HK1110748A - Method for producing tomato paste and powder using reverse osmosis and evaporation - Google Patents

Description

Method for preparing tomato paste and powder by reverse osmosis and evaporation

Technical Field

The present invention relates generally to a system and method for producing tomato products, and more particularly to a system and method for producing tomato paste and powder using reverse osmosis and evaporation.

Background

For processing food products, reverse osmosis and evaporation are used in different processes and processing methods. As is well known, juice is concentrated by osmotic means. In reverse osmosis, the juice undergoes membrane permeation under sufficient pressure so that moisture passes through the membrane, leaving behind a concentrated liquid product on the other side of the membrane. Also, it is known to reduce the moisture content of food products by evaporation, such as by concentrating the liquid product.

For example, one method is known to process using only evaporation, and not reverse osmosis. Tomato juice is treated to promote its separation into a pulp and fiber component. In particular, the tomatoes are crushed to separate their skins and seeds into tomato juice, which is then placed in a separator. However, tomato juice is treated with a coagulant such as calcium ions before being placed in the separator. Coagulation can improve the separation rate of juice and fiber in a tray (e.g., in a gravity decanter). The juice in the tray can be poured out for evaporation. The evaporated juice is mixed with fibres and the mixture is treated with phosphoric acid to eliminate the coagulant effect and convert the colloids to the original state to produce highly concentrated tomato juice.

Another conventional approach is to use a combination of membrane permeation and evaporation (i.e., pervaporation). In particular, the fruit juice is concentrated using a process that avoids direct heating and evaporation of the liquid. This indirect way is to achieve the separation of moisture from the liquid by treating and evaporating the moisture. More specifically, this method uses a self-contained process in which moisture permeates through a permeable membrane while moisture is evaporated on the other side of the membrane with a warm gas stream. However, the pressure of the liquid against the membrane is not the high pressure necessary for typical reverse osmosis. Conversely, the pressure is less than the osmotic pressure of the juice relative to the water, and more specifically, the pressure is not capable of performing reverse osmosis. In other words, the method is a pervaporation method that combines permeation and evaporation. The concentrate from the evaporator is then mixed with the particulate material previously separated to form the product.

However, the known methods can be modified. For example, the system and method may use a more energy efficient reverse osmosis process to remove a first portion of the water from the juice, or may use an evaporator to further reduce the water content to achieve a desired concentrate at a lower cost. The reverse osmosis is enhanced by initial cleaning and filtration of the juice, eliminating particulate matter that may clog the membrane.

Furthermore, the evaporation technique can be improved by a plurality of evaporation stages or effects. For example, multi-effect evaporation may employ smaller evaporation units and operate at lower temperatures. The purposes of reducing cost and further reducing energy consumption can be achieved by combining multiple-effect evaporation and thermal evaporation recompression. Because the steam used in the evaporator can be recycled and not wasted, the amount of steam that needs to be produced and put into the process is reduced.

In addition, the end product made with tomatoes can be improved. These methods or methods should also allow for the remixing of concentrated juice and slurry ingredients to produce a product having a fiber viscosity build capacity that is better than known tomato paste processing methods. By exposing the fibers and pectin to reduce the heat and mechanical load, the viscosity of the resulting final product can be enhanced. It should also be possible to produce sauces and powders using these methods or methods.

Accordingly, there is a need for an improved system and method for processing tomato juice in a lower cost and energy efficient manner to produce improved pastes and powders.

Disclosure of Invention

According to one embodiment, a method of processing tomato juice to produce tomato paste comprises separating tomato juice into a juice component and a first pulp component; processing said juice component to produce a clarified juice and a second pulp component; removing a first portion of water from the clarified juice by reverse osmosis to produce a first concentrated juice; removing a second portion of the water from the first concentrated juice with a multi-stage evaporator to produce a second concentrated juice. The reverse osmosis step and the multi-stage evaporation step are respectively carried out; mixing the secondary concentrated juice with the primary and secondary pulp components, and processing the mixture to obtain tomato sauce.

According to another embodiment, a method of making tomato paste from tomato juice comprises separating tomato juice into a juice component and a first pulp component. The juice component is processed to produce a clarified juice and a second pulp component. A first portion of the water is removed from the clarified juice by reverse osmosis to produce a first concentrated juice. Removing the second portion of the water from the preliminary juice concentrate using a multi-stage evaporator to produce a juice concentrate, wherein the evaporation is performed separately after the reverse osmosis process. Mixing the concentrated juice with the first and second pulp components to form an intermediate paste, and processing the intermediate paste into tomato paste.

In yet another embodiment, a method for making tomato paste from tomato juice comprises separating tomato juice into a juice component and a first pulp component, and then processing the juice component to form a clarified juice and a second pulp component. A first portion of the water is removed from the clarified juice by reverse osmosis to produce a first concentrated juice. Removing the second portion of the water from the first concentrated juice with a multi-stage evaporator to form a concentrate. The multistage evaporation and reverse osmosis are carried out with separate components at different times, wherein the steam used in the multistage evaporation is recyclable. The concentrated juice is then mixed with the pulp to form an intermediate paste, which is then processed to form a tomato paste.

