silicone bakeware: does it deliver a better product?

copy 2007 The Authors

43

Journal compilation copy 2007 Blackwell Publishing

Journal of Foodservice

18

pp 43ndash51

Blackwell Publishing IncMalden USAFRIFoodservice Research International1524-8275copy 2007 The Authors Journal compilation copy 2007 Blackwell Publishing

2007

18

14351

Original Articles

Silicone bakewareNelson Barber et al

Original article

Silicone bakeware does it deliver a better product

Nelson Barber Joe Scarcelli

dagger

Barbara A Almanza

dagger

James R Daniel

Dagger

and Doug Nelson

dagger

PO Box 41162 Department of Nutrition Hospitality and Retailing Texas Tech University Lubbock TX 79409 USA

dagger

Department of Hospitality and Tourism Management Purdue University West Lafayette IN USA

Dagger

Department of Food and Nutrition Purdue University West Lafayette IN USA

Abstract

Current research on the effectiveness of silicone bakeware is extremely lim-ited trade journals magazine articles and newspapers are the only availablesources of information on this topic This literature claims that siliconebakeware is nonstick with ease of product removal and cleaning and providesfor even heat distribution The purpose of this work is to evaluate theseclaims and to compare the quality of silicone-baked items to similar itemsbaked in standard bake pans using visual physical and sensory evaluationtechniques The results of this study determine that cake products baked intraditional metal bakeware showed better crust color and texture develop-ment and delivered a moister product The silicone bakeware produced acake with greater volume

Introduction

Very little academic research is available regard-ing the performance of silicone bakeware com-pared to traditional metal glass or ceramicbakeware Baked good characteristics such as vol-ume crust color moisture content and texture areall important to a consistent finished product andconsumer acceptance

Volume is an important characteristic in theevaluation of cake quality and relates to the under-lying structural development of the cake The vol-ume of a baked cake is generally determined usingtwo standard methods rapeseed displacement andcross-sectional tracings (an indirect measure ofvolume) and a comparison with height profileanalysis to determine the accuracy of the methodfor cake volume analysis (Whitaker amp Barringer2004) The American Association of CerealChemists also has approved these two methodsof volume determination for cakes rapeseed dis-placement and the use of a template with cross-sectional areas (Whitaker amp Barringer 2004)

Water activity (

a

w

) affects the textural and stor-age properties of food Foods with high

a

w

aredescribed as being moist juicy tender and chewyWhen the water level is lowered undesirablecharacteristics such as dryness staleness or hard-ness are observed Water activity is commonlymeasured using a Decagon Aqua lab CX-2 instru-ment (Decagon Devices Pullman WA) Wateractivity plays an important role in the preserva-tion of food and in the control of microbialgrowth especially pathogens Decagon Aqua Labmodels CX-2 and Series 3 use the chilled-mirrordew point technique to measure the water activityof a product Water activity is the ratio of thewater vapor pressure in any food system to thewater vapor pressure of pure water at the sametemperature The Aqua Lab repeats readings untiltwo consecutive readings are within

plusmn

0001

a

w

ofeach other (Wilson 2001)

Crust color of cakes and other baked productscooled to room temperature is most commonlydetermined with a BYK Gardner Color ViewSpectrophotometer as CIE

L

a

and

b

values

Correspondence

Nelson Barber PO Box 41162 Department of Nutrition Hospitality and Retailing Texas Tech University Lubbock TX 79409 USA Tel (806) 742 3068 Fax (806) 741 3042 E-mail nelsonbarbermsncom

Keywords

cake pans nonstick sensory evaluation silicone bakeware

Silicone bakeware

Nelson Barber et al

copy 2007 The AuthorsJournal compilation copy 2007 Blackwell Publishing


18

pp 43ndash51

44

(Hunter Associates Lab Reston VA) The instru-ment settings are Illuminant C Display

L

a

and

b

Standard Observer 2

deg

The spectro-photometer is calibrated with white and blackporcelain ceramic plaques supplied by the manu-facturer Resulting values are typically recordedin triplicate for each observation Additionalcolor attributes such as total color difference(AE) whiteness value saturation index and yel-lowness index are calculated from

