A1260944415TIlFs - PowerPoint PPT Presentation

Title: A1260944415TIlFs


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Radio Frequency Treatments as Alternative to
Chemical Fumigation for Insect Control in Nuts
Juming Tang S. Wang J. Hansen, J. Johnson, E.
Mitcham, S. Drake, G. Hallman
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Juming Tang Shaojin Wang, Bio. Systems Eng.,
WSU, WA James D. Hansen, USDA-ARS, Wapato,
WA Judy A. Johnson, USDA-ARS, Fresno,
CA Elizabeth Mitcham, UC Davis, CA Stephen R.
Drake, USDA-ARS, Wenatchee, WA Guy Hallman,
USDA-ARS, Weslaco, TX
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RF Treatments as Alternative to Chemical
Fumigation for Insect Control in Nuts

• Introduction
• Insect mortality
• Fruit quality curve
• Dielectric property
• Heating uniformity
• Differential heating
• Process protocols for walnuts

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INTRODUCTION
Washington State University started working on
developing effective thermal processes based on
RF and microwave energy in 1996, with original
focus on codling moth. We now expand to other
insect pests for international and intrastate
trades
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• In 2000, formed a consortium entomologists,
  plant physiologists and engineers from two
  universities (WSU and UC Davis), and four USDA
  ARS Stations in Three States (WA, CA and TX).

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Targeted commodities and insects
Walnut Almond Cherry Apple Orange
Grapefruit
Codling moth Navel orangeworm
Indianmeal moth Fly
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RF and Microwave Heating Volumetric heating
-- the electromagnetic waves directly couple
with material to generate heat.
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Electromagnetic spectrum
915 MHz
2450 MHz
Microwaves
27.12 MHz
Quantum energy gt5 eV
Radio waves
Infrared
Ultra violet
Quantum energy lt0.00001 eV
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Molecular Agitation
Polarity is reversed 27 MILLION times per second
(27MHz) (Courtesy of Strayfield, UK)
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RF Treatments as Alternative to Chemical
Fumigation for Insect Control in Nuts

• Introduction
• Insect mortality
• Fruit quality curve
• Dielectric property
• Heating uniformity
• Differential heating
• Process protocols for walnuts

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• Acceptable time-temperature treatment area
  obtained from different mortality and quality
  curves

Source Tang et al., 2000. Postharvest Bio.
Technol., 21, 129-145.
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The heating block system developed at WSU
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• Schematic diagram of the heating block system
  developed at WSU

Source Wang et al., 2002. J. Stored Prod. Res.,
in press.
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Mortality curve of fifth-instar navel orangeworm
at different temperatures. N0 and N stand for
initial (600) and survival insect numbers
Source Wang et al., 2002. J. Stored Prod. Res.,
in press.
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TDT curve of 5th-instar Indianmeal moth (IMM),
codling moth (CM) and navel orangeworm (NOW)
Source Wang et al., 2002. Postharvest Bio.
Technol. in review.
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Mortality () of NOW for three different life
stages at a heating rate of 18C/min (3
replicates)
Source Wang et al., 2002. Postharvest Bio.
Technol. in review.
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RF Treatments as Alternative to Chemical
Fumigation for Insect Control in Nuts

• Introduction
• Insect mortality
• Fruit quality curve
• Dielectric property
• Heating uniformity
• Differential heating
• Process protocols for walnuts

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TDT curve of codling moths and fruit quality of
PNW cherries Quality data from Steve Drake, USDA
ARS Wenatchee
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RF Treatments as Alternative to Chemical
Fumigation for Insect Control in Nuts

• Introduction
• Insect mortality
• Fruit quality curve
• Dielectric property
• Heating uniformity
• Differential heating
• Process protocols for walnuts

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HP Dielectric Property Measurement System
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Source Tang et al., 2000. Postharvest Bio.
Technol., 21, 129-145.
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RF Treatments as Alternative to Chemical
Fumigation for Insect Control in Nuts

• Introduction
• Insect mortality
• Fruit quality curve
• Dielectric property
• Heating uniformity
• Differential heating
• Process protocols for walnuts

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Walnut kernel temperature at five locations on
three layers when subjected to RF (P0.6kW) and
hot air treatments ( air temp.53C, air speed
1 m/s)
Source Wang et al., 2001. ASAE paper No. 016170,
16p.
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RF Treatments as Alternative to Chemical
Fumigation for Insect Control in Nuts

• Introduction
• Insect mortality
• Fruit quality curve
• Dielectric property
• Heating uniformity
• Differential heating
• Process protocols for walnuts

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Temperature profiles of walnut kernels and
codling moth slurry when subjected to 27 MHz RF
system
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RF Treatments as Alternative to Chemical
Fumigation for Insect Control in Nuts

• Introduction
• Insect mortality
• Fruit quality curve
• Dielectric property
• Heating uniformity
• Differential heating
• Process protocols for walnuts

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Treating Infested Walnuts Using 27.12 MHz RF
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Schematic view of the combined RF and hot air
treatments of in-shell walnuts for drying and
insect control
Source Wang et al., 2002. Postharvest Bio.
Technol. in review.
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Temperature of in-shell walnut kernel when
subjected to RF and forced hot air treatments
(air temperature, 53oC air velocity, 1m/s)
Source Tang et al., 2000. Postharvest Bio.
Technol., 21, 129-145.
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Mortality of 5th instar codling moth in walnuts
after RF treatments (year 2000)
Source Wang et al., 2001. Postharvest Bio.
Technol., 22, 29-38.
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Mortality of 5th Instar Navel Orangeworms in
in-shell walnuts after RF treatments (Year 2001)
Source Wang et al., 2002. Postharvest Bio.
Technol. in review.
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Quality characteristics of in-shell walnuts
treated by RF energy (53C5min) (year 2000)
Source Wang et al., 2001. Postharvest Bio.
Technol., 22, 29-38.
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Quality characteristics of in-shell walnuts
treated by radio frequency energy with 3
replicates (Year 2001)
Tests conducted by Diamond Walnuts, CA
Source Wang et al., 2002. Postharvest Bio.
Technol. in review.
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CONCLUSIONS

• It is possible to use radio frequency heating as
  a short-time treatment for insect pest control.
• The process completely kills insect pests without
  causing damage to selected commodities.
• We may be ready to scale-up RF process for
  inshell walnut nut treatment.

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RF HeatingFCC approved frequencies for ISM
Applications13.56 MHz (22 m), 27.12 MHz (11 m),
and 40.68 MHz (7.4 m)
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Please visit our USDA-IFAFS Websitehttp//www.b
syse.wsu.edu/IFAFS
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Thanks!