SHORT-TERM WASH TREATMENT OF PRODUCE
A produce wash system, method, and short-term wash treatment are provided. For example, the produce wash system includes a produce line including a short-term wash device followed by a wash device, a short-term wash treatment that is applied by the short-term wash device to a product, wherein the short-term wash treatment is applied using a spray device that creates micrometer sized droplets, and wherein the short-term wash treatment remains on the product for a pretreatment time that lasts until the product reaches the wash device, and a wash treatment that is applied by the wash device to the product, wherein the wash treatment rinses the short-term wash treatment from the product defining the end of the pretreatment time. The pretreatment time is set at or below a damage threshold time beyond which the short-term wash treatment damages the product beyond a damage threshold.
This application is a continuation of U.S. patent application Ser. No. 15/285,875, filed on Oct. 5, 2016, which claims benefit of priority to U.S. Provisional Application No. 62/264,456, filed on Dec. 8, 2015, and which is a continuation-in-part (CIP) of U.S. patent application Ser. No. 15/208,999, filed on Jul. 13, 2016, and a CIP of U.S. patent application Ser. No. 15/208,927, filed on Jul. 13, 2016, both of which claim benefit from U.S. Provisional Application No. 62/264,456 filed on Dec. 8, 2015, all of which are incorporated by reference herein in their entireties.
BACKGROUND Technical FieldApparatuses and methods consistent with exemplary embodiments relate to a novel synergistic sanitation strategy for fresh produce processing using a short-term wash treatment applied by a short-term wash device followed by a wash device in a produce line.
Description of the Related ArtMost Ready-To-Eat (RTE) produce is processed with two stage washing. Repeating the same wash a third time generally yields no further benefits if the first two stages have been properly managed. For example, the primary wash system may remove dirt and debris. The primary wash system may also handle the bulk of the soluble organic load from any cutting or chopping operation. The secondary wash, whose water chemistry is generally easier to manage, is intended to complete the sanitation of the product. In recent years, the improved control of the water chemistry of both the primary and secondary wash systems has led to improvements in the sanitation of washed products and the control of cross contamination; however, more improvement is still needed to better mitigate microbial risk to consumers.
Much research has been done exploring the various compatible sanitizing agents for use in these two stage wash systems including chlorine, chlorine dioxide, ozone, and other active oxygen species. Other sanitizing agents have been considered such as fatty acids, organic acids, and silver ions but are not in use. None of these chemicals has provided a 4 log lethality to achieve a chemical pasteurization of the RTE product in a commercial setting. In fact, most processes fail to yield a consistent 2 log reduction. Some have asserted greater lethality in bench scale tests, but these greater lethality values do not carry over to commercial processing and often involve artificial conditions where a large number of organisms are applied and removed without time to become established on the product under test. Thus, currently no one is reporting a commercial pasteurization of an RTE produce product.
Engineering efforts have produced various flumes and tanks to provide agitation and mechanical action to enhance the sanitation process. For example, air jets and turbulence are designed into these systems. None of these designs has been so overwhelmingly successful that all pervious equipment designs were superseded. In some cases, different designs are preferred for certain product types for product quality reasons. For these and other reasons, the RTE industry includes a wide variety of equipment.
Researchers have attempted to incorporate other sanitation strategies into process lines. The considered mechanisms of lethality include ultra-violet light, sonic energy, electric fields and electrical current and other exotic mechanisms. Here too, none of these approaches have entered into commercial practice. The search for additional lethality continues.
In spite of all this effort, pathogens remain at low levels on RTE produce as delivered to consumers. The hazard is generally small but is not zero as there continue to be outbreaks and recalls. Some of these problems probably reflect poor application of existing art. Nevertheless, the RTE produce industry seeks more robust processes to assure consumer safety. Such processes will require the industry to do something different.
SUMMARYExemplary embodiments overcome the above disadvantages and other disadvantages not described above. Also, an exemplary embodiment is not required to overcome the disadvantages described above, and an exemplary embodiment may not overcome any of the problems described above.
According to an embodiment, a produce wash system is provided. The produce wash system includes a produce line including a short-term wash device followed by a wash device, a short-term wash treatment that is applied by the short-term wash device to a product, wherein the short-term wash treatment is applied using a spray device that creates micrometer sized droplets, and wherein the short-term wash treatment remains on the product for a pretreatment time that lasts until the product reaches the wash device, and a wash treatment that is applied by the wash device to the product, wherein the wash treatment rinses the short-term wash treatment from the product defining the end of the pretreatment time. The pretreatment time is set at or below a damage threshold time beyond which the short-term wash treatment damages the product beyond a damage threshold.
In addition to one or more of the features described above, or as an alternative, further embodiments may include, wherein the short-term wash treatment provides at least one or more from a group consisting of antimicrobial properties, potentiating properties for the antimicrobial action of the subsequent wash device and wash treatment, and controlling properties for controlling lachrymator release from the produce.
