Regarding claim 14, Habeych, Bell, and Liderfelt teach the method according to claim 1.
Habeych also discloses that the one or more second salts are selected from ammonium salts of a mineral acid – (NH4)2HCO3 ([0049]). Therefore, claim 14 is rendered obvious.
Regarding claim 15, Habeych, Bell, and Liderfelt teach the method according to claim 1.
Habeych also discloses that the one or more second salts are selected from salts of monovalent inorganic anions and cations – NaCl, KCl ([0046]). Therefore, claim 15 is rendered obvious.
Regarding claim 17, Habeych, Bell, and Liderfelt teach the method according to claim 1.
Habeych also teaches that the conductivity of the first retentate remains within the range of 1 to 50 mS/cm during step (iii) – “It has been found that for any solution comprising a native protein isolate as herein defined, it is essential that during the whole isolation process, the conductivity is relatively high. The salt solution against which the diafiltration is performed must have a conductivity of at least 5 mS/cm, and the feed solution must have a conductivity of 2-20 mS/cm.” ([0040]). “Preferably, the conductivity of the solution to be diafiltered (the diafiltration feed solution or feed) remains within the ranges herein specified.” ([0054]). Therefore, claim 17 is rendered obvious.
Regarding claim 18, Habeych, Bell, and Liderfelt teach the method according to claim 1.
Habeych also teaches that the pH of the first retentate remains within the range of 4.5 to 8.5 during step (ii) and step (iii) – the pH of the diafiltration feed solution is preferably 5.5-7.0 ([0044]). “Preferably, the conductivity of the solution to be diafiltered (the diafiltration feed solution or feed) remains within the ranges herein specified. Preferably in this embodiment, the pH remains the same throughout all diafiltration stages.” (0054]). “In further preferred embodiments, the salt solution may have a pH of… 5.5-8.0…In preferred embodiments, this pH is maintained throughout the diafiltration.” ([0050]). Since the pH of both the diafiltration feed solution and the salt solution are within the claimed range throughout the diafiltration process, the pH of the first retentate would also be within the claimed range. Claim 18 is therefore rendered obvious.
Regarding claim 19, Habeych, Bell, and Liderfelt teach the method according to claim 1
The method according to claim 1, wherein the first retentate remains at a temperature in the range of 1 to 60 °C during step (ii) and step (iii) – “…the method is performed so as to keep the temperature of the tuber processing water below 40° C during the pretreatment, the diafiltration and any other step prior to drying.” ([0103]). The disclosed range of below 40 °C overlaps with the claimed range of 1-60 °C. In a case where the claimed ranges overlap or lie inside ranges disclosed by the prior art, a prima facie case of obviousness exists, MPEP § 2144.05(I). Therefore, claim 19 is rendered obvious.
Regarding claim 20, Habeych, Bell, and Liderfelt teach the method according to claim 1.
Habeych also teaches that the addition of the one or more second salts and water in step (iii) is performed substantially continuously – “In preferred embodiments, the diafiltration is performed as a continuous (cross-flow) process. Operation flux can for example be between 3 and 300 l/(h m2).” ([0038]).
The cited prior art is silent as to the one or more second salts and water being added at substantially the same flow rate as the diafiltrate migrates through the membrane.
However, logic dictates that since the process is disclosed as being continuous, one of ordinary skill in the art would have found it obvious to add the diafiltration solution at substantially the same flow rate as the diafiltrate migrates across the membrane to maintain the continuity of the process and flux rate. Claim 20 is therefore rendered obvious.
Regarding claim 22, Habeych, Bell, and Liderfelt teach the method according to claim 1.
Habeych also teaches that the total volume of water added during diafiltration step (iii) is in the range of 4 to 20 times the volume of the first retentate – “Diafiltration is preferably performed at dilution rate of 5:1 to 1:10, preferably, 1:1 to 1:10 (feed:salt solution), preferably in the range of 1:1 to 1:5, more preferably 1:1 to 1:4” ([0051]). Claim 22 is therefore rendered obvious.
