IN-PROCESS MEASUREMENT OF INGREDIENTS IN FOOD COMPOUNDS

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Patent Application No. 60/815,231, filed June 20, 2006, the entire disclosure of which is hereby incorporated herein by reference.

FIELD OF THE INVENTION The present invention relates generally to a device and method for measuring ingredients in compounds and more particularly to a device and method for the in- process measurement of ingredients in food compounds.

BACKGROUND OF THE INVENTION

Food products are typically manufactured by mixing and processing various elements, or ingredients, together. The ingredients may be mixed and processed in batches to facilitate quality control. For example, batch processing may enable manufacturers to more easily control the amount of each ingredient being added to the food compound. Maintaining a proper mixture of ingredients is often critical in producing a food product with certain characteristics, such as a desired shape, color, consistency, flavor, and the like. Conventionally, the food compound is often sampled during processing and taken to a laboratory where the content of the mixture is determined. However, this type of quality control process may be slow and inefficient. The time delay associated with testing the compound may preclude the manufacturer from taking corrective actions during production to correct any mixture imbalances. Therefore, the batch may become unusable, and may have to be discarded. This may increase both the time and cost to produce the food product. Therefore, a need exists for a system and method that overcomes these difficulties to permit in-process measurement of ingredients in food compounds.

SUMMARY OF THE INVENTION

The described embodiments contemplate a device and method for the in- process measurement of ingredients, individually or proportionally in combination in a mixture, in food compounds. In one embodiment, the device may include an electrical sensing component having at least two conductive elements. Each conductive element may be disposed proximally to the food compound. The electrical sensing component may measure an electrical property of the food compound as it is disposed between the conductive elements. The device may also include a correlation component for determining an amount of the ingredient, or proportions of a combination of ingredients, in the food compound based on the measured electrical property of the food compound. In another embodiment, the device may include a temperature sensing component for measuring a temperature of the food compound. In addition, the correlation component may determine the amount of the ingredient, or proportions of a combination of ingredients, based on the measured electrical property and the measured temperature of the food compound.

The method may include disposing a food compound between conductive elements of an electrical sensing component, applying an electrical signal to at least one of the conductive elements, measuring an electrical property of the food compound disposed between the conductive elements, and determining whether there is a desired amount of at least one ingredient (individually or proportionally in a . combination of ingredients) based on the measured electrical property of the food compound. The method may also include measuring a temperature of the food compound and determining the amount of the ingredient, or proportions of a combination of ingredients, based on the measured electrical property and the measured temperature of the food compounds. Further, the method may also include controlling the process as a function of the determination.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described by way of example with reference to the following drawings in which:

Figures 1 A and 1B are side and top views, respectively, of a portion of an exemplary system for in-process measurement of ingredients in a food compound during production;

Figure 1C is a top view of an alternative embodiment of a system for in-process measurement of ingredients in a food compound during production;

Figure 2 is a flow diagram illustrating a method for measuring an ingredient in a food compound during production;

Figure 3 is a schematic diagram of an exemplary system for processing a food compound, including the system for in-process measurement of ingredients in a food compound of Figures 1A and 1 B; and

Figure 4 is a schematic diagram of a correlation component of Figure 3.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Although the term "step" may be used herein to connote different elements of methods employed, the term should not be interpreted as requiring any particular order among or between various steps herein disclosed unless otherwise stated.