In addition to one or more of the features described above, or as an alternative, further embodiments may include wherein the product is fresh produce that is at least one selected from a group consisting of whole, sliced, cut, and chopped leafy greens, including, but not limited to, lettuce, spinach, cabbage, and kale, and vegetables, including, but not limited to, broccoli, onions, bell peppers, and squash.
In addition to one or more of the features described above, or as an alternative, further embodiments may include wherein the product is a meat product that is at least one selected from a group consisting of beef, pork, lamb, veal, game, and poultry that includes, but is not limited to, whole, parted, and boned poultry.
In addition to one or more of the features described above, or as an alternative, further embodiments may include, wherein the spray device of the short-term wash device includes at least one nozzle that is configured to spray the short-term wash treatment on the product with micrometer sized droplets, wherein the micrometer sized droplets range from approximately 5 micrometers to approximately 20 micrometers in diameter.
In addition to one or more of the features described above, or as an alternative, further embodiments may include, wherein the short-term wash device further includes at least one from a group consisting of a rotating drum short-term wash device, an air column short-term wash device, a slicer/dicer short-term wash device, a spray curtain, a shaker, and a timing belt. The spray device is integrated with at least one from the group to spray the short-term wash treatment on the product.
In addition to one or more of the features described above, or as an alternative, further embodiments may include, wherein the short-term wash device includes a product submersing device that is configured to receive and submerse the product into the short-term wash treatment followed by the product being sifted out of the short-term wash treatment.
In addition to one or more of the features described above, or as an alternative, further embodiments may include, wherein the product submersing device is at least one selected from a group consisting of a rotating drum short-term wash device, a submersing pool pretreatment device, an agitating pool pretreatment device, and a spray curtain with brushes.
In addition to one or more of the features described above, or as an alternative, further embodiments may include, wherein the short-term wash treatment includes an acidulant and a polyol.
In addition to one or more of the features described above, or as an alternative, further embodiments may include wherein the acidulant is one selected from a group consisting of a phosphoric acid and lactic acid, and the acidulant is from 0.1% to 10% of the short-term wash treatment. The polyol is one selected from a group consisting of a glycerin and a propylene glycol, and the polyol is from 0.1% to 10% of the short-term wash treatment.
In addition to one or more of the features described above, or as an alternative, further embodiments may include, wherein the pretreatment time that the short-term wash treatment remains on the product is between 3 seconds and 1.5 minutes at a temperature between 30° F. and 50° F.
In addition to one or more of the features described above, or as an alternative, further embodiments may include, wherein the wash treatment includes free active chlorine from 2 to 40 ppm of the wash treatment, a compatible acidulant selected from a group consisting of phosphoric acid, citric acid, and lactic acid, and wherein the compatible acidulant is from 10 to 1000 ppm of the wash treatment, and a polyol selected from a group consisting of a glycerin and a propylene glycol, and wherein the polyol is from 2 to 500 ppm of the wash treatment.
In addition to one or more of the features described above, or as an alternative, further embodiments may include, wherein the short-term wash treatment includes a coordinating acid and silver ions, wherein the coordinating acid is one selected from a group consisting of a citric acid and a lactic acid and is from 3% to 5% of the short-term wash treatment, and wherein the silver ions are from 10 to 50 ppm of the short-term wash treatment.
In addition to one or more of the features described above, or as an alternative, further embodiments may include, wherein the pretreatment time that the short-term wash treatment remains on the product is between 3 seconds and 1.5 minutes at a temperature between 30° F. and 50° F.
In addition to one or more of the features described above, or as an alternative, further embodiments may include a compatible acidulant selected from a group consisting of phosphoric acid, citric acid, and lactic acid, wherein the compatible acidulant is from 10 to 1000 ppm of the wash treatment, a polyol selected from a group consisting of glycerin and propylene glycol, wherein the polyol is from 1 to 500 ppm of the wash treatment, free active chlorine from 2 to 40 ppm of the wash treatment, and chloride from 1 to 100 ppm of the wash treatment.
In addition to one or more of the features described above, or as an alternative, further embodiments may include a transfer belt between the short-term wash device and the wash device, wherein the transfer belt is configured to serve as a drain scroll to recycle the short-term wash treatment, and a timing belt that is configured to help complete the pretreatment time.
In addition to one or more of the features described above, or as an alternative, further embodiments may include, wherein the short-term wash treatment and short-term wash device are configured to account for at least one of product overload, inadequate chlorine in a flotation tank, and incomplete pH control.
In addition to one or more of the features described above, or as an alternative, further embodiments may include, wherein the short-term wash treatment provides a supplemental wash lethality of greater than 1 log against microbes found on the product as compared to the lethality of the wash treatment in the wash system alone.