Regarding claims 23 and 24, Habeych, Bell, and Liderfelt teach the method according to claim 1.
Habeych also teaches that step (iii) comprises a second phase of diafiltration following the addition of one or more second salts and water wherein the diafiltration is continued with the addition of water without adding any further salts (re: claim 23) and wherein the second phase of diafiltration is continued with water and without the addition of further salts until the conductivity of the retentate is less than 10 mS/cm (re: claim 24) – “The DF retentate may be subjected to a second, third or even further DF stage.” ([0051]). “In preferred embodiments, diafiltration is performed against a salt solution throughout all diafiltration stages. In a further preferred embodiment, in particular in cases where the salt solution was applied at relatively high conductivity within the ranges herein specified, the diafiltration against a salt solution can be followed by a diafiltration stage against water at lower conductivity, or against regular water, in order to remove salts and isolate native tuber protein essentially free of salt.” ([0053]). The disclosed “essentially free of salt” is considered to lie inside the claimed conductivity range of the retentate of less than 10 mS/cm. Therefore, claims 23 and 24 are rendered obvious.
Regarding claims 28 and 29, Habeych, Bell, and Liderfelt teach the method according to claim 1.
Habeych also teaches that the method further comprises a step of eliminating enzymatic activity by exposing the first retentate obtained in step (ii) prior to step (iii) or a solution of the separated potato proteins to pH values between 2.0 and 4.5 in a time and temperature interval sufficient to eliminate unwanted enzymatic activity of the potato proteins without adversely affecting functionality of the potato proteins (re: claim 28), and (re: claim 29) the method according to claim 28, wherein the first retentate obtained in step (ii) prior to step (iii) or a solution of the separated potato proteins is exposed to:
a pH value between 2.0 and 4.5;
a temperature in the range of 1-70 °C; and
in a time span of up to 240 minutes.
Habeych teaches that the tuber processing water (i.e., potato fruit juice) is subjected to a pretreatment prior to the diafiltration step ([0020]). Pretreatment can comprise at least one of concentration, pH adjustment, solids removal, and/or heat treatment, resulting in a pretreated tuber processing water comprising native protein, and these steps can be performed in any order ([0070]). Paragraph [0082] reads:
[A] pH adjustment to 4.0-5.5 can be used to precipitate at least part of the patatin fraction…so as to obtain tuber processing water comprising a higher relative quantity of native protease inhibitor. Precipitated protein can subsequently be removed during a step of solids removal as elsewhere defined. This increases the relative quantity of native protease inhibitor in the native tuber protein isolate.
Paragraph [0084] reads:
A heat treatment may also be applied as a pretreatment, provided that the heat treatment does not result in full protein coagulation. For example, a heat treatment to 40-55° C. for 1-120 minutes may remove a significant portion of the patatin, which can subsequently be removed by a solids removal step. Also, it is known that protease inhibitor from tuber has higher heat stability than patatin, and that heating may lead to partial or full denaturation of patatin. Thus, a heating step may be performed in combination with a solids removal step for example to obtain a tuber processing water enriched in native protease inhibitor. For example, a heat treatment at 60-80° C., preferably 70-73° C. can be used to precipitate at least part of the patatin fraction, which can be followed by a step of solids removal, in order to isolate native tuber protein enriched in native protease inhibitor.
The pretreatment may also comprise a concentration step via cross-flow ultrafiltration ([0074]). As the pretreatment steps may be performed in any order ([0070]), Habeych therefore teaches an embodiment where the solution of separated potato proteins comprising the first retentate obtained in step (ii) prior to step (iii) is exposed to:
a pH value between 2.0 and 4.5 – 4.0-5.5 ([0082]);
a temperature in the range of 1-70 °C – 40-55 °C ([0084]); and
in a time span of up to 240 minutes – 1-120 minutes ([0084]).
