ASTM F874-98(2003)
(Test Method)Standard Test Method for Temperature Measurement and Profiling for Microwave Susceptors
Standard Test Method for Temperature Measurement and Profiling for Microwave Susceptors
ABSTRACT
This test method covers the standard procedures for measuring and profiling surface temperatures attained by microwave interactive packaging and cooking aids (that is, susceptors). This procedure is useful for measuring susceptor/food interface temperatures during microwave preparation of foods with susceptor-based packaging, heating pads, and crisping sleeves, etc. It may also be used in the temperature profiling of susceptors exposed in vials used for volatile extractives testing, or in liquid (PTFE-fluorocarbon polymer) extraction cells used for nonvolatile extractives testing. The latter procedures are performed to establish test conditions for conducting extraction and migration studies using temperature versus time profiles approximating those for actual microwave preparation of the product.
SCOPE
1.1 This is a test method for measuring surface temperatures attained by microwave interactive packaging and cooking aids (that is, susceptors). It is useful for measuring susceptor/food interface temperatures during microwave preparation of foods with susceptor-based packaging, heating pads, and crisping sleeves, etc. It may also be used to measure the temperature of a susceptor exposed to extractives testing or in a liquid extraction cell to be used for nonvolatile extractives testing. The latter procedures are performed to establish test conditions for conducting extraction and migration studies using temperature versus time profiles approximating those for actual microwave preparation of the product.
1.1.1 Several of the steps of this test method are taken directly from Test Method F 1308 which gives extraction testing procedures for susceptors.
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Designation: F 874 – 98 (Reapproved 2003)
Standard Test Method for
Temperature Measurement and Profiling for Microwave
Susceptors
This standard is issued under the fixed designation F 874; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope lizing Solvents as Food Simulants
1.1 Thisisatestmethodformeasuringsurfacetemperatures
3. Apparatus
attained by microwave interactive packaging and cooking aids
3.1 Microwave Oven, no turntable, unmodified except for
(that is, susceptors). It is useful for measuring susceptor/food
small holes to allow for probe lead access to the oven cavity.
interface temperatures during microwave preparation of foods
The oven should be calibrated in accordance with Test Method
with susceptor-based packaging, heating pads, and crisping
F 1317.
sleeves, etc. It may also be used to measure the temperature of
3.2 Fluoroptic Thermometry System.
a susceptor exposed to extractives testing or in a liquid
3.3 Vials, headspace, 20 mL.
extraction cell to be used for nonvolatile extractives testing.
3.4 Septa,polytetrafluorethylene(PTFE)polymerfacedsili-
The latter procedures are performed to establish test conditions
cone rubber.
for conducting extraction and migration studies using tempera-
3.5 Vial Crimp Caps.
ture versus time profiles approximating those for actual micro-
3.6 Microwave Nonvolatile Extraction Cell —This cell
wave preparation of the product.
must be constructed of PTFE-fluorocarbon polymer. Addi-
1.1.1 Several of the steps of this test method are taken
tional details on this cell may be found in Test Method F 1349.
directly from Test Method F 1308 which gives extraction
3.7 Beakers, 600 and 250 mL, or other sizes as appropriate.
testing procedures for susceptors.
3.8 Aluminum Foil, household roll.
1.2 This standard does not purport to address all of the
3.9 Adhesive Tape, such as Kapton high-temperature tape,
safety concerns, if any, associated with its use. It is the
vinyl tape, silicone tape, etc.
responsibility of the user of this standard to establish appro-
3.10 High-Vacuum Silicone Grease.
priate safety and health practices and determine the applica-
3.11 Syringe Needle, 13 gage diameter.
bility of regulatory limitations prior to use.
3.12 Corn Oil, Miglyol 812 (a fractionated coconut oil), or
2. Referenced Documents synthetic fat simulant HB 307. See Test Method F 1349 for
2 details.
2.1 ASTM Standards:
3.13 Petri Dishes.
F 1308 Test Method for Quantitating Volatile Extractables
in Microwave Susceptors Used for Food Products
F 1317 Test Method for Calibration of Microwave Ovens
F 1349 Test Method for Nonvolatile Ultraviolet (UV) Ab-
Luxtron Model 750 or equivalent, with Luxtron MIH or MIW temperature
probes, or equivalent.Available from Luxtron Inc., 106 Terra BellaAve., Mountain
sorbing Extractables from Microwave Susceptors
View, CA 90403.
F 1500 Test Method for Quantitating Non-UV-Absorbing
AvailablefromShamrockGlassCo.,200N.DelawareAve.,Seaford,DE19973
Nonvolatile Extractables from Microwave Susceptors Uti-
(Catalog No. 667601) or Chemical Research Supplies, PO Box 888, Addison, IL
60101 (Catalog No. 237502), or equivalent.
Available from Shamrock Glass Co. (Catalog No. 778173A) or Hewlett
This test method is under the jurisdiction ofASTM Committee F02 on Flexible Packard (Catalog No. 5080-8726), or equivalent.