In addition to one or more of the features described above, or as an alternative, further embodiments may include a pre-rinse prior to the short-term wash treatment, wherein the pre-rinse removes an initial organic load, soil, and debris, and wherein the pre-rinse is the last use of wash water prior to disposal.
According to an embodiment, a method of produce washing using a short-term wash device is provided. The method includes processing a product through the short-term wash device followed by a wash device, applying a short-term wash treatment in the form of micrometer sized droplets using a spray device of the short-term wash device to the product such that the short-term wash treatment remains on the product for a pretreatment time that lasts until the product reaches the wash device, applying a wash treatment using the wash device to the product such that the wash treatment rinses the short-term wash treatment from the product defining the end of the pretreatment time, wherein the pretreatment time is set at or below a damage threshold time beyond which the short-term wash treatment damages the product beyond a damage threshold.
Other aspects and advantages of the invention will be apparent from the following description and the appended claims.
Throughout the drawings and the detailed description, unless otherwise described, the same drawing reference numerals will be understood to refer to the same elements, features, and structures. The relative size and depiction of these elements may be exaggerated for clarity, illustration, and convenience.
DETAILED DESCRIPTIONIn the following detailed description of the illustrative embodiments reference is made to the accompanying drawings that form a part thereof and is provided to assist the reader in gaining a comprehensive understanding of the methods, apparatuses, and/or systems described herein. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is understood that other embodiments may be utilized and that logical structural, mechanical, electrical, and chemical changes may be made without departing from the spirit or scope of the invention. Accordingly, various changes, modifications, and equivalents of the methods, apparatuses, and/or systems described herein will be suggested to those of ordinary skill in the art. The progression of processing operations described is an example; however, the sequence of and/or operations is not limited to that set forth herein and may be changed as is known in the art, with the exception of operations necessarily occurring in a particular order.
To avoid detail not necessary to enable those skilled in the art to practice the embodiments described herein, the description may omit certain information known to those skilled in the art. Also, the respective descriptions of well-known functions and constructions may be omitted for increased clarity and conciseness. Further, the description of an exemplary embodiment of the present invention is merely an exemplary embodiment for structural and functional explanation of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the illustrative embodiments is defined only by the appended claims.
Unless otherwise specified, any use of any form of the terms “connect,” “engage,” “couple,” “attach,” or any other term describing an interaction between elements is not meant to limit the interaction to direct interaction between the elements and may also include indirect interaction between the elements described. In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion and thus should be interpreted to mean “including, but not limited to.” Unless otherwise indicated, as used throughout this document, “or” does not require mutual exclusivity.
Terms such as “first” and “second,” etc., may be used to distinguish one component from another. Additionally, it will be understood that when an element is referred to as being “connected to” or “communicatively connected to” another element, it can be directly connected to the other element, wirelessly connected to the other element, or intervening elements may also be present. In contrast, when an element is referred to as being “directly connected to” another element, no intervening elements are present. Meanwhile, other expressions describing relationships between components such as “between,” “immediately between” or “adjacent to” and “directly adjacent to” may be construed similarly.
The following description describes methods and systems for washing product/produce using a short-term wash treatment and short-term wash device along with a wash device in a produce line. Specifically, methods and systems are disclosed that can provide additional wash benefits such as additional microbial lethality through the use of a short-term wash treatment and device. The product may be fresh produce that is at least one selected from a group consisting of whole, sliced, cut, and chopped leafy greens including, but not limited to, lettuce, spinach, cabbage, and kale, and vegetables including, but not limited to, broccoli, onions, bell peppers, and squash. The produce product may alternatively be a meat product that is at least one selected from a group consisting of beef, pork, lamb, veal, game, and poultry that includes, but is not limited to, whole, parted, and boned poultry.
According to another exemplary embodiment, similar benefits can be derived from a pre-rinse wherein the rinse removes the initial organic load and debris such as soil. This pre-rinse allows the short-term treatment to be more effective and potential reduces total water usage. The pre-rinse is done prior to the short-term wash treatment. This pre-rinse is positioned so as to prevent soil and debris from interfering with the short-term wash treatment or from being carried over into the wash system. It can be advantages to make this pre-rinse the last use of wash water prior to disposal.
According to another exemplary embodiment,
According to an exemplary embodiment,
It is instructive to consider a specific embodiment. For example, to prepare chopped Romaine lettuce with a two tank flotation line using a silver dihydrogen citrate short-term wash treatment, a system such as illustrated in
According to one or more exemplary embodiments one or more short-term wash devices may be included in the produce line 601, one or both of which may be used to apply the same or different short-term wash treatments. For example,
Further, in another embodiment,
According to one or more embodiments,
According to one or more embodiments,
A short-term wash, which may also be called an intense prewash treatment or prewash treatment, using a short-term wash treatment and device as well as a wash treatment and device synergistically enhances the lethality of traditional wash systems for ready-to-eat (RTE) produce. A short-term wash treatment and short-term wash device, which may also be called a prewash system, permits the usage of materials that would otherwise potentially damage or otherwise prevent the sale of RTE produce. For example, a prewash with a phosphoric acid and propylene glycol solution or with a silver dihydrogen citrate solution has proved particular effective when exposure times are controlled and limited. Such short-term wash systems are compatible with high levels of water recycling to manage total water use.