The claimed pH range of between 2.0 and 4.5 overlaps with the disclosed pH range of 4.0-5.5. In a case where the claimed ranges overlap or lie inside ranges disclosed by the prior art, a prima facie case of obviousness exists, MPEP § 2144.05(I).
Since Habeych teaches the exposure of the potato proteins to the claimed conditions, it is reasonably considered that such treatment would confer the claimed effect of eliminating unwanted enzymatic activity of the potato proteins without adversely affecting functionality of the potato proteins. Furthermore, one of ordinary skill in the art of potato protein purification would have had an understanding of the biochemical properties of the potato proteins and would have used process parameters to obtain desired functional properties of said proteins. Therefore, claims 28 and 29 are rendered obvious.
Claims 9 and 10 are rejected under 35 U.S.C. 103 as being unpatentable over Habeych Narvaez et al. in view of Bell et al. and Liderfelt et al. as applied to claim 1 above, and further in view of Edens et al. (WO 97/42834).
Regarding claims 9 and 10, Habeych, Bell, and Liderfelt teach the method according to claim 1.
The cited prior art does not teach the method comprising the step of continuing the addition of said one or more second salts and water to the first retentate in step (iii) while continuing the membrane filtration process until the first retentate contains less than a target amount of the phenolic and/or total glycoalkaloid compounds, whereby the separation of the potato proteins from phenolic and/or total glycoalkaloid compounds has been achieved, wherein the target amount of remaining phenolic and/or total glycoalkaloid compounds in the first retentate corresponds to less than 5000 mg phenolic and/or total glycoalkaloid compounds per kg potato protein on the basis of dry weight (re: claim 9) or wherein the amount of phenolic and/or total glycoalkaloid compounds having a molecular weight below 10 kDa remaining in the first retentate in step (iii) is less than 1500 mg/kg measured as mg phenolic and/or total glycoalkaloid compounds/kg potato protein on the basis of dry weight (re: claim 10).
However, Edens teaches a method for isolating undenatured potato protein from potato fruit juice comprising a pretreatment, concentration by ultrafiltration using a 5 kDa cut-off membrane, and washing by diafiltration in the presence of bisulfite until salts and metal concentrations reach acceptable levels (p. 5, lines 10-28). Membranes with cut-off ranging from 3-100 kDa are disclosed (p. 3, lines 27-29). HPLC analysis of the freeze-dried powder indicated no detectable levels of glycoalkaloids (p. 5, lines 26-27). Thus, Edens teaches that the continuous diafiltration of the ultrafiltration retentate comprising molecules over 5 kDa reduces the glycoalkaloid amount to levels undetectable by HPLC.
It would have been obvious for one of ordinary skill in the art, before the effective filing date of the claimed invention, to apply the continuous diafiltration wash technique of Edens to the method of Habeych modified by Bell and Liderfelt as an improved way to remove glycoalkaloids from the potato protein retentate as claimed. See MPEP § 2143(I)(D). First, Habeych teaches the base method of ultrafiltration and diafiltration of potato proteins from potato fruit juice as described regarding claim 1 above. Habeych teaches that glycoalkaloids can be removed at any step, and that glycoalkaloid extraction is performed by other known techniques, such as adsorption ([0092]) to reach at most 200 mg/kg glycoalkaloids ([0091]). Edens teaches the applicable known technique of continuous diafiltration to wash away non-protein components, including glycoalkaloids, such that the final amount of glycoalkaloids in the protein product is undetectable by HPLC (p. 5, lines 21-28). Since Habeych teaches the reduction of glycoalkaloids to at most 200 mg/kg, one of ordinary skill in the art would have recognized that applying the technique of Edens would have yielded predictable results and resulted in an improved system by eliminating the need for an additional adsorption step to remove glycoalkaloids. Therefore, claims 9 and 10 are rendered obvious.
Claim 16 is rejected under 35 U.S.C. 103 as being unpatentable over Habeych Narvaez et al. in view of Bell et al. and Liderfelt et al. as applied to claim 1 above, and further in view of Mendiratta et al. (WO 2018/158716 A1).