L

a

and

b

values (Bilgen

et al

2004) Figure 1 shows theuniform diagram of color relationship

Characteristics of quality bakeware

To work effectively bakeware should be made ofa material that conducts heat quickly and evenlyThe speed with which a material conducts heat isnot only affected by the material but also by itsthickness thin materials conduct heat quicklywhile thick materials conduct heat more slowlyFood professionals believe that a materialrsquos abilityto conduct heat quickly is one of the most im-portant considerations in choosing cookwareFigure 2 shows copper to be the fastest conductorof heat aluminum is second Glass ceramic andheat-resistant glass are the slowest conductors ofheat Copper cookware should be lined withanother material such as stainless steel or tin sothe food will not come into contact with thecopper which interacts with foods to form toxicsubstances

Aluminum is considered a fast conductor ofheat Although its conductivity is only half that

of copper it is four times that of iron or steelAluminum cookware is made by stamping draw-ing or casting and comes in a variety of gaugesfrom very thin to very thick (Hawks 2003)

Manufacturersrsquo data on silicone

Silicone is a class of inorganic rubbers of variouscompositions and formulas that is made by link-ing variously bonded silicon atoms to oxygen andother organic groups Silicone is developed for itssuperior reliability long life and extreme tem-perature adaptability and stability ndash it will notbecome misshapen or break down because ofextreme temperature exposure Silicones can befound in liquid and solid forms depending uponuses and curing processes Silicone bakewareis made using a high-temperature compressionmolding process Products are sold in various col-ors which cost more than a clear product (DVOEnterprises Inc 2003)

Silicone bakeware was introduced to the mar-ket in early 2000 The thermal conductivity ofpure silicon 105 Wm (Almazoptics 2006) is lessthan half of the 240 Wm

deg

K of aluminum butmore than six and a half times the 16 Wm

deg

K ofstainless steel (Perry

et al

1997) The meltingpoint of silicone is 932

deg

F however the maximumsustained temperature use is 675

deg

F meaning thatthe bakeware can be left at 675

deg

F indefinitelywithout breaking down Silicone bakeware canalso be used at temperatures as low as

minus

58

deg

F(Dow Corning Corporation 2006)

The purity of silicone paired with high-qualitymanufacturing processes ensures even heat distri-bution The use of high-density silicone in com-bination with very even wall thickness allows for

Figure 1

CIELAB uniform diagram showing relation-ship of redgreen (

a

+

minus

) and yellowblue (

b

+

minus

) oppo-nent coordinates to lightness

L

chroma

C

and hue angle

h

Figure 2

Heat conductivity for selected materials

Silicone bakeware

Nelson Barber et al



18

pp 43ndash51

45

consistent heat distribution and promotes evenbaking and browning

Sensory testing

The sensory evaluation of food is made via sighttouch taste and smell The very complex in-teraction of these senses arouses complex sensa-tions that are used to assess food quality andpreference

Sensory evaluation may be carried out underformal restricted-panel situations or under lessformal consumer-type situations As with any sit-uation that involves human subjective evaluationsensory assessment is difficult and tends to beinfluenced by many factors unrelated to the fooditem being tested (Meilgaard

et al

1991)The three fundamental types of sensory tests

are preference tests (used to determine if the judgehas a preference based on a given measurementof preference) discrimination tests (used to deter-mine whether a difference exists between sam-ples) and descriptive tests (used to determine thenature and intensity of the differences) (Meil-gaard

et al

1991)Product controls are very important in sensory

evaluations The preparation and presentation ofthe samples are key control features of a goodsensory test thereby ensuring that extraneousvariables are not introduced and that no treat-ment variables are obscured (Meilgaard

et al

1991)For all testing apart from consumer testing it

is critical to select an appropriate panel Trainingoften needs to take place so that the same kind ofinformation is being selected and that similarvocabulary is being used to describe the sensoryexperience At a minimum panelists must be pre-pared to participate in a laboratory sensory testwith no instruction from the sensory analystsonce the test has started They should be thor-oughly familiar with the test procedures the scoresheet design and the type of judgmentevaluationrequired (Meilgaard amp

et al

1991)This study developed a combined baking pro-

cedure for measuring the possible differences inbaking white layer cakes using silicone bakewarecompared to conventional aluminum metal bake-ware (lsquononsiliconersquo) The objectives were to deter-mine (i) if quality was equal in color moisture

volume and texture and (ii) if a panel of judgesthrough the use of controlled discriminatory test-ing could determine whether a difference existsbetween the cakes baked in silicone or nonsiliconebakeware

