Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
METHOD AND APPARATUS FOR PRODUCING PARTICULATED WHEY PROTEIN CONCENTRATE
Document Type and Number:
WIPO Patent Application WO/2019/153087
Kind Code:
A1
Abstract:
A method for producing particulated whey protein concentrate (WPC) in a continuous-flow high shear reactor (CHSR) is provided. The method includes providing a WPC solution as input, recirculating the WPC solution in the CHSR, and simultaneously heat treating and mechanically heating the WPC solution. The heat to the WPC solution is generated only by the thermal energy created by fluid friction within the recirculated WPC solution.

Inventors:
BADAYEV, Oleksandar (5295 4th Avenue, Delta, British Columbia V4M 1G8, V4M 1G8, CA)
ANTOSHYN, Ihor (4/9 General Vitruk Street, apartment 8Kiev, 03115, UA)
Application Number:
CA2019/050164
Publication Date:
August 15, 2019
Filing Date:
February 07, 2019
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
PACIFIC MEMBRANE FILTRATION SOLUTIONS LTD. (5295 4th Avenue, Delta, British Columbia V4M 1G8, V4M 1G8, CA)
International Classes:
A23J3/08; A23C9/13; A23C21/00; A23L33/19; B01J19/24
Foreign References:
CA2748217A12010-07-01
Attorney, Agent or Firm:
RATTRAY, Todd A. et al. (Suite 480 - 601 W. Cordova Street, Vancouver, British Columbia V6B 1G1, V6B 1G1, CA)
Download PDF:
Claims:
WHAT IS CLAIMED IS:

1 . A method for producing a particulated WPC solution, the method comprising:

providing a WPC solution as input;

recirculating the WPC solution in a continuous-flow high shear reactor (CHSR), wherein recirculating the WPC solution in the CHSR comprises heat treating the recirculated WPC solution using thermal energy created by fluid friction within the recirculated WPC solution to thereby promote protein denaturation within the recirculated WPC solution; and

simultaneously with the heat treating, mechanically treating the recirculated WPC solution, thereby particulating the denatured protein to obtain the particulated WPC solution.

2. A method as defined in claim 1 or any other claim herein, wherein heat treating the recirculated WPC solution comprises only supplying heat to the recirculated WPC solution by the thermal energy created by fluid friction within the recirculated WPC solution.

3. A method as defined in any one of claims 1 to 2 or any other claim herein, wherein mechanically treating the recirculated WPC solution comprises shaping a conduit of the CHSR and controlling a flow rate of the recirculated WPC solution in the CHSR to thereby provide a laminar flow regime to the recirculated WPC solution within the CHSR.

4. A method as defined in claim 3 or any other claim herein, wherein the laminar flow regime has a Reynolds number in the range of 1 ,000 Re to 2,300 Re.

5. A method as defined in any one of claims 1 to 2 or any other claim herein, wherein mechanically treating the recirculated WPC solution comprises shaping a conduit of the CHSR and controlling a flow rate of the recirculated WPC solution in the CHSR to thereby provide a turbulent flow regime to the recirculated WPC solution within the CHSR.

6. A method as defined in claim 5 or any other claim herein, wherein the turbulent flow regime has a Reynolds number in the range of 4,000 Re to 50,000 Re.

7. A method as defined in any one of claims 1 to 6 or any other claim herein, wherein mechanically treating the recirculated WPC solution comprising subjecting the WPC input solution to a shear rate of 500s 1 to 2,000s 1.

8. A method as defined in any one of claims 1 to 7 or any other claim herein, wherein mechanically treating the recirculated WPC solution comprising subjecting the WPC input solution to a shear rate of 500s 1 to 1 ,000s 1.

9. A method as defined in any one of claims 1 to 8 or any other claim herein, wherein mechanically treating the recirculated WPC solution comprises passing the recirculated WPC solution through a homogenizing valve.

10. A method as defined in any one of claims 1 to 9 or any other claim herein, further comprising pre-heating the WPC input solution before recirculating the WPC input solution.

1 1 . A method as defined in claim 10 or any other claim herein, wherein pre-heating the WPC input solution comprises pre-heating the WPC input solution to within a range of about 60-65 °C and wherein heat treating the recirculated WPC solution using thermal energy created by fluid friction within the recirculated WPC solution comprises heating the recirculated WPC solution to a temperature of higher than 80°C.

12. A method as defined in any one of claims 1 to 1 1 or any other claim herein, wherein recirculating the WPC solution in the CHSR comprises recirculating the recirculated WPC solution for time in a range of about 1 minute to about 5 minutes.

13. A method as defined in any one of claims 1 to 12 or any other claim herein, further comprising flowing the WPC solution through a hydrocyclone to promote separation of aggregated whey protein particles.

14. A method as defined in claim 13 or any other claim herein, further comprising separating aggregated whey protein particles larger than about 1 15 pm to 120 pm.

15. A method as defined in any one of claims 1 to 14 or any other claim herein, further comprising pasteurizing the particulated WPC solution.

16. A method as defined in claim 15 or any other claim herein, further comprising

mechanically treating the particulated WPC solution.

17. A method as defined in any one of claims 1 to 16 or any other claim herein, further comprising cooling the particulated WPC solution.

18. A method as defined in any one of claims 1 to 17, further comprising applying

acoustic energy to the particulated WPC solution.

19. A method as defined in any one of claims 1 to 18 or any other claim herein, wherein mechanically treating the recirculated WPC solution comprises particulating the denatured protein to an average size in a range from about 300nm to about 10pm.

20. A method for increasing the protein content of a food product by including the

particulated WPC solution prepared by a method as defined in any one of claims 1 to 19.

21 . A method as defined in claim 20 or any other claim herein, wherein the food product is yoghurt.

22. A continuous-flow high shear reactor (CHSR) comprising

a recirculation loop comprising a reactor channel for conveying a recirculated WPC solution; and

a recirculation pump connected to recirculate the recirculated WPC solution within the reactor channel; wherein thermal energy created by fluid friction within the recirculated WPC solution heats the recirculated WPC solution in the reactor channel to thereby promote protein denaturation.

23. A CHSR as defined in claim 22 or any other claim herein, wherein the recirculated WPC solution within the recirculation loop is heated only by the thermal energy created by the fluid friction within the recirculated WPC solution.

24. A CHSR as defined in any one of claims 22 to 23 or any other claim herein, wherein the reactor channel is shaped and dimensioned to promote a laminar flow regime to the recirculated WPC solution.

25. A CHSR as defined in any one of claims 22 to 24 or any other claim herein, wherein the recirculation pump outputs a recirculation pump pressure which causes the recirculated WPC solution to exhibit laminar flow within the reactor channel .

26. A CHSR as defined in claim 25 or any other claim herein wherein the laminar flow of the recirculated WPC solution within the reactor channel mechanically treats the recirculated WPC solution, thereby particulating the denatured protein to obtain a particulated WPC solution.

27. A CHSR as defined in any one of claims 22 to 24 or any other claim herein, wherein the recirculation pump outputs a recirculation pump pressure which causes the recirculated WPC solution to exhibit turbulent flow within the reactor channel.

28. A CHSR as defined in claim 27 or any other claim herein wherein the turbulent flow of the recirculated WPC solution within the reactor channel mechanically treats the recirculated WPC solution, thereby particulating the denatured protein to obtain a particulated WPC solution.

29. A CHSR as defined in any one of claims 22 to 28 or any other claim herein, wherein the reactor channel is shaped to comprise a serpentine tube, a helical tube, or a bayonet tube.

30. A CHSR as defined in any one of claims 22 to 29 or any other claim herein, wherein the recirculation pump is a positive placement pump or a centrifugal pump.

31 . A CHSR as defined in any one of claims 22 to 30 or any other claim herein, wherein the reactor channel comprises a static mixing element on an inner bore-defining surface thereof.

32. A CHSR as defined in claim 31 or any other claim herein, wherein the static mixing element protrudes from the inner bore-defining surface and towards a central axis of the reactor channel.

33. A CHSR as defined in claim 32 or any other claim herein, wherein the static mixing element comprises a hemispherical protrusion.

34. A CHSR as defined in any one of claims 22 to 33 or any other claim herein, wherein the recirculation loop comprises a homogenizing valve in fluid communication with the reactor channel for mechanically treating the recirculated WPC solution.

35. A CHSR as defined in claim 34 or any other claim herein, wherein the homogenizing valve is a low pressure homogenizing valve.