According to one or more embodiments, the quenching of the short-term treatment solution could overwhelm the water management of the primary flume wash system. As illustrated in drawing 12A, under these conditions, it may be desirable to have a rinse transition component 1222 placed after the application of the short-term treatment solution by a short-term wash device 1220 and before a wash device 1210. Specifically, as shown, a produce wash system 1200 includes a wash device 1210 and a short-term wash device 1220 with a rinse transition component 1222 there between. According to some embodiments, the rinse transition component 1222 may include a multistage stage transition and an independent water source from the main wash device 1210.
For example as shown in
According to another embodiment, each stage (1222.1 and 1222.2) could be further subdivided if necessary to affect the desired transition. For example, according to one or more embodiments, in the first stage 1222.1, the objective may be to remove as much of the short-term treatment solution as possible. This solution can be recycled in some cases such as when used with the previously described phosphoric acid system. In others, such as the silver ion system, recycling is not practical so that application levels must be minimized to be cost effective. The second zone 1222.2 can use water from the primary flume to further wash the product before in it enters the primary flume. This water is applied using, for example, a water spray 1222.3. The water used in this stage would otherwise just have gone to the drain as make up water is added to the primary flume. Accordingly, additional use can be made of water from the primary flume prior to discarding. Further, according to one or more embodiments, another benefit of this two zone or multi zone system is to avoid overloading the primary flume with treatment chemicals.
Next, the rinse transition component rinses the product (operation 1425). This rinsing can be done in a multistage arrangement were the product is rinsed more than once using water from different sources. For example the rinse transition component can include a first drain scroll that rinses the product using water from an independent source or from the short-term wash device and a second drain scroll that uses water from the main wash.
Further, a wash treatment is then applied using the wash device to the product such that the wash treatment rinses any remaining short-term wash treatment from the product defining the end of the pretreatment time if it was not already ended during the rinse transition component rinsing (operation 1430). The pretreatment time is set at or below a damage threshold time beyond which the short-term wash treatment damages the product beyond a damage threshold. The damage can be defined as, for example, the point at which the produce discolors, wilts, changes taste, or other properties shift such that it can no longer be sold to a consumer. Finally, the product treatment process is either completed or may continue on through another round of washing in a second wash device or onto other processing and packaging steps (operation 1440).
The above noted need for more robust processes for RTE produce provided a starting point for providing short-term wash treatments while managing overall water usage. In one more embodiments, four considerations for implementing this additional process strategy can be taken into consideration without compromising water management. First, one determines the best location for treatment. Second, one determines how that treatment will be carried out. Third, one determines the formulation of the treatment. And finally, one determines how this short-term wash treatment fits into the water reuse needs of the specific produce line. These considerations are combinatorial yielding many specific embodiments as discussed herein.
With regards to location, the range of possibilities is limited but not without choices. Given the nature of the intense treatments and their short durations, for example less than 1 minute, the treatment should be somewhat proximal to the primary wash stage such as the rotating drum short-term wash device 320 stage as illustrated in
With regards to how the treatment is applied, there are several operating parameters that are important to consider and also multiple types of equipment that can be considered as ways to control these parameters. Feed rate, dispersion, uniformity of coverage, and treatment time are operating parameters to consider. These are all interrelated and will depend on the equipment used for the treatment. For example, according to an embodiment, about 1 liter per minute is sufficient to wet the surface of all leaves when nozzles are place in a slicer/dicer short-term wash device 865, which may also be called a pilot plant shredder or a chopper/shredder short-term wash device as shown in
According to one or more embodiments, a system and method of wetting product surfaces using pretreatment and other elements is provided. According to one or more embodiments, an addition of surfactants can be provided and can provide advantageous features and outcomes. Further, in accordance with one or more embodiments, a small nozzle opening can be used along with a high pressure nozzle to yield very small droplet size. These small droplets can improve surfaces wetting. For example, in one or more embodiments, the very small droplets are approximately 5 micrometers to approximately 20 micrometers. In another embodiment, the droplets are approximately 2 to approximately 40 micrometers. In one or more embodiments, the mechanism of action for the small droplets is believed to be diffusion which is enabled by the removal of the steric hindrances associated with the naturally occurring protective niches on the product surfaces. In other words, and in accordance with one or more embodiments, the small droplets go where big droplets could not due to physical or chemical barriers. The appropriate size for various products and pretreatment solutions can reasonable by expected to vary on a case by case basis. For example, in accordance with one embodiment, about 15 micrometers droplet size can be used to start optimization.
