1. The Application of Biosensors in Monitoring Internal Cooking Temperature in Poultry Products Fenghua Jin Bio-imaging & Machine Vision Laboratory University of Maryland

2. Outbreak Alert! (CSPI report, 2001)

3. Introduction Foodborne outbreaks: 76 million cases foodborne illness occurs and 5,000 dead annually Foodborne outbreaks: 76 million cases foodborne illness occurs and 5,000 dead annually (Morbidity and Mortality Weekly Report, 1999). (Morbidity and Mortality Weekly Report, 1999). Cost of foodborne diseases is considerable Cost of foodborne diseases is considerable — Annual cost of medical treatment and productivity lost $1.8 to $4.8 billion — Annual cost of medical treatment and productivity lost $1.8 to $4.8 billion (Agricultural Economic report, 1996). (Agricultural Economic report, 1996).

4. Introduction (cont.) most outbreaks are linked to inadequate cooking of meat and poultry products most outbreaks are linked to inadequate cooking of meat and poultry products  Handling the food with sufficient cooking  Handling the food with sufficient cooking What does the sufficient mean? What does the sufficient mean? — Undercook  bacteria would survive and threaten consumers’ health — Undercook  bacteria would survive and threaten consumers’ health — Overcook  the bacteria are cooked away, as well as meat tenderness and juiciness — Overcook  the bacteria are cooked away, as well as meat tenderness and juiciness (USDA: Chicken breast: 76.7 o C ) (USDA: Chicken breast: 76.7 o C )

5. Problem How to confirm that the internal cooking temperatures of meat products have reached the requirements? How to confirm that the internal cooking temperatures of meat products have reached the requirements?

6. Methods to Measure Internal Cooking Temperature One simple Method: Using Thermocouple One simple Method: Using Thermocouple —Thermocouple is the most widely used temperature sensor. —Thermocouple is the most widely used temperature sensor.

7. What are thermocouples and how do they work? Any two wires of different materials can be used as a thermocouple if connected together Any two wires of different materials can be used as a thermocouple if connected together T Jct : Junction temperature T Jct : Junction temperature T Ref : Reference temperature T Ref : Reference temperature E : A low-lever DC voltage E : A low-lever DC voltage (depends on the materials A and B, T Jct, and T Ref ) (depends on the materials A and B, T Jct, and T Ref )

8. What are thermocouples and how do they work? (cont.) Thermocouple materials Thermocouple materials —The three most common thermocouple alloys are: —The three most common thermocouple alloys are: 1. Iron-Constantan (Type J) 1. Iron-Constantan (Type J) 2. Copper-Constantan (Type T) 2. Copper-Constantan (Type T) 3. Chromel-Alumel (Type K) 3. Chromel-Alumel (Type K) * The first named element of the pair is the positive element and the negative wire is color coded red (current U.S. standards) * The first named element of the pair is the positive element and the negative wire is color coded red (current U.S. standards)

9. What are thermocouples and how do they work? (cont.) Establish Reference Temperature Establish Reference Temperature — Ice Baths — Ice Baths accurate and inexpensive accurate and inexpensive — Electronically Controlled References — Electronically Controlled References not as accurate as ice-baths but convenient not as accurate as ice-baths but convenient

10. Circuit Circuit — The signal is brought out of the reference temperature region to a voltmeter at room temperature. This is done using a pair of copper wires. — The signal is brought out of the reference temperature region to a voltmeter at room temperature. This is done using a pair of copper wires. What are thermocouples and how do they work? (cont.)

11. Limitation of the thermocouple It is sporadic and does not ensure that all portions of the meat reach the required cooking temperature. It is sporadic and does not ensure that all portions of the meat reach the required cooking temperature. The process is slow, invasive and susceptible to cross-contamination. The process is slow, invasive and susceptible to cross-contamination.  Need new approaches to measure the internal cooking temperatures of poultry meat  Need new approaches to measure the internal cooking temperatures of poultry meat

12. Infrared Imaging in Food Analysis What is Infrared Imaging? What is Infrared Imaging? — Infrared means "below red" and has longer wavelength than red light. — Infrared means "below red" and has longer wavelength than red light. — Infrared light is invisible to the unaided eye, but can be felt as heat on one’s skin. — Infrared light is invisible to the unaided eye, but can be felt as heat on one’s skin. — Warm objects emit infrared light. — Warm objects emit infrared light. electromagnetic spectrum