36. A CHSR as defined in claim 35 or any other claim herein, wherein the low pressure homogenizing valve is configured to decrease pressure by 1 to 10 bar.

37. A CHSR as defined in claim 36 or any other claim herein, wherein the low pressure homogenizing valve is configured to decrease pressure by 3 to 5 bar.

38. A CHSR as defined in any one of claims 22 to 37 or any other claim herein, wherein the recirculation loop further comprises a hydrocyclone in fluid communication with the reactor channel.

39. A system for producing a particulated WPC solution, the system comprising a CHSR as defined in any one of claims 22 to 38.

40. A system as defined in claim 39 or any other claim herein, further comprising one or more of a holding tube, a cooling recirculation loop, a heat exchanger, a

ultrasonication device and a storage tank.

41 . A method for producing a particulated WPC, the method comprising:

preparing a WPC solution;

delivering the WPC solution to a CHSR;

heat treating the WPC solution using thermal energy created by fluid friction in the CHSR;

mechanically treating the WPC solution in the CHSR simultaneously with the heat treating.

42. A method according to claim 41 or any other claim herein, further comprising

recirculating the WPC solution through the CHSR to simultaneously thermally and mechanically treat the WPC solution to particulate the WPC solution to a desired extent.

43. A method according to claim 41 or any other claim herein, wherein mechanically treating the WPC solution comprises providing a laminar flow regime or a turbulent flow regime to the WPC solution.

44. A method according to claim 43 or any other claim herein, wherein the laminar flow regime or the turbulent flow regime has a Reynolds number in the range of about 500 Re to about 100,000 Re.

45. A method according to claim 43 or any other claim herein, wherein the WPC solution in the CHSR has an average shear rate in the range of about 500s 1 to about 1 ,500s 1 and a maximum shear rate of about 2,000s 1.

46. A method according to claim 43 or any other claim herein, wherein the WPC solution has a mean residence time in the CHSR in the range of about 1 minute to about 15 minutes.

47. A method according to claim 43 or any other claim herein, wherein the WPC solution is heated in the CHSR to a temperature in the range of about 70°C to about 120°C.

48. A method according to claim 43 or any other claim herein, wherein mechanically treating the WPC solution comprises passing the WPC solution through one or more homogenizing valves.

49. A process according to claim 43 or any other claim herein, further comprising

delivering the WPC solution to one or more of a holder tube, a cooling recirculation loop, a heat exchanger, a ultrasonication device, and a storage tank.

50. A process according to claim 43 or any other claim herein, wherein the heat treating the WPC solution and the mechanically treating the WPC solution are concurrent.

51 . A particulated WPC produced according to the process recited by any one of claims 43 to 50.

52. A particulated WPC according to claim 51 or any other claim herein, wherein the particulated WPC has an average whey protein particles size in the range of about 300 nm to about 10 pm.

53. A particulated WPC according to claim 51 or any other claim herein, wherein the particulated WPC has a particle size having a coefficient of variation (CV) of less than about 0.5.

54. An apparatus for producing a particulated WPC, the apparatus comprising a CHSR for concurrently thermally and mechanically treating a WPC solution.

55. An apparatus according to claim 54 or any other claim herein, wherein the CHSR comprises one or more reactor channels configured to provide a laminar flow regime or a turbulent flow regime to the WPC solution.

56. An apparatus according to claim 55 or any other claim herein, wherein the CHSR further comprises a hydrocyclone configured to separate aggregated WPC particles in the WPC solution.

57. An apparatus according to claim 55 or any other claim herein, wherein the CHSR further comprises one or more homogenizing valves configured to shear the WPC solution.

58. An apparatus according to claim 55 or any other claim herein, further comprising one or more of a holder tube, a cooling recirculation loop, a heat exchanger, a ultrasonication device, and a storage tank downstream from the CHSR for further processing the WPC solution.

59. An apparatus according to any one of claims 55 to 58 or any other claim herein, wherein the particulated WPC has a protein content in the range of about 30% to about 85% of dry matter of the particulated WPC.

60. An apparatus according to any one of claims 55 to 59 or any other claim herein, wherein a resulting solution of the particulated WPC has a protein content in the range of about 5% w/w to about 18% w/w.

61 . An apparatus according to any one of claims 55 to 59 or any other claim herein, wherein the one or more reactor channels comprise a serpentine tube.

Description:
METHOD AND APPARATUS FOR PRODUCING PARTICULATED WHEY PROTEIN

CONCENTRATE

Reference to Related Applications

[0001] This application claims priority from, and, for the purposes of the United States, the benefit of 35 USC 1 19(e) in association with, United States application No. 62/627480 filed 7 February 2018 which is hereby incorporated herein by reference.

Technical Field

[0002] The present invention relates to a method and apparatus for producing

microparticulated (MP) and/or nanoparticulated (NP) whey protein concentrate (WPC). In particular, the present invention relates to a method and apparatus for producing particulated WPC using concurrent thermal and mechanical treatment.

Background

[0003] Whey protein concentrate (WPC) is typically either provided: (i) in the form of a solution typically prepared by ultrafiltration (UF) of whey; or (ii) in the form of a powder typically prepared by ultrafiltration (UF) of whey followed by drying using some suitable technique (such as, for example, spray drying). WPC in solution form typically comprises native whey protein, the average particle size of which is in the range of 1 -5nm depending on the molecular weight cut-off of ultrafiltration membrane, e.g. in the range of 5,000 - 20,000 Dalton. WPC is classified according to its protein content. For example, WPC35 refers to WPC containing 35% whey protein by weight and WPC 60-70 refers to WPC containing 60% to 70% whey protein by weight. The following are examples of WPC products that are available commercially: WPC35, WPC60-70, WPC80, and whey protein isolate (WPI).

[0004] Microparticulation is conventionally based on a combination of heat and shear treatment of a solution of WPC. The solution is typically heated (using some form of external heater) to a temperature in the range of 70 °C to 1 10Ό, which causes the native protein to unfold and aggregate. Unless shear treatment is applied, applying heat causes the WPC solution to form a gel. When the WPC solution is heat-treated under shear treatment conditions, the shear forces prevent the formation of the gel and individual “particulated” protein particles are produced. This process is known as microparticulation.

[0005] According to Spiegel, T.“Whey protein aggregation under shear conditions - effects of lactose and heating temperature on aggregate size and structure,” (1999) International Journal of Food Science and Technology, 34: 523-531 and Spiegel, T. & Huss, M.“Whey protein aggregation under shear conditions - effects of pH-value and removal of calcium,” (2002) International Journal of Food Sciences and Technology, 37: 559-568, whey protein particle size is a function of protein content, lactose content, pH, and calcium content of the WPC solution. For example, heat and shear treating a WPC60 solution having a lactose content of more than 7% resulted in a median value of the volume-based particle size distribution (D 50 ) of between 60 pm to 80 pm. The D 50 was observed to be in the range of 80 pm to 100 pm when the pH of the WPC60 solution was greater than 6. Particle size is the main cause of different mouth feel of particulated WPC when foods containing the particulated WPC are consumed (eaten) by humans. For particle sizes in the range of about

2 pm to about 5 pm, mouth feel is smooth and creamy. Mouth feel of particles having sizes of about 10 pm is slightly mealy. Mouth feel of particles having sizes of about 50 pm and more is rough and gritty.

[0006] Processes and systems for heat and shear treating liquid WPC are known. Such processes and systems employ one or more of a scraped surface heat exchanger (SSHE), high pressure homogenizing a pre-heated WPC, and using a batch mode special mixer with a high shear rate of more than 5,000 sec 1 .

[0007] Canada Patent No. 2,625,176 describes a microparticulation process for heat and shear treating a liquid WPC in a SSHE under a shear rate of 600 sec 1 to 900 sec 1 and a rotation speed of 600 rpm to 1 ,200 rpm. Average whey protein particle size in the range of

3 pm to 5 pm is observed. Particle size distribution is narrow around the average particle size (i.e. typically about 95% of particles are within ± 3 pm of the average particle size). A disadvantage associated with SSHEs includes high wear of the blades due to high rotation speed and corresponding shear rate. Further, to increase production capacity multiple SSHEs must be connected in series. This increases capital expenses and production costs.

