Patent Application
20210251249
The field of the invention is the sterilization of a powdered food substance.
The background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided in this application is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
For a wide variety of reasons, there is always demand for powderized foods. Breast milk, for example, is needed particularly in neonatal intensive care units. Although the background description focuses on the breast milk use case, these deficiencies exist across a spectrum of powdered food markets. Unlike cow's milk prepared for the normal consumer market, donated breast milk intended for neonates must be prepared in a way that not only renders it safe for consumption, but also maximizes nutrient retention. Nutrient retention in the context of neonatal care not only pertains to macronutrient and micronutrient availability but the bioactivity of key enzymes present in milk, e.g. lysozyme, lactoferrin, sIgA etc., as well. Heat-based pasteurization techniques damages the structure, and therefore, function of these nutrients to varying degrees.
Whereas dairy products are typically created for well-baby and adult markets, donor breast milk is a food that becomes a therapeutic when used for pre-term infants in neonatal intensive care units (NICUs). Such infants rely on the biologically active nutrients contained within the milk to grow and thrive. Many of these infants do not have access to their own mother's milk, or, in certain cases, their own mother's milk is nutritionally insufficient to power their growth, giving rise to a need for pasteurized, screened donor milk products.
The problem within the donor breast milk industry concerns that of balancing the three key customer demands of creating a product: safety, nutrient retention, and affordability. Preterm infants are particularly vulnerable to infection and therefore bacterial load in donor breast milk must be significantly reduced and viruses must ideally be completely inactivated. Key immunoprotective proteins do not work if they have been denatured in the process of pasteurization, rendering traditional pasteurization an unfit technique for these narrow situations. Depending on the type of pasteurization used, milk may need to be kept frozen until bedside use, dramatically increasing shipping costs compared to its shelf-stable counterparts.
In 2020, hospitals routinely incur costs of between $7 and $13 per ounce for donor breast milk—higher than many less ideal alternatives. While studies show that using donor breast milk lowers the overall cost of care for preterm infants, some NICUs may struggle with convincing hospital administrators to look beyond the up-front cost at the potential savings. The result is that these hospitals either do not use donor breast milk or donor breast milk use is limited to a select demographic of NICU patients (e.g., 32 weeks' gestation and under).
Existing products successfully satisfy two of the three key consumer demands. With safety an absolute must, this means products either compromise on nutrient retention to favor a lower cost or vice versa. Even so, all products compromise on nutrient retention to some degree. This is due to the use of various heat-based processes (e.g., Holder's, high-temperature short-time, retort) and hospitals seem more willing to sacrifice nutrition than cost or safety. Heat denatures proteins and speeds up biochemical degradation reactions, and, in doing so, causes the loss of the biologically active proteins to varying degrees. For example, in retort processing, milk is made “commercially sterile” and shelf-stable but at the expense of the bioactivity of key immunoprotective nutrients (e.g., sIgA). The protein may still exist in the milk but no longer plays a role in protecting the infant from infection. Donor breast milk banks use thermal processing to pasteurize milk for lack of a better alternative. Milk banks that use pasteurization techniques that cause relatively less damage to the nutrients require milk to remain frozen post-processing up through delivery. Breast milk banks are then restricted to local delivery due to the high cost of shipping frozen milk.
To maximize nutrient retention, some employ pasteurization methods that do not completely reduce certain strains of bacteria (e.g., B. Cereus). To eliminate remaining bacteria, milk is routinely screened post-pasteurization, and any milk that continues to be contaminated with such bacteria is thrown out, leading to increased donor breast milk costs due to waste. Moreover, milk sterilized in this way must be kept frozen until use at the bedside, increasing its cost via cold-storage shipping and the drain on clinician time for thawing it prior to use. Cold-storage shipping becomes an increasing drain on a donor breast milk business's supply chain based on shipping distances.
One way to solve the problems outlined above would be to sterilize unpasteurized, powdered breast milk, but no suitable solutions currently exist. Once these problems are solved, it can become possible to create a low-cost, high-nutritional value powdered breast milk with a long shelf-life to make storage and shipment easier.