In various embodiments, a decanter can be used to separate the tomato juice into juice and a first pulp component. The fruit juice component may contain 5 to 6% by weight of total solids.

The clarified juice may be made using a centrifuge and/or filter.

The first portion of water removed from the tomato juice is about 50% of the total water removed, and the second portion of water removed is about 40-45% of the total water removed. Thus, reverse osmosis and multi-stage evaporation can remove 92% of the total water to be removed.

The multi-stage evaporation may be with a falling film evaporator and may be performed using different evaporation stages, for example, 2 to 8 evaporation stages, where each successive evaporation stage operates at a lower temperature than the preceding evaporation stage, the first stage may be performed at about 140 ° f, and the last stage may be performed at about 110 ° f. The steam can be recycled in the evaporation stage by hot steam recompression, wherein the steam coming out of the outlet of the last evaporation stage is recycled to the inlet of the first evaporation stage.

Depending on the system design, tomato paste can be made using varying amounts of pulp components. For example, in one embodiment using a decanter and a centrifuge, the first pulp component is produced by the decanter and the second pulp component is produced by the centrifuge. In another alternative embodiment, a filter is used instead of the centrifugal separator, wherein the filter produces the second pulp component. In yet another embodiment, a first pulp component is produced using a decanter, a second pulp component is produced using a filter, and a third pulp component is produced using a centrifuge.

Drawings

Referring now to the drawings in which like reference numbers represent corresponding parts throughout:

fig. 1A-B are process flow diagrams illustrating a method of making tomato paste and powder, wherein the method components and process steps are illustrated.

Fig. 2A-B are flow charts showing the process steps for making tomato paste and powder.

For ease of understanding, FIGS. 1A and 1B should be referenced side-by-side, in the order A-B-C-D.

Detailed Description

Examples of systems and methods for fractionating/separating juice by decantation, clarification and/or microfiltration followed by reverse osmosis and evaporation to make tomato paste and powder are now described. Separating a fruit juice, such as tomato juice. This juice can be separated, for example, by a decanter, clarifier, and/or microporous filter.

In particular, the tomato juice is separated into a decanter juice component and a first pulp component. The juice component is processed to produce clarified juice/microfiltered juice (commonly referred to as clarified juice) which is then processed by membrane and reverse osmosis to produce a primary juice concentrate. While processing the juice component to produce clarified juice, a second pulp component is produced, possibly a third pulp component, depending on the system design, i.e., whether both a centrifuge and a filter are used.

For example, if both a centrifuge and a filter are used, a third pulp component may be produced. Reference herein to the production of the first and second pulp components is for illustrative purposes only and is not intended to be limiting, the first pulp component being produced by a decanter and the second pulp component being produced by a centrifuge or filter. Also, for illustrative purposes, juice produced by a centrifuge/filter is often referred to as clarified juice. One skilled in the art will recognize that different numbers and stages of clarification may be used as desired.

The first and second pulp components can be mixed to form a pulp mixture. The juice concentrate is prepared by placing the initial concentrate in a multi-stage evaporator using different stages or effects of evaporation and a recycling unit (e.g., a hot vapor recompression unit) to reuse or recycle the steam used in the previous evaporation process. Mixing the concentrated juice with the first and second pulps to form an intermediate paste, and processing the intermediate paste to form the tomato paste. Or making into tomato powder. Thus yielding two final products-sauce and flour. In a specific embodiment, the juice and pulp components are mixed by reverse osmosis and evaporation to form the tomato paste. Further, the specific embodiments propose a new method for producing sauce/powder, thereby saving energy consumption, reducing cost, and improving product quality.

In the following description, reference is made to the accompanying drawings while also illustrating a method of practicing a certain embodiment, it being understood that other embodiments may be utilized. Further, one of ordinary skill in the art will recognize that various juices can be produced with the present system and method embodiments. The use of tomato juice for making tomato paste and powder is described in this specification for illustrative purposes only. In addition, the specific examples and descriptions are provided to illustrate processing ingredients, temperatures, and amounts required. These parameters in the examples are adjustable as desired, and therefore the concentrate, temperature and desired amount in the examples are not limited.

Referring to fig. 1A, a tomato juice or feed stream 100 is provided, which may be made using known hot/cold juicers (not shown in the drawings).

The juice stream 100 is fed into a separation device, such as a decanter 105. Other separation devices than decanters may also be used by those skilled in the art. The decanter referred to in this description is intended to be illustrative only and not limiting in scope. The decanter separates the insoluble/soluble fibers, including insoluble/soluble pectin, from the feed stream 100 (e.g., most of the insoluble fibers and insoluble pectin). The physicochemical state of the juice stream 100 can be described as solids suspended in an aqueous sugar solution. In the illustrated embodiment, the initial tomato juice 100 contains about 7% by weight total solids. In other words, the solids comprise insoluble fiber and partially soluble pectin, as well as fructose, glucose, citric acid, malic acid, protein, cellulose, hemicellulose, etc., which make up 7% by weight of the juice, while other non-solids, such as water, make up about 93% by weight of the juice. Juice stream 100 is at a temperature of about 180.0 ° f and a flow rate of 98.6 tons/hour. Different amounts of tomato juice stream 100 can be added depending on the structure, capacity and other process factors of decanter 105.