Materials and methods

Preparation of cakes

Using four 9-in round pans ndash two silicone pansan aluminized steel pan and a nonstick black-coated aluminum pan ndash the following controlledcommercial preparation procedures were de-signed Not all tests were performed on the steelpan because the interior coating flaked offcausing the pan to be removed from the study atthat time

Seventy-two ounces of white layer cake mixwas measured from a 5-lb box of Gold Medalwhite cake mix (Betty Crocker General MillsInc Minneapolis MN) and finely sifted to a mix-ing bowl The ratio of water to cake mix used was43 oz of cake mix to 29 oz of water One half ofthe water amount was added to the mixing bowlUsing a Hobart C-100 mixer (Hobart CorpTroy OH) with a paddle attachment the batterwas mixed at low speed for 05 min the sideswere scraped down and the batter was mixed asecond time at medium speed for 05 min Finallythe remaining water was added and the batterwas mixed at low speed for 05 min the sideswere scraped down and the batter was mixed asecond time at medium speed for 05 min Duringthis time the four test pans were sprayed with avegetable product lightly floured and tapped toremove any excess flour Eighteen ounces of themixed batter was weighed and added to each ofthe four pans Additional testing was performedfollowing the previously mentioned procedureswithout flouring the bottom of each pan to verifythe claim by silicone pan manufacturers of thepansrsquo nonstick qualities

When the cakes were baked in convectionovens oven temperature was typically reducedby 25

deg

F Times are generally determined to beapproximately the same and preheating is stillrecommended if the recipe calls for it The cakesin this study were baked approximately 19 minin a pre-heated 350

deg

F convection oven (the

Silicone bakeware

Nelson Barber et al



18

pp 43ndash51

46

desired conventional oven baking temperaturewas 375

deg

F) until each cakersquos internal temperaturemeasured between 185 and 190

deg

F These baketimes and temperatures were arrived at throughmultiple tests with the oven

Physical testing procedures

The following controlled tests were designed toevaluate the differences among the cake pansbull Pan release ndash a comparison of cake pan weightbefore adding batter was made with the cake panweight after removal of the baked cake (bakedcakes were allowed to cool for 20 min after bak-ing to provide the best removal of the cakeaccording to standard baking procedures)bull Crust browning ndash top and bottom surfaces werecompared for color using a LabScan XE Huntercolorimeter (Hunter Lab Associates Inc RestonVA) standardized with white and black platesTristimulus color coordinates were used to mea-sure the degree of lightness (

L

) redness or green-ness (

+minus

a

) and yellowness or blueness (

+minus

b

)bull Cake cross-sectional area ndash measured with acompensating polar planimeter The planimeterwas used for measurement of a cross section ofthe cakes and evaluated overall volume with stan-dard formula comparisonsbull Water activity ndash measured using a DecagonAqua lab CX-2 instrument that evaluated wateractivity (

a

w

) of each cake to describe whether thecakes tested were moist tender dry stale or hardbull Cake texture ndash measured using a TAXT2 tex-ture analyzer (Stable Micro Systems LtdGodalming UK) with a TAK-16 flat probe Thetexture analyzer used cake texture settings (test5 mms rupture test 1 mm distance 5 mmforce 2000 g time 5 s and trigger force 4 g)and applied a known force onto the cake samplesto measure the resistance to that pressurebull Relative overall heat transfer coefficient of thepans ndash estimated by placing the pans in a 3-galstock pot filled with hot water The water temper-ature as well as the inside surface of the pans weremeasured the water with a K-type thermocoupleand the pans with an infrared thermometer Oncesteady state was reached the ratio of the heatleaving the two pans was calculated based on thepan temperatures and the air temperature Thesecalculations assumed that the convection coeffi-

cient was approximately the same for both pansThe ratio of the heat leaving both pans was usedto calculate the ratio of the overall heat transfercoefficient for the two pans