Some have made efforts to innovate in this space, but none have developed adequate solutions. For example, U.S. Pat. No. 8,007,847 to Biderman et al. teaches the use of UV light for sterilization of water in reservoirs in the context of handling milk/formula, but Biderman et al. does not contemplate using UV light to sterilize powdered milk. In another example, U.S. Pat. No. 7,572,632 to Fike et al. teaches that irradiation may be accomplished by exposing a powdered media, media supplement, media subgroup or buffer, prior to packaging, to a source of gamma rays or a source of ultraviolet light. But this reference is virtually absent on details about how this process can work, and it makes no mention of breast milk nor how this can be accomplished while retaining nutrients. Neither reference contemplates solutions to the “shadow effect” problem whereby only thin layers of an opaque (or mostly opaque) substance can be exposed to UV light at any given time. Whereas gamma radiation can effectively sterilize dense, opaque substances, UV light is classically limited with powders due to the tendency for the top layer to cast a shadow on deeper layers.
These and all other extrinsic materials discussed in this application are incorporated by reference in their entirety. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided in this application, the definition of that term provided in this application applies and the definition of that term in the reference does not apply.
Thus, there remains a need for improved systems and methods directed to sterilization of a powderized food product.
The present invention provides apparatuses, systems, and methods directed to sterilization of powdered food product. In one aspect of the inventive subject matter, a sterilization chamber for powdered food product is contemplated, the sterilization chamber comprising: a cylindrical basin configured to receive the powdered food product; a first end wall and a second end wall disposed on each end of the cylindrical basin, wherein the first end wall comprises a door; a transparent tube having a UV-C light tube disposed therein, where the transparent tube is positioned along a central axis of the cylindrical basin; where the transparent tube couples with the first end wall and with the second end wall; a paddle ribbon configured to rotate about the central axis of the cylindrical basin; and a set of UV-C light strips disposed above the cylindrical basin.
In some embodiments, the UV-C light tube and the UV-C light strips are configured to emit light having a wavelength between 100 nm and 400 nm. The UV-C light tube and the UV-C light strips can be configured to apply 20-200 mJ/cm3 of UV-C light to the powdered food product to create sterilized powdered food. In some embodiments, the sterilization chamber also includes a push plate having a shape complementary to the cylindrical basin and a push rod configured to move the push plate, where the push rod and push plate are together configured move the powdered food product or sterilized food product out of the cylindrical basin through the door on the first end wall.
In another aspect of the inventive subject matter, a sterilization chamber for powdered food product is contemplated, the sterilization chamber comprising: a cylindrical basin configured to receive the powdered food product; a first end wall and a second end wall disposed on each end of the cylindrical basin, wherein the first end wall comprises a door; a lid coupled with the first end wall and the second end wall; a transparent tube having a UV-C light tube disposed therein, where the transparent tube is positioned along a central axis of the cylindrical basin; where the transparent tube couples with the first end wall and with the second end wall; a set of UV-C light strips disposed above the cylindrical basin; and a motor coupled with a paddle ribbon, where the paddle ribbon is configured to rotate about the central axis of the cylindrical basin upon activating the motor.
In some embodiments, the UV-C light tube and the UV-C light strips are configured to emit light having a wavelength between 100 nm and 400 nm. The UV-C light tube and the UV-C light strips can be configured to apply 20-200 mJ/cm3 of UV-C light to the powdered food product to create sterilized powdered food. In some embodiments, the sterilization chamber also includes a push plate having a shape complementary to the cylindrical basin and a push rod configured to move the push plate, where the push rod and push plate are together configured move the powdered food product or sterilized food product out of the cylindrical basin through the door on the first end wall.
Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.
The following discussion provides example embodiments of the inventive subject matter. Although each embodiment represents a single combination of inventive elements, the inventive subject matter is considered to include all possible combinations of the disclosed elements. Thus, if one embodiment comprises elements A, B, and C, and a second embodiment comprises elements B and D, then the inventive subject matter is also considered to include other remaining combinations of A, B, C, or D, even if not explicitly disclosed.
