WO2006058312A2

WO2006058312A2 - Apparatus and method of contaminant detection for food industry

Info

Publication number: WO2006058312A2
Application number: PCT/US2005/043032
Authority: WO
Inventors: Jones T. Arthur Jr.
Original assignee: Arthur Jones T Jr
Priority date: 2004-11-29
Filing date: 2005-11-29
Publication date: 2006-06-01
Also published as: WO2006058312A3

Abstract

A method and apparatus (2) for use In the food industry for the detection of contaminants (40) in foodstuffs (10). Air (16) is caused to circulate about the foodstuff (10) in order to aerosolize contaminants. Samples of along with the aerosolized contaminants (42) are collected by a collector (20) and analyzed for the presence of the contaminants. It is desired to use an Aerosol Lab-On-Chip (ALOC) and/or other electronic nose-type devices (24) for the detection of the contaminants.

Description

APPARATUS AND METHOD OF CONTAMINANT DETECTION FOR FOOD INDUSTRY

TECHNICAL FIELD

The present invention involves detection of contaminants such as bacteria and foreign chemicals on food. More particularly, it detects such contaminants in nano- to microscale, most typically in food production and other areas of the food industry.

BACKGROUND ART

The Centers for Disease Control and Prevention (CDC) estimates that approximately 76 million people suffer from foodborne illnesses and 5,000 die from these illnesses in the United States each year. While many foodborne illnesses may be caused by poor food handling and preparation, they may also be caused by eating contaminated or adulterated foods. To reduce the number of foodborne illnesses from contaminated and adulterated foods, manufacturers can recall food that poses a risk of illness or injury. The U.S. Department of Agriculture (USDA) and the Food and Drug Administration (FDA) documented more than 3,700 food recalls from the mid-1980s through 1999. The USDA identified 515 recalls of fresh and processed meat and poultry from calendar year 1984 through 1999. The FDA identified 3,248 recalls of other food from fiscal year 1986 through fiscal year 1999. The USDA and FDA indicate approximately 61 of these recalls were outbreaks of foodborne illnesses, and have identified at least five bacteria and two viruses responsible for the outbreaks: E.coli 0157:1-17, Staphyloccocus species (toxin related), Vibrio parahaemolyticus, Listeria monocytogenes, Salmonella species, Hepatitis virus type A, Norwalk or Norwalk-like viruses. Foods involved in recalls vary widely, but some of the more common ones include oysters, ground beef, sprouts/seeds, strawberries/strawberry products, unpasteurized fruit juices/ciders, cold cuts hot dogs, chicken and pork.

The General Accounting Office (GAO) noted that food industry officials indicated recalls have a significant economic impact on affected companies through lost sales and food retrieval costs. The extent of the impact depends on such factors as the amount and value of the food recalled, its location in the distribution process, and the severity of the health risk. In addition, following a recall, consumers may stop buying a company's products or switch to another company's brand for future purchases. In some cases, this impact may lead to a company going out of business, particularly if the company is marginally profitable or already experiencing other problems. For example, a well-known company, Hudson Foods, went out of business after recalling approximately 25 million pounds of ground beef patties. Recalls may also have an economic impact on companies other than the one conducting the recall. For example, according to the Food Marketing Institute, retail supermarkets may experience a drop in sales if consumers avoid the recalled food and other products by the same manufacturer or even other brands of the recalled item. In addition, companies that use a recalled product as an ingredient can incur significant costs from a recall. For example, if a particular brand of pepperoni is recalled a company using that brand in its frozen pizzas may have to recall the pizzas. Although the pizza manufacturer would be reimbursed for the lost revenues and replacement costs, it may also experience a drop in future sales if consumers have a negative impression of the pizza because of the recall. Because of the economic impact of recalls, many food companies have determined it necessary to carry "recall insurance" to cover lost revenues and retrieval costs, although many in the food industry have determined it cost prohibitive, leaving them open to the losses. GAO Report to Congressional Requesters "Food Safety: Actions Needed by the USDA and FDA to Ensure that Companies Promptly Carry Out Recalls", GAO/RCED-00-195, August 2000.

The food processing industry, in an effort to avoid such problems and reduce costs, carries out more than 144 million microbial tests costing five to ten dollars each. About twenty-four million of these tests are for detection of food pathogens based on biochemical profile analysis, immunogenic tests (such as enzyme linked immunosorbent assays or ELISA) and DNA/RNA probes. These tests are reliable, but most require two to seven days to complete because of the steps that are needed to resuscitate cells, increase cell numbers or amplify genetic material needed for detection. This time period is too long for real-time detection of contamination in a food plant and is sufficiently long for contaminated food to be formulated, processed, packaged, shipped, and purchased and eaten by the consumer. Current tests require at least several days to confirm presence of Listeria monocytogenes, for example. The number of annual tests is only expected to increase due to heightened consumer concerns about food safety and the requirement of compulsory testing.

In general, diagnostic tools typically used for detecting or quantitating biological analytes rely on ligand-specific binding between a ligand and a receptor. Ligand/receptor binding pairs used commonly in diagnostics include antigen-antibody, hormone-receptor, drug-receptor, cell surface antigen-lectin, biotin-avidin, substrate/enzyme, and complementary nucleic acid strands. The analyte to be detected may be either a member of the binding pair; alternatively, the analyte may be a ligand analog that competes with the ligand for binding to the complement receptor.