[0008] Canada Patent No. 2,712,978 describes a method of denaturing whey protein using a cylindrical static mixing vessel and a rotary blade that rotates at a high speed creating high shear rates in the range of 5,000 sec 1 to 25,000 sec 1 at a temperature in the range of 76 °C to 120°C . Such method produces whey protein particles having sizes in the range 0.5 pm to 10 pm. Processing whey protein at high rotation speeds consumes significant amounts of energy. For example, the FILMIX Model 56-50 mixer has a 5.5 kW motor. To process a WPC sample having a volume of between 50 mL to 90 mL at a processing rate of 1 1 L/hr requires about 1 ,800 J/mL.

[0009] United States Patent No. 8,889,209 describes a method of treating WPC by microparticulation using high pressure homogenization of a pre-heated WPC. The whey protein solution is pressurised at a pressure in the range of 40 bar to 80 bar to produce particles having a size in the range of 3 pm to 10 pm. According to lordache, M & Jelen, P., High pressure microfluidization treatment of heat denatured whey proteins for improved functionality (2003), Innovative Food Science and Emerging Technologies, 4 , 367-376, high pressure microfluidization treatment using a pressure up to 1 ,500 bar is used to increase solubility and improve functionality of whey protein products based on a 5% (w/w) protein solution. Microfluidization at high pressure requires a significant amount of energy. For example, the microfluidizer M-1 10 EH uses 700J/mL to provide a pressure of 1 ,500 bar for a product flow of 320 mL/min using a 3.7 kW pump. To achieve the appropriate particle size and heat stability the sample must be passed through the system three times using 2,000 J/mL.

[0010] Canada Patent No. 2,748,217 describes a method and device for producing a whey protein product by microgelling and microparticulation. Shearing forces are produced by rotating a rotor that engages a stator. To achieve high shear rates, high rotation speeds are needed, which requires significant energy expenditure.

[0011] International Publication No. WO 2006/058538 describes a method for producing microparticulated whey protein whereby a whey protein solution is heated to a temperature above 70 °C and then quench-cooled to a temperature below 55 °C within less than 20 seconds. A disadvantage of this method is that it is not generally possible to control particle size distribution during quench (rapid) cooling.

[0012] The methods described in the aforesaid documents require high pressures (e.g. up to 1 ,500 bar) and high shear rates (e.g. up to 25,000 sec 1 ) to produce particles having sizes in the range of 0.5 pm to 10 pm. Significant amounts of energy must be consumed and/or high capital and operating expenses incurred, which may limit scaling up from laboratory and pilot plants to full-scale industrial applications.

[0013] There is a general desire to produce whey protein particles having a controllable particle size distribution (e.g. with a coefficient of variation (CV) less than 0.5, where the coefficient of variation is a ratio of the standard deviation (s) of the distribution to the mean of the distribution). There is a general desire to produce whey protein particles having average particle sizes in the range of about 300 nm to about 10 pm. There is a general desire to produce whey protein particles using processes and systems that are less energy intensive and/or more economical than conventional thermal and mechanical treatment methods/systems.

[0014] The foregoing examples of the related art and limitations related thereto are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.

Summary

[0015] The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the above- described problems have been reduced or eliminated, while other embodiments are directed to other improvements.

[0016] One aspect of the invention relates to a method for producing a particulated WPC solution. The method includes providing a WPC solution as input. The WPC solution is recirculated in a continuous-flow high shear reactor (CHSR). The recirculating step includes heat treating the recirculated WPC solution using thermal energy created by fluid friction within the recirculated WPC solution to thereby promote protein denaturation within the recirculated WPC solution.

[0017] Heat treating the recirculated WPC solution comprises only supplying heat to the recirculated WPC solution by the thermal energy created by fluid friction within the recirculated WPC solution. [0018] In some embodiments, the recirculated WPC solution is recirculated at a

recirculation rate in a range of about 20m 3 /hr to about 220m 3 /h.

[0019] In some embodiments, the recirculated WPC solution has an average shear rate in the range of about 500s 1 to about 2,000s 1 .

[0020] In some embodiments, the recirculated WPC solution has an average residence time in the CHSR in the range of about 3 minute to about 15 minutes.

[0021] One aspect of the invention relates to a continuous-flow high shear reactor (CHSR). The CHSR has a recirculation loop comprising a reactor channel for conveying a recirculated WPC solution and a recirculation pump connected to recirculate the

recirculated WPC solution within the reactor channel. The thermal energy created by fluid friction within the recirculated WPC solution heats the recirculated WPC solution in the reactor channel to thereby promote protein denaturation.

[0022] The recirculated WPC solution within the recirculation loop is heated only by the thermal energy created by the fluid friction within the recirculated WPC solution.

[0023] The reactor channel is shaped and dimensioned to promote a laminar flow regime to the recirculated WPC solution. The recirculation pump outputs a recirculation pump pressure which causes the recirculated WPC solution to exhibit laminar flow or turbulent flow within the reactor channel. When the recirculated WPC solution is in either one of laminar flow or turbulent flow, the denatured whey protein is mechanically treated and is particulated.

[0024] In some embodiments, the CHSR has a capacity in a range of about 250 L/hr to about 2,000 L/hr.

[0025] In some embodiments, the pressure within the reactor channel is in a range of about 5 bar to about 12 bar. In some embodiments, the pressure within the reactor channel is in a range of about 9 bar to about 10 bar.

[0026] One aspect of the invention provides a method and apparatus for producing particulated WPC having a customizable average particle size in the range of about 300 nm to about 10 pm. In some embodiments the average particle size has a coefficient of variation (CV) of less than about 0.5. By customizing the average particle size, the WPC produced may be used in specific food applications including, but not limited to producing cheese, high protein yogurts, high protein beverages, low fat sauces, low fat dressings, ice cream, etc. to achieve a desired mouth feel (e.g. smooth and/or creamy). The desired particle size may be achieved using standard processing equipment components and/or without the need for special heavy duty equipment, such as SSHEs and high-pressure homogenizers (e.g. a microfluidizer), that is typically energy and/or cost intensive.

[0027] By concurrently applying thermal and mechanical treatment to a WPC solution, the present invention enable thermal treatment of a WPC solution that is more uniform and/or gradual than conventional treatment processes/systems. Accordingly, the present invention may reduce or avoid high temperature gradients and/or whey protein aggregation and/or whey protein sticking to the inner walls of processing equipment and/or fouling of whey proteins. To apply thermal and mechanical treatment simultaneously, a continuous-flow high shear reactor (CHSR) is provided. In some embodiments, thermal and mechanical (i.e. shear) treatment in the CHSR is followed by ultrasonication (e.g. with a pre-determ ined applied energy density (J/mL)).

[0028] One aspect of the invention provides a process for producing a particulated WPC, the process comprising: preparing a WPC solution; delivering the WPC solution to a CHSR; heat treating the WPC solution using thermal energy created by fluid friction in the CHSR; mechanically treating the WPC solution in the CHSR simultaneously with the heat treating.

[0029] The process may further comprise recirculating the WPC solution through the CHSR to simultaneously thermally and mechanically treat the WPC solution to particulate the WPC solution to a desired extent.

[0030] Mechanically treating the WPC solution may comprise providing a laminar flow regime or a turbulent flow regime to the WPC solution. The laminar flow regime or the turbulent flow regime may have a Reynolds number in the range of about 500 Re to about 100,000 Re.

[0031] The WPC solution in the CHSR may have an average shear rate in the range of about 500s 1 to about 1 ,500s 1 and a maximum shear rate of about 2,000s 1 . The WPC solution may have a mean residence time in the CHSR in the range of about 1 minute to about 15 minutes. The WPC solution may be heated in the CHSR to a temperature in the range of about 70 °C to about 120°C. [0032] Mechanically treating the WPC solution may comprise passing the WPC solution through one or more homogenizing valves.

[0033] The process may comprise delivering the WPC solution to one or more of a holder tube, a cooling recirculation loop, a heat exchanger, a ultrasonication device, and a storage tank.

[0034] Heat treating the WPC solution and mechanically treating the WPC solution is concurrent.

[0035] Another aspect of the invention provides a particulated WPC produced according to any of the process described herein. The particulated WPC may have average whey protein particles size in the range of about 300 nm to about 10 pm. The particulated WPC may have a particle size having a coefficient of variation (CV) of less than about 0.5.

[0036] Another aspect of the invention provides an apparatus for producing a particulated WPC, the system comprising a CHSR for concurrently thermally and mechanically treating a WPC solution. [0037] The CHSR may comprise one or more reactor channels configured to provide a laminar flow regime or a turbulent flow regime to the WPC solution. The CHSR may further comprise a hydrocyclone configured to separate aggregated WPC particles in the WPC solution. The CHSR may further comprise one or more homogenizing valves configured to shear the WPC solution. [0038] The apparatus may further comprise one or more of a holder tube, a cooling recirculation loop, a heat exchanger, a ultrasonication device, and a storage tank downstream from the CHSR for further processing the WPC solution.