More specifically, the decanter 105 separates the initial juice stream 100 into two portions — tomato juice or decanted juice 105a and a first pulp component 105 b. Thus, the initial 98.6 ton/hr flow of juice stream 100 is separated into 87.8 ton/hr flow of decant juice 105a and 10.8 ton/hr flow of first pulp component 105 b. In contrast to some conventional methods, it is not necessary to separate the tomato juice 100 with a coagulant such as calcium ions, but rather a decanter 105 can be used to achieve satisfactory separation without additional chemical treatment.

In the illustrated embodiment, decant juice 105a has a total solids content of between about 5 and 6% by weight, for example about 5.5% by weight total solids, and decant juice 105a has a temperature of about 170F and a flow rate of about 87.8 tons/hour. The total solids content of the first pulp component 105b was about 18.9% by weight, with a flow rate of about 10.8 tons/hour. The first pulp component 105b is composed of solid portion (insoluble fiber, pectin, protein, fat, etc.) and colloidal fiber, pectin and dissolved sugar (fructose and glucose) contained in the water of the liquid portion. The first pulp component 105b is separated from the initial juice stream 100 to promote reverse osmosis to reduce or prevent membrane clogging, as will be discussed further below.

To ensure flexible articulation of unit operations, balanced machining or interengagement may be used throughout the process. For example, decanted tomato juice 105a may be added to a balancer 107, which is connected to decanter 105 and clarifier 110. The decanted tomato juice 105a is added to a clarifier 110, wherein the clarification device 110 reduces the solids content of the decanted tomato juice 105a to produce clarified juice 110 a. Specifically, the remaining undissolved/dissolved fibers, including undissolved/dissolved pectin, are separated from the decanted tomato juice 105a to produce clarified juice 110 a.

In one embodiment, the clarifier 110 is a centrifuge. In an alternative embodiment, the clarifier 110 is a filter (e.g., a microporous filter), however, in another alternative embodiment, both a centrifuge and a filter are used. Both devices are used to separate solids from decanted juice 105a to produce clarified tomato juice 110a, although the centrifuge and filter operate differently. For example, centrifuges utilize high gravity centrifugation, and filters, such as microporous filters, utilize filtration media such as polyamide, sintered metal, or ceramic for filtration. Further, as previously discussed, in alternative embodiments, a centrifuge and a microporous filter may be used after processing using a decanter. Thus, the clarified juice 110a may be produced by a variety of different machines and processes, and FIG. 1A is not intended to be limiting.

In the particular example shown, the clear tomato juice 110a contains 5% solids by weight, primarily including sugars (glucose and fructose) and other low molecular dissolved compounds dissolved in water. In this example, the temperature of the clarified juice 110a is 160F and the flow rate is about 85.2 tons/hour. Thus, the clarified juice 110a is lower in temperature and total solids content than the decanted tomato juice 105 a.

In addition to producing clarified juice 110a, the clarifier 110 also produces a second pulp component 110b that comprises primarily pectin undissolved/dissolved fibers, including pectin undissolved/dissolved pectin, in an aqueous sugar-containing solution. The total solids weight of the second pulp component 110b is about 24% of the total weight. Thus, the microporous filter or centrifuge 110 produces a majority of the clarified tomato juice 110a and a small portion of the second pulp component 110 b. Moreover, in the illustrated embodiment, the second pulp component 110b has a higher total solids content (24%) and contains more solids than the first pulp component 105b, wherein the first pulp component has a total solids content of about 18.9%. The flow rate of the first pulp component 105b (10.8 tons/hour) is greater than the flow rate of the second pulp component (2.6 tons/hour). Thus, the majority of the resulting pulp is the first pulp component 105b, which is made from the preliminary decantation 105 of the tomato juice 100.

Of course, if an additional membrane clarification unit is used, additional pulp components may be produced. For example, a third pulp component can be produced using both a centrifuge and a filter. This description is intended for purposes of illustration only and is not intended to be limiting. Reference herein to a first pulp component and a second pulp component, wherein the first pulp component is made by a decanter and the second pulp component is made by a clarifier.

To form pulp mixture 120b, first and second pulp components 105b and 110b are mixed together in-line mixer 120. The pulp mixture 120b contains about 20% by weight total solids (insoluble fiber and pectin, protein, fat, etc.) and liquid ingredients including colloidal fiber, fructose, and sugar dissolved in water. The first pulp component 105a (the majority of the pulp mixture 120 b) and/or the pulp mixture 120b can ultimately be used to make tomato paste or tomato powder. The mixture of the two batches of pulp components or the individual pulp components can be used to make tomato paste.

A second process balancer 117 connects the clarifier 110 and the cooler 130. The clarified juice 110a is cooled for better functioning of the reverse osmosis membrane, as will be discussed in detail below. The reduced temperature favors the action of semi-permeable reverse osmosis membranes such as polyamide.