Regarding claim 16, Habeych, Bell, and Liderfelt teach the method according to claim 1.
The cited prior art does not teach that the one or more second salts are selected from sodium sulfate and potassium sulfate. Instead, Habeych teaches salts including sodium chloride and potassium chloride ([0046]).
However, in the field of protein purification, Mendiratta teaches a method of preparing an antibody protein-drug complex (trastuzumab maytansinoid conjugate) that uses diafiltration wherein the diafiltration medium is buffer or water (claim 16). The formulations optionally comprise suitable tonicity modifiers such as sodium chloride, potassium chloride, potassium sulfate or sodium sulfate (p. 6, lines 9-11). Therefore, these salts are seen as interchangeable for the purpose of modifying the tonicity of a solution.
It would have been obvious for one of ordinary skill in the art, before the effective filing date of the claimed invention, to substitute the sodium chloride or potassium chloride in the method of Habeych with sodium sulfate or potassium sulfate as a simple substitution of one known element for another to obtain predictable results. See MPEP § 2143(I)(B). First, Habeych teaches diafiltration of isolated potato proteins using salts such as sodium chloride or potassium chloride ([0046]). Habeych also teaches that it is essential that the conductivity is relatively high during the protein isolation process ([0040]), indicating that the solution must have a tonicity to have conductivity. Mendiratta teaches purifying an antibody-drug conjugate using diafiltration (claim 16) and that suitable tonicity modifiers may be present in the formulation; the disclosed tonicity modifiers are sodium chloride, potassium chloride, potassium sulfate, and sodium sulfate (p. 6, lines 9-11). Since Mendiratta discloses that these salts are suitable tonicity modifiers for use in a protein-drug conjugate, one of ordinary skill in the art would have had a reasonable expectation of success in substituting any one of these salts for each other to obtain the predictable result of modifying the tonicity and hence, conductivity of the solution. Therefore, claim 16 is rendered obvious.
Claim 25 is rejected under 35 U.S.C. 103 as being unpatentable over Habeych Narvaez et al. in view of Bell et al. and Liderfelt et al. as applied to claim 1 above, and further in view of Rajuva et al. (Rajuva, T. R., Divya, B., & Joy, P. (2016). Chapter P40 Non Thermal Processing Of Foods: Pulsed Electric Fields, Pulsed Light, Ionizing Radiation And High Hydrostatic Pressure. pp. 1-43).
Regarding claim 25, Habeych, Bell, and Liderfelt teach the method according to claim 1.
The cited prior art does not teach that the method further comprises a germicidal step at a temperature in the range of 2-60 °C using high intensity UV light, X-rays, pulsed electric field treatment or high-pressure pasteurization.
However, Rajuva teaches non-thermal processes used in food processing to inactivate microorganisms, including pulsed electric field, high pressure processing (i.e., high-pressure pasteurization), and ionizing radiation (i.e., x-ray or UV light) (p. 2, ¶¶ 4-5). Pulsed electric field treatment is conducted at 50-60°C (p. 7, ¶ 3, “Treatment Temperature”). High pressure processing may be conducted at 45-50°C (p. 18, ¶ 5). Ionizing radiation treatment is a “cold process” that only increases the product temperature by about 1°C (p. 25, ¶ 6), and as such is seen to be conducted more-or-less at room temperature. Therefore, Rajuva teaches that these processes are conducted at a temperature in the range of 2-60°C.
It would have been obvious for one of ordinary skill in the art, before the effective filing date of the claimed invention, to add a non-thermal germicidal step as disclosed by Rajuva to the method of Habeych as modified by Bell and Liderfelt to ensure that the potato protein is food-safe while maintaining the native properties of the proteins. First, Habeych teaches the isolation of native potato proteins ([0006]) for use in human food applications ([0002]), and that it is much preferred that the temperature is kept below 40°C in steps prior to drying to prevent denaturation ([0103]). Since the potato protein isolate is intended for human consumption, and Habeych is silent regarding germicidal treatment for food safety, one of ordinary skill in the art would have been motivated to consult Rajuva to find methods for germicidal treatment of food products that maintain the native properties of said food products. One of ordinary skill in the art would have had a reasonable expectation of success for doing so because Rajuva teaches non-thermal processes used in food processing to inactivate microorganisms, including pulsed electric field, high pressure processing (i.e., high-pressure pasteurization), and ionizing radiation (i.e., x-ray or UV light) (p. 2, ¶¶ 4-5), as claimed, and, as described above, these processes are carried out within the claimed 2-60°C. Therefore, claim 25 is rendered obvious.