Food product manufacturers often sample their food product at various stages of production in order to maintain a certain level of quality and to ensure that the food product is being manufactured according to predetermined standards. For example, if the food product contains a combination of ingredients, a sample of the food compound may be tested to determine the amount of one or more ingredients in the food compound or may be tested for the presence or absence of a particular ingredient. The Karl Fischer method has been commonly used to determine the water content in a particular food compound, for instance. However, conventional sampling and testing methods are not typically performed in real-time. Instead, food compound samples are removed from the manufacturing process and tested outside of the manufacturing process, which may proceed continuously. Accordingly, test results may not be available until after the food compound has already proceeded through one or more stages of the production process. Thus, if testing of the sample reveals a deficiency or defect in the food compound, the manufacturer may have to take certain corrective actions. For example, the manufacture may have to repeat certain

processing steps and/or perform new processing steps to remedy the problem. Furthermore, if processing has progressed beyond a certain point, the manufacturer may be forced to dispose of an entire batch of the food compound. Such actions may result in higher manufacturing costs. Figures 1 A and 1 B illustrate a side view and top view, respectively, of a portion of an exemplary system for in-process measurement of ingredients in food compound 135 during production. As shown in Figure 1A, the system may include container 105 for retaining food compound 135, which may consist of any type of food product. Container 105 may be hollow and may define inner surface 110 and outer surface 165. Container 105 may also define ends 120 and 160, which may be open or closed. Container 105 may define any form or shape and may serve any function related to a system for the processing of food compound 135. Preferably, container 105 is disposed along a manufacturing process line, such that container 105 receives and at least temporarily contains food compound to be sampled during the manufacturing process. For example, container 105 may serve as a holding tank or as an outlet pipe for a food processing cooker (not shown).

Container 105 may contain rod 115, which is preferably disposed at or near the center of container 105. Rod 115 may be solid or hollow and may define outer surface 130. Rod 115 may extend along a portion or the entire length of container 105.

Container 105 is provided with electrically conductive elements 145, 150 disposed in position to be proximal to, and preferably in contact with, the food compound during the manufacturing process. For example, electrically conductive elements 145, 150 may be disposed on inner surface 110 and outer surface 130. Conductive elements 145 and 150 may form part of electrical sensing component 155, which may measure one or more electrical properties, or the electrical signature, of food compound 135 in container 105. For example, electrical sensing component 155 may be able to determine the resistive, capacitive, and/or inductive properties of food compound 135 by applying an electrical signal (e.g., an A/C sine wave) with a predetermined amplitude (e.g., 3 volts) at a predetermined frequency (e.g., 100 kHz) to conductive element 145 and/or conductive element 150 and by measuring the

signal between conductive elements 145 and 150 (i.e., as the signal passes through food compound 135). It will be appreciated that electrical sensing component 155 may include any suitable circuit for measuring such signals. For example, electrical sensing component 155 may include a bridge circuit for measuring a differential voltage across one or more resistors that form the bridge circuit.

In one embodiment, container 105 and rod 115 consist of a non-conductive material, such as plastic. In such an embodiment, the electrically conductive elements 145, 150 may be discrete elements disposed on inner surface 110 and outer surface 130, respectively. Alternatively, both electrically conductive elements 145, 150 may be provided as separate elements apart, e.g., on separate rods or probes within the container, as shown in the example of Figure 1C. For example, electrically conductive elements 145 and 150 may be any type of metal contact, plate, and/or sheet.

In a preferred embodiment, both the container 105 and the rod 115 consist of any type of conductive material, such as a metal or alloy, but may also consist of other suitable materials, such as plastic. In such an embodiment, the container 105 and rod 115, e.g. the inner surface 110 of container 105 and outer surface 130 of rod 115, may serve and/or function as conductive elements 145 and 150, respectively.

It will be appreciated that the effective sample size of food compound 135 may be increased by increasing the lengths of conductive elements 145 and 150. This, in turn, may increase the accuracy of the test results.

In one embodiment, rod 115 may be solid and may have an outside diameter of approximately 0.375 inches and may be centered axially and extend longitudinally along container 105 (structural supports for rod 115 being omitted for illustrative clarity). As noted above, container 105 may serve as an outlet pipe for a food processing component (not shown) and may have an inside diameter of approximately 2 inches. It will be appreciated that such dimensions are for illustrative purposes only, and can be varied to any suitable size while remaining consistent with an embodiment. As food compound 135 is processed through or within container 105 as part of the manufacturing process, food compound 135 may come into contact with conductive elements 145 and 150. An electrical signal may be applied to either

conductive element 145, 150, between the conductive elements. Thus, electrical sensing component 155 may measure the electrical properties of food compound 135 disposed between inner surface 110 and outer surface 130. The measured electrical properties may then be used to determine the amount of a particular ingredient, or the proportion of ingredients, in food compound 135.