As used in the description in this application and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description in this application, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
Also, as used in this application, and unless the context dictates otherwise, the term “coupled to” is intended to include both direct coupling (in which two elements that are coupled to each other contact each other) and indirect coupling (in which at least one additional element is located between the two elements). Therefore, the terms “coupled to” and “coupled with” are used synonymously.
In some embodiments, the numbers expressing quantities of ingredients, properties such as concentration, reaction conditions, and so forth, used to describe and claim certain embodiments of the invention are to be understood as being modified in some instances by the term “about.” Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. The numerical values presented in some embodiments of the invention may contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements. Moreover, and unless the context dictates the contrary, all ranges set forth in this application should be interpreted as being inclusive of their endpoints and open-ended ranges should be interpreted to include only commercially practical values. Similarly, all lists of values should be considered as inclusive of intermediate values unless the context indicates the contrary.
Although this application is primarily directed to milk and, specifically, human breast milk, its applicable ranges far beyond these uses. Systems and methods of the inventive subject can be used to sterilize any powderized food product without deviating from the inventive subject matter. The detailed description included below focuses on breast milk for illustrative purposes.
In the dairy industry, different techniques have been developed to pasteurize and otherwise sanitize milk. But these relatively commonplace processes are often inadequate for breast milk and other milks that require maximum nutrients preservation. It is often advantageous to powderize milk so that it can be preserved for long periods of time, but ordinary powdered milk is pasteurized before it is powderized, which can diminish the nutritional content of the milk. Embodiments of the inventive subject matter solve this problem by powderizing breast milk first, and then sanitizing the powderized milk using ultra-violet light (e.g., UV-C light), thereby maintaining as much of the milk's nutritional content as possible.
Furthermore, the application utilizes the example of donor breast milk (commonly used in neonatal intensive care units) as a substance with which the invention may be used to elucidate its role in sterilizing a substance without damaging its sensitive nutrients (e.g., sIgA, lactoferrin, and lysozyme among others). This should not be construed as an intention to limit its applicability to other substances in the dairy, food, or biopharmaceutical industries (e.g., human plasma).
Embodiments of the inventive subject matter facilitate meeting safety, nutrition retention, and affordability requirements for donor breast milk to become the best possible option for infants in need. Breast milk subject to treatment by systems of the inventive subject matter is rendered shelf stable via, e.g., powderization (e.g., lyophilization) and UV-C pasteurization.
Systems and methods of the inventive subject matter can result in powdered breast milk being UV-C pasteurized (e.g., under air-fluidized conditions). Research overwhelmingly indicates exposure to UV-C is an effective method for gentle pasteurization of breast milk. This, in part, can depend on the wavelength of UV-C light that is used. Different wavelengths of UV-C light have different effects on biological compounds. Some wavelengths (e.g., 250-298 nm) favor induction of reactive oxygen species (ROS) from aromatic side chains of some amino acids (e.g., tyrosine). This can lead to ROS mediated protein degradation, which is a mechanism of action for eliminating bacteria and inactivating viruses. Other wavelengths can selectively target nucleic acids, causing thymine dimers and other damage to the DNA superstructure to the point it overwhelms the native repair machinery. This selective targeting of nucleic acids is key for UV-C to work as a gentle pasteurization implement: the DNA/RNA material of bacteria and viruses is rendered inert while the immunoglobulins and other immunoprotective proteins are less affected.
Heretofore, UV-C has only been used on breast milk and dairy in liquid form. But when milk is a liquid, it is virtually impossible to expose all the liquid milk in a batch to UV-C light due to the “shadow effect.” The “shadow effect,” as briefly mentioned above, refers to a phenomenon that has largely limited the use of UV light to sterilize surfaces and transparent liquids. Because, e.g., UV-C is a light, any opaque substance it touches casts a shadow on anything beneath it. Therefore, if UV-C is aimed at a heap of powder it would effectively sterilize only a top layer. A similar effect is seen with liquid milk due to its opacity, necessitating UV-C sterilization while vigorously stirring or while spreading milk into extremely thin layers. UV-C is therefore not typically used on powdered breast milk. Embodiments of the inventive subject matter solve this problem by functionally fluidizing powdered milk with sterile air. Air-suspended, constantly circulating particles within a closed, transparent environment can be effectively UV-C pasteurized.