A variety of devices for detecting ligand receptor interactions are known. The most basic of these are purely chemical/enzymatic assays in which the presence or amount of analyte is detected by measuring or quantitating a detectable reaction product, such as a detectable marker or reporter molecule or ligand. Ligand/receptor interactions can also be detected and quantitated by radiolabel assays.

Quantitative binding assays of this type involve two separate components: a reaction substrate, e.g., a solid-phase test strip and a separate reader or detector device, such as a scintillation counter or spectrophotometer. The substrate is generally unsuited to multiple assays, or to miniaturization, or for handling multiple analyte assays. Further, these methods typically don't operate in "real time" situations. In recent years, there has been a merger of microelectronics and biological sciences to develop what are called "biochips." The term "biochip" has been used in various contexts but can be defined as a "microfabricated device that is used for delivery, processing, and analysis of biological species (molecules, cells, etc.)." Such devices have been used, among other things, for the direct interrogation of the electric properties and behavior of cells and optical detection of DNA hybridizations using fluorescence signals in the commercially available "DNA-chips". Prior art chips have used impedance spectroscopy or simple impedance to detect microorganismal presence. U.S. Patent Application to Gomez et al., Pub. No. 2003/0157587, Aug. 21, 2003. The Gomez et al. application, utilizes bioseparation techniques on a biochip to detect a microbiological entity. The Gomez et al. method however, requires utilization of fluid samples and, preferably, a purification process prior to injection of the fluid on the biochip. Additionally, these types of biochips are usually limited to a detection capability of one or two organisms per chip.

There is clearly a need in the art for faster contaminant detection capability to facilitate a quick, reliable answer to the food industry of the presence of contaminants at potentially multiple stages in the manufacturing or preparation process. Further, the process needs to be repeatably reliable. Additionally, it would be extremely desirable to avoid complicated processes such as preparing solutions of, for example, ground beef, in order to detect contaminants. Such solutions are only spot reliable and time consuming. Therefore, there is a great need in the art for a method and apparatus which will detect contaminants, preferably multiple types of contaminants, on food during the preparation process and potentially at multiple points in the preparation process, for the entire supply instead of for small samples, and without having to prepare a liquid solution of the food product.

DISCLOSURE OF THE INVENTION

Summary of the Invention

The present invention is a method and apparatus for contaminant detection in the food industry.

Particularly, the method and apparatus involve collecting air samples containing aerosolized contaminate particles from a foodstuff and analyzing the sample for presence of a contaminate. Aerosol lab-on-a-chip

(ALOC) and/or electronic nose and/or other detection devices are utilized for the detection of contaminant particles.

More particularly, the invention includes a method for detecting contamination of foodstuffs including providing a foodstuff; collecting air surrounding the foodstuff; and analyzing the collected air to determine the presence of contaminated particles. Additional steps may include creating airflow across a foodstuff before collecting the air; providing at least one of conductometric sensors, capacitive sensors, potentiometric sensors, calorimetric sensors, gravimetric sensors, optical sensors, and amperometric sensor for analyzing collected air. These sensors may be contained within ALOC detectors and/or electronic nose detectors that can be combined in any combination for analyzing collected air; utilizing an odor marker to mark identify the presence of food stuffs; and/or utilizing a contaminate marker to identify the presence of contaminated food stuffs.

The apparatus for detecting contamination of foodstuffs includes a collector unit; a detector unit in fluid connection with said collector unit; and a telemetry unit in electrical connection with said detector unit. A controller unit may be in electrical connection with the detector unit and/or with a telemetry unit. The collector unit has a collecting surface with at least one air inlet, and optionally, at least one funnel-type device surrounding the air inlet. Multiple air inlets may be used. An air manifold may also be utilized to control flow to and from particular inlets.

An air handling unit may be disposed to create air flow across a foodstuff and into the collector.

It may have at least one air nozzle disposed within a cavity of a foodstuff and/or within a food processing machine to allow passage of air through particulate food. It may be electronically controlled by said controlling unit. Also, a purge mechanism may be utilized.

The apparatus can be a portable unit, including a hand held unit. An odor marking unit and/or a contaminate marking unit may be used on the apparatus.

Detailed Description of the Invention

The present invention comprises a novel detection apparatus and method for detection of contaminants in and on food products. More particularly, it involves use of a contaminant detector utilizing an aerosol lab-on-a-chip (ALOC) device and/or electronic nose device and/or other detectors as described herein to chemically detect contaminants on food products by sampling the air surrounding the products.

For the purposes of this disclosure the following definitions shall apply:

Aerosol lab-on-a-chip (ALOC) is a device which integrates one or more of a variety of aerosol collection, classification, concentration (enrichment), and characterization processes onto a single substrate or layered stack of substrates;

Contaminants are materials found in or on food products which are foreign to the product itself and may include, but are not limited to, chemicals, fecal material, dirt and other detritus, microbes, viruses, fungi and protozoa;

Electronic noses are devices which are used for automated detection and classification of odors, vapors and gases. They are comprised of a chemical sensing system typically comprising a sensor array and a pattern recognition system (artificial neural network), often comprised in an integrated or separate computer. Several types of electronic nose devices are recognized in the art. A definitive work, to be incorporated by reference herein is the Handbook of Machine Olfaction, ed. T.C. Pearce, S. S. Schiffman, HT. Nagle, and J.W. Gardner; Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim GERMANY (2003). Food products comprise any commonly known food stuff including raw or processed foods at any stage of production in any piecemeal or whole fashion.

The preferred embodiment of the invention comprises a contaminant detection apparatus for use in the food industry, with particular usefulness to the meat industry. The detection method comprises providing a foodstuff for analysis, collecting aerosolized contaminant particles from air surrounding the foodstuff, and analyzing the air to detect the presence of contaminant. Optionally, the additional step of creating airflow across the foodstuff may be used before the collection step. The contaminant detector of the invention comprises an aerosol collector in fluid connection with a detector. The detector may utilize an aerosol-lab-on-a-chip and/or an electronic nose device and/or other detection devices as described herein. The apparatus may additionally comprise a controller and/or telemetry devices in electrical and/or electronic connection with the detector. Optionally, the controller may be in electrical and/or electronic connection with an optional air handling unit which provides an air flow across and/or through a foodstuff which is to be evaluated. Further optionally, an odor marker may be utilized for detection which will alert the controller that a food stuff is in place and could be used to validate that the detector is operating correctly. Also, contaminant markers may be utilized to mark a contaminated foodstuff to allow for non-batch level removals of contaminated foodstuffs. Finally, the apparatus may additionally utilize typical food industry food handling devices. The preferred contaminant detector apparatus 2 of the invention, as shown depicted in Figure 1, comprises placing the foodstuff 10 for testing, optionally in a hanging position on hook or other positioning device known in the art (e.g., hanger, holders, clamps) 12 in somewhat close proximity with aerosol collector 20, for allowing maximum beneficial airflow across carcass 10. Preferably, the foodstuff is placed approximately fifteen feet or less from the collector. More preferably, the foodstuff is placed approximately five feet or less from the collector. Air and/or gas flow handling apparatus 14 may be optionally employed to create a sustained or varied air current 16 across foodstuff 10, or ambient air 16 may be used. Naturally or mechanically aerosolized contaminant particles 42 will be moved by air current or fluid ambient air 16 from carcass 10 and combined air current/aerosolized contaminant particles 18 will flow naturally (or in an assisted manner if forced air current 16 is applied) to aerosol collector 20. An assisted air flow is not required, but may be helpful in moving aerosolized contaminant particles or in providing the mechanical assist to aerosolize the particles from the surface of the food product. Aerosol collector 20 is maintained in fluid (gaseous) connection with detector 24. Detector 24 preferably comprises an electronic nose device, as more thoroughly described herein, or an aerosol lab-on-a-chip as described in U.S. Patent No. 6,386,015 to Rader, et al. Detector 24 is preferably electrically connected to optional controller 28 which may include electrical devices known in the art for controlling air flow from handler 14 to provide a range of air flow rates, and may include sensors for detecting presence of foodstuffs particularly "odor markers", such as but not limited to the particular scent of blood to identify the presence of meat within the apparatus or identifiers of the foodstuff such as barcodes, smart tag codes which may be read by a corresponding RFID reader, or other identification methods known in the art. Controller 28 is electrically connected to telemetry 32 (or detector 24 is electrically connected thereto if controller 28 is not utilized).

Detector 24 comprises an electronic nose device (see description infra) or an ALOC device as disclosed in Rader '015 which is a tool to collect, classify, concentrate, and/or characterize gas-borne particles. The basic principle underlying the ALOC is to take advantage of micro-machining capabilities to integrate a variety of aerosol collection, classification, concentration (enrichment), and characterization processes into a single package which is compact, rugged, self-contained, and inexpensive to manufacture. Thus, a suite of discrete laboratory aerosol characterization techniques could be combined onto a single substrate, or stack of substrates, along with aerosol preconditioners and gas handling processes. The ALOC is analogous to the integrated circuit, wherein a variety of discrete electronic (aerosol) components are combined onto a single chip to build-up complex electrical (aerosol characterization) systems. The performance of several of these analytic aerosol characterization techniques would benefit by miniaturization (e.g., particularly the inertial techniques). By constructing arrays of identical parallel modules, it should be possible to reduce gas velocities that could give a quadratic reduction in pressure drop and consequently a quadratic reduction in power consumption. As pointed out above, sampling discrepancies would also be reduced; i.e., by virtue of their close proximity on the chip, each technique could be analyzing essentially the same sample. The performance of preconditioners, such as concentrators or size sorters, would also benefit by miniaturization, and could be built into layers above the diagnostics as needed. Gas-moving devices, such as pumps or fans, can be provided external to or fabricated onto the ALOC to provide the gas throughput needed for the aerosol sampling and analysis but are optional not essential. Electronic circuitry could also be fabricated onto the ALOC to provide for process control (valves, switches, etc.), signal processing, data analysis, and telemetry. Moreover, if the ALOC can be made sufficiently small and rugged, it could be placed directly into harsh (corrosive, high temperature, etc.) environments.

A schematic of an embodiment of the ALOC is shown for a single aerosol characterization technique in Fig. 2a. The device components in the flow path are formed on a substrate 210, and comprise an aerosol inlet 211, an aerosol condition (preconditioner) 212, an aerosol characterization module 213, and a gas moving means, or "pump", 214, necessary in the absence of a moving gas stream, to establish a gas flow through the aerosol characterization module(s) of sufficient volume and velocity to ensure that an adequate number of particles are sampled. Pump 214 may be provided external to substrate 210, or it may be fabricated onto substrate 210 (onboard configuration is shown in Fig. 2a). Preconditioner 212 may or may not be needed depending on the application. Support components are also shown which provide an active process control 215, signal processing/data analysis (signal processor) 216, and telemetry 217. The aerosol inlet 211 is designed to receive gas-borne particles from an ambient aerosol cloud 218. Note that none, some, or all of the support components 215, 216, and 217 may be needed for a particular characterization technique. Any number of characterization modules (and support processes) may be combined in parallel or in series on a single- chip or stacked-chip ALOC; by combining characterization modules based on independent physical measurements, it would be possible to perform simultaneous analysis of a wide array of particle properties. In addition, construction of parallel arrays of identical devices (i.e., multiple copies of Fig.2a) on a single substrate would have the advantage of providing, increased overall device efficiency, signal enhancement, and in particular, increased operational flexibility. For example, an ALOC could be made to handle high total gas flow rates by assembling large numbers of individual devices operating at low flow rates (with lower pressure drops).

Finally, power for the device is provided by a standard low-voltage source, such as a battery 219, through a set of leads 220 connected to a data/power bus 221 located on the integrated chip. Power also may be supplied by a battery incorporated directly onto the ALOC substrate, or by any other means known to those skilled in the art.

The functions of the individual components are described briefly now. 1) The aerosol inlet must provide a path that admits the particle-laden gas into the ALOC assembly. The shape of the inlet must be designed carefully, as is well known in the prior art, so as to avoid particle inertial inlet losses and to provide a suitable gas inlet velocity profile, and to avoid large pressure drops. 2) The term aerosol condition is used hereinafter to describe any collection of processes that may be used to either classify, concentrate, or in some way manipulate an incoming stream of particles comprising an aerosol prior to those particles reaching a characterization module. As a classifier, the conditioner can be used to accept or reject particles above or below a desired size, or within a desired size range. As a concentrator, the conditioner can be used to preferentially increase the local concentration of particles in a desired size range. 3) The purpose of the aerosol characterization module is to provide a measurement of some physical property of the particle, including prior art such as techniques based on particle light including prior art such as techniques based on particle light scattering, inertial response, or electric mobility. Many of the in situ or extractive techniques discussed above would be suitable for miniaturization. A complete characterization of the aerosol would require a determination of the distribution of size, shape, and chemical, physical, and biological composition of the suspended particles comprising the aerosol. 4) A gas moving device may be necessary, in the absence of a moving gas stream, in order to establish a flow of a sufficient volume and velocity of gas, and therefore, an adequate number of particles, through the characterization module(s) in order to ensure an accurate measurement. The gas moving device can be any means capable of generating a pressure differential such as a mechanical pump, a sorp pump, a fan, or ion or diffusion pumps, and can be external to or fabricated onto the ALOC. 5) Active process control would include sensors, circuitry, and control devices on-board the ALOC that would collectively act to maintain critical process parameters within acceptable operating ranges. Lumped into this module are additional flow handling devices, such as channels and valves, which may be needed to distribute/direct the gas flow among the various characterization modules. 6) Circuitry could also be provided to allow on-board signal processing or data analysis that would be used to reduce raw physical measurements from the aerosol characterization module into useful form. As an example, a pulse-height analyzer could be used to determine the peak scattering intensity needed to size a particle based on its scattering profile while passing through an illumination source. Systems could also be envisioned that would collect single-particle data and reduce it to obtain size distribution functions. 7) Telemetry could be used to send the acquired data to a remote collection unit. 8) Power to the ALOC is supplied by a standard low-voltage source, such as by a battery, which could be either external to, or built onto, the ALOC substrate.

As discussed above, the apparatus of the invention may utilize electronic nose technology as detector 24. The two main components of an electronic nose are the sensing system and the automated μauem ieouyiiiuuii system, me sensing system can be an array of several different sensing elements (e.g., chemical sensors), where each element measures a different property of the sensed chemical, or it can be a single sensing device (e.g., spectrometer) that produces an array of measurements for each chemical, or it can be a combination. (A more detailed explanation of these "chemosensors", is contained within the next paragraph below.) Each chemical vapor presented to the sensor array produces a signature or pattern characteristic of the vapor. By presenting many different chemicals to the sensor array, a database of signatures is built up. This database of labeled signatures is used to train the pattern recognition system. The goal of this training process is to configure the recognition system to produce unique classifications of each chemical so that an automated identification can be implemented.

A chemosensor is a device that is capable of converting a chemical quantity into an electrical signal and respondate the concentration of specific particles such as atoms, molecules, or ions in gases or liquids by providing an electrical signal. Chemosensors are very different from physical sensors. Although approximately one hundred (100) physical measurands can be detected using physical sensors, in the case of chemosensors, this number is higher by several orders of magnitude. The types of chemosensors that can be used in an e-nose need to respond to odorous molecules in the gas phase, which are typically volatile organic molecules with different relative molar masses. Handbook of Machine Olfaction, ed. T.C. Pearce, S.S. Schiffman, HT. Nagle, and J.W. Gardner; Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim GERMANY (2003), pp. 79-81.

Chemosensors such as those listed in Table 1 , below, have been exploited and some already manufactured. Principles such as electrical, thermal, optical, and mass can be used to organize these chemosensors according to their device class, particularly conductometric, capacitive, potentiometric, calorimetric, gravimetric, optical and amperometric sensors. The chemosensors using metal oxide semiconductors (MOS), organic conducting polymers (CP), chemocapacitors, MOS field-effect transistors (MOSFET), quartz crystal microbalance (QCM), surface acoustic wave (SAW), surface plasmon resistance (SPR), fluorescence, and others can easily be used as a sensor for an e-nose. TABLE 1 : Classification of Chemosensors:

Metal Oxide Semiconductors (MOS), MOS field Effect Transistor (MOSFET), Quartz Crystal Microbalance (QCM),

Surface Acoustic Wave (SAW), Surface Plasmon Resonance (SPR) SPECIFIC F SENSOR TYPE

The quantity and complexity of the data collected by sensors can make conventional chemical analysis of data in an automated fashion difficult. One approach to chemical vapor identification is to build an array of sensors, where each sensor in the array is designed to respond to a specific chemical. With this approach, the number of unique sensors must be at least as great as the number of chemicals being monitored. It is both expensive and difficult to build highly selective chemical sensors, so arrays allow similar results to be achieved by combining data from each sensor. The type of chemosensors described above and known in the art, and as described in Handbook of Machine Olfaction, ed. T.C. Pearce, S.S. Schiffman, HT. Nagle, and J.W. Gardner; Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim GERMANY (2003), an incorporated by reference herein, can be utilized as the electronic nose device, or devices, described as the sensor for the apparatus described supra and infra.

Other sensor devices known in the art could additionally be employed as one or more of the sensors (noting that some are already parts of sensor arrays already known and used in the art). For example, gas chromatographs, spectrometers, micro-machined field asymmetric ion mobility filter detection systems (as described in U.S. Patent No. 6,495,823 to Miller et al., and incorporated by reference herein), and longitudinal field driven field asymmetric ion mobility filter detection systems (as described in U.S. Patent No. 6,512,224 to Miller et al., and incorporated by reference herein) could all serve as sensors in the apparatus described herein.

One particularly useful electronic nose detector that could be utilized as the detector of the apparatus described herein is described fully in U.S. Patent No. 6,354,160 to Staples, et al. and U.S. Patent No. 6,212,938 to Staples et al. The '160 reference discloses a method and apparatus for identifying and analyzing vapor elements, using a preconcentrator collector. The preconcentrator collector collects and preconcentrates chemical vapors to be detected and identified before chromatographic analysis using surface acoustic wave gas chromatograph (SAW/GC) technology. The preconcentrator collector is used in conjunction with a sensor in an SAW/GC detector in the apparatus, thereby achieving specificity and selectivity simultaneously with high sensitivity. The '938 reference discloses a method whereby the olfactory response of a gas chromatograph, equipped with a focused surface acoustic wave interferometer integrating detector is converted to a visual image for the purpose of performing pattern recognition. This form of electronic nose provides a recognizable visual image of specific vapor mixtures containing possibly hundreds of different chemical species. Because the method provides a means of adapting and learning to recognize new vapors using these images, it is a useful method for testing chemical compositions as well as the vapors associated with bacteria and human disease.

Another useful electronic nose detector that could be utilized as the detector of the apparatus described herein is described in U.S. Patent No. 6,883,364 to Sunshine et al., and is hereby incorporated by reference. As shown in the prior art device schematic of Fig. 2b, the device uses a senor module incorporating a sample chamber and a plurality of sensors located on a chip releasebly carried within or adjacent to the sample chamber. Vapors are directed to pass through the chamber whereupon the sensors provide a distinct combination of electrical signals in response to each. The sensors of the sensor module can take the form of chemically sensitive resistors having resistances that vary according to the identity and concentration of an adjacent vapor. These chemically sensitive resistors can each be connected in series with a reference resistor, between a reference voltage and ground, such that an analog-to-digital converter produces the corresponding digital signals which are then analyzed for vapor identification. Specifically, the diagram shows an electrical subsystem 410 and a substantially mechanical subsystem 412 that processes test samples. Within subsystem 412, a test sample received via a nose 430 and provided to a manifold 440. Similarly, a reference or background sample is received via an intake port 432 and provided through a filter 436 to manifold 440. Filter 436 can be a blank filter, a carbon filter or others. Manifold 440 directs the test and clean samples to a solenoid 444 that selects one of the samples as the solenoid output. The selected sample is directed through manifold 440 to a sensor module 450. Sensor module 450 includes at least two sensors that detect analytes in the selected sample. Sensor module 450 generates a signal (or a "signature") indicative of the detected analytes and provides this signal to electrical subsystem 410. The selected sample is the provided from sensor module 450, through manifold 440, further through a pump 460, and to an exhaust port 434.

Alternate embodiments of the present invention apparatus may utilize natural air flows instead of or in addition to fans or pumps for directing aerosol particles into collector 20. Figure 3 depicts a natural air flow resulting from carcass 10 having a higher temperature than its surrounding ambient air. Draft 102 crosses contaminant 40 on carcass 10 and combines with naturally aerosolized contaminant particles 42 to form combined contaminant particle/air stream 44 and carry combined contaminant particles 42 into collector 20. Figure 4 depicts a natural air flow resulting from carcass 10 having a lower temperature than its surrounding ambient air. Draft 104 crosses contaminant 40 on carcass 10 and combines with naturally aerosolized contaminant particles 42 to form combined contaminant particle/air stream 44 and carry particles 42 into collector 20 for analysis by the detector. The inventive apparatus may additionally comprise devices known in the art for movement of foodstuffs, including but not limited to trolleys, conveyors, conveyor belts, buckets, augers, grinders, packaging devices and extruders. Figure 5 in particular depicts use of movement of foodstuff 10 to generate an air current. In the figure shown, meat 10 is hung by hook 12 to trolley wheel 111 of trolley 110. Trolley wheel 111 is rotated by an external force or gravity to convey meat 10 along trolley support rail 112 to a desired destination. As meat 10 is moved along trolley support rail 112, turbulent air flow 116 is created by the movement of the meat through surrounding air.

Quality control devices may be utilized to ensure that the air flow is sufficient and directionally oriented to detect contaminants. In particular, odor markers 50 such as known chemicals sprayed or otherwise distributed onto the surface of a foodstuff 10, or the foodstuff itself (for example, utilizing chemicals within the blood of meat as the odor marker) can be utilized to determine sufficient detection by prespraying foodstuffs and analyzing for the presence of the marker or alternately by spraying contaminated foodstuffs with odor markers after they have been determined to be contaminated, thereby allowing for disposal of only the contaminated foodstuffs instead of entire batch runs. Aerosolized particles 52 of odor marker 50 may be carried by combined air flow/contaminate particle stream 54 to a collector. Collectors may be placed in locations surrounding the path of travel of the meat to collect particles 42 aerosolized and combined with air flow to form combined contaminant particle/air stream 44.

Further, in the case of some types of foodstuffs, it may be beneficial to provide an embodiment for detecting contaminants within a cavity, for example, in the body cavity of poultry. Figure 6 depicts an embodiment of the invention wherein air nozzle 140 is placed within a body cavity 134 of poultry. Air 142 flows from handler 14 through nozzle 140 and into cavity 134. Air stream 142 contacts a surface of body cavity 134 and is diverted away from the surface. In this flow, air stream 142 combines with aerosolized contaminant particles 146 to form combined contaminate particle/air stream 148. This combined particle/air stream 148 is then obtained by collector 20 for analysis. Meanwhile (or at another time during the processing procedure), air flow 16 flows across an outer surface of carcass 10 to obtain aerosolized particulates for analysis by collector 20.

Figures 7 and 8 depict an embodiment of the apparatus of the invention adapted for use with a conveyor assembly. Foodstuff 10, here depicted as hamburger patties, is disposed on an upper surface and conveyed along conveyor belt 152 in direction 155 to a desired destination. Air handler 14 is disposed to direct airflow across a surface of patties 10. Collector 20 is proximately disposed for receipt of deflected air from a surface of patties 10. Contaminate food marker 154 preferably comprises a General Regulated as Safe marker (GRAS) and is disposed to spray 156, stamp, or otherwise mark foodstuffs that are determined to have a contaminate to ensure removal of the contaminated food, and also to ensure that only the contaminated food must be disposed. Contaminate food markers may comprise other marking methods including but not limited to applying stickers to the foodstuff identified as contaminated. Figures 9, 10, 11 , 15, 16, 17, and 18 are directed to utilization of the inventive apparatus as an embodiment adapted for a meat grinder or other foodstuff grinder, shredder, distributor. Figure 9 shows output flange 190 of a meat grinder in use. Detector housing flange 192 is disposed at the outer edge of output flange 190. Air nozzle 140 is disposed into interior 193 of housing flange 192 and directs clean air 142 into interior 193. Foodstuff 196 flows through flange 190 in direction 198 and passes nozzle 140. Air flow 142 passes through ground foodstuff 196 and flows out of housing flange 192. Aerosolized contaminant particles combine with airflow 142 to form contaminant particle/air stream 18 which flows into collector 20 for analysis.

Figure 12 depicts an air receiving surface or "collecting surface" 21 of collector 20, particularly depicting cone-shaped funnels 180 to aid with directing air flow to air inlet holes 182 of collector 20. The air receiving surface may have any surface configuration of inlet holes and/or funnels or otherwise configured openings to assist air collection. It should be noted that while flow-directing surfaces are preferable, they are not essential. A simple air inlet hole into collector would serve the purposes of the invention. Further, the number of inlets may be any number greater than or including one. The number of funnels/ducts/directional air devices may be any number greater than or including zero. The configuration shown may be altered to nonlinear patterns and may include any size and shape. However, it is beneficial to use a known pattern for the configuration of the collectors, since it may aid in determining exactly where the contaminant lies, therefore allowing only the contaminated foodstuff to be removed and preventing the waste of an entire batch run or carcass. This is easily comprehended. For example, if the collectors are placed, for instance, in a grid four inches apart and if a particular collector identifies contaminant, but the surrounding collectors do not, then it will be clear that the contaminant can be narrowed to at least the four inch radius surrounding the identifying collector. It is envisioned that this could be accomplished vertically and horizontally on a hanging foodstuff. It is also envisioned that detection may be assisted with rotation of the collectors or the foodstuffs in relation to the detectors since a positive reading would be checked by a series of readings.

Figure 13 depicts a cross section of row of funnels 180 showing air flow of a combined contaminant particle/air stream with contaminant particles 42 through inlet holes 182 of funnels 180 and into tubing or ductwork 184 for transport of aerosol to detector 24 for analysis. Figure 14 depicts an optional manifold assembly to direct airflow with use of multiple collections of contaminant particle/air streams. If more than one manifold assembly is used, the assemblies would be tied together pneumatically as is well-known in the art to result in only one air flow output 186. Collected air flows into manifold 160 through tubing 184 from air inlet holes of collector 20. The tubings 184 are fittingly connected to fittings 164 of manifold 160 and are directed into one or more manifolds 162. The manifolds contain solenoid valves 166 which can determine flow of the sample contaminant particle/air streams. The valves 166 may have electrical connections thereto 168 as known in the art for manual or computerized control of the opening and closing of the respective valves. The use of a manifold assembly for the invention may be particularly important for quality control assurances. A faulty intake may be determined by individual testing each intake through a particular funnel (or system). Additionally, optional air purge 176 would allow a reverse air flow through the system to purge blockages in the tubing which may occur through use or cleaning. Air flow 186 comprises the resultant air flow of the manifold.

Fig. 15 depicts the apparatus of the invention disposed in relation to a belt 1072 or other conveyance device wherein the foodstuff particles 1074 travel along and fall or are otherwise carried through the apparatus, wherein air flow handling apparatus 14 may be optionally employed to create a sustained or varied air current across foodstuff particles 1076, or ambient air may be used. Aerosol collector 20 is maintained in fluid (gaseous) connection with the detector as described supra.

Fig. 16 depicts a side on view of the apparatus of Fig. 15 showing foodstuff particles 1074 traveling along and falling through the apparatus of the invention, wherein air flow handling apparatus 14 is optionally employed to create a sustained or varied air current 16 across falling foodstuff particles 1076. Naturally or mechanically aerosolized contaminant particles 42 will be moved by air current or fluid ambient air 16 from foodstuff 1076 and combined air current/aerosolized contaminant particles 44 will flow naturally (or in an assisted manner if forced air current 16 is applied) to aerosol collector 20. An assisted air flow is not required, but may be helpful in moving aerosolized contaminant particles or in providing the mechanical assist to aerosolize the particles from the surface of the food product. Aerosol collector 20 is maintained in fluid (gaseous) connection with the detector as described supra.

Fig. 17 likewise shows the apparatus of the invention disposed in relation to an auger 1082 disposed within a tray or other conveyance device 1084 wherein the foodstuff particles 1086 travel along and fall or are otherwise carried through the apparatus, wherein air flow handling apparatus 14 may be optionally employed to create a sustained or varied air current across fallen foodstuff particles 1088, or ambient air may be used. Aerosol collector 20 is maintained in fluid (gaseous) connection with the detector as described supra. Fig. 18 depicts a side on view of the apparatus of Fig. 17 showing foodstuff particles 1086 traveling along and falling through the apparatus of the invention, wherein air flow handling apparatus 14 is optionally employed to create a sustained or varied air current 16 across falling foodstuff particles 1088. Naturally or mechanically aerosolized contaminant particles 42 will be moved by air current or fluid ambient air 16 from foodstuff 1088 and combined air current/aerosolized contaminant particles 44 will flow naturally (or in an assisted manner if forced air current 16 is applied) to aerosol collector 20. An assisted air flow is not required, but may be helpful in moving aerosolized contaminant particles or in providing the mechanical assist to aerosolize the particles from the surface of the food product. Aerosol collector 20 is maintained in fluid (gaseous) connection with the detector as described supra.