Furthermore, one or more embodiments using this surface wetting can overcome the limitations caused by surface tension which would normally provide safe havens for bacteria sheltering in the protective niches. Without surface wetting, the wash solution flows over the surface of the protective niches on the product surface. Once the surface is wet, it appears that normal wash action is more effective. According to one or more embodiments, this relates to diffusion in the liquid wetting the surface as opposed to migration from solution to the air space in the niche. Expressed more simply, after spraying the surface with the very small droplets, the wash solutions are better able to reach and therefore inactivate the bacteria of interest.
The use of small droplets such as described herein affords another benefit. The resulting mist provides better coverage with less spray material. This affords a cost savings and less material for disposal if the spray solution is used once in a single pass treatment system. For example, in accordance with one or more embodiments, silver ion solutions often need to be used as single pass.
With regards to formulation of the short-term wash treatment, a distinction is differential sensitivity to the intense solution components. It has been observed that the more intense short-term wash treatments have more impact on the bacteria/microbes of interest than on the produce allowing shorter treatment times with greater lethality and less quality loss. For each product, one can balance the lethality of the concentration and time of the process against the damage to the product and the related loss in shelf life. This is similar to the situation with thermal processing. Ultra-high-temperature (UHT) processing utilizes extremely high temperatures to process milk but for very short times. This extreme yields the best quality sterile milk. In contrast, fresh pasteurized eggs are processed for long times at moderate temperatures to avoid denaturing or cooking the eggs because the eggs are more sensitive to temperature than the bacteria. Using the short-term wash treatment allows for the process of produce processing to be more like milk in that we can use intense chemical treatments with short durations. In the extreme as with UHT milk, the minimum durations will only be limited by the ability to handle the RTE product without physical damage. The concentration and treatment times for any of these short-term wash treatments can be adjusted based on the product to be treated.
In accordance with one or more exemplary embodiments, it is possible, but not required, that any residues from the short-term wash treatment be removed from the product by the conventional wash treatment and wash device/system. If there are no residues and no residual activity, the treatment is to be considered a processing aid and not require inclusion on the ingredient statement. When this is the case, the conventional wash system can be viewed as quenching the short-term wash treatment.
There are many short-term wash treatments that can meet the different sensitivity and residue removal requirements. This number can be increased by including inert or at least non-interfering ingredients at various concentrations. As an example, a combined solution of about 6% phosphoric acid and about 2.5% propylene glycol is useful. This solution provides greatly enhanced lethality at the end of the conventional wash with treatment durations of 10 to 60 seconds. According to other exemplary embodiments, with different product handling equipment, higher concentrations and shorter durations are obvious extensions. In a traditional wash system adjuvants are generally present at levels less than a few hundred ppm which represent a lower bound where the short-term wash treatment becomes just another wash stage and would not be expected to add useful additional lethality.
It is possible that this intense short-term wash treatment renders the bacterial microbes more susceptible to inactivation by the chlorine in the wash system. The phosphoric acid and propylene glycol residual are lost in the wash system where they act in concert with the other constituents of the wash system. Similar behavior is observed with other acids and simple polyols. Treatments with this family of materials are generally limited to less than a minute with an optimum around 30 seconds to avoid quality loss. Short-term wash treatment solutions without the polyol and just the acid, particularly citric, lactic, or acetic acids, are beneficial, but such solutions are often less effective than the comparable solution with the polyol. As part of managing the overall water usage of the wash system, the short-term wash treatment can be formulated with water from the primary wash system. There are other water management opportunities discussed in the exemplary embodiments provided herein.
As another formulation example, 10-50 ppm silver dihydrogen citrate in 3-5% citric acid can be provided in the short-term wash treatment. This combination adds a new mechanism of lethality which acts synergistically with the conventional wash system. For example, the chlorine in a conventional wash system will produce chloride which will inactivate the silver and facilitate removal during the wash leaving minimal residues. This short-term wash treatment solution is made with essentially chloride-free water—otherwise the silver ions are sequestered by any present chloride.
Another formulation example of the short-term wash treatment is a hybrid between the two mentioned above. Particularly, silver dihydrogen citrate can be diluted in a lactic acid glycerin solution maintaining the neutral charge for the silver complex and gaining the complementary benefits of the acid polyol system.
Further, water use and reuse are increasingly important in RTE produce wash systems. This complexity devolves from the cost of water, the cost of discharging water, the cost of water treatment chemicals and the cost of chilling the water. A short-term wash treatment that does not intrinsically include water reuse will be less desirable than a process that includes water reuse. Additionally, a process where the short-term wash treatment can be used for multiple passes will be inherently more interesting than one which does not allow reuse provided the pretreatment does not lose effectiveness. With these constraints in mind, one approach to this water management challenge is to filter and reuse the wash treatment solution. There will be some losses to the conventional wash system, but these losses will partially avoid the addition of make-up water to the conventional wash system. Alternatively, the short-term wash treatment can be used once prior to being used with dilution in the primary wash treatment and system. Some of the numerous approaches are specifically examined in the specific embodiments discussed herein.