Sensory testing procedures

As discussed earlier several different sensoryevaluation methods have been developed Thisresearch project used the ranking attribute dif-ference testing process (simple ranking) Thismethod tests samples according to a number ofattributes For the testing of cakes theseattributes are defined as

1 Moistness

dry need water to swallow unac-ceptable very moist melts in mouth dissolveseasily

2 Crust color

pale yellow undercooked noforms of browning apparent at all dark brownovercooked

3 Adhesiveness

crumbles flaky breaks apart intosmall pieces very tender rubbery elastic denserequires an unpleasant force to break apart

4 Firmness

soft has a low degree of resiliencesimilar to that of a sponge cake dense highdegree of resilience similar to that of pound cake

5 Mouthfeel

tender cakelike smooth andpleasant to the tongue chewy breadlike unpleas-ant for a muffinMeilgaard

et al

(1991) have outlined testing pro-cedures for ranking attribute sample testing Thepanelists selected a sample randomly from thetray presented For each of the five tests outlinedon the testing form they marked the box thatclosely matched the test attribute (see furtherexample) These scales used anchors at either endwith corresponding opposite attribute values Thescale was then coded from one to nine for statis-tical analysis For those tests that required tastingthe samples the panelists took a sip of water inbetween samples to cleanse the palate

Coding example

Sweetness (evaluated by taste) not at all sweet

much too sweet To supplement the objective measurements of

this study a semitrained panel of judges was usedPrior to testing all procedures were approved bythe Committee on the Use of Human Research

Silicone bakeware

Nelson Barber et al



18

pp 43ndash51

47

Subjects Thirty panelists volunteered from theHospitality and Tourism Management graduateand undergraduate departments at Purdue Uni-versity These students were enrolled in food ser-vice and research courses at the time of testingand had various levels of exposure to sensorytechniques To standardize sensory testing there-fore the students were provided with samples ofdifferent foods with similar texture attributes ofthe cakes they were sampling For examplecrackers dry bread and cupcakes were providedin sensory training sessions These judges were toassess the differences in color volume textureand taste between baking with silicone and non-silicone bakeware

Results of testing

Expectations of testing

Overall the silicone bakeware was not expectedto perform better as compared with the nonsili-cone bakeware primarily because the inherentvalue offered by the new bakeware is notimprovement in baking technology rather it is inflexibility attractiveness through multiple colorsand ease of storage

Visual testing by researchers

The results on color were noticeable The cakesbaked in the nonsilicone pans had a uniform crustcolor with no visible lsquofryingrsquo around the edgesVisually volume and texture appeared to be con-sistent between the four cakes

The pictures in Fig 3 show residual cake on thesides and bottom of each pan The pan on the left(blue) is a silicone bake pan and the pan in thecenter is a nonsilicone conventional metal bakingpan The pan on the right is also a silicone bakepan Both the pans on the left and in the centerwere sprayed with a nonstick vegetable spray and

lightly floured prior to adding the cake batter toaid in product release The photo on the right isa silicone pan that did not receive the nonstickvegetable spray or flouring prior to the additionof the cake batter

The manufacturers of silicone bake pans claimthey are lsquonaturallyrsquo nonstick with easy removalThe presence of residue on the bottom and sideof the silicon pans indicate that they are not aslsquonaturallyrsquo nonstick as the manufacturer claimedThis fact was confirmed by the researchers whenthey removed the cakes from the pans the diffi-culty level to remove the cake was approximatelythe same for both sprayed and floured pans Inaddition it is clear from the residual cake in thebottom of the two sprayed and floured pans thata greater degree of browning took place in thealuminum pan

Objective measurements

Sensory testing

The results of the sensory tests are shown inTable 1 With the exception of crust color therewere no significant differences between the sen-sory attributes and the type of bakeware usedHowever nonsilicone bakeware was significantlydifferent as compared to the silicone bakewarewhen the attributes of light crust color (df

=

500

t

=

533

P

=

lt

00001) and yellow crustcolor (df

=

500

t

= 423 P = lt00001) werecompared

Physical testingAs discussed previously the physical testingincluded pan release temperature moisture con-tent volume crust color texture measurementsand thermal conductivity The results are reflectedin Tables 2 and 3 and in Figs 4ndash7