Methods of the inventive subject matter include several steps, which are shown in
In some embodiments, the vat incorporates UV lights that immediately begin the sanitization process. Next, in step 102, the powdered milk is fluidized so that it can be further sanitized. Fluidization is a process like liquefaction whereby a granular material is converted from a static solid-like state to a dynamic fluid-like state. This process occurs when a fluid (liquid or gas) is passed up through the granular material. Fluidization of the powdered milk causes the powdered milk to mix during step 104, which exposes the fluidized powdered milk to UV light to sanitize the powdered milk (e.g., fluidized milk powder is exposed to UV light to sanitize the powder). In addition, or in the alternative, to exposing powderized milk to UV light during fluidization, powderized milk can also be exposed to UV light by stirring a UV light through the powderized milk, e.g., after the fluidized powder is exposed to UV light. In some embodiments, UV light exposure begins immediately after milk is powderized and before fluidization begins.
During step 104, the fluidized milk is sanitized without significantly diminishing the nutritional content of the milk. Maintaining nutritional value is critical for breast milk to ensure that the babies and children consuming the milk are getting all the nutrition their bodies need to grow and develop. In some embodiments, after the powderized milk is sanitized, it is loaded into syringes according to step 106. Syringes loaded with powdered, sanitized breast milk, can then be distributed. Various systems and devices that can be used to carry out steps of the flowchart shown in
Durations of time that powderized milk (e.g., spray dried milk 208) should remain in a vat before moving to sterilization chamber can depend on several factors, including intensity of UV light applied to the powder. For example, exposure of powderized milk to between 20 mJ/cm2 to 200 mJ/cm2 can result in sufficient sterilization, and recent studies have even shown exposure to between 5 mJ/cm2 to 400 mJ/cm2 can similarly result in sufficient sterilization. Mixing using compressed air can be implemented to reach these exposure levels. In some embodiments, vat 206 is not the primary vessel for sterilization and no sterilization requirement is imposed before powdered milk can exit.
Lights 210 disposed in vat 206 (or in any device or component of systems of the inventive subject matter featuring lights) can be configured to emit ultraviolet radiation into the vat 206. Different wavelengths of UV radiation are considered in this application, including ultraviolet A (400-315 nm), ultraviolet B (315-280 nm), ultraviolet C (280-100 nm), near ultraviolet (400-300 nm), middle ultraviolet (300-200 nm), far ultraviolet (200-122 nm), hydrogen Lyman-alpha (122-121 nm), vacuum ultraviolet (200-10 nm), and extreme ultraviolet (121-10 nm). Thus, lights 210 can emit radiation at or within any of these ranges, depending on a desired outcome. For example, ultraviolet light having a wavelength between 220 nm and 280 nm (or, more broadly, between 200 and 400 nm) has been found to be effective at breaking down undesirable bacteria and the like while simultaneously maintaining most of the milk's nutritional value. In this way, spray dried milk can be sterilized with minimal impact on the milk's nutritional value. Wavelength ranges described in this paragraph are applicable to all light described in this application, and although the ranges above have different cutoff values, it is contemplated that a range spanning multiple ranges, or portions of ranges, described above can be implemented into embodiments of the inventive subject matter.
To ensure powderized milk is sufficiently exposed to UV light, powderized milk from vat 206 is next passed through a sterilization chamber 212. Sterilization chamber 212 blows air (e.g., compressed air) into its interior while spray dried milk is contained therein. Sterilization chamber 212 can be configured as any one of the sterilization chambers described in this application, and embodiments of the inventive subject matter can include multiple sterilization chambers featuring more than one of the sterilization chambers described in this application, where multiple sterilization chambers are coupled to one another in sequence.