[0039] The apparatus may produce the particulated WPC having a protein content in the range of about 30% to about 85% of dry matter of the particulated WPC. [0040] The apparatus may produce a resulting solution of the particulated WPC having a protein content in the range of about 5% w/w to about 18% w/w. [0041] In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following detailed descriptions.

Brief Description of the Drawings

[0042] Exemplary embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive.

[0043] FIG. 1 is a schematic illustration of a system for producing particulated WPC according to an example embodiment.

[0044] FIG. 2 is a grade-efficiency curve showing the separation efficiency of a

hydrocyclone as a function of the particle size of different viscosities of a whey protein solution prepared according to an example embodiment of the present invention.

[0045] FIG. 3 shows a schematic illustration of a method for producing particulated WPC according to an example embodiment.

[0046] FIG. 4A shows a perspective view of a reactor channel of a CHSR according to an example embodiment.

[0047] FIG. 4B shows a perspective view of another reactor channel of a CHSR according to another example embodiment.

[0048] FIGS. 5A-5C show exemplary particle size distributions of particulated WPC obtained using system of FIG. 1 .

Description

[0049] Throughout the following description specific details are set forth in order to provide a more thorough understanding to persons skilled in the art. However, well known elements may not have been shown or described in detail to avoid unnecessarily obscuring the disclosure. Accordingly, the description and drawings are to be regarded in an illustrative, rather than a restrictive, sense. [0050] Unless context dictates otherwise,“whey protein” (as used herein) refers to a mixture of globular proteins isolated from whey, (e.g. where whey is the liquid material created as a by-product of cheese and/or yogurt production).

[0051] Unless context dictates otherwise,“whey protein concentrate” (WPC) (as used herein) refers to a product derived from whey (in some cases, water, minerals, and at least some lactose may have been removed from the whey) and having a protein purity greater than about 30% by weight. WPC is typically either provided: (i) in the form of a solution typically prepared by ultrafiltration (UF) of whey; or (ii) in the form of a powder typically prepared by ultrafiltration (UF) of whey followed by drying using some suitable technique (such as, for example, spray drying). WPC in solution form typically comprises native whey protein, the average particle size of which is in the range of 1 -5nm depending on the molecular weight cut-off of ultrafiltration membrane, e.g. in the range of 5,000 - 20,000 Dalton.

[0052] Unless context dictates otherwise,“whey protein isolate” (WPI) (as used herein) refers to a product derived from whey (in some cases, water, minerals, and lactose may have been removed from the whey) and having a protein purity greater than about 80% by weight.

[0053] Unless context dictates otherwise,“microparticulate” (as used herein) means particles between about 1 pm and about 100 pm in size (e.g. volume equivalent sphere diameter).

[0054] Unless context dictates otherwise,“nanoparticulate” (as used herein) means particles between about 1 nm and about 500 nm in size (e.g. volume equivalent sphere diameter).

[0055] Unless context dictates otherwise,“ultrafiltration” (as used herein) means low pressure (i.e. up to about 5 bar) filtration through a semipermeable membrane in which colloidal particles are retained, while smaller solutes and the solvent are forced through the membrane by hydrostatic pressure forces.

[0056] Unless context dictates otherwise,“volume-based median D x =y” or, for brevity, “D^y” (as used herein) means that x% of the particles have a size (e.g. a volume or other particle size parameter) less than y. [0057] Unless context dictates otherwise,“mouth feel” (as used herein) refers to the physical sensations in the mouth produced by a particular beverage or food.

[0058] Unless context dictates otherwise,“energy density” (as used herein) means the amount of energy applied or stored in a given system or region of space per unit volume (e.g. J/mL).

[0059] Unless context dictates otherwise,“scraped surface heat exchanger” (SSHE) (as used herein) refers to a device commonly used in food, chemical, and pharmaceutical industries for heat transfer, crystallization, and other continuous processes. During operation, the product is brought into contact with a heat transfer surface that is rapidly and continuously scraped, thereby exposing the surface to the passage of untreated product. In addition to maintaining high and uniform heat exchange, scraper blades also provide simultaneous mixing and agitation.

[0060] Unless context dictates otherwise,“high pressure homogenization” (as used herein) means subjecting a (primarily) liquid stream to mechanical treatment, such as one or more of shear forces, impact, and cavitation. For example, high pressure is applied to a liquid sample inside a tank to force the liquid sample through a valve or membrane with narrow slits. This causes high shear, a large pressure drop, and cavitation, all of which act to homogenize the sample. To aid in homogenization, the high pressure stream may be directed at a blade, ring, or plate, upon which the sample collides at a high speed.

[0061] Unless context dictates otherwise,“positive displacement pump” (as used herein) means a pump that makes a fluid move by trapping a fixed amount and forcing (i.e.

displacing) that trapped volume into a discharge pipe. A positive displacement pump may be classified according to the mechanism used to move the fluid. Examples include rotary- type positive displacement pumps (e.g. internal gear, screw, shuttle block, flexible vane or sliding vane, circumferential piston, flexible impeller, helical twisted roots (e.g. the

Wendelkolben pump), liquid-ring pumps, etc.), reciprocating-type positive displacement pumps (e.g. piston pumps, plunger pumps, diaphragm pumps, etc.), and linear-type positive displacement pumps (e.g. rope pumps, chain pumps, etc.).

[0062] Unless context dictates otherwise,“hydrocyclone” (as used herein) means a mechanical device used to reduce or increase the concentration of a dispersed phase, solid, liquid, or gas of different density, by means of centripetal forces or centrifugal forces within a vortex.

[0063] Unless context dictates otherwise,“laminar flow” (as used herein) refers to the flow of fluid in parallel layers, with no appreciable disruption between the layers. At low velocities, the fluid tends to flow without lateral mixing, and adjacent layers slide past one another. There are no appreciable cross-currents perpendicular to the direction of flow, nor eddies or swirls of fluid. In laminar flow, the motion of the particles of the fluid is orderly with particles adjacent to a solid surface moving in straight lines parallel to that surface. Laminar flow is a flow regime characterized by high momentum diffusion and low momentum convection. Laminar flow may, in some circumstances, be characterized by Reynolds number of less than 2300.

[0064] Unless context dictates otherwise,“turbulent flow” (as used herein) refers to a flow of a fluid characterized by chaotic changes in pressure and flow velocity. Turbulent flow is caused by excessive kinetic energy in parts of a fluid flow, which overcomes the dampening effects of the fluid’s viscosity. For this reason, turbulent flow is easier to create in low viscosity fluids, but more difficult in highly viscous fluids. In turbulent flow, unsteady vortices appear of many sizes which interact with each other, consequently drag due to friction effects increases. Turbulent flow may, in some circumstances, be characterized by

Reynolds number greater than 4000.

[0065] Unless context dictates otherwise,“Reynolds number” (Re) (as used herein) refers to the dimensionless constant used to predict the onset of turbulent flow by calculating the balance between kinetic energy and viscous damping in a fluid flow. Re may be defined according to:

Re = puD/m (1 )

where p is fluid density (kg/m 3 ), m is fluid dynamic viscosity (Pa * s), u is fluid velocity (m/s), D is a characteristic length (m) (e.g. the inner diameter of a conduit with circular cross- section).

[0066] Unless context dictates otherwise,“w/w” (as used herein) means % weight per weight. [0067] Unless context dictates otherwise,“about” (as used herein) means near the stated value (e.g. within ± 10% of the stated value)

[0068] Some embodiments of the present invention provide processes and systems for concurrent thermal and mechanical treatment of whey protein to yield particulated whey protein concentrate (WPC) having a desired average whey protein particle size and/or whey protein particle size distribution. Additional treatment for the WPC may be provided. The resulting particulated WPC may be used to produce (e.g. by mixing into or otherwise combining with) food having a desired mouth feel.

[0069] The inventors have developed a continuous-flow high shear reactor (CHSR) for producing particulated WPC using concurrent thermal and mechanical treatment. CHSR has a reactor channel, a pump and valves. The heat for the thermal treatment is created by fluid friction in the reactor channel(s), pump and/or valves. The heat provided by fluid friction denatures the native whey protein in a WPC input solution. In some embodiments, no additional (external) heat is introduced when the material is being treated in the CHSR, and all of the heat used to treat the material when it is being processed in the CHSR originates from fluid friction. The mechanical treatment in the CHSR is provided by a laminar flow regime or a turbulent flow regime. The mechanical treatment particulates the denatured whey protein.