The objective tests performed (and resultsshown in Table 2) did not show any significantdifference in performance of the two types of pans

Figure 3 Photographs of test pans

Blue Silicone Pan Aluminum Pan Silicone Pan no spray or flour

Silicone bakeware Nelson Barber et al

copy 2007 The AuthorsJournal compilation copy 2007 Blackwell Publishing Journal of Foodservice 18 pp 43ndash51

48

related to cake temperature or pan release weightFigure 4 reports the differences in water activitybetween the nonsilicone and silicone bakewareThe objective testing procedures for cake wateractivity did not result in significant differencesbetween silicone and nonsilicone pans althoughthe cakes from the nonsilicone bakeware tendedto have greater reported water activity

Figure 5 reports the testing differences in cross-sectional area between cakes baked in the nonsil-

icone and silicone bakeware The objective testingfor cake cross-sectional area showed a significantdifference in volume with the silicone cake panshowing a larger increase in volume Only twopans were used for volume measurement as thestructure of the cakes in the other two pans wascompromised by internal temperature probes

Figure 6 reports the differences in colorbetween the nonsilicone and silicone bakewareThe two objective tests for crust browning were

Table 1 Mean scores of sensory attributes by bakeware

n = 57Bakeware

Sensory attribute ndash mean score

Color light Color yellow Firmness Adhesiveness Mouthfeel Moistness

Silicone 24a 27a 25 45 35 64Nonsilicone 40b 41b 29 49 38 64

The scales used for each attribute tested were the following crust color 1 = light 9 = dark and 1 = yellow and9 = brown firmness 1 = soft 9 = dense adhesiveness 1 = crumbles 9 = rubber mouthfeel 1 = tender 9 = chewymoistness 1 = dry 9 = very moistMeans with different superscript letters were significant at P = 01

Table 2 Test results of cake pan weight and temperature testing

Blue silicone Nonstick black-coated aluminum

Weight w oil and flour (g) 2324 2467Weight of pan after cake is removed (g) 2268 2410Difference (g) 57 57Time started 44011 44017Time finished 45836 45847Difference 01825 01830Temperature ndash internal 856degC 856degC

Table 3 Thermal conductivity testing

ReadingTime lapse(s)

Bluesilicone

Temperature reading

Watertemperature

Black-coatedmetal pan

Watertemperature

Initial reading 0 76 184 71 1811st reading in water 5 102 184 158 1812nd reading 5 127 184 169 1813rd reading 5 143 184 173 1814th reading 5 152 184 174 1805th reading 5 157 184 174 1806th reading 5 161 184 174 1807th reading 5 164 184 174 1808th reading 5 165 184 175 1799th reading 30 168 182 175 17910th reading 30 168 182 175 17911th reading 30 167 181 175 179



49

based upon two samples from each cake Theresults indicate significant differences in measure-ment between the silicone and nonsilicone cakepans with the lightness factor (L) greatest for thesilicone pans

Figure 7 reports the testing differences in tex-ture between cakes baked in the nonsilicone andsilicone bakeware The objective testing for caketexture used samples from two different sectionsof each cake The results did not show any signif-icant differences between the pans although thealuminized steel pan showed the least amount offorce This would indicate a cake that is tenderhowever the variance found throughout thesetests made it impossible to identify trends

The final test was to determine the relativeoverall heat transfer coefficient of the silicone pancompared to the aluminum pan the results of thistest are shown in Table 3 The 10th reading(steady state) was used to calculate the ratio ofthe overall heat transfer coefficient for the twopans The overall heat transfer coefficient for thesilicone pan was 27 of that for the aluminumpan

Discussion

The visual sensory and physical testing did notshow any significant differences in the final bakedproducts except for volume and crust color anddevelopment The results of these tests showedthat nonsilicone pans did produce a darker andbetter developed crust while the silicone bake-ware had significantly greater cake volume Bothof these variations are a direct result of the rateof heat transfer through the pans

According to Potter (1973) crust color anddevelopment depend on Maillard reactions cara-melization of the sugar and crust surface dehydra-tion In order for the crust to brown sufficient

Figure 4 Cake water activity from different pans

Figure 5 Cake pan cross-sectional area measurements from different pans

Figure 6 Cake pan color from different pans

Figure 7 Cake texture from different pans



50

moisture must leave the cake to allow the temper-ature at the crust to rise sufficiently to allow theMaillard reaction to occur The rate at whichmoisture leaves the cake is directly related to therate of heat entering the cake The rate of heatentering the cake depends on the thermal conduc-tivity of the pan The silicone pan had an overallheat transfer rate that was 27 of the aluminumpan This meant that heat was able to enter thecake much faster for the aluminum pan than forthe silicone pan If heat enters the cake quickerthen the moisture will be driven off faster and thecake will brown quicker Based on the higherdegree of browning for the aluminum pan theresults of this test were as expected

Surface browning of cakes baked in the siliconepan may have been further retarded by the impactof the 1-in handle around the blue silicone pan(see Fig 3 left picture) The cakes were cookedin a convection oven The large lip may haveinterrupted the air flow to the surface of the cakewhich in turn would have reduced the rate of heattransfer to the surface thus lengthening the timerequired for the surface temperature to rise suffi-ciently for the Maillard reaction to have takenplace

The increased volume of the cake baked in thesilicone pan can also be explained by the rate ofheat transfer and crust development Once thecrust develops it makes it more difficult for thecake to expand further Because the cake bakedin the aluminum pan received more heat anddeveloped a darker crust it is reasonable toexpect it to rise less than the one cooked in thesilicone pan

Clearly the slower rate of heat transfer throughthe silicone pan affected the cooking processHowever the internal temperatures of both cakeswere the same at the end of the approximately19 min of cooking time This means that the lim-iting factor for heat transfer was not the pan butthe cake itself While the heat transfer rate throughthe silicone was slower it was fast enough to keepup with the rate that the cake was capable ofaccepting the heat at least for most of the cookingtime What this means is that the cake pan inter-face (transfer and acceptance of heat) for the sil-icone would be at a lower temperature than thatfor the aluminum The lower interface tempera-ture would have an impact on the browning that

occurred Additionally the silicone bakewaremanufacturers claim that the cooking processstops as soon as the food is removed from theoven preventing further browning of the bottomor sides of the food This can have a positive effecton preventing the cake from becoming overcookedat the interface before the remainder of the cakeis done Indeed the cake cooked in the siliconepan had less crust formation at the pan interface

In the final analysis the silicone pans per-formed on par with more conventional bakewareThe sticking characteristics of a silicone pancoated with a nonstick vegetable spray thenlightly floured were the same as for a metal panreceiving the same treatment The one advantageof the silicone pan was the greater volume of thefinal product ndash an advantage offset by the lowerdegree of top browning The degree of browningcould have been increased if the cakes were bakedlonger however this would have affected theirother characteristics (eg moisture) The endresult may have been a drier cake with a lessdesirable texture Additionally the flexible natureof the pans made them harder to handle than therigid metal pans To determine the true value ofusing silicone pans further testing is necessary todetermine the performance of the pans in differ-ent types of ovens at different temperatures uti-lizing different cooking times Additionally a costanalysis comparing price with durability and lifeexpectancy should be conducted

Acknowledgement

The researchers would like to recognize the Pur-due University Avery Foodservice Laboratory forits contribution of the cake mix and use of itsconvection ovens and the Purdue UniversityFood and Nutrition Laboratory for the use of itstesting equipment (LabScan XE Hunter color-imeter TAXT2 texture analyzer compensatingpolar planimeter and the Decagon Aqua labCX-2)

References

Almazoptics (2006) Available at httpwwwalmazopticscomSihtm (accessed 5 May 2006)

Bilgen S Yalcin C Karababa E (2004) Effects of bak-ing parameters on the white layer cake quality by



51

combined use of conventional and microwave ovensJournal of Food Processing and Preservation 2889ndash102

Dow Corning Corporation (2006) httpwwwdowcorningcomcontentrubberrubberproprubber_thermalasp (accessed May 3 2006)

DVO Enterprises Inc (2003) Available at httpwwwdvocomsiliconehtml (accessed June 7 2006)

Hawks L (2003) Cooktops and Cookware Utah StateUniversity Logan UT

Meilgaard M Civille GV Carr BT (1991) SensoryEvaluation Techniques 3rd edn CRC Press IncBoca Raton FL