Barrier Materials and is the direct responsibility of Subcommittee F02.15 on Available from Shamrock Glass Co. (Catalog No. 778704) or Hewlett Packard
Chemical/Safety Properties. Computer Supplies Operation, PO Box 62124, San Francisco, CA 94162 (Catalog
Current edition approved Oct. 10, 1998. Published March 1999. Originally No. 07675-20625), or equivalent.
published as F 874 – 90. Last previous edition F 874 – 91. Available from Waldorf Corp., 2250 Wabash Ave., St. Paul, MN 55114.
2 8
For referenced ASTM standards, visit the ASTM website, www.astm.org, or PTFE-fluorocarbon polymer materials may be purchased from Read Plastics,
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Rockville, MD, or equivalent.
Standards volume information, refer to the standard’s Document Summary page on Available from Curtin Mattheson Scientific (Catalog No. 301-911).
the ASTM website. Available from Curtin Mattheson Scientific (Catalog No. 218-636).
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
F 874 – 98 (2003)
FIG. 1 Probe Configuration for Popcorn Bag Temperature
Measurement
3.14 Fan, tabletop.
3.15 Blue Ice.
3.16 Vials, for alternative profile method, 40-mL clear
11 FIG. 2 Effect of Foil Sleeve Window Size (cm ) on Temperature
vials.
Attained by Frozen Fish Product Susceptor
3.17 Screw Caps.
4. Procedure
outer bag surface and inner bag surface temperatures are
equivalent,thentapingtheprobestotheoutersurfacewouldbe
4.1 General:
satisfactory.
4.1.1 Start all tests with a cool microwave oven, that is,
5.4 For products prepared on a susceptor board, such as
ambient temperature. Use a fan and blue ice to cool oven floor
microwave pizza, the probe should be immobilized to the
or any other reliable method to suitably return the oven to
susceptor board in parallel contact by applying a suitable
ambient temperature between replicates.
adhesive tape 0.5 in. behind the probe tip.
4.1.2 Test three replicates per variable.
5.5 For products without free fat or oil at the food susceptor
interface, it is advisable to apply high-vacuum silicone grease
5. Measurement of Food/Susceptor Interface
Temperature During Microwave Cooking to the tip of the probe to assure good thermal contact with the
susceptor.
5.1 Place product in center of the microwave oven as a
5.6 Microwave at full power for the maximum directed
consumer would. Mark the position of first replicate on oven
cooking time of the product, recording the temperature of each
floor, and position subsequent replicates similarly.
probe, preferably at 5-s intervals, but at intervals not to exceed
5.2 Position probes at food susceptor interface in such a
15 s. It is suggested that readings be taken at 1-s intervals if
manner that good probe/susceptor contact is maintained during
possible, in order to generate a smoother curve. Calculate the
cooking, disturbing the food load as little as possible. The
average of the replicate runs at each recorded time for each
analyst may wish to position multiple probes on different
probe position. Do not use data if discontinuities appear in plot
regions of the susceptor, such as the center and edge, as the
(indicative of loss of susceptor/probe contact).
temperature attained at different locations may differ signifi-
cantly.
6. Temperature Profiling of Susceptors in Vials Used for
5.2.1 If the nature of the product permits, the analyst may
Volatile Extractives Testing
wish to determine whether probes positioned parallel to the
6.1 First determine the temperature versus time profile for
susceptor surface, or abutted to the susceptor surface would
the product during microwave preparation in accordance with
result in better temperature measurement as evidenced by
Section 5.
better reproducibility between replicate runs and less discon-
2 2
6.2 Cut a 10 by 65-mm (6.5 cm or 1-in. ) portion from the
tinuity, due to loss of contact, of temperature readings versus
susceptor sample to be tested. Insert carefully into vial,
time.
positioning the sample on the vial side, with the active side
5.3 For in-package measurements for products such as
facing into the vial.
microwave popcorn, probe access into the package is achieved
6.3 Using a 13-gage syringe needle, pierce a hole into a
by drilling approximately 0.1-in. holes through the package.
septum, place septum on vial and crimp.
(SeeFig.1forprobeplacementinsideapopcornbag.)Itisalso
6.4 Insert one temperature–sensing probe through the sep-
advisable to route the probes along the bottom of the package
tum hole into the vial and manipulate it until it is in contact
to avoid disruption of probe/susceptor contact as the bag
with the active face of the susceptor material.
expands during cooking. If it has been demonstrated that the
6.5 Place vial on its side in the center of the microwave
oven, marking the exact location on the oven floor for
subsequent replicates. Place the cap of the vial towards the
Available from Alltech Associates, Inc. 2051 Waukegan Rd., Deerfield, IL
probe access port in the oven cavity, with susceptor active face
60015 (Catalog No. 9534), or equivalent.
Available from Alltech Associates, Inc., (Catalog No. 95321), or equivalent. up.
F 874 – 98 (2003)
TABLE 1 Reproducibility of Single-Probe Readings in One
Representative Laboratory,° F
NOTE 1—Triplicate analyses of popcorn susceptor in vials with 250 mL
of water in a 400-mL beaker.
Mean (coeffi-
Time, s #1 #2 #3 Average cient of vari-
ance)
120 318.1 300.4 321.5 313 2.9
135 324.4 301.4 319.0 315 3.2
150 322.5 294.0 314.8 310 3.9
...
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