In some embodiments, lights 302 can be configured to have the same characteristics (e.g., wavelength emissions, etc.) as lights 210, described above. In some embodiments, lights 302 can expose powderized milk 304 to a different wavelength or set of wavelengths of light than lights in an associated vat expose the powderized milk to. In some embodiments, sterilization chamber 300 can include a single light (e.g., just top light 302 as shown in
Vat 406, as mentioned above, can feature one or more lights 410 (two lights are depicted in the Figure). These lights can be moving or non-moving, and, as powderized milk 408 is added to vat 406, the first steps of sterilization immediately begin. In some embodiments, vat 406 acts only as a gravity feeding funnel that passes powderized milk into a sterilization chamber 412. Sterilization chamber 412 can be any one of the sterilization chambers described in this application. In some embodiments, sterilization chamber 412 can include more than one of the sterilization chambers described in this application, where multiple sterilization chambers are coupled to one another in sequence. To improve movement of powderized milk 408 into sterilization chamber 412, vat 406 can be agitated (e.g., by component 414, which can be configured to vibrate, introduce pressurized air into vat 406, etc., to motivate movement of powderized milk into sterilization chamber 412).
Sterilization chamber 412 can be configured in a variety of ways. In some embodiments, sterilization chamber 412 can be configured as a sterilization chamber, described above regarding
Once powdered milk 508 is inside drum 502, it is agitated while exposed to UV light from light source 506. Agitation can be accomplished in a variety of ways, and the embodiment in
In addition to stirring, compressed air is injected into drum 502 according to arrows coming up from the bottom of the drum as shown in
Stirring is caused by stirring mechanism 504, causes light 506 to turn through the powder 508 to bring about more even exposure of UV light to the powder 508. In some embodiments, stirring mechanism includes an electronic motor and can be electronically controlled. Rotation of light 506 can occur between 100 and 3,000 rpm. Stirring speed can be based on, e.g., the amount of powderized milk added to the drum, and in embodiments featuring a controller, programs can be implemented to cause the light 506 to turn at different speeds, even changing speed in the course of mixing a single batch depending on factors such as how much of a batch has already been added to drum 502.
As shown in
In some embodiments, light 506 (and any other light like it) extends from arm 522 down to near the bottom of drum 502. In some embodiments, the bottom portion of light 506 extends down to within a half inch of the bottom of drum 502, leaving enough room for air to come up from the bottom of drum 502 to fluidize the powderized milk therein. The bottom surface of light 506 (and any other matching light, as shown in
In some embodiments, light 506 (and any other light or stirring component disposed within drum 502) can be configured as a blade (e.g., as a blade without lights incorporated therein, or a blade with lights incorporated therein).
Once powderized milk 508 is sufficiently sterilized it can be pushed out powder outlet 512. Powder outlet 512 can include a door 532 that opens to allow sterilized powderized milk 508 to be pushed out of drum 502. Pressure from incoming air pushes the sterilized powderized milk out through powder outlet 512. To avoid over pressurization, which could lead to explosion, pressure relief valve 518, which can feature an air filter, is located at the top of drum 502. In embodiments with an air filter, the air filter allows air to escape without allowing powder to escape.
Thus, returning to
Motor 610 can be a high torque, high RPM (e.g., 5,000-20,000) electric motor such as a DC motor or a universal motor (e.g., one that can operate on AC or DC voltage). Other electric motors can also be implemented without deviating from the inventive subject matter. In some embodiments, motor 610 includes a gearbox that is coupled between motor 610 and shaft 608. Causing powderized milk 602 to circulate within drum 606 improves its exposure to sterilizing UV light.
Inlet 614 can be used to introduce pressurized air. Pressurized air from inlet 614 can be introduced for several functions. In some embodiments, it is used to introduce air via holes—shown as upward pointing arrows—on the bottom of the interior of drum 606. In some embodiments, pressurized air entering via inlet 614 is used to push powderized milk 602 out through outlet 616, which couples with a syringe loader as shown in
Sterilization chamber 600 can feature a removable top 618 (e.g., a top that is configured to screw on, to clip on, or to otherwise be coupled with a top portion of drum 606 without the use of an adhesive or other fastening mechanism that would result in damage upon removal). Top 618 includes holes at least for inlet 604, motor 610, and inlet 614.
