Smart Combination of Heating Modes for

Improved Quality, Speed and Safety of Food

Processing

Ashim K. Datta, Cornell University

Laurie D. Hall, Cambridge

University

Introduction

Aim: Faster Cooking

Microwaves

Non-Uniformity

Combination Heating

Speed and Quality

Goals

How to combine the various modes of heating (microwave, infrared, hot air) in what sequence to obtain a desired temperature or moisture profile, thus relating to the quality of the cooked food?

How do the combinations change as we change the composition, size and other characteristics of the food material?

Methodology

Microwave Heating Model

Combination Heating Model (Microwave

with Infrared and/or Jet Impingement)

MRI Measurement of Temperature and

Moisture after combination heating

Validation

Optimization

Preliminary Results

Combination microwave-infrared oven

Specifications Infrared from top and

bottom

Microwaves from the side

AdvantiumTM from General Electric, Louisville, Kentucky

Temperature Contours

Microwave

Heating– Edge

– Internal

Infrared

Heating– Surface

Combination

Heating– Uniform

Combination microwave-jet impingement oven

Specifications Infrared from top and

bottom

Microwaves from the side

Thermador CJ302UB Double Jet from Enersyst Development Center, Dallas, Texas

Temperature Contours

Microwave

Heating

Jet

Impingeme

nt Heating

Combinatio

n Heating

Heating Non-Uniformity

Duration of Heating: 1 min

Duration of Heating: 2 min

Microwave Jet Combination

Mean Rise Difference/ Rise

Microwave Infrared Combination

Mean Rise Difference/ Rise

Oven 3

Mode Heating Method

Broil Upper Element

Speed

Broil

Upper Element, Fan,

Microwave

Bake Upper Element, Lower

Element, Fan

Speed

Bake

Back Element, Fan,

Microwave

GE ProfileTM Single Wall Oven (Model JT930BHBB)

Oven 3

Ithaca, New YorkMicrowave modelingTemperature measurementsProperty measurements

Cambridge, UKMRI of temperature and moisture

Synthesis of the models and experiments

Gel Heating

TX151 powder mixed with water (1: 10) ,

preconditioned

NaCl added to change dielectric

properties

Gel samples heated in a 250 ml beaker

on the oven middle rack

4 different heating modes: convection

broil, bake, speed broil and speed bake

Computational Model

Schematic Mesh

Tetrahedral Elements

Total: 117,394 nodes

Food: 19,221 nodes

Difficulties

– Complex Waveguide system

– Solver node restrictions

Magnetic Resonance Imaging

3-D temperature maps using Phase

Mapping

2 Tesla, 100 cm bore magnet

Matrix: 32 X 128 X 32

Resolution: 3.125 X 0.78125 X 3.125 mm

Scan time: 51.2 s

Procedure:

HeatingTemperature Contours

MRI

Experimentations- Properties

Thermal properties (KD2, Decagon Devices)

Dielectric properties (HP85070 Probe, 8722ES

Network Analyzer, Agilent Technologies)

Heat transfer coefficients (HFS-3 Heat flux

sensors, Fiber Optic Probe, FISO)

Microwave-Infrared Oven Microwave-Jet Impingement Oven

Results- Comparison of Modes

30 s of heating

Sample without salt

Broil Speed Broil

Computed MRI

Effect of CompositionBake (sample with salt)

Bake (sample with no salt)

Conventional Heating-- No effectSpeed Bake (no salt)

Speed Bake (salt)

Microwave heating: Corners and bottom

Effect aggravated when salt is present

Preliminary publication

Datta, A. K., S.S.G. Geedipalli and M.

Almeida. 2005. Microwave combination

heating. Food Technology. 59(1):36-40.

Refereed journal publications are coming

Future Work

Moisture: Model Development & MRI

Experimentation

Thank You !!!