For example, food compound 135 may consist of caramel, for which it may be desired to have a specific amount of water in its composition. If the caramel contains too much water, it may have a low viscosity and may not retain its desired shape. If the caramel contains too little water, it may lack other desired characteristics, such as a certain flavor. The amount of water in the caramel may also affect the electrical properties of the caramel. Thus, by initially measuring the electrical properties of caramel containing different amounts of water, it is possible to construct a correlation component (e.g., providing a look-up table) that correlates various values of a specific electrical property (e.g., a resistance, capacitance, inductance, etc.) with a respective particular amount of water content in the caramel. Therefore, during processing of a particular batch of caramel (e.g., as it flows through container 105), electrical sensing component 155 may measure such electrical properties, and the measured values may then be compared against the look-up table to determine the corresponding amount of water currently contained in the caramel. It will be appreciated that the look-up table may be a physical table and/or exist in electronic format, e.g. accessible via a PC, single-board computer, or other microprocessor-controlled device.

The electrical properties of food compound 135 may also be influenced by other factors, such as temperature. Thus, in order to ensure that the measured electrical properties correlate to an accurate amount of the ingredient, the temperature of food compound 135 may also be measured in order to compensate for its effect on the electrical properties of food compound 135. Accordingly, the look-up table may also include a temperature correction factor. For example, the table may be organized to determine the amount of an ingredient, or proportions of a combination of ingredients, in the food compound as a function of the measured electrical properties at a given temperature.

In another exemplary embodiment, rod 115 may be hollow and may define inner surface 140. Rod 115 may have an outside diameter of approximately 0.375 inches and may be centered axially and extend longitudinally along container 105. Rod 115 may also contain temperature sensor 125, which may be used to measure the temperature of food compound 135. Temperature sensor 125 may be in contact with inner surface 140 of rod 115 and may define any suitable shape or size. Thus, temperature sensor 125 may be encapsulated, embedded or otherwise housed within rod 115 and, therefore, may not make direct contact with food compound 135. It will be appreciated that temperature sensor 125 may also be disposed at any suitable location relative to container 105. For example, temperature sensor 125 may alternatively be disposed on inner surface 110 of container 105.

As noted above, container 105 may take the form of an outlet pipe and may have an inside diameter of approximately 2 inches. As food compound 135 is processed through container 105 as part of the manufacturing process, food compound 135 may come into contact with conductive elements 145 and 150. An electrical signal may be applied to conductive element 145 and/or conductive element 150. Thus, electrical sensing component 155 may measure the electrical properties of food compound 135 disposed between inner surface 110 and outer surface 130. In addition, temperature sensor 125 may measure the temperature of food compound 135 as it comes into contact with outer surface 130 of rod 115. The measured electrical properties and temperature of food compound 135 may then be used to determine the amount of a particular ingredient, or proportions of a combination of ingredients, in food compound 135 via the look-up table.

It will be appreciated that conventional hardware, software, sensors and measurement technology may be used for obtaining the electrical property and temperature measurements, and implementing a correlation component capable of receiving measurement data, referencing a lookup table and, if desired, initiating appropriate control signals for controlling a manufacturing process. By way of example, a conventional LCR meter may be used to obtain inductance, capacitance and resistance measurements. By way of further example, other devices may be used for measuring electrical properties, temperature properties or combinations of

electrical and/or temperature properties may be measured to obtain an electrical "signature" measurement for comparison to reference data stored in the lookup table. For example, an Ametek Drexelbrook admittance meter, typically used for measure a level of a material in a vessel, may be used to obtain a suitable property measurement that is proportional to the capacitance and resistance applied to its input terminals. Such measurements are communicated to the correlation component, such as a personal or single-board computer having an I/O board and an A/D converter configured to receive such measurements. By way of further example, the correlation component may be implemented as a microprocessor-based device, such as a personal computer, having a memory for storing correlation data, and software permitting access to the memory to look-up stored correlation data as a function of measurement data.

Figure 2 is a flow diagram illustrating a method for measuring an ingredient in a food compound during processing. As shown in Figure 2, at 205, food compound 135 may be disposed between conductive elements 145 and 150 of electrical sensing component 155. For example, container 105 may serve as an outlet pipe and conductive elements 145 and 150 may define inner surface 110 of container 105 and outer surface 130 of rod 115, respectively. Thus, food compound 135 may be disposed between conductive elements 145 and 150 as it is displaced through container 105. At 210, an electrical signal may be applied to conductive element 145 and/or conductive element 150, between the conductive elements. At 215, one or more electrical properties of food compound 135 may be measured. For example, an amount of resistance, capacitance, and/or inductance associated with food compound 135 may be determined by measuring the signal as it passes between conductive elements 145 and 150 (i.e., as it passes through food compound 135 disposed therebetween). At 220, the temperature of food compound 135 may be measured. As noted above, temperature sensor 125 may be embedded within rod 115. Thus, as food compound 135 comes into contact with outer surface 130 of rod 115, temperature sensor may measure the temperature of food compound 135. At 225, the amount of an ingredient, or proportions of a combination of ingredients, in food compound 135 may be determined based on the electrical property and/or the

temperature of food compound 135. For example, one or more measured electrical properties and/or the measured temperature may be compared to a look-up table to determine whether there is a desired amount of one or more ingredients contained in food compound 135. For example, this may involve communication measurement data from the electrically conductive elements 145, 150 and the temperature sensor to the correlation component, and using the measured values to reference data stored in a database that correlates measured values of temperature and/or electrical properties to previously gathered empirical or other data for known samples of food compounds having known ingredients and/or combinations of ingredients. Optionally, the correlation component is capable of controlling a food manufacturing process as a function of the determination referenced above, as shown at 235. For example, this may involve transmitting or initiating transmission of a control signal to control processing of the food compound within the container. The control signal is transmitted as a function of the correlation component's determination of whether there is the desired amount of one or more ingredients in the food compound. For example, the system may be used in a feedback loop and may repeatedly or continuous monitor a process in which an ingredient is being added to a food compound, and a control signal may be issued to stop the addition of the ingredient when it is determined that there is a desired amount of the ingredient in the food compound, as determined by the measured properties approaching or matching a reference value stored in the lookup table.

Figure 3 is a schematic diagram of an exemplary system 300 for processing a food compound, including the systems 155 for in-process measurement of ingredients in a food compound of Figures 1 A and 1 B. In the simplified exemplary system 300 of Figure 3, the food processing system includes a first mixing container 305 for combining ingredients in a first manufacturing process, a second mixing container 315 for combining ingredients in a second manufacturing process, and a cooker container 325 for heating the resulting food compound in a third manufacturing process. Food compound is transported between these containers by conduits 310, 320 such as piping. In this illustrative embodiment, a system 155 for in-process measurement of ingredients in a food compound is installed in container 305, and in each of conduits

310 and 320, which are upstream and downstream of the second mixing container 315, respectively.

Each system 155 is operatively connected to the correlation component 400 by communications link 330, such as electrical signal conducting wiring, for transmitting measurement data obtained by the system. In this embodiment, the correlation component is implemented as a specially configured personal computer, as discussed in greater detail below. In alternative embodiments, the correlation component may be implemented using a single-board computer of a type commonly used in embedded applications. As known in the art, such single-board computers may be configured to store an application program and data in non-volatile "flash" or other memory, and to carry out various functions.