[0070] CHSR has a reactor channel, a pump for recirculating a WPC input solution within the reactor channel, and a homogenizing valve. To heat a WPC input solution, CHSR uses the thermal energy created by fluid friction in the reactor channel, pump and/or

homogenizing valve. External heat is not supplied to CHSR and thermal treatment is created by fluid friction inside CHSR. Fluid friction causes a frictional pressure drop (DR) which is converted into heating power. This allows for more uniform and/or gradual heating of the WPC input solution as compared to heating the solution using a conventional heat exchanger. One advantage is that CHSR reduces or prevents high temperature gradients from occurring and/or whey protein aggregation and/or whey protein from sticking to an inside surfaces and/or fouling of whey protein.

[0071] Pressure drop ( DR ) due to fluid friction may be converted into heating power ( W) in the CHSR according to: W = QAP ( 2 ) where Q is the volume flow rate and AP is the frictional pressure drop in CHSR. The temperature of WPC solution inside CHSR increases by DT for a period of time At according to: AT=WAt/C p Vp (3) where V \s the internal volume of CHSR, C p is the specific heat of WPC input solution, and p is the density of WPC solution inside CHSR.

[0072] To mechanically treat WPC input solution, CHSR provides laminar or turbulent flow regimes. One advantage of CHSR is that it does not require a separate mechanical device, such as a scraped surface heat exchanger or the like, which can be costly.

[0073] In some embodiments, CHSR comprises a circular (inner diameter) cross-section pipe forming a spiral tube, linear fluid velocity (u) for an element of Newtonian fluid with a laminar flow (Re < 2,300) may be expressed as follows: Where: r is the distance of the fluid element from a central pipe axis, R is a pipe bore (inner pipe) radius, m is the fluid dynamic viscosity of WPC input solution, and DR is the pressure drop over a length (L) of the pipe.

[0074] It follows that the average velocity {u avr ) of the Newtonian fluid may be expressed as follows:

Where: Q is the volume recirculation flow rate in the pipe.

[0075] The shear rate {SR) at a pipe inner wall of a Newtonian fluid with a laminar flow (Re<2300) may then be expressed as follows:

[0076] It follows that the maximum shear rate ( SR max ) at the pipe inner wall may be expressed as follows: where D equals ( 2R - inner (bore) diameter of the circular pipe).

[0077] Accordingly, the average shear rate ( SR avg ) may be expressed as follows:

APR

SR avg — = -SR (8)

3mZ, 3

[0078] For a turbulent flow regime (Re > 4,000) formulas (4) - (8) are not valid and shear rate may be calculated using conventional computational fluid dynamics (CFD). The average value according to equation (8) may be used as a first approach where

[0079] When the volume of WPC solution inside CHSR and the inlet feed flow rate are relatively constant, the mean residence time { t ) in CHSR may be expressed as follows:

V_

T (9)

f where V \s the internal volume of CHSR and / is the inlet feed flow rate.

[0080] With reference to FIG. 1 , a system 10 for producing particulated WPC according to an example embodiment of the present invention is shown.

[0081] System 10 comprises a CHSR 20 for producing particulated WPC using concurrent thermal and mechanical treatment. System 10 comprises a feed pump 14 and an exit pump 30. Feed pump 14 is used for feeding WPC input solution Ai into CHSR 20. Exit pump 30 is used for withdrawing particulated WPC solution A 2 out from CHSR 20.

[0082] CHSR 20 comprises a recirculation loop having a reactor channel 22 that is a circular pipe forming a spiral tube. In some embodiments, CHSR 20 has more than one reactor channel. Reactor channel 22 may have any suitable shapes and/or configurations and/or geometries depending on the desired internal volume of CHSR 20 and/or shear rate and/or laminar and/or turbulent flow regime. For example, the bores of reactor channels 22 may be one or more of circular, cylindrical, rectangular, consisting of parallel plates and/or the like. Reactor channel 22 may be a serpentine tube (as shown in FIG. 4A), a helical tube (as shown in FIG. 4B), a bayonet tube and/or the like. In some embodiments, the presence of bends in reactor channel 22 promotes fluid mixing.

[0083] In some embodiments, static mixing elements (e.g. one or more of inserts, protrusions, etc.) may be provided to an inside (bore-defining) surface of reactor channel 22 to enhance fluid mixing. In some embodiments, the inside (bore-defining) surface of reactor channel 22 includes hemispherical protrusions having a diameter of about 1/7 of the reactor channel inner pipe (bore) diameter. In some embodiments, the diameters of such hemispherical protrusions may be in a range of about 1/10-1/5 of the inner pipe (bore) diameter. In some embodiments, the hemispherical protrusions are uniformly spaced by distances of about 10 inner pipe (bore) diameters from each other. In some embodiments, such spacing may be in range of 5-15 inner pipe (bore) diameters.

[0084] CHSR has a recirculation pump 24 for recirculating WPC input solution A within reactor channel 22. Recirculation pump 24 may comprise any suitable pump known in the art, with a design duty point, including, but not limited to, a positive displacement pump. In some embodiments, recirculation pump 24 is a centrifugal pump. Recirculation pump 24 is selected to provide a desired volume recirculation flow rate (Q) and/or pressure drop {DR), so that the temperature of the material being treated in CHSR is maintained at a desired temperature, e.g. at about 85^, 90 or 100 < Ό in some embodiments. In some

embodiments, recirculation pump is 16kW.

[0085] In a testing embodiment, reactor channel 22 comprises a 1” circular pipe having an inner (bore) diameter (D) of about 27.86 mm and recirculation pump 24 provides a volume flow rate/recirculation rate of about 8 m 3 /hr to WPC input solution A having a viscosity of about 60 cP, the corresponding laminar flow would be about Re=1 ,850 (see equations (1 ) and (5)), the average shear rate {SR avg ) would be about 700s 1 (see equation (8)), and the maximum shear rate ( SR max ) would be about 1 ,048 sec 1 (see equation (7)).

[0086] In some embodiments, system 10 has a capacity of about 250 L/hr. Reactor channel has a volume of about 40L to 42L. Recirculation pump 24 provides a recirculation rate of about 27 m 3 /hr to 28 m 3 /hr. The average shear rate is about 900 s 1 to 920 s 1 and the residence time is about 10 min.

[0087] In some embodiments, system 10 has a capacity of about 500 L/hr. Reactor channel has a volume of about 80L to 84L. Recirculation pump 24 provides a recirculation rate of about 55 m 3 /hr to 57 m 3 /hr. The average shear rate is about 900 s 1 to 920 s 1 and the residence time is about 10 min.

[0088] In some embodiments, system has a capacity of about 1 ,000 L/hr. Reactor channel has a volume of about 160L to 168L. Recirculation pump 24 provides a recirculation rate of about 1 10 m 3 /hr to 1 15 m 3 /hr. The average shear rate is about 900 s 1 to 920 s 1 and the residence time is about 10 min.

[0089] CHSR 20 also comprises one or more homogenizing valves 26, 28. In some embodiments, homogenizing valves 26, 28 are low pressure homogenizing valves.

Homogenizing valves 26, 28 may be used for the additional shear treatment of WPC input solution Ai to decrease the particle size of denatured whey protein and achieve more uniform particle distribution. A pressure drop of more than about 3 bar across homogenizing valves 26, 28 provides the additional shear treatment. In some embodiments, the pressure drop across homogenizing valves 26, 28 is in a range of about 1 -10 bar. In some embodiments, this range is about 3-5 bar.

[0090] Homogenizing valves 26, 28 can be any suitable valve as long as it provides a pressure drop. For example, homogenizing valves 26, 28 may be globe valve, control valve and/or the like. In some embodiments, homogenizing valves 26, 28 provide cyclic impulse mechanical treatment with high shear rate up to 10,000 sec-1 and cyclic time (period) of about 4-7 sec.

[0091] CHSR 20 optionally comprises a hydrocyclone 25. Hydrocyclone 25 may be used to separate aggregated WPC particles having sizes greater than about 80 pm in WPC input solution A Ϊ having a viscosity in the range of about 1 cP to about 50 cP. This may limit whey protein particle size growth and residence time of whey protein particles in CHSR 20 having a volume based D 90 in the range of about 10 pm to about 100 pm. Persons skilled in the art would appreciate that the efficiency of hydrocylone 25 may depend on the viscosity of WPC solution A 1 and may be calculated using CFD.