Another embodiment can be superior for a mechanically sensitive product that does need to be chopped or cut. For example, baby leaf product including spinach can be treated with an air column spray system 970, which can also be called an air column short-term wash device 970, as illustrated in
The embodiment shown in
According to an exemplary embodiment, spinach that is inoculated to 104 cfu/g with a mixed culture of generic E. coli can be washed using the short-term wash treatment. For example, this spinach can be sliced and treated with various short-term wash treatments prior to washing through a commercial two stage Jacuzzi wash system at pH 5 at 15 ppm free chlorine. Treatments included city water as a control, SW™ and SWO™ (SmartWash Solutions LLC, Salinas, Calif.) and 50% Citric acid. It should be noted that although the citric acid solution was most effective, it turned the product unacceptably yellow when a 30-second treatment time is used in such an exemplary embodiment. After short-term wash treatment, samples collected and examined for residual E. coli may provide the following comparative total log reductions are reported in the following table 1:
Further, according to another embodiment a short-term wash treatment can work with a produce wash system in the control of lachrymator release from cut, chopped or sliced onions. Specifically, the coordination between the wash system and the short-term wash treatment is one of contrast. A solution of 0.05 to 0.25% bisulfite in dilute acid with a diol or other small polyol is applied to onions during the cutting process. Normally this would prompt labeling requirements on the finished product. However, in this case, the bisulfite reacts completely with the oxidizer in the wash system removing the sulfite residue. This treatment protected sensitive individuals from the lachrymators of the onions during a chopping operation. Also, sulfite levels were considerably less than the raw onions which are noted to be a high sulfite food.
In reducing this embodiment to practice, it has been found that 20 g of sodium bisulfite and 500 mls of either SmartWash Solution SW, SWO, or SWPro (SmartWash Solutions LLC, Salinas, Calif.), all of which are sources of acidity and diol functionalities, can be mixed with 30 gallons of water to effect treatment of onions. The described short-term wash treatment solution can be sprayed at a rate of 1 liter/min into the cutting chamber where onions are chopped at a rate of 200 pounds per hour. Clearly, there is a range of application rates that can be considered depending on the onion feed rate and the specific configuration of the equipment. It is important that the solution contact the onion close to simultaneously with the cutting because delays allow time for lachrymator generation. The duration of treatment and the time to removal of the solution is not of particular importance. In this reduction to practice, according to an exemplary embodiment, it may be convenient to go directly from the chopper to flume wash system given treatment times of a couple seconds.
According to one or more embodiments, strong oxidants such as electrolyzed water or plasma activated water and other active oxygen species such as ozone or peroxides can be used at higher concentrations for short treatments which are too aggressive for extended exposure. These treatments are readily quenched by dilution in the main wash system. Therefore, the short-term wash treatment can include one or more of these strong oxidants.
It should be apparent from the foregoing that embodiments of an invention having significant advantages have been provided. While the embodiments are shown in only a few forms, the embodiments are not limited but are susceptible to various changes and modifications without departing from the spirit thereof.
For example, in an alternative embodiment, a produce wash system including a process stream including a short-term wash device followed by a wash device, a short-term wash treatment that is applied by the short-term wash device to a product, wherein the short-term wash treatment remains on the product for a pretreatment time that lasts until the product reaches the wash device, and a wash treatment that is applied by the wash device to the product, wherein the wash treatment rinses the short-term wash treatment from the product defining the end of the pretreatment time. The pretreatment time is set at or below a damage threshold time beyond which the short-term wash treatment damages the product beyond a damage threshold.
The short-term wash treatment may provide at least one or more from a group consisting of antimicrobial properties, potentiating properties for the antimicrobial action of the subsequent wash device and wash treatment, and controlling properties for controlling lachrymator release from the produce.
In another embodiment, the product may be fresh produce that is at least one selected from a group consisting of whole, sliced, cut, and chopped leafy greens including but not limited to lettuce, spinach, cabbage, and kale, and vegetables including but not limited to broccoli, onions, bell peppers, and squash.
In another embodiment, the product may be a meat product that is at least one selected from a group consisting of beef, pork, lamb, veal, game, and poultry that includes but is not limited to whole, parted, and boned poultry.
In another embodiment, the short-term wash device includes a spray device that is configured to spray the short-term wash treatment on the product.
In another embodiment, the short-term wash device may further include at least one from a group consisting of a rotating drum short-term wash device, an air column short-term wash device, a slicer/dicer device, a spray curtain, a shaker, and a timing belt, wherein the spray device may be integrated with the at least one from the group to spray the short-term wash treatment on the product.