Response to Arguments
Claim Objections:
Applicant has overcome the objections to claims 7, 17, and 24 by amendment. Accordingly, the objections have been withdrawn.
Claim Rejections – 35 U.S.C. § 112:
Applicant has overcome the 35 U.S.C. § 112(b) rejections of claims 4-6, 9, 10, 15-19, 22, 24-25, 28, and 29 based on amendment to the claims. Accordingly, the 35 U.S.C. § 112(b) rejections have been withdrawn.
Claim Rejections – 35 U.S.C. § 103: Applicant’s arguments filed on 10 July 2025 have been fully considered, but they are not persuasive.
Applicant first argued that where Habeych does not disclose to remove phenols and/or glycoalkaloids by membrane filtration, nor attempts to recover the phenols and/or glycoalkaloids (p. 8, ¶ 3), Bell does not remedy this deficiency. Applicant argued that Bell teaches separation of potato proteins from the phenolic and/or glycoalkaloid compounds, corresponding to step (ii) of the claimed method, and does not teach to separate the phenolic and/or glycoalkaloid compounds from the salts by a cross-flow membrane filtration process, corresponding to step (iv) of the claimed method (p. 8, ¶ 4).
Applicant’s argument has been considered, but it is not persuasive. Applicant is reminded that the test for obviousness is not whether the features of a secondary reference may be bodily incorporated into the structure of the primary reference; nor is it that the claimed invention must be expressly suggested in any one or all of the references. Rather, the test is what the combined teachings of the references would have suggested to those of ordinary skill in the art. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981).
The applicable teaching of Bell is that phenolic and glycoalkaloid compounds can be separated from potato water by additional cross-flow filtration using appropriate rejection characteristics or smaller pore sizes, such as ultrafiltration, nanofiltration, or reverse osmosis ([0012]). Therefore, one of ordinary skill in the art would have found it obvious to apply this teaching from Bell to the disclosed method of Habeych as described in the rejection of claim 1 hereinabove, and in doing so would have arrived at the claimed method step (iv).
Applicant next argued that where Habeych does not disclose to recover and/or reuse added salts (p. 8, ¶ 3), and neither Bell (p. 8, ¶ 4) nor Liderfelt remedy this deficiency (pp. 8-9, bridging ¶). Applicant argued that Liderfelt teaches microfiltration as a first step wherein the protein permeates the membrane. Then, as a second step, the permeate is passed through an ultrafiltration membrane to concentrate the target protein in the retentate. The ultrafiltration permeate can then be recycled back for washing the concentrated biomass in the first step (pp. 9-10, bridging ¶). Applicant argued that the teachings of Liderfelt, in the context of the present invention, correspond to microfiltration to separate starch from the remaining compounds within the potato juice, which does not relate to steps of claim 1, but possibly to claim 7, and ultrafiltration to separate proteins from the salts and phenolic and/or glycoalkaloid compounds, which would correspond to step (ii) of the claimed method (p. 10, ¶ 1). Applicant also argued that Liderfelt does not teach, or in any way suggest, to recover phenols and/or glycoalkaloids from the ultrafiltration permeate, by further nanofiltration and then recirculating the nanofiltration permeate in order to reuse the added salts, or even mention phenols or glycoalkaloids at all (p. 10, ¶ 3). Applicant has argued against Liderfelt individually.
In response to applicant's arguments against the references individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986).