[0092] In some embodiments, hydrocyclone 25 is a 2” hydrocyclone that is used to separate whey protein particles from a 10% protein WPC solution having a density of 1 ,030 kg/m 3 . A grade-efficiency curve showing the separation efficiency of hydrocyclone 25 is shown in FIG. 2. The FIG. 2 CFD calculations demonstrate hydrocyclone efficiency when WPC solution Ai has a viscosity of 1 cP: about 98% of whey protein particles greater than 20 pm are separated by hydrocyclone 25. For a WPC solution having a viscosity of 50 cP, about 80% of whey protein particles greater than 1 15 pm to 120 pm are separated by

hydrocyclone 25.

[0093] CHSR 20 simultaneously shears and heats WPC input solution Ai when the solution is treated in CHSR 20. Since heating is accomplished by fluid friction, heating is achieved without the need for heat transfer surfaces.

[0094] CHSR 20 enables processing parameters (such as shear rate, residence time, system capacity, etc.) to be modified by simply altering flow components and/or

corresponding flow parameters, such as tube and homogenizing valve sizes, pump design duty point, etc.

[0095] With reference to FIG. 3, CHSR 20 may be operated in the following four modes of operation: (i) start-up 102; (ii) production 104; (iii) emptying 106; and (iv) cleaning-in-place (CIP) 108.

[0096] In the start-up mode 102, WPC input solution A 1 at about 65 °C is fed into CHSR 20. The material being processed in CHSR 20 may be referred to as WPC solution A 3 and/or the recirculating/recirculated WPC solution A 3 . The recirculated WPC solution A 3 is recirculated by recirculation pump 24 within reactor channel 22. The thermal energy created by fluid friction heats the recirculated WPC solution A 3 to a temperature in the range of about 80°C to about 1 10°C. During the start-up mode, the WPC input solution Ai is in a transitional flow regime. In such a transitional flow regime, the Reynolds number may be in a range of 2,300<Re<4,000. In this transitional flow regime, the recirculated WPC solution A3 may be heated from a range of about 60-65 °C to its desired recirculation temperature range (e.g. a range of about 90-95 °C). At the low temperature, the viscosity of the recirculated WPC solution A3 is relatively low. As the temperature of the recirculated WPC solution A3 increases, particles may agglomerate, viscosity increases and the flow regime stabilizes in a laminar flow range (e.g. Re less than about 2300) or a turbulent flow range (e.g. Re greater than about 4000).

[0097] Production mode refers to a continuous mode of operation. During the production mode 104, WPC solution A 3 is recirculated by recirculation pump 24 within reactor channel 22. WPC solution A 3 is recirculated at a sufficiently high speed to provide fluid friction so that recirculated WPC solution A 3 in reactor channel 22 is maintained at a temperature of about 80 °C to 1 10 *0. In some embodiments, recirculated WPC solution A 3 is recirculated at a recirculation rate in a range of about 20m 3 /hr to about 220m 3 /h so that recirculated WPC solution A 3 in reactor channel 22 is maintained at a temperature range of about 80-1 10 °C. The inlet flow rate of WPC input solution entering CHSR 20 is substantially the same as the outlet flow rate of a particulated WPC solution A 2 leaving CHSR 20. For example, in some embodiments, the inlet input flow rate and/or the outlet output flow rate are in the range of about 0.25 m 3 /hr (i.e. 250 L/hr) to about 2 m 3 /hr (i.e. 2,000 L/hr). In some embodiments, the recirculation rate of WPC solution A 3 within reactor channel 22 is in a range of about 20m 3 /hr to about 220m 3 /hr. Laminar and/or turbulent flow regimes may be provided by reactor channel 22. WPC solution A 3 is recirculated through reactor channel 22 during the production mode to achieve a desired average whey protein particle size and/or whey protein particle size distribution.

[0098] The particle size of particulated whey proteins affects its applicability in food products. When smaller particles, e.g. ranging from about 300nm to 1 pm, are to be obtained, recirculated WPC solution A 3 is recirculated in CHSR 20 at a relatively high recirculation rate. The relatively high recirculation rate minimizes agglomeration and results in a relatively high shear rate. The relatively high shear rate results in smaller particles and the overall viscosity of recirculated WPC solution A 3 decreases. Recirculated WPC solution A 3 containing smaller particles tends to have a higher Reynolds number (e.g. Re greater than about 4000) and stabilizes in a turbulent flow regime. [0099] When larger particles, e.g. ranging from about 1 to 10 pm, are to be obtained, recirculated WPC solution A 3 is recirculated in CHSR 20 at a relatively low recirculation rate. The relatively low recirculation rate results in a relatively low shear rate. The relatively low shear rate results in larger particles and the overall viscosity of recirculated WPC solution A 3 increases. Recirculated WPC solution A 3 containing larger particles tends to have a lower Reynolds number (e.g. Re less than about 2300) and stabilizes in a laminar flow regime.

[0100] The denaturation rate affects its applicability in food products. Residence time ( T) in CHSR 20 may be controlled to to achieve a desired level of WPC aggregation and denaturation. In some embodiments, a denaturation rate of 95% is achieved when the mean residence time ( T) in CHSR 20 is about 15 minutes. When a lower denaturation rate is to be achieved, the mean residence time ( T) in CHSR 20 is shortened.

[0101] In emptying mode 106, particulated WPC solution A 2 may be displaced out of CHSR 20 with water.

[0102] CIP mode 108 refers to the ability to clean the system without dismantling the system (typically using a mix of chemicals, heat and water).

[0103] As WPC input solution A^ flows into CHSR 20 during the start-up mode 102 and recirculated WPC solution A 3 is processed in CHSR 20 during production mode 104, recirculated WPC solution A 3 undergoes thermal and mechanical treatment simultaneously. WPC solution A 3 in CHSR 20 is heated with the thermal energy created by fluid friction in reactor channel 22, recirculation pump 24, homogenizing valve 26, and/or homogenizing valve 28 during start-up and/or production mode. External heat is not supplied to CHSR 20 (for example, no heat is transferred to recirculated WPC solution A 3 via the walls of CHSR 20 and/or its channel 22) and thermal heat for heating recirculated WPC solution A 3 in CHSR 20 is rather created by fluid friction inside CHSR 20. Fluid friction causes a frictional pressure drop (DR) which is converted into heating power. This allows for more uniform and/or gradual heating of WPC input solution A 1 as compared with heating the WPC solution in a conventional heat exchanger. In this way, CHSR 20 reduces or prevents high temperature gradients from occurring and/or whey protein aggregation and/or whey protein from sticking to the inside surfaces of reactor channel 22 and/or fouling of whey protein. [0104] Pressure drop ( DR ) due to fluid friction is converted into heating power ( W) according to equation (2). The temperature of recirculated WPC solution A 3 inside CHSR 20 increases by DT according to equation (3).

[0105] During the start-up mode 102, a preheating transitional flow regime having a Reynolds number in the range of about 2,300 Re to about 4,000 Re may be achieved.

During the production mode 104, laminar or turbulent flow regimes are achieved. As the thermal energy created by fluid friction heats recirculated WPC solution A 3 in CHSR 20, the denatured whey protein particles tend to agglomerate. Denatured whey protein particles are sheared using laminar or turbulent flow regimes. In some embodiments, the laminar or turbulent flows regimes has a Reynolds number in the range of about 1 ,000 Re to about 50,000 Re. In some embodiments, during the start-up mode 102, transitional flow regime, e.g. having Reynolds numbers in a range 2300<Re<4000, can be achieved for a short period of time, but, during production mode 104, laminar or turbulent flow is achieved.

[0106] Linear fluid velocity of recirculated WPC solution A 3 in a laminar flow regime within reactor channel 22 can be expressed according to equation (4) and the average velocity {u avr ) can be expressed according to equation (5).

[0107] The shear rate {SR) at an inner wall reactor channel 22 of recirculated WPC solution A 3 with a laminar flow (Re<2300) can be expressed according to equation (6). It follows that the maximum shear rate ( SR max ) at the inner wall reactor channel 22 of recirculated WPC solution A 3 can be expressed according to equation (7). The average shear rate ( SR avg ) may be expressed according to equation (8).