In another embodiment, the short-term wash device may include a product submersing device that is configured to receive and submerse the product into the short-term wash treatment followed by the product being sifted out of the short-term wash treatment.
In another embodiment, the product submersing device may be at least one selected from of a group consisting of a rotating drum short-term wash device, a submersing pool pretreatment device, an agitating pool pretreatment device, and a spray curtain with brushes.
In another embodiment, the short-term wash treatment may include an acidulant and a polyol. The acidulant may be one selected from a group consisting of a phosphoric acid and lactic acid, and the acidulant is from 0.1% to 10% of the short-term wash treatment, and the polyol maybe one selected from a group consisting of a glycerin and a propylene glycol, and the polyol is from 0.1% to 10% of the short-term wash treatment.
In another embodiment, the pretreatment time the short-term wash treatment remains on the product may be between 3 seconds and 1.5 minutes at a temperature between 30° F. and 50° F.
In another embodiment, the wash treatment may include free active chlorine from 2 to 40 ppm of the wash treatment, a compatible acidulant selected from a group consisting of phosphoric acid, citric acid, and lactic acid, and wherein the compatible acidulant is from 10 to 1000 ppm of the wash treatment, and a polyol selected from a group consisting of a glycerin and a propylene glycol, and wherein the polyol is from 2 to 500 ppm of the wash treatment.
In another embodiment, the short-term wash treatment may include a coordinating acid and silver ions, wherein the coordinating acid is one selected from a group consisting of a citric acid and a lactic acid and is from 3% to 5% of the short-term wash treatment, and wherein the silver ions are from 10 to 50 ppm of the short-term wash treatment.
In another embodiment, the pretreatment time the short-term wash treatment remains on the product may be between 3 seconds and 1.5 minutes at a temperature between 30° F. and 50° F.
In another embodiment, the wash treatment may include a compatible acidulant selected from a group consisting of phosphoric acid, citric acid, and lactic acid, wherein the compatible acidulant is from 10 to 1000 ppm of the wash treatment, a polyol selected from a group consisting of glycerin and propylene glycol, wherein the polyol is from 1 to 500 ppm of the wash treatment, free active chlorine from 2 to 40 ppm of the wash treatment, and chloride from 1 to 100 ppm of the wash treatment.
In another embodiment, the produce wash system may further include a transfer belt between the short-term wash device and the wash device, the transfer belt configured to serve as a drain scroll to recycle the short-term wash treatment, and a timing belt that is configured to help complete the pretreatment time.
In another embodiment, the short-term wash treatment and short-term wash device may be configured to account for at least one of product overload, inadequate chlorine in a flotation tank, and incomplete pH control.
In another embodiment, the short-term wash treatment may provide a supplemental wash lethality of greater than 1 log against microbes found on the product as compared to the lethality of the wash treatment in the wash system alone.
In another embodiment, there is provided a pre-rinse prior to the short-term wash treatment. This pre-rinse is positioned so as to prevent soil and debris from interfering with the short-term wash treatment or from being carried over into the wash system. It can be advantages to make this pre-rinse the last use of wash water prior to disposal. In another alternative embodiment, for example, there is provided a method of produce washing using a short-term wash device. The method includes processing a product through the short-term wash device followed by a wash device, applying a short-term wash treatment using the short-term wash device to the product such that the short-term wash treatment remains on the product for a pretreatment time that lasts until the product reaches the wash device, and applying a wash treatment using the wash device to the product such that the wash treatment rinses the short-term wash treatment from the product defining the end of the pretreatment time, wherein the pretreatment time is set at or below a damage threshold time beyond which the short-term wash treatment damages the product beyond a damage threshold. In another embodiment, applying a short-term wash treatment in done in the form of micrometer sized droplets using a spray device of the short-term wash device to the product such that the short-term wash treatment remains on the product for a pretreatment time that lasts until the product reaches the wash device.
In another alternative embodiment, for example, there is provided a short-term wash treatment that includes an acidulant selected from a group consisting of a phosphoric acid and lactic acid, wherein the acidulant is from 0.1% to 10% of the short-term wash treatment, and a polyol selected from a group consisting of a glycerin and a propylene glycol, wherein the polyol is from 0.1% to 10% of the short-term wash treatment, wherein a pretreatment time the short-term wash treatment remains on the product is between 3 seconds and 1.5 minutes at a temperature between 30° F. and 50° F.
While exemplary embodiments have been described with respect to a limited number of embodiments, those skilled in the art, having the benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope as disclosed herein. Accordingly, the scope should be limited only by the attached claims.
Claims
1. (canceled)
2. A method of washing a food product, the method comprising:
- applying, with a spray device, a short-term wash treatment to the food product as spray droplets, of the short-term wash treatment, having a volume median diameter (VMD) between 2 micrometers and 40 micrometers; and
- applying, with a wash device downstream of the spray device, a wash treatment to the food product, wherein the short-term wash treatment is applied for a shorter duration and is chemically different from the wash treatment.
3. The method of claim 2, wherein the spray device comprises at least one nozzle that creates the VMD of the spray droplets to be between 5 micrometers and 20 micrometers.
4. The method of claim 2, wherein the short-term wash treatment comprises propylene glycol.
5. The method of claim 4, wherein the propylene glycol is from 0.1% to 10% by weight of the short-term wash treatment.
6. The method of claim 2, wherein the short-term wash treatment is a combined solution comprising an acidulant and a polyol.
7. The method of claim 6, wherein:
- the acidulant is one selected from a group consisting of a phosphoric acid and lactic acid;
- the acidulant is from 0.1% to 10% by weight of the combined solution;
- the polyol is one selected from a group consisting of a glycerin and a propylene glycol; and
- the polyol is from 0.1% to 10% by weight of the combined solution.
8. The method of claim 6, wherein applying the short-term wash treatment to the food product comprises applying the combined solution for a pretreatment time between 3 seconds and 1.5 minutes at a temperature between 30° F. and 50° F.
9. The method of claim 6, wherein the wash treatment comprises:
- free active chlorine from 2 to 40 ppm by weight of the wash treatment;
- a compatible acidulant selected from a group consisting of phosphoric acid, citric acid, and lactic acid, wherein the compatible acidulant is from 10 to 1000 ppm by weight of the wash treatment; and
- another polyol selected from a group consisting of a glycerin and a propylene glycol, wherein the other polyol is from 2 to 500 ppm by weight of the wash treatment.
10. The method of claim 2, wherein:
- the short-term wash treatment comprises a coordinating acid and silver ions;
- the coordinating acid is one selected from a group consisting of a citric acid and a lactic acid and is from 3% to 5% by weight of the short-term wash treatment; and
- the silver ions are from 10 to 50 ppm of the short-term wash treatment.
11. The method of claim 10, wherein the wash treatment comprises:
- a compatible acidulant selected from a group consisting of phosphoric acid, citric acid, and lactic acid, wherein the compatible acidulant is from 10 to 1000 ppm by weight of the wash treatment;
- a polyol selected from a group consisting of glycerin and propylene glycol, wherein the polyol is from 1 to 500 ppm by weight of the wash treatment;
- free active chlorine, wherein the free active chlorine is from 2 to 40 ppm by weight of the wash treatment; and
- chloride from 1 to 100 ppm by weight of the wash treatment.
12. The method of claim 2, wherein applying the short-term wash treatment to the food product comprises applying the short-term wash treatment for a pretreatment time between 3 seconds and 1.5 minutes at a temperature between 30° F. and 50° F.
13. The method of claim 2, wherein the short-term wash treatment comprises silver dihydrogen citrate and wherein the silver dihydrogen citrate is from 10 to 50 ppm by weight of the short-term wash treatment.
14. The method of claim 2, further comprising:
- submersing, with a product-submersing device, the food product into the short-term wash treatment; and
- sifting the food product out of the short-term wash treatment after the submersing of the food product.
15. The method of claim 14, wherein the product-submersing device is at least one selected from a group consisting of a rotating drum short-term wash device, a submersing pool pretreatment device, an agitating pool pretreatment device, and a spray curtain with brushes.
16. The method of claim 2, further comprising:
- transferring the food product between the spray device and the wash device using a transfer belt, wherein the transfer belt is configured to serve as a drain scroll; and
- draining the short-term wash treatment from the food product using the transfer belt.
17. The method of claim 16, further comprising controlling, with a timing belt, a period that the short-term wash treatment is applied to the food product.
18. The method of claim 2, further comprising controlling at least one of the spray device or the short-term wash treatment to account for at least one of product overload, inadequate chlorine in a flotation tank, or incomplete pH control.
19. The method of claim 2, wherein applying the short-term wash treatment provides a supplemental wash lethality of greater than 1 log against microbes found on the food product as compared to the lethality of applying the wash treatment alone.
20. The method of claim 2, further comprising applying a pre-rinse to the food product prior to applying the short-term wash treatment, wherein the pre-rinse removes at least one of an initial organic load, soil, or debris.
21. The method of claim 2, wherein the short-term wash treatment comprises at least one of a peroxide, electrolyzed water, or plasma-activated water.
Type: Application
Filed: Feb 10, 2023
Publication Date: Aug 24, 2023
Inventors: James M. BRENNAN (Pleasanton, CA), Danny Elmer LINDSTROM (Rio Vista, CA), Christopher Michael MCGINNIS (Salinas, CA), Eric Child WILHELMSEN (Milpitas, CA)
Application Number: 18/167,679