The rejection of claim 1 is based on the combination of Habeych, Bell, and Liderfelt. The rejection acknowledges that Habeych does not teach step (iv) or recycling the second permeate (permeate of step (iv)) to use the salts and water as at least part of the diafiltration solution of step (iii). The rejection states that the teachings of Bell render obvious the claimed step (iv). The concept of permeate recycling to an earlier filtration step for washing a retentate and buffer conservation taught by Liderfelt is then applied to the method of Habeych as modified by Bell to incorporate recycling of the second permeate of step (iv) as part of the diafiltration solution of step (iii). Applicant’s argument is therefore not persuasive.
Applicant next argued that Liderfelt is not related to food processing, let alone the processing of juice from potatoes, thus a person skilled in the art would first and foremost not consider Liderfelt when seeking for a solution to separating compounds from potato juice, and moreover would not learn the key steps of the claimed method (p. 10, ¶¶ 1 & 3).
In response to applicant's argument that Liderfelt is nonanalogous art, it has been held that a prior art reference must either be in the field of the inventor’s endeavor or, if not, then be reasonably pertinent to the particular problem with which the inventor was concerned, in order to be relied upon as a basis for rejection of the claimed invention. See In re Oetiker, 977 F.2d 1443, 24 USPQ2d 1443 (Fed. Cir. 1992). In this case, the field of endeavor is membrane ultrafiltraton/diafiltration of aqueous solutions. Even if one considers the field of endeavor to be separation of potato fruit juice components by ultrafiltration/diafiltration, the concepts taught by Liderfelt are still applicable to the problem of separating potato proteins from phenolics and glycoalkaloids, further separating phenolics and glycoalkaloids from diafiltration solution, and, particularly, recycling the diafiltration solution for use in diafiltration of the protein retentate.
Liderfelt teaches first and second stages of cross-flow filtration, and recycling the permeate from the second stage back to the first stage in order to wash out the product and minimize buffer volumes (Fig. 23.9, caption). The buffer solution described in Liderfelt is comparable to the diafiltration solution (one or more second salts and water) of step (iii) of instant claim 1. The UF permeate of Liderfelt is comparable to the second permeate generated in step (iv) of instant claim 1. While Liderfelt shows that the first membrane filtration is microfiltration, the advantage taught by Liderfelt of more thorough washing while conserving wash/buffer solution is maintained, regardless of whether the first filtration is microfiltration or ultrafiltration. One of ordinary skill in the art would have easily reasoned that the microfiltration membrane of Liderfelt could be replaced by any suitable membrane such that desired components are retained in the retentate, and components desired to pass through the filter are able to pass through. In the present case, the proteins of the first retentate are retained during the diafiltration process of Habeych, and phenolics and/or glycoalkaloids, salts and water pass through in a first diafiltrate/permeate. The second permeate is generated upon modification of the method of Habeych with the teachings of Bell to capture phenolics and/or glycoalkaloids by a second cross-flow filtration step and allow salts and water to pass through in a second permeate. Applying the concept of recycling the second permeate as disclosed by Liderfelt to the method of Habeych as modified by Bell would result in recycling at least part of one or more second salts and water in step (iii) of the invention, as claimed. Applicant’s argument is therefore not persuasive.
Applicant also argued that the combined cited prior art documents do not teach to recover phenolic and/or glycoalkaloid compounds from a potato fruit juice by separating these compounds from added salts by a cross-flow membrane filtration process, or to recycle the thus obtained separated added salts to the retentate of a first cross-flow membrane filtration process of potato fruit juice for performing a diafiltration step (p. 9, ¶ 4).
Applicant’s argument has been considered, but it is not persuasive in view of the discussion above.
For at least these reasons, Applicant’s arguments are not found to be persuasive, and claims 1-2, 4-20, 22-25, and 28-29 are rejected as presented hereinabove. Applicant has cancelled claim 3.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/JAMES P. SHELLHAMMER/Examiner, Art Unit 1793
/EMILY M LE/Supervisory Patent Examiner, Art Unit 1793