[0108] When recirculated WPC solution A 3 is in a turbulent flow regime (Re > 4,000), the average value according to equation (8) may be used as a first approach where [0109] In some embodiments, to prevent whey protein aggregation, the average shear rate in reactor channels 22 is in the range of about 500s 1 to about 1 ,000s 1 . A shear rate within this range may be achieved by laminar or turbulent flow regimes, e.g. about

1 ,000<Re<about 50,000. To meet these desires the appropriate size of one or more of the reactor channels pipe diameter (D), total reactor channels pipe length (L), and flow rate (Q) may be selected according to equations (5), (7), and (8). Total reactor channels pipe length ( ) may be determined by the required reactor volume { V).

[0110] In some embodiments, recirculation pump 24 is selected to provide the desired volume recirculation flow rate (Q) and/or desired pressure drop ( DR ). [0111] During production mode 104, the volume of recirculated WPC solution A 3 inside

CHSR 20 and the inlet flow rate of WPC solution A provided by feed pump 14 may be relatively constant. The mean residence time ( T) in CHSR 20 may be expressed according to equation (9). In some embodiments, T is in the range of about 3 minutes to about 15 minutes to achieve a desired level of WPC aggregation and denaturation. More effective microparticulation may be achieved with a denaturation rate as high as possible up to 95%. The denaturation rate represents the difference between native and denatured protein concentration before and after thermo-mechanical treatment.

[0112] In use, an aqueous WPC input solution A 1 may be prepared, e.g. using conventional methods of whey ultrafiltration (UF) and/or by formulating the WPC solution from

reconstituted WPC powder. WPC input solution A 1 may be prepared by third parties and received as an input to system 10. WPC input solution A 1 may have a protein concentration of about 4 to 20 % percent weight/volume and may have a pH of about 4 to 7. Other protein concentrations and/or pHs are useable for WPC input solution A

[0113] WPC input solution Ai typically comprises native whey proteins which have average sizes in a range of about 3-5nm. In some embodiments, this average particle size range is 1 -1 Onm. In other embodiments, WPC input solution Ai may have other average protein particle sizes.

[0114] WPC input solution Ai enters system 10 at inlet 12. In some embodiments, inlet 12 may be connected to a UF outlet (not shown) and/or to a feed tank (not shown) containing the WPC solution constituted from WPC powder.

[0115] Feed pump 14 is used to feed WPC input solution Ai into system 10. Feed pump 14 pumps solution Ai to heat exchanger-recuperator (HE-R) cold side elements 16 and then into CHSR 20. Feed pump 14 may provide an inlet flow rate in a range of about 0.25 m 3 /hr (i.e. 250 L/hr) to about 2 m 3 /hr (i.e. 2000 L/hr). [0116] HE-R cold side elements 16 may be used to pre-heat WPC input solution Ai via heat exchange with particulated WPC solution A 2 flowing through HE-R hot side elements 18. In some embodiments, WPC input solution A 1 is pre-heated (for example, in HE-R cold side elements 16 by particulated WPC solution A 2 ) to a temperature in the range of about 60°C to about 65°C before it is delivered to CHSR 20.

[0117] WPC input solution Ai flows into CHSR 20 and reaches a transitional flow regime having a Reynolds number in the range of about 2,300 Re to about 4,000 Re. Inside CHSR 20, recirculated WPC solution A 3 undergoes thermal treatment concurrently with mechanical treatment. CHSR 20 uses the thermal energy created by fluid friction in channel 22, recirculation pump 24 and/or homogenizing valves 26, 28.

[0118] When recirculated WPC solution A 3 is in a laminar or turbulent flow regimes, recirculated WPC solution A 3 undergoes mechanical treatment concurrently with heat treatment. When recirculated WPC solution A 3 is in a laminar regime, it has a Reynolds number in the range of about 1 ,000 Re to about 2,300 Re. When recirculated WPC solution A 3 is in a turbulent regime, it has a Reynolds number in the range of about 4,000 Re to about 50,000 Re.

[0119] In some embodiments, to prevent whey protein aggregation when recirculated WPC solution A 3 is heated, the average shear rate in reactor channel 22 is in the range of about 500s 1 to about 1 ,000s 1 . A shear rate within this range may be achieved by laminar or turbulent flow regimes (e.g. about 1 ,000<Re<about 50,000). In some embodiments, recirculated WPC solution A 3 is in laminar or turbulent flow regimes for about 3 minutes to about 15 minutes to achieve a desired level of WPC aggregation and denaturation. More effective microparticulation may be achieved with a denaturation rate as high as possible up to 95%. The denaturation rate represents the difference between native and denatured protein concentration before and after thermo-mechanical treatment.

[0120] For a laminar flow regime, the mechanical treatment of recirculated WPC solution A 3 may be enhanced by static mixing elements (e.g. one or more of inserts, protrusions, etc.) on an inside (bore-defining) surface of reactor channel 22. [0121] Additional shear treatment may be provided by homogenizing valves 26, 28. This is provided when there is a pressure drop in the range of about 1 bar to 10 bar across one or more of homogenizing valves 26, 28.

[0122] The recirculated WPC solution A 3 is not subjected to a mechanical shear process other than providing a laminar flow regime or a turbulent flow regime to the recirculated WPC solution A 3 and passing the recirculated WPC solution A 3 through homogenizing valves

[0123] When recirculated WPC solution A 3 exits CHSR 20, it has become particulated WPC solution A 2 containing WPC in an average particle size in the range of about 300 nm to about 10 pm. Particulated WPC solution A 2 exiting CHSR 20 may be pumped by exit pump 30 through a holder tube 40 to a cooling recirculation loop 50. Exit pump 30 provides an outlet flow rate about 0.25 m 3 /hr to 2.0 m 3 /hr. Exit pump 30 may comprise a positive displacement pump. In some embodiments, particulated WPC solution A 2 is heated by holder tube 40 to a temperature in the range of about 85°C to about 100°C to pasteurize particulated WPC solution A 2 . The temperature in holder tube 40 is largely determined by the temperature of particulated WPC solution A 2 entering holder tube 40. Residence time in holder tube 40 may be altered by modifying holder tube 40 size and/or exit pump 30 flow rate. In some embodiments, particulated WPC solution A 2 is heat treated by holder tube 40 for a time sufficient to extend the shelf life of particulated WPC solution A 2 . For example, in some embodiments, particulated WPC solution A 2 may be heat treated by holder tube 40 for a period of about 15 sec to about 180 sec.

[0124] In some embodiments, particulated WPC solution A 2 exits holder tube 40 to enter a recirculation loop 50. Recirculation loop 50 of the illustrated embodiment includes a pump 52 and a heat exchanger hot side element 54. Pump 52 is operated to provide particulated WPC solution A 2 with a desired flow rate through heat exchanger hot side element 54 to quench (fast) cool the solution A 2 via a heat exchange with a heat exchanger cool side element 60. Pump 52 may also provide additional shear treatment to particulated WPC solution A 2 . In some embodiments, particulated WPC solution A 2 in heat exchanger hot side element 54 is cooled by heat exchanger cool side element 60 to a temperature in the range of about 50°C to about 65°C. Cold/ice water may be used as a coolant medium inside heat exchanger cool side element 60. [0125] Particulated WPC solution A 2 may be further cooled by HE-R hot side elements 18 by transferring heat to WPC solution flowing through HE-R cool side elements 16.

[0126] After cooling, particulated WPC solution A 2 may, in some embodiments, enter an ultrasonication device 70, where it is sonicated as is conventionally known under an applied energy density. In some embodiments, the applied energy density is in the range of about 20 J/mL to about 300 J/mL. Ultrasonication provides further thermal and mechanical treatment to WPC solution A 2 . In some embodiments, ultrasonication assists system 10 to produce nanoparticulated WPC having a minimum median particle size (D 50 ) of about 250 nm. High-amplitude ultrasound may be an effective technique for

pasteurization/sterilization of particulated WPC solution A 2 .

[0127] Particulated WPC solution A 2 may then be cooled in a heat exchanger 80. Many features and components of heat exchanger 80 are similar to features and components of recirculation loop 50. In some embodiments, particulated WPC solution A 2 is cooled by heat exchanger 80 to a temperature in the range of about 4°C to about 6°C. [0128] A resulting WPC solution A 4 exits system 10 and, in some embodiments, is conveyed to one or more storage tanks (not shown) via conduit 90. Resulting WPC solution A 4 has a protein concentration in the range of about 5% w/w to about 18% w/w. Resulting WPC solution A 4 may be used as the raw material for different food applications depending on the desired WPC particle size and particle size distribution. For example, for cheese making, an average WPC particle size of about 5 pm may be desired. For yogurt product, an average WPC particle size of about 1 pm to about 2 pm may be desired. For high protein beverages and drinkable yogurts, an average WPC particle size of less than about 1 pm may be desired. In some embodiments, WPC solution A 4 may be directed to additional processing equipment, such as a spray dryer for producing WPC powder. The resulting particulated WPC has a protein content in the range of about 30% by weight to about 85% by weight.