For example, the cooler 130 may be an evaporative cooler or an indirect cooler. For purposes of illustration, and not limitation, evaporative cooling will be further described below. To cool the clarified juice 110a prior to reverse osmosis, a vacuum generator and steam condenser are used as part of the evaporative cooling in this specification. For example, clear tomato juice 110a is chilled from about 160F to about 120F or less. Minor changes in the concentration of clear tomato juice can also occur, so that the total solids content of the cooled juice concentrate is between 4.97% and 5.16% by weight. The flow rate of chilled juice 130a is about 82.1 tons/hour and the rate of water removal from the clarified juice is about 3.1 tons/hour.

The chilled juice 130a is treated by a reverse osmosis unit 140 to remove water therefrom to produce a primarily concentrated or primarily concentrated tomato juice 140 a. In particular, the cooled clarified juice 130a is placed under high pressure into a reverse osmosis membrane. Depending on the application of the reverse osmosis membrane, suitably high pressures of about 400 and 600 pounds per square inch (psi) may be used. The primary or primary juice concentrate 140a passes through the membrane filter 140, leaving solids on the other side of the membrane.

Reverse osmosis device 140 may be used to remove varying amounts of water 140b from the cooled clarified juice 130 a. For example, in the illustrated embodiment, the reverse osmosis unit 140 is designed to remove 50% of the total water evaporation or half of the water to be removed (or 39 tons/hour) in conjunction with processing the tomato paste. In an alternative embodiment, in combination with processing tomato paste, a reverse osmosis membrane may be used to remove 30% to 70%, preferably 50% (or 39 ton/hour) of the total water evaporation. As a result, the concentration of the preliminary tomato juice 140a is about 9.8% total solids and is maintained at a chilled temperature of about 120F. Thus, the concentration of the primary juice concentrate 140a is higher than that of the chilled clarified juice 130a, and the flow rate of the primary juice concentrate 140a obtained is about 43.1 tons/hour.

The chilled clear tomato juice 130a is preferably treated using a reverse osmosis unit 140. The cooled clarified tomato juice 130a contains mainly large free molecular compounds such as pectin, which may aggravate the clogging of the membranes of the reverse osmosis plant. In addition, in order to ensure a high dehydration rate, the reverse osmosis apparatus 140 is preferably performed in a lower concentration range throughout the entire process of removing water. In other words, as shown in FIGS. 1A-B, the reverse osmosis unit 140 is disposed in front of the multi-stage evaporation apparatus. Thus, the reverse osmosis unit 140 is used to remove most of the water at a lower cost and with less energy consumption than the second stage of dewatering by thermal evaporation.

The primarily concentrated tomato juice 140a produced by the reverse osmosis unit 140 is fed to the de-aeration unit 150. a third balancing unit may be used to connect the outlet of the reverse osmosis unit 140 to the de-aeration unit 150. The degassing is similar to the first evaporative cooling stage 130, thus using a vacuum generator and a steam condenser. As a result, the temperature of the initially concentrated tomato juice 140a drops from about 121F to 107F with a slight increase in concentration (due to the about 0.5 ton/hr dewatering 150b) from about 9.82% by weight total solids to 9.94% by weight total solids. The flow rate of the degassed and initially concentrated juice 150a is approximately 42.6 tonnes/hour.

The de-aeration process removes non-condensable gases (in this case air) from the initially concentrated tomato juice, thus ensuring a higher heat transfer efficiency in the evaporation apparatus or device. In addition, the removal of air may improve the efficiency of the thermal vapor recompression operation, the details of which are discussed further below. In addition, removing air from the primarily concentrated tomato juice 140a can reduce or minimize the color change reaction or that occurs in the multi-stage evaporator 160. The degasser 150, among other things, minimizes the negative effects of non-condensable gases on heat transfer while positively inhibiting the effects of oxygen on its color change reactions in the multi-stage evaporator 160.

The degassed primary juice 150a is added to an evaporator 160 to produce tomato juice concentrate or secondary juice concentrate 160 a. The evaporation process 160 includes multiple stages of evaporation 162 and thermal vapor recompression 164. Further discussion of various aspects will be provided later herein.

During processing, the evaporation device 160 removes a second, substantial amount of moisture 160b (reverse osmosis removes a greater portion of the moisture). In one embodiment, the evaporation device 160 removes about 40-45% by weight of the total water to be removed from the juice component, as shown in FIG. 1B, from the juice component, and about 42.8% of the total removed water 160B. As a result, the reverse osmosis unit 140 in combination with the evaporation unit 160 may remove about 92.3% of the total evaporated moisture, and the remaining about 7.7% of the moisture may be removed using other means.

In the illustrated embodiment, the evaporation device 160 is a multi-stage evaporator 162. The multi-stage evaporation method 162 in the illustrated embodiment includes four stages 162 a-d. The multistage evaporator 162 is preheated by the preheating device 163. The preheating means heats incoming de-aerated juice 150a from about 107.4 to about 160 degrees Fahrenheit, with the juice temperature gradually decreasing in each evaporation stage. For example, four connected multi-stage evaporators as shown, the preheat temperature is about 160.5F, the temperature in the first evaporator is about 142.5F, the temperature in the second evaporator is about 129.9F, the temperature in the third evaporator is about 120.6F, the temperature in the fourth evaporator is about 109.0F, and the fourth evaporator produces tomato juice concentrate 160 a. The tomato concentrate 160a has a concentration of about 47.8% wt. ts and a flow rate of about 8.86 tons/hour.