The device of the invention could easily be modified to be used in a handheld or otherwise portable device, and/or in conjunction with already existing detectors such as fluorescence, metal, plastic or other types of contaminant detectors or for any configuration necessary to accommodate the processing devices of the industry. The essentials for the operation of the device are air flow over a food surface into collectors for analysis. It is envisioned that many differing configurations will be utilized and the embodiments depicted herein are offered to be illustrative but not limiting of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a generalized drawing of the method of the present invention, generally representing the components of the invention including an air handler, a collector, a detector, a controller, and telemetry;

Fig. 2a is a box diagram of an aerosol lab-on-a-chip device; Fig. 2b is a box diagram of an electronic nose device;

Fig. 3 depicts an updraft and placement of the collector unit of the apparatus to utilize natural air flow;

Fig. 4 depicts a downdraft and placement of the collector unit of the apparatus to utilize natural air flow; Fig. 5 depicts an air stream created by movement of a foodstuff and the aerosolized contaminate/particle air stream created;

Fig. 6 depicts an air nozzle inserted into a body cavity of a foodstuff to detect contaminates;

Fig. 7 depicts an embodiment of the apparatus adapted for use with a conveyor belt to detect contaminant on multiple items;

Fig. 8 depicts an embodiment of the apparatus with optional contaminant marker unit to identify contaminated areas/parts individually;

Figs. 9-11 depict an output flange of a meat or food grinder and the use of an inserted nozzle to provide air through the particulate foodstuff for detection of contaminate; Fig. 12 depicts an air controller surface showing multiple air collection funnels leading to air inlets in gaseous fluid connection with the detection unit;

Fig. 13 depicts a cross-section of the center of a line of funnels as shown in Fig. 12, demonstrating contaminate particle/air stream flow through the air inlets;

Fig. 14 depicts an air manifold for use in controlling air flow to each particular inlet; Fig. 15 depicts a belt as conveyance device of food particles wherein the apparatus of the invention is disposed at an end and the particles fall through the device, between the air handler and the collector; Fig. 16 is a side view of the device of Fig. 15 further showing air current directed from the air handler through the food particles and showing aerosolization of the contaminant particles and the combined contaminant/air stream as collected by the collector;

Fig. 17 depicts an auger as conveyance device of food particles wherein the apparatus of the invention is disposed at an end and the particles fall through the device, between the air handler and the collector; and

Fig. 18 is a side view of the device of Fig. 17 further showing air current directed from the air handler through the food particles and showing aerosolization of the contaminant particles and the combined contaminant/air stream as collected by the collector.

Claims

CLAIMSWhat is claimed is:

1. A method for detecting contamination of foodstuffs comprising: providing a foodstuff; collecting air surrounding the foodstuff; and analyzing the collected air to determine the presence of contaminated particles.

2. The method of claim 1 further comprising the step comprising: creating airflow across and/or through a foodstuff before collecting the air.

3. The method of claim 1 further comprising at least one of the following steps: providing a conductometric sensor for analyzing collected air; providing a capacitive sensor for analyzing collected air; providing a potentiometric sensor for analyzing collected air; providing a calorimetric sensor for analyzing collected air; providing a gravimetric sensor for analyzing collected air; providing an optical sensor for analyzing collected air; providing an amperometric sensor for analyzing collected air; providing a gas chromatograph sensor for analyzing collected air; providing an ion mobility spectrometry sensor for analyzing collected air; and providing a mass spectrometry sensor for analyzing collected air.

4. An apparatus for detecting contamination of foodstuffs comprising: a collector unit 20; a detector unit 24 in fluid connection with said collector unit 20; a telemetry unit 32 in electrical connection with said detector unit 24.

5. The apparatus of claim 4 wherein a controller unit 28 is in electrical connection with said detector unit 24 and/or said telemetry unit 32.

6. The apparatus of claim 4 wherein said detector unit comprises at least one sensor selected from the group consisting of conductometric sensors, capacitive sensors, potentiometric sensors, calorimetric sensors, gravimetric sensors, optical sensors, amperometric sensors, gas chromatographic sensors, ion mobility spectrometry sensors, and mass spectrometery sensors.

7. The apparatus of claim 6 wherein said detector unit comprises at least one sensor selected from the group consisting of aerosol lab-on-a-chip sensors, electronic nose sensors, ion mobility spectrometry sensors, and SAW/GC sensors.

8. The apparatus of claim 4 wherein said collector unit 20 comprises a collecting surface.

9. The apparatus of claim 8 wherein said collecting surface 21 comprises at least one air inlet 182.

10. The apparatus of claim 8 wherein said collecting surface 21 comprises at least one funnel-type device 180 surrounding said air inlet 182.

11. The apparatus of claim 4 additionally comprising an air handling unit 14 disposed to create air flow across a foodstuff and into said collector 20.

12. The apparatus of claim 11 wherein said air handling unit 14 comprises at least one air nozzle 140 disposed within a cavity 134 of a foodstuff.

13. The apparatus of claim 11 wherein said air handling unit 14 comprises an air nozzle 140 disposed within a food processing machine to allow passage of air through particulate food.

14. The apparatus of claim 11 wherein said air handling unit 14 is electronically controlled by said controlling unit 28.

15. The apparatus of claim 4 wherein said apparatus is a portable unit.

16. The apparatus of claim 9 wherein said collector unit 20 additionally comprises multiple air inlets 182 and/or an air manifold 160.

17 The apparatus of claim 16 wherein said manifold 160 may additionally comprise a purge mechanism 162.

18. The apparatus of claim 4 additionally comprising an odor marking unit.

19. The method of claim 1 comprising the additional step of utilizing an odor marker 50 to identify the presence of food stuffs.

20. The method of claim 1 comprising the additional step of utilizing a contaminate marker 40 to identify the presence of contaminated food stuffs.

21. The apparatus of claim 4 additionally comprising a contaminate marking unit.