13. Infrared Imaging in Food Analysis (cont.) The theoretical foundation behind this technology is described by Stefan-Boltzmann law: The theoretical foundation behind this technology is described by Stefan-Boltzmann law: — E is the radiation intensity of an emitter — σ is Stefan-Boltzmann constant —ε is emissivity, a material property of the object — T is the absolute surface temperature of the object  E depends on the fourth power of T

14. Infrared Imaging in Food Analysis (cont.) Sequential Infrared images: Sequential Infrared images: Time (second) thermocouple (1) (2) (i) 47 57 70 83 95 Temperature ( o C) 0 10

15. Advantage of Infrared Imaging 1. can measure the surface temperature of solid materials for which it is difficult to insert the probe; 2. can measure the temperature of some material that can erode the probe or reduce its usage time; 3. nondestructive, high-speed, automatic monitoring and accuracy

16. Infrared Imaging in Food Analysis (an example) Ibarra et al. (1999) developed a method using IR imaging to estimate the internal cooking temperature in chicken breast. Ibarra et al. (1999) developed a method using IR imaging to estimate the internal cooking temperature in chicken breast.  The internal temperatures recorded by thermocouples (TCs).  The internal temperatures recorded by thermocouples (TCs).  External temperatures was recorded by an IR camera  External temperatures was recorded by an IR camera  Time series observations of simultaneous internal and external temperatures were obtained.  Time series observations of simultaneous internal and external temperatures were obtained.  Using Artificial Neural Network (ANN) to model the nonlinear heat transfer process and to predict the internal cooking temperature  Using Artificial Neural Network (ANN) to model the nonlinear heat transfer process and to predict the internal cooking temperature

17. Infrared Imaging in Food Analysis (an example cont.) Limitations: The chicken samples had similar shape and thickness Limitations: The chicken samples had similar shape and thickness — Variant shapes and thickness may directly affect the heat transfer process in meats. — Variant shapes and thickness may directly affect the heat transfer process in meats.  We need to extract 3D information of poultry meat  We need to extract 3D information of poultry meat — Laser range imaging is a well-established technique to get 3D information of the object. — Laser range imaging is a well-established technique to get 3D information of the object.

18. Laser Range Imaging laser projector camera (0, 0, 0) detector lens (x i, y i ) (x s, y s, z s ) object (x o, y o, z o ) f θxθx z ref d encoder pulse x z y.

19. Artificial Neural Network Modeling Internal temperature Internal temperature External temperature External temperature 3D information of poultry meat 3D information of poultry meat  use Artificial Neural Network to model the nonlinear heat transfer process and to predict the internal cooking temperature

20. Introduction to Artificial Neural Network Two procedures of ANN modeling: Two procedures of ANN modeling: — Learning — Learning — Testing — Testing Outputs: a hidden layer Inputs: p w ij bibi node input layeroutput layer

21. Learning Process Initialize W, b Calculate E W = W + ∆W b = b + ∆b E < E max Y N Stop E = 0 E: Performance index; E max : Performance goal. * performance of network is defined by performance index e.g.: mean square errors (MSE) e.g.: mean square errors (MSE)

22. Two procedures of ANN modeling Training Training weights and biases of the ANN were determined by the ANN training process; weights and biases of the ANN were determined by the ANN training process;. Testing Testing The surface temperature and the geometric information were inputted into the ANN to predict the internal cooking temperature in chicken samples. The surface temperature and the geometric information were inputted into the ANN to predict the internal cooking temperature in chicken samples.

23. Illustration of the IR and laser range imaging system IR camera Oven CCD camera Laser projector

24. Oven

25. Infrared Camera

26. Laser projector and CCD cameral

27. T type thermocouple

28. System block diagram Monitoring System Cooking System Laser Range ImagingIR Imaging ANN Modeling Endpoint Temperature Internal Temperature Recording

29. Extended real-time endpoint temperature estimation system Extended real-time endpoint temperature estimation system Monitoring System Cooking System Laser Range ImagingIR Imaging ANN Modeling Endpoint Temperature Decision System Control Unit