Thus, each successive evaporation stage is at a lower temperature than the preceding stage. Other multi-stage devices, which may include 2-8 stages, may also be used. Thus, the process flow diagram may also illustrate various other suitable devices. The multi-stage evaporator 162 is greatly reduced in volume and operates at a lower temperature than a conventional evaporator. Since the solids content of the juice components is reduced, especially the sugar content in the water, the juice is characterized by a lower viscosity (compared to tomato paste) and a higher heat transfer capacity.

In order to minimize the buffer capacity (buffer 123 of tomato pulp and buffer 142 of tomato concentrate), the multistage evaporator 162 preferably has a low residence time. Buffering can be performed during the initial stages of membrane filtration or during multi-stage evaporator processing.

One suitable evaporator which can meet the low residence time is a falling film evaporator which has a short relative residence time and provides a higher heat transfer coefficient. If the falling film evaporator is operated at a low temperature, the degree of discoloration reaction due to glucose or fructose in the preliminary concentrated juice can be reduced.

If a circulation device is provided in the multistage evaporator 162, the effect of reducing the energy consumption can be further achieved. In one embodiment, the recycling device is a thermal vapor recompression device 164. The steam consumption of the multi-stage evaporator 162 can be reduced by using the multi-stage evaporator 162 in combination with the hot vapor recompression device 164. In the illustrated embodiment, the multi-stage evaporator 162 includes four evaporation stages 162a-d, and a thermal vapor recompression device 164 may be applied to each of the four stages. In alternative embodiments, the thermal vapor recompression device 164 may be applied in different stages or only in some stages. Accordingly, FIG. 1A is merely illustrative of various thermal vapor recompression devices.

More specifically, a portion of the secondary vapor from the last or fourth evaporation stage is fed to the ejector 165 of the thermal vapor recompression device. The steam consumption in the ejector 165 is about 8.8 tons of evaporated water per ton of steam consumed. The heating steam 165a provided by the ejector 165 to the first stage evaporator 162a is at a temperature of 152.8F. The secondary steam remaining in the fourth stage 162d is condensed in a barometric condenser 168, which is connected to the multistage evaporator 162 d.

As shown in fig. 1A and 1B, the juice 150a is dewatered by the use of the reverse osmosis unit 140 and the multi-stage evaporator 160 without further processing of the pulp component or mixture 120B in other mechanical or heating devices. Compared with the existing tomato paste processing method, the method improves the aggregation viscosity capability of fiber and pectin in the tomato paste, thus reducing the heating and mechanical load for processing fiber and pectin, and producing the final product with higher viscosity.

The tomato concentrate 160a produced by the reverse osmosis unit 140 and the subsequent multi-stage evaporator 162 is mixed with one or more pulp components, for example, by a mixing and evaporating conditioning unit 170. In one embodiment, the hybrid evaporative conditioning device 170 is designed as a combination of a mixer, a heater, and an evaporation device in series. The present exemplary apparatus uses a closed flow loop to properly direct all of the solid components of the intermediate paste 170 a. Moisture (and air) is removed using a vacuum generator and a steam condenser.

In one embodiment shown, the intermediate paste 170a is made by mixing tomato concentrate 160a with a mixture 120b of first and second pulp components 105b, 110 b. In an alternative embodiment, the concentrated juice is mixed with only the first pulp component 105b (which is more pulp content than the second pulp component 110 b) to make the intermediate paste 170 a. Thus, the intermediate paste 170a comprising only the first pulp component is less viscous than the intermediate paste comprising the pulp mixture 120. The present description will further discuss the intermediate paste 170a containing the two batches of pulp ingredient mixture for purposes of illustration only and not for limitation.

The hybrid evaporative trimming process 171 produces an intermediate paste 170a of the target total solids concentration. In other words, the hybrid evaporative conditioning device 170 compensates for the composition of the tomato juice concentrate 160a and tomato pulp 120 b. The mixing and evaporative conditioning device 170 simultaneously ensures removal of air and/or moisture present in the tomato pulp 120 b. The resulting intermediate paste contains pulp mixture 120, with a total solids weight of about 32.1%, a temperature of about 140F, and a flow rate of about 21.5 tons/hour.

In the illustrated embodiment, when the reverse osmosis device 140 and the multi-stage evaporator 162 are used to remove moisture from the clarified juice 130a, the tomato pulp 120b need not be further processed by mechanical or heating means. In the initial stages of the process, particularly after washing, more time is required to produce concentrated tomato juice than to produce the tomato pulp 120b and place it in the mixing and evaporating trim set 170. This is due in part to the initial procedure involving the multi-stage evaporator 162, as it takes some time to transition to a steady state and be able to produce tomato concentrate. The start-up of the multi-stage evaporator 162 is performed in water. In contrast, during this time, the tomato pulp 120b is still being produced continuously.

Thus, the buffering capacity can be used for serial production, one for buffering the tomato pulp buffer 123 and another for buffering the tomato concentrate buffer 143, wherein the concentration of the tomato concentrate is still below the target concentration. When the concentration of tomato concentrate 160a has reached the target concentration, the hybrid evaporative conditioner 170 process may begin. However, the hybrid evaporative conditioning device 170 takes a period of time to reach a stable stage. During this time, excess tomato concentrate 160a is circulated in buffer 143. When the hybrid evaporative conditioning device 170 reaches a steady state, the intermediate paste 170a can be processed in the indirect/direct heating device 180. Once the tomato paste processing reaches a steady state, the buffered tomato pulp and tomato concentrate are then slowly introduced into the processing method. At this rate the steady state of the tomato paste processing line is not affected.

The intermediate paste 170a is pasteurized by various suitable heat exchangers, such as wide-mouth plate heat exchangers and direct (viscous dissipation) heat exchangers. This device can be used in particular for intermediate pastes 170a that are more viscous than the currently known ketchup, the ideal temperature of the intermediate paste 170a being 200 ° f after the indirect/direct heater action, the consistency and flow rate being similar to those before heating.

To ensure that the duration at 200 ° f is sufficient to achieve lethal thermal damage to the target microorganisms, the heated intermediate paste 180a is retained in the retainer 182. If the pH of the intermediate paste 170a is low, the thermal destruction mode can destroy most of the viable microbial cells.

After sterilization, the intermediate paste 180a is cooled in a sterile environment in a second steam cooler 190. Since the intermediate paste 180a becomes relatively viscous, steam cooling may replace indirect cooling in this regard. If indirect cooling is used, more mechanical energy needs to be invested. In indirect cooling equipment, a large mechanical energy input can overcome the large pressure drop, but can also have a negative effect on the viscosity of the final product. Thus, a high scorch rate will reduce the final product yield and lower its viscosity. Therefore, it is preferable to apply the steam cooling method.

The second steam cooling stage 190 serves to adjust the amount of water 190b removed from the intermediate batter 180a in such a way that a final adjustment of the target solids content of the paste can be made. Because moisture is removed during evaporative cooling, a vacuum generator and a steam condenser are employed.

One adjustment to the target total solids concentration may be made during the hybrid evaporative conditioning device process 170 and, in addition, the evaporative cooling 190 allows another adjustment to be made. In use, the total solids concentration is adjusted by mixing the process operating parameters of the evaporative conditioning apparatus 170 and the evaporative cooler 150.

Water 190b is separated from the intermediate mash 180a by a cooling process 190 at a flow rate of about 1.7 tons/hour to form a paste 190a, which yields a paste 190a having a consistency of about 34.9% wt. TS, a temperature of about 114F, and a flow rate of about 19.8 tons/hour. Thereafter, the final ketchup product 190a can be packaged. For example, sterile packaging 191 may be performed (e.g., box-and-bag techniques may be used) or sterile storage 192 may be performed in a large storage box for later use.

In addition to producing tomato paste 190a, tomato powder 195b may also be produced using this example. To produce tomato powder 195b, the intermediate paste is placed directly into a dryer (e.g., a spray dryer), although other types of dryers, such as drum dryers, may also be used. The final product of tomato powder has a total solids content of about 98.000% and is packaged in bags or drums or silos for later use.

Although the process flow diagram illustrates example operating parameters, other operating parameters may be applied as desired. Accordingly, the parameters discussed and illustrated in the process flow diagrams are not limiting in scope, but are for explanation purposes.

Claims (85)

1. A method for preparing tomato sauce from tomato juice comprises:

providing tomato juice;

separating said tomato juice into a juice component and a first pulp component;

processing said juice component to produce a clarified juice and a second pulp component;

removing a first portion of the water from the clarified juice with a reverse osmosis unit to produce a first concentrated juice;

removing a second portion of the water from the primary juice concentrate using a multi-stage evaporation apparatus to produce a secondary juice concentrate, the reverse osmosis and multi-stage evaporation steps being performed separately;

processing the mixture of the second juice concentrate and the first and second pulp components to form a tomato paste.

2. The process as claimed in claim 1, wherein separating the tomato juice comprises separating the tomato juice using a decanter.

3. The method of claim 1 wherein separating the tomato juice comprises separating the tomato juice without using a coagulant.

4. The method of claim 1, wherein the juice component is at a temperature of about 170 ° f.

5. The process of claim 1 wherein said juice component contains about 5 to 6% by weight total solids.

6. The method of claim 1 wherein the temperature of the clarified juice is lower than the temperature of the juice component.

7. The method of claim 1 wherein the clarified juice has a total solids content that is less than the total solids content of the juice components.

8. The method of claim 1, wherein treating the juice component comprises filtering the juice component to produce the clarified juice.

9. The method of claim 1, wherein processing the juice component comprises processing the juice component using a centrifuge to produce the clarified juice.

10. The method of claim 1, wherein processing the juice component comprises processing the juice component using a centrifuge and a filter, thereby producing the clarified juice.

11. The method of claim 1, further comprising: cooling the clarified juice from about 160 ° f to about 120 ° f before removing the first portion of water, the cooled clarified juice being subjected to reverse osmosis.

12. The method of claim 1, wherein removing the first portion of the water comprises placing the clarified juice into a membrane filter at a sufficiently high pressure so that the first concentrated juice passes through the membrane filter.

13. The method of claim 1, wherein removing a first portion of water comprises removing about 50% of the total amount of water removed from the tomato juice.

14. The process of claim 1 wherein said primary clarified juice contains about 10% total solids.

15. The process of claim 1, wherein removing the second portion of water comprises removing about 40-45% of the total amount of water removed from the tomato juice.

16. The method of claim 1, wherein the temperature of the primary juice concentrate is reduced by about 50 ° f during the removing of the second portion of water.

17. The method of claim 1, further comprising preheating the primary juice concentrate to about 160 ° f and reducing the temperature of the primary juice concentrate to about 110 ° f in a multi-stage evaporation process.

18. The method of claim 1 wherein said secondary juice concentrate contains about 47% total solids.

19. The method of claim 1 wherein reverse osmosis and multi-stage evaporation remove about 92% of the total water removed from the tomato juice.

20. The method of claim 1, wherein the multi-stage evaporation is performed using a falling film evaporator.

21. The method of claim 1, wherein removing the second portion of the water comprises removing the second portion of the water using about 2 to 8 evaporation stages.

22. The process of claim 1, wherein each successive evaporation stage is operated at a lower temperature than the preceding evaporation stage.

23. The method of claim 22, wherein the multi-stage evaporation is performed by four stages, wherein:

the first stage temperature of the primary juice concentrate is about 140 deg.f,

the second stage temperature of the primary juice concentrate is about 130 deg.f,

the third stage temperature of the primary juice concentrate is about 120 ° F, an

The fourth temperature of the primary juice concentrate is about 110F.

24. The method of claim 1, further comprising recycling steam in the multi-stage evaporation.

25. The method of claim 24, wherein circulating steam comprises thermal steam recompression.

26. The method of claim 25, wherein the hot vapor recompression comprises providing vapor from an outlet of an evaporation stage of the last stage and providing recycled vapor to an inlet of the first evaporation stage.

27. The method of claim 26, further comprising increasing the temperature of the recycle steam prior to introducing the recycle steam to the first evaporation stage.

28. The method of claim 27, wherein the temperature of the cycle steam is increased from about 110 ° f to about 150 ° f.

29. The method of claim 1, wherein the amount of the first pulp component is greater than the amount of the second pulp component.

30. The method of claim 1 wherein the total solids content of the second pulp component is higher than the total solids content of the first pulp component.

31. The method of claim 1 wherein the total solids content of the first pulp component is about 19% and the total solids content of the second pulp component is about 24%.

32. The method of claim 1, wherein the mixture of the first and second pulps contains about 20% total solids.

33. The method of claim 1, further comprising processing said juice component to produce a clarified juice, a second pulp component, and a third pulp component.

34. The method of claim 1, wherein processing the juice component includes processing the juice component with a centrifuge to produce a second pulp component and filtering the centrifuged juice component to produce a clarified juice and a third pulp component.

35. The method of claim 34, further comprising buffering the pulp mixture during initial stages of the membrane and the multi-stage evaporation process.

36. The method of claim 1, wherein the tomato powder comprises about 98% by weight total solids.

37. The method of claim 1 wherein the reverse osmosis and multistage evaporation steps are performed using separate devices.

38. The method of claim 1 wherein the reverse osmosis and multi-stage evaporation steps are performed at respective times.

39. A method for preparing tomato sauce from tomato juice comprises:

providing tomato juice;

separating said tomato juice into a juice component and a first pulp component;

processing said juice component to produce a clarified juice and a second pulp component; removing a first portion of the clarified juice with a reverse osmosis unit to produce a preliminary concentrated juice;

removing a second portion of water from the preliminary juice concentrate using a multi-stage evaporation process to produce a juice concentrate, the multi-stage evaporation process being performed independently after reverse osmosis;

mixing said concentrated juice with said first and second pulp components to produce an intermediate paste; and

processing the intermediate paste to obtain tomato sauce

40. The process as claimed in claim 39, wherein separating said tomato juice comprises separating said tomato juice using a decanter.

41. The method of claim 39 wherein separating said tomato juice comprises separating said tomato juice without using a coagulant.

42. The method of claim 39, wherein said juice component is at a temperature of about 170 ° F.

43. A process as claimed in claim 39, wherein the juice component contains about 5 to 6% by weight total solids.

44. The method of claim 39 wherein said clarified juice is at a lower temperature than the juice component.

45. The method of claim 39 wherein the total solids content of the clarified juice is lower than the total solids content of said juice components.

46. The method of claim 39, wherein processing the juice component comprises filtering the juice component to produce the clarified juice and a second pulp component.

47. The method of claim 39, wherein processing the juice component comprises processing the juice component using a centrifuge to produce the clarified juice and a second pulp component.

48. The method of claim 39, further comprising: the clarified juice temperature is cooled from about 160F to about 120F before removing the first portion of water.