[0129] Resulting WPC solution A* may be subject to further heat treatment, such as retorting or ultra-high-temperature processing. The particulated whey protein in resulting WPC solution A 4 is heat stable. [0130] Resulting WPC solution A 4 may be used to produce nutritional beverages with high concentration of whey protein up to 1 1 -12% w/w. The nutritional beverages may be heat treated to ensure product safety and prolong shelf life. Because the particulated whey protein in resulting WPC solution A 4 is heat stable, the particulated whey protein is suitable in such applications. In some embodiments, food products, such as nutritional beverages, containing particulated whey protein, are shelf stable for up to 12 months.

EXAMPLE 1

[0131] A WPC60 input solution containing 60% whey protein by weight in dry matter was obtained from Saputo Dairyland in Abbotsford, BC, Canada. [0132] When measured at 20 °C, the WPC60 solution had a total solid concentration of 16.3 percent weight/volume consisting of (protein content is measured by Kjeldahl):

[0133] The WPC60 input solution had a pH of 6.5.

[0134] The WPC60 input solution was fed at an input flow rate of 150L/hr to a CHSR having 1” helical tube using a positive displacement feed pump 14 (FIG. 1 ) with a delivery pressure of approximately 1 bar.

[0135] Before entering CHSR, the WPC60 input solution passed through the cold side elements of a heat exchanger-recuperator (HE-R) so that the solution was preheated to approximately 60 °C before it was fed to CHSR. [0136] The WPC60 input solution was circulated in the CHSR at a circulation flow rate of

20m 3 /hr. Residence time was about 9 minutes. In the CHSR, the temperature of the material being processed was maintained at approximately 90 °C using only heat generated by fluid friction of the material being processed in the CHSR - i.e. no external heat need be applied once the material in in the CHSR. CHSR pump 24 (FIG. 1 ) delivered pressure at about 5 bar. [0137] The WPC60 solution was subject to an average shear rate ( SR avg ) of 900s 1 .

[0138] The processed material (i.e. particulated output solution) exited CHSR at a flow rate of 150L/hr using a positive displacement pump 30 (FIG. 1 ).

[0139] The particulated output solution extracted from the CHSR was analyzed and it retained the same composition, namely

[0140] Particle size distributions were determined using standard techniques and were conducted using a laser diffraction system, Mastersizer 2000™, Malvern Panalytical Ltd. Measurements were made using a refractive index (Rl) of 1 .456 for the particles and Rl=1 .33 for the dispersant water. Particulated Whey protein Concentrate 60 with average particle size expressed as the volume-weighted average particle size, also known as the D [4,3] value. As shown in FIGS. 5A to 5C, measurements were made by 3 consecutive days and they are:

EXAMPLE 2

[0141] A WPC80 input solution containing 80% whey protein by weight in dry matter was obtained from BFD Nutrition, Tempe, AZ 85281 .

[0142] The WPC80 powder had the following composition (protein content is measured by Kjeldahl):

Total solids: 97.4

[0143] WPC 80 powder was reconstituted in water in the ratio of 1 kg of WPC80 to 7 liters of water. WPC80 input solution has the following composition:

[0144] The WPC80 input solution had a pH of 6.5.

[0145] The WPC80 input solution was fed at an input flow rate of 250L/hr to a CHSR having 1” helical tube using a positive displacement feed pump 14 (Figure 1 ) with a delivery pressure of approximately 1 bar.

[0146] Before entering CHSR, the WPC80 input solution passed through the cold side elements of a heat exchanger-recuperator (HE-R) so that the solution was preheated to approximately 60 °C before it was fed to CHSR.

[0147] The WPC80 input solution was circulated in the CHSR at a circulation flow rate of 20m 3 /hr. Residence time was about 9 minutes. In the CHSR, the temperature of the material being processed was maintained at approximately 90 °C using only heat generated by fluid friction of the material being processed in the CHSR - i.e. no external heat need be applied once the material is in the CHSR. Pump 24 (FIG. 1 ) delivered pressure at about 5 bar. [0148] The WPC80 solution was subject to an average shear rate (SR avg ) of 900s 1 .

[0149] The processed material (i.e. particulated output solution) exited CHSR at a flow rate of 150L/hr using a positive displacement pump 30 (FIG. 1 ). [0150] The particulated output solution extracted from the CHSR was analyzed and it retained the same composition, namely

[0151] Particle size distributions were determined using standard techniques and were conducted using a laser diffraction system, Mastersizer 2000™, Malvern Panalytical Ltd. Measurements were made using a refractive index (Rl) of 1 .456 for the particles and Rl=1 .33 for the dispersant water. Particulated Whey protein Concentrate 80 with average particle size expressed as the volume based median value D0.5 = 0.28 pm and Do.e = 4 pm.

EXAMPLE 3

[0152] Particulated output solution obtained in EXAMPLE 2 was further subjected to a retort treatment of 1 10^ for 10 min.

[0153] Bottles, each containing 500ml of particulated output solution obtained in EXAMPLE 2, were subjected to steam sterilization at the stainless steel pressure steam portable autoclave sterilizer at 1 10^ for 10 min. The particulated output solution obtained in EXAMPLE 2 contained 9.94% w/w whey protein.

[0154] After the retort treatment, the particulated output solution was visually inspected. Visible aggregation and gelation did not.

EXAMPLE 4

[0155] Particulated output solution obtained in EXAMPLE 2 was further subjected to ultra- high temperature treatment at 95 °C for 10 min. [0156] Bottles, each containing 500ml of particulated output solution obtained in EXAMPLE 2, were subjected to microwave sterilization treatment at 95 °C for 10 min. The particulated output solution obtained in EXAMPLE 2 contained 9.94% w/w whey protein.

[0157] After the microwave sterilization treatment, the particulated output solution was visually inspected. Visible aggregation and gelation did not occur.

EXAMPLE 5

[0158] A liquid microparticulated WPC having whey protein particle sizes in the range of about 1 pm to 2 pm may be used to produce low-fat yogurt with increased protein content and the creamy taste of full-fat yogurt.

[0159] An example of how the microparticulated WPC60 (MP-WPC60) produced from Example 1 may be used for yogurt production is shown in the Table 1 .

Table 1

* The low-fat, high protein yogurt comprised 70 g liquid skimmed milk, 1 g skimmed milk powder, 27 g MP-WPC 60%, and 2 g of bacteria culture.

Interpretation of Terms [0160] Unless the context clearly requires otherwise, throughout the description and the claims:

• “comprise”,“comprising”, and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”; · “connected”,“coupled”, or any variant thereof, means any connection or coupling, either direct or indirect, between two or more elements; the connection or coupling between the elements can be physical, logical, or a combination thereof; • “herein”,“above”,“below”, and words of similar import, when used to describe this specification, shall refer to this specification as a whole, and not to any particular portions of this specification;

• “or”, in reference to a list of two or more items, covers all of the following

interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list;

• the singular forms“a”,“an”, and“the” also include the meaning of any appropriate plural forms.

[0161] Where a component (e.g. a substrate, assembly, device, manifold, etc.) is referred to above, unless otherwise indicated, reference to that component (including a reference to a“means”) should be interpreted as including as equivalents of that component any component which performs the function of the described component (i.e., that is functionally equivalent), including components which are not structurally equivalent to the disclosed structure which performs the function in the illustrated exemplary embodiments described herein.

[0162] Specific examples of systems, methods, and apparatus have been described herein for purposes of illustration. These are only examples. The technology provided herein can be applied to systems other than the example systems described above. Many alterations, modifications, additions, omissions, and permutations are possible within the practice of this invention. This invention includes variations on described embodiments that would be apparent to the skilled addressee, including variations obtained by: replacing features, elements and/or acts with equivalent features, elements and/or acts; mixing and matching of features, elements and/or acts from different embodiments; combining features, elements and/or acts from embodiments as described herein with features, elements and/or acts of other technology; and/or omitting combining features, elements and/or acts from described

[0163] It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions, omissions, and sub-combinations as may reasonably be inferred. The scope of the claims should not be limited by the preferred embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole.