The Application of Biosensors in Monitoring Internal The Application of Biosensors in Monitoring Internal Cooking Temperature in Poultry ProductsCooking Temperature in Poultry Products

Fenghua JinFenghua Jin

Bio-imaging & Machine Vision LaboratoryBio-imaging & Machine Vision Laboratory

University of MarylandUniversity of Maryland

Outbreak Alert!Outbreak Alert!

(CSPI report, 2001)

IntroductionIntroduction

• Foodborne outbreaks: 76 million cases foodborne illFoodborne outbreaks: 76 million cases foodborne illness occurs and 5,000 dead annually ness 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 productiviAnnual cost of medical treatment and productivi

ty lost ty lost $1.8 to $4.8 billion $1.8 to $4.8 billion (Agricultural Economic report, 1996).(Agricultural Economic report, 1996).

Introduction (cont.)Introduction (cont.)

• most outbreaks are linked to inadequate cooking of meat and most outbreaks are linked to inadequate cooking of meat and poultry products poultry products

Handling the food with sufficient cookingHandling the food with sufficient cooking

• What does the What does the sufficientsufficient mean? mean? — — Undercook Undercook bacteria would survive and threaten bacteria would survive and threaten

consumers’ healthconsumers’ health — — Overcook Overcook the bacteria are cooked away, as well as meat the bacteria are cooked away, as well as meat

tenderness and juicinesstenderness and juiciness

(USDA: Chicken breast: 76.7(USDA: Chicken breast: 76.7ooC )C )

ProblemProblem

• How to confirm that the internal cooking How to confirm that the internal cooking temperatures of meat products have reached temperatures of meat products have reached the requirements?the requirements?

Methods to Measure Internal Cooking TemperatureMethods to Measure Internal Cooking Temperature

• One simple Method: One simple Method: Using ThermocoupleUsing Thermocouple

— —Thermocouple is the Thermocouple is the most widely used most widely used temperature sensor.temperature sensor.

What are thermocouples and how do they work?What are thermocouples and how do they work?

• Any two wires of different materials can be used as a thermocouple if Any two wires of different materials can be used as a thermocouple if connected togetherconnected together

• TTJctJct : Junction temperature: Junction temperature

• TTRefRef: Reference temperature: Reference temperature• E E : A low-lever DC voltage : A low-lever DC voltage

(depends on the materials A and B, T(depends on the materials A and B, TJct Jct , and T, and TRefRef ) )

What are thermocouples and how do they work? (cont.)What are thermocouples and how do they work? (cont.)

• Thermocouple materialsThermocouple 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 neThe first named element of the pair is the positive element and the ne

gative wire is color coded red (current U.S. standards)gative wire is color coded red (current U.S. standards)

What are thermocouples and how do they work? What are thermocouples and how do they work? (cont.)(cont.)

• Establish Reference TemperatureEstablish Reference Temperature

— — Ice Baths Ice Baths

accurate and inexpensiveaccurate and inexpensive

— — Electronically Controlled References Electronically Controlled References

not as accurate as ice-baths but convenientnot as accurate as ice-baths but convenient

• CircuitCircuit

— — The signal is brought out of the reference temperature The signal is brought out of the reference temperature region to a voltmeter at room temperature. This is done using region to a voltmeter at room temperature. This is done using a pair of copper wires.a pair of copper wires.

What are thermocouples and how do they work? What are thermocouples and how do they work? (cont.)(cont.)

Limitation of the thermocoupleLimitation of the thermocouple

• It is sporadic and does not ensure that all portions of It is sporadic and does not ensure that all portions of the meat reach the required cooking temperature.the meat reach the required cooking temperature.

• The process is slow, invasive and susceptible to The process is slow, invasive and susceptible to cross-contamination. cross-contamination.

Need new approaches to measure the internal Need new approaches to measure the internal cooking temperatures of poultry meatcooking temperatures of poultry meat

Infrared Imaging in Food AnalysisInfrared Imaging in Food Analysis

• What is Infrared Imaging?What is Infrared Imaging?

— — Infrared means "below red" Infrared means "below red" and has longer wavelength than and has longer wavelength than red light.red light.

— — Infrared light is invisible to Infrared light is invisible to the unaided eye, but can be felt the unaided eye, but can be felt as heat on one’s skin.as heat on one’s skin.

— — Warm objects emit infrared Warm objects emit infrared light.light.

electromagnetic spectrum electromagnetic spectrum

Infrared Imaging in Food Analysis (cont.)Infrared Imaging in Food Analysis (cont.)

• The theoretical foundation behind this technology is The theoretical foundation behind this technology is described by Stefan-Boltzmann law:described by Stefan-Boltzmann law:

4E T— — E is the radiation intensity of an emitterE is the radiation intensity of an emitter— — σ is Stefan-Boltzmann constantσ is Stefan-Boltzmann constant——ε is emissivity, a material property of the object ε is emissivity, a material property of the object

— — T is the absolute surface temperature of the objectT is the absolute surface temperature of the object E depends on the fourth power of TE depends on the fourth power of T

Infrared Imaging in Food Analysis (cont.)Infrared Imaging in Food Analysis (cont.)

• Sequential Infrared images:Sequential Infrared images:

Time (second)

thermocouple

(1)

(2)

(i)47

57

70

83

95

Temperature (oC)

0

10

Advantage of Infrared ImagingAdvantage of Infrared Imaging

1.1. can measure the surface temperature of solid materials can measure the surface temperature of solid materials for which it is difficult to insert the probe;for which it is difficult to insert the probe;

2.2. can measure the temperature of some material that can can measure the temperature of some material that can erode the probe or reduce its usage time;erode the probe or reduce its usage time;

3.3. nondestructive, high-speed, automatic monitoring and nondestructive, high-speed, automatic monitoring and accuracyaccuracy

Infrared Imaging in Food Analysis (an example)Infrared Imaging in Food Analysis (an example)

• Ibarra et al. (1999) developed a method using IR imaging Ibarra et al. (1999) developed a method using IR imaging to estimate the internal cooking temperature in chicken brto estimate the internal cooking temperature in chicken breast. east.

The internal temperatures recorded by thermocouples The internal temperatures recorded by thermocouples (TCs). (TCs).

External temperatures was recorded by an IR cameraExternal temperatures was recorded by an IR camera Time series observations of simultaneous internal and eTime series observations of simultaneous internal and e

xternal temperatures were obtained. xternal temperatures were obtained. Using Artificial Neural Network (ANN) to model the nUsing Artificial Neural Network (ANN) to model the n

onlinear heat transfer process and to predict the internal conlinear heat transfer process and to predict the internal cooking temperatureooking temperature

Infrared Imaging in Food Analysis (an example Infrared Imaging in Food Analysis (an example cont.)cont.)

• LimitationsLimitations: The chicken samples had similar shape and : The chicken samples had similar shape and thicknessthickness

— — Variant shapes and thickness may directly affect the Variant shapes and thickness may directly affect the

heat transfer process in meats.heat transfer process in meats.

We need to extract 3D information of poultry meatWe need to extract 3D information of poultry meat

— — Laser range imaging is a well-established technique to Laser range imaging is a well-established technique to

get 3D information of the object.get 3D information of the object.

Laser Range ImagingLaser Range Imaging

xzxz

zsrefi

ref

o f

1

( )

cosref o

x

Z Zd

laser projectorcamera

(0, 0, 0)detector

lens(xi, yi) (xs, ys, zs)

object(xo, yo, z

o)

f

θxzref

d

encoder pulse

x

zy.

Artificial Neural Network ModelingArtificial Neural Network Modeling

• Internal temperature Internal temperature

• External temperatureExternal temperature

• 3D information of poultry meat 3D information of poultry meat

use Artificial Neural Network to model the nonlinear heat use Artificial Neural Network to model the nonlinear heat transfer process and to predict the internal cooking transfer process and to predict the internal cooking temperaturetemperature

Introduction to Artificial Neural NetworkIntroduction to Artificial Neural Network

• Two procedures of ANN modeling:Two procedures of ANN modeling:

— — Learning Learning

— — Testing Testing

Outputs: a

hidden layer

Inputs: p

wij

bi

node

input layer output layer

Learning ProcessLearning Process Initialize W, b

a

baWfaa

M

mmmmm

a

p

1111

0

Calculate E

W = W + ∆W

b = b + ∆b

E < Emax

Y

N

Stop

E = 0

E: Performance index;

Emax: Performance goal.

* performance of network is defined by performance index* performance of network is defined by performance index

e.g.: mean square errors (MSE)e.g.: mean square errors (MSE)

Two procedures of ANN modelingTwo procedures of ANN modeling

• Training Training weights and biases of the ANN were determined by the weights and biases of the ANN were determined by the

ANN training process; ANN training process;

..

• TestingTesting The surface temperature and the geometric information The surface temperature and the geometric information

were inputted into the ANN to predict the internal cooking were inputted into the ANN to predict the internal cooking temperature in chicken samples. temperature in chicken samples.

Illustration of the IR and laser range imaging systemIllustration of the IR and laser range imaging system

IR camera

Oven

CCD camera

Laser projector

OvenOven

Infrared CameraInfrared Camera

Laser projector and CCD cameralLaser projector and CCD cameral

T type thermocouple T type thermocouple

System block diagramSystem block diagram

Monitoring System

Cooking System

Laser Range Imaging IR Imaging

ANN Modeling Endpoint Temperatur

e

Internal Temperature Recording

Extended real-time endpoint temperature estimatioExtended real-time endpoint temperature estimation systemn system

Monitoring System

Cooking System

Laser Range Imaging IR Imaging

ANN ModelingEndpoint

Temperature

Decision System

Control Unit