49. The method of claim 39, wherein removing the first portion of water comprises placing the clarified juice into a membrane filter under sufficiently high pressure so that the first concentrated juice passes through the membrane filter.

50. The method of claim 39, wherein removing a first portion of water comprises removing about 50% of the total amount of water removed from the tomato juice.

51. The process of claim 39 wherein said first clarified juice contains about 10% total solids.

52. The process as claimed in claim 39, wherein removing the second portion of water comprises removing about 40-45% of the total amount of water removed from the tomato juice.

53. The method of claim 39, wherein the temperature of the primary juice concentrate is reduced by about 50 ° F during the removing of the second portion of water.

54. The method of claim 39, further comprising preheating the primary juice concentrate to about 160F and reducing the temperature of the primary juice concentrate to about 110F in a multi-stage evaporation process.

55. The method of claim 39 wherein said secondary juice concentrate contains about 47% total solids.

56. The method of claim 39 wherein reverse osmosis and multi-stage evaporation remove about 92% of the total water removed from the tomato juice.

57. The method of claim 39, wherein the multi-stage evaporation is performed using a falling film evaporator.

58. The method of claim 39, wherein removing the second portion of the water comprises removing the second portion of the water using about 2 to about 8 evaporation stages.

59. The process of claim 39, wherein each successive evaporation stage is operated at a lower temperature than the preceding evaporation stage.

60. The method of claim 59, wherein the multistage evaporation is carried out by four stages, wherein:

the primary juice concentrate is at a temperature of about 140 deg.f in the first stage of evaporation,

the temperature of the primary juice concentrate during the second stage evaporation is about 130 deg.f,

said primary juice concentrate having a temperature of about 120 ° F in a third stage of evaporation, an

The primary juice concentrate is at about 110 ° f during the fourth stage of evaporation.

61. The method of claim 39, further comprising recycling steam used in the multi-stage evaporation.

62. The method of claim 61, wherein recycling steam comprises performing thermal steam recompression.

63. The method of claim 62, wherein performing thermal vapor recompression further comprises providing vapor from an outlet of an evaporation stage of the final stage and providing recycled vapor to an inlet of the first evaporation stage.

64. The process of claim 63, further comprising increasing the temperature of the recycle steam prior to introducing the recycle steam to the first evaporation stage.

65. The method of claim 64, wherein the temperature of the cycle steam is increased from about 110F to about 150F.

66. The method of claim 39, wherein the amount of the first pulp component is greater than the amount of the second pulp component.

67. The method of claim 39 wherein the total solids content of the second pulp component is higher than the total solids content of the first pulp component.

68. The method of claim 67, wherein the first pulp component has a total solids content of about 19% and the second pulp component has a total solids content of about 24%.

69. The method of claim 39, wherein the mixture of the first and second pulps contains about 20% total solids.

70. The method of claim 39, further comprising processing said juice component to produce a clarified juice, a second pulp component, and a third pulp component.

71. The method of claim 70, wherein processing the juice component includes processing the juice component with a centrifuge to produce a second pulp component and filtering the centrifuged juice component to produce a clarified juice and a third pulp component.

72. The method of claim 39, further comprising buffering the pulp mixture during initial stages of the membrane and the multi-stage evaporation.

73. A process as claimed in claim 39, wherein the intermediate paste is processed to produce tomato powder.

74. The method of claim 73, wherein said tomato powder comprises about 98% by weight total solids.

75. The method of claim 39 wherein the reverse osmosis and multi-stage evaporation steps are performed using separate devices.

76. The method of claim 39 wherein the reverse osmosis and multi-stage evaporation steps are performed at respective times.

77. A method of making tomato paste comprising:

providing tomato juice;

separating tomato juice into a juice component and a first pulp component;

processing the juice component to produce a clarified juice and a second pulp component;

removing a first portion of the clarified juice by reverse osmosis to produce a preliminary concentrated juice;

removing a second portion of water from the preliminary juice concentrate using a plurality of stages of evaporation and reverse osmosis to produce a concentrated juice concentrate, wherein the plurality of stages of evaporation and reverse osmosis are performed using respective devices at respective times;

recycling steam used in the multi-stage evaporation process for a subsequent multi-stage evaporation process;

mixing said concentrated juice with first and second pulp components to form an intermediate paste;

processing the intermediate paste to obtain tomato paste.

78. The method of claim 77, wherein separating said tomato juice comprises separating tomato juice without using a coagulant.

79. The method of claim 77, wherein processing the juice component includes filtering the juice component to produce a clarified juice and a second pulp component.

80. The method of claim 77, wherein processing the juice component includes processing the juice component with a centrifuge to produce a clarified juice and a second pulp component.

81. The method of claim 77, wherein removing a first portion of water comprises removing about 50% of the total amount of water removed from the tomato juice.

82. The process of claim 77, wherein removing the second portion of water comprises removing about 40-45% of the total amount of water removed from the tomato juice.

83. The method of claim 77, wherein each successive evaporation stage in the plurality of evaporation stages has a lower temperature than the previous evaporation stage.

84. The method of claim 77, wherein recycling steam comprises performing thermal steam recompression.

85. The method of claim 77, further comprising forming the intermediate paste into tomato powder.