In some embodiments, drum 606 features transparent (e.g., transparent to all or some UV radiation wavelengths discussed in this application, preferable at least transparent to UV wavelengths emitted by lights a sterilization chamber) walls where lights 620 are disposed outside drum 606. As powderized milk 602 is mixed by rotating blades 612 attached to shaft 608, it is sterilized by UV radiation emitted from lights 620. Although lights 620 are drawn to show two lights, any number of lights can be used to improve exposure of powderized milk 602 to UV light. In some embodiments, lights 620 are disposed outside of drum 606, and lights 620 can be configured in elongated packages (e.g., like fluorescent lights or LED light strips) with multiple lights surrounding the entirety of drum 606. Before powderized milk 602 is introduced into drum 606, and thus before blades 612 rotate, top 618 is coupled with drum 606 to create an air-tight seal. Drum 606 is also sealed around all other coupling points to prevent unwanted air from exiting or entering.
Components disposed within drum 606 can be made from reflective materials such as aluminum (e.g., polished aluminum) to reflect UV light to improve exposure of powderized milk 602 to sterilizing UV light. Moreover, drum 606 can be surrounded by a reflective shield 622. Reflective shield 622 can be configured as a cylinder to surround drum 606, thus reflecting UV light that would otherwise project away from drum 606 back into drum 606. In some embodiments, lights 620 are integrated into shield 622. In some embodiments, lights 620 are integrated into the interior of drum 606 like what is shown in sterilizing chamber 500. In any embodiment discussed in this application, UV lights can be integrated into the walls of a sterilization chamber's drum to improve efficiency using, e.g., UV LEDs. In such embodiments, the interior of drum 606 can include a reflective material. Lights 620 can be configured to project light at any wavelength discussed in this application, preferably between 248 and 310 nm.
Sterilization chamber 600 additionally includes a bottom cap 624. Bottom cap 624 is configured to hold a bottom portion of shaft 608 in place (e.g., so that it is vertically oriented as shown in
Another sterilization chamber of the inventive subject matter is shown in
In some embodiments, motor 716 includes with a gearbox that is in turn coupled with shaft 704. It is also contemplated that a motor can be remotely located and instead, motor 716 can be a device or system that is configured to receive mechanical energy by belt, chain, rotating shaft, etc. Regardless of configuration, shaft 704 can be configured to rotate between 100 and 1000 RPM. Rotating screw feature 702 can create air currents and other interactions with powderized milk 706 that can be used to motivate powderized milk 706 out of drum 708 via outlet 724 and toward a syringe loading device as shown in
In some embodiments, compressed air can be introduced into drum 708 as demonstrated by arrows pointing inward from the interior walls of drum 708. This can facilitate additional mixing of powderized milk 706 to improve its exposure to sterilizing UV light from lights 710. Powderized milk 706 can enter drum 708 via inlet 714, which can be closed during the mixing and sterilization process. End cap 720 features through holes for both powder inlet 714 as well as inlet 722 for compressed air to enter drum 708. Shaft 704 is coupled with motor 716 such that motor 716 can cause shaft 704 to turn, thereby turning screw feature 702. Mechanical energy passes through end cap 718, which couples with drum 708 to create a seal that powderized milk 706 cannot escape through. End cap 720 can include a bearing (e.g., a ball bearing, a friction bearing, etc.) for shaft 704 to couple with to keep it from moving off axis and to facilitate rotation.
Sterilization chamber 1000 comprises many different components that make its functionality possible.