With respect to first mixing container 305, at least two different ingredients may be added and mixed in container 305. The electrical and/or temperature measurements may be repeatedly obtained, and the lookup table of the correlation component may be repeatedly referenced until a desired proportion of ingredients is obtained, as reflected by comparing measured values to reference values stored by the correlation component. The proportions may be inferred and/or represented by the measurements obtained for the food compound mixture in view of the individual, dissimilar electrical properties of each ingredient added to the container. Accordingly, this arrangement is illustrative of a feedback loop that can be used to control, e.g., start and/or stop, addition of each individual ingredient to the first mixing container until the desired proportions, as represented by the measured properties, is obtained. It should be noted that in certain instances the measured properties will be indicative of a specific amount, e.g. by weight, of a specific ingredient, and that in other instances the measured properties will be indicative of desired proportions of one or more ingredients without identifying a specific amount of each of one or more ingredients.

With respect to Process 2 and the second mixing container 315, the electrical and/or temperature properties of the food compound 135 may be measured by the upstream system 155 at A before entering container 315, and then be again measured by the downstream system 155 at B after exiting the container 315.

Accordingly, for example, if a single ingredient is added to the food compound in mixing container 315, an amount of that ingredient in the resultant food compound can be determined as a function of measurements taken upstream and downstream of the second mixing container 315. In should be noted that in some embodiments the upstream systems may be omitted. It should further be noted that the downstream process, e.g. Process 3, may be controlled, e.g., started, stopped, altered or modified, in a suitable manner as a result of measurements obtained by an upstream system 155, e.g. at B in the example of Figure 3.

Figure 4 is a schematic diagram of an exemplary correlation component 400 of Figure 3. As is well known in the art, the exemplary correlation component 400 of Figure 4 includes a general purpose microprocessor (CPU) 462 and a bus 464 employed to connect and enable communication between the microprocessor 462 and the components of the correlation component 400 in accordance with known techniques. The correlation component 400 typically includes a user interface adapter 466, which connects the microprocessor 462 via the bus 464 to one or more interface devices, such as interface device 472, which can be any user interface device, such as a touch sensitive screen, digitized entry pad, LCR device, I/O board, A/D converter, etc. In embodiments in which the correlation component comprises a specially- configured PC, the interface devices may further include a keyboard 468 and mouse 470. The bus 464 also connects a display device 474, such as an LCD screen or monitor, to the microprocessor 462 via a display adapter 476. The bus 464 also connects the microprocessor 462 to memory 478 and long-term storage 480 (collectively, "memory") which can include a hard drive, diskette drive, tape drive, etc. The memory stores previously gathered correlation data in a look-up table for reference and comparison to measurement data.

The correlation component 400 may communicate with other computers or networks of computers, for example via a communications channel, network card or modem 482. For example, signals may be transmitted via the communications channel to control the manufacturing process. The correlation component 400 may be associated with such other computers in a local area network (LAN) or a wide area

network (WAN). All of these configurations, as well as the appropriate communications hardware and software, are known in the art.

Software programming code for carrying out the inventive method is typically stored in memory. Accordingly, correlation component stores in its memory microprocessor executable instructions. These instructions may include microprocessor-executable instructions stored in the memory and executable by the microprocessor to carry out any combination of the steps described above. For example, the instructions may relate to generating a signal to be applied to the electrically conductive members, obtaining measurement data, referencing the look- up table, and transmitting control signals to start, stop, alter, modify or otherwise influence the manufacturing process as a result of the measurements and/or correlation data obtained.

While there have been described herein the principles of the invention, it is to be understood by those skilled in the art that this description is made only by way of example and not as a limitation to the scope of the invention. Accordingly, it is intended by the appended claims, to cover all modifications of the invention which fall within the true spirit and scope of the invention.