In some embodiments, powdered milk (or other powdered food product) enters sterilization chamber 1000 by lifting lid 1034 so that an operator can pour the powdered product inside. In some embodiments, this process can be automated using actuators to lift lid 1034 to allow for the powderizing components of a system to automatically introduce powdered milk to sterilization chamber 1000. Once lid 1034 is closed, paddle ribbon 1016 rotates to toss and mix powder contained within sterilization chamber 1000. During mixing, UV-C light strips 1002 shine from beneath and above a mixing cavity (formed by, e.g., cylindrical basin 1008, inner side-walls 1030 as well as lid 1034), along with light from UV-C light tube 1004, which together expose powder within the sterilization chamber 1000 to UV-C light that sterilizes the powder. Mixing and UV-C exposure can go for as long as necessary to reduce bacteria levels. All discussion included above regarding UV-C lights, exposure, mixing, etc. can also be applied to sterilization chamber 1000. It is expressly contemplated that any aspect of the systems described above in this application can be adapted to operate with sterilization chamber 1000.
Paddle ribbon 1016 is rotated by motor 1014. Motor 1014 has an output shaft that couples with shaft coupling 1012 that in turn couples with tube connector 1010. Tube connector 1010 couples with paddle right end 1018. Paddle right end 1018 couples with a right end of paddle ribbon 1016 and paddle left end 1020 couples with a left end of paddle ribbon 1016. Thus, causing motor 1014 to turn causes paddle ribbon 1016 to rotate within the sterilization chamber.
Inner side-walls 1030 are configured to extend upward from top edges of cylindrical basin 1008 to help to create a continuous inner surface of the mixing cavity. It is contemplated that these inner walls can be made from a UV-transparent material or a UV-opaque material. In some embodiments, the inner side-walls 1030 can feature a reflective inward-facing surface or have a reflective coating applied to an inward-facing surface. Outer side-walls 1032 can be made from a material having a reflective inner surface or a reflective coating on its inner surface, as well. Reflective inner surfaces of either the inner side-walls 1030 or the outer side-walls 1032 can improve UV-C sterilization that occurs within sterilization chamber 1000 by reflecting UV-C light within the chamber, causing it to reach powdered food product from angles that it otherwise might not. This can reduce an amount of time that powdered food product needs to remain in sterilization chamber 1000 before it reaches a desired degree of sanitization.
Once the mixing is complete (e.g., the powder within the mixing cavity is sterilized to a desired degree), powder can be pushed from sterilization chamber 1000. First, paddle ribbon 1016 is rotated to a top portion of the mixing cavity and then emptying assembly (which includes at least push plate 1024 and push rod 1028) slides into the mixing cavity. Push plate 1024 is moved by push rod 1028 to push sterilized powder through a door disposed on emptying end-wall 1022. Not all powder may be evacuated in a single push, so emptying assembly can be configured to slide back and forth multiple times. Emptying door and emptying assembly can be operated by, e.g., a motor-controlled rack-and-pinion or an operator moving them manually.
Because UV-C sterilization is a “line-of-sight” technology, sterilization chamber 1000 is configured to agitate, e.g., freeze-dried, human breast milk powder within the main cavity of the device such that all the powder is exposed evenly to UV-C light. UV-C light shines from three points into the main cavity: UV-C light strips shine up from the bottom through cylindrical basin 1008, UV-C light strips shine down from the top, and UV-C light tube 1004 radiates light outward from, e.g., an axis of paddle ribbon 1016 rotation and out of transparent tube 1008. Paddle ribbon 1016 can be configured according to cross-sectional shapes shown in
Thus, specific systems and methods of sanitizing powdered milk (e.g., human breast milk) have been disclosed. It should be apparent, however, to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts in this application. The inventive subject matter, therefore, is not to be restricted except in the spirit of the disclosure. Moreover, in interpreting the disclosure all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to the elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps can be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced.
This application is a continuation-in-part of and claims priority to U.S. patent application Ser. No. 17/000,129 filed Aug. 21, 2020, which claims priority to U.S. Provisional Patent Application No. 62/894,254 filed Aug. 30, 2019. All extrinsic materials identified in this application are incorporated by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| 62894254 | Aug 2019 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 17000129 | Aug 2020 | US |
| Child | 17245612 | US |