Perry RH Green DW Maloney JO (1997) PerryrsquosChemical Engineerrsquos Handbook Table 2-374 7th edMcGraw-Hill Companies Inc New York

Potter N (1973) Food Science 2nd edn AVI PublishingCompany Inc West Port CT

Whitaker AM Barringer SA (2004) Measurement ofcontour and volume changes during cake bakingCereal Chemistry 81177ndash81

Wilson P (2001) Determination of Water ActivityUsing the Decagon Aqua lab CX-2 and Series 3Laboratory Procedure MFLP-66 Health Productsand Food Branch Canadian Food InspectionAgency

Silicone bakeware

Nelson Barber et al



18

pp 43ndash51

44

(Hunter Associates Lab Reston VA) The instru-ment settings are Illuminant C Display

L

a

and

b

Standard Observer 2

deg

The spectro-photometer is calibrated with white and blackporcelain ceramic plaques supplied by the manu-facturer Resulting values are typically recordedin triplicate for each observation Additionalcolor attributes such as total color difference(AE) whiteness value saturation index and yel-lowness index are calculated from

L

a

and

b

values (Bilgen

et al

2004) Figure 1 shows theuniform diagram of color relationship

Characteristics of quality bakeware

To work effectively bakeware should be made ofa material that conducts heat quickly and evenlyThe speed with which a material conducts heat isnot only affected by the material but also by itsthickness thin materials conduct heat quicklywhile thick materials conduct heat more slowlyFood professionals believe that a materialrsquos abilityto conduct heat quickly is one of the most im-portant considerations in choosing cookwareFigure 2 shows copper to be the fastest conductorof heat aluminum is second Glass ceramic andheat-resistant glass are the slowest conductors ofheat Copper cookware should be lined withanother material such as stainless steel or tin sothe food will not come into contact with thecopper which interacts with foods to form toxicsubstances

Aluminum is considered a fast conductor ofheat Although its conductivity is only half that

of copper it is four times that of iron or steelAluminum cookware is made by stamping draw-ing or casting and comes in a variety of gaugesfrom very thin to very thick (Hawks 2003)

Manufacturersrsquo data on silicone

Silicone is a class of inorganic rubbers of variouscompositions and formulas that is made by link-ing variously bonded silicon atoms to oxygen andother organic groups Silicone is developed for itssuperior reliability long life and extreme tem-perature adaptability and stability ndash it will notbecome misshapen or break down because ofextreme temperature exposure Silicones can befound in liquid and solid forms depending uponuses and curing processes Silicone bakewareis made using a high-temperature compressionmolding process Products are sold in various col-ors which cost more than a clear product (DVOEnterprises Inc 2003)

Silicone bakeware was introduced to the mar-ket in early 2000 The thermal conductivity ofpure silicon 105 Wm (Almazoptics 2006) is lessthan half of the 240 Wm

deg

K of aluminum butmore than six and a half times the 16 Wm

deg

K ofstainless steel (Perry

et al

1997) The meltingpoint of silicone is 932

deg

F however the maximumsustained temperature use is 675

deg

F meaning thatthe bakeware can be left at 675

deg

F indefinitelywithout breaking down Silicone bakeware canalso be used at temperatures as low as

minus

58

deg

F(Dow Corning Corporation 2006)

The purity of silicone paired with high-qualitymanufacturing processes ensures even heat distri-bution The use of high-density silicone in com-bination with very even wall thickness allows for

Figure 1

CIELAB uniform diagram showing relation-ship of redgreen (

a

+

minus

) and yellowblue (

b

+

minus

) oppo-nent coordinates to lightness

L

chroma

C

and hue angle

h

Figure 2

Heat conductivity for selected materials

Silicone bakeware

Nelson Barber et al



18

pp 43ndash51

45


Sensory testing



et al



et al



et al



et al









deg


deg


Silicone bakeware

Nelson Barber et al



18

pp 43ndash51

46


deg


deg




L


+minus

a


+minus

b


a

w





1 Moistness


2 Crust color


3 Adhesiveness


4 Firmness


5 Mouthfeel


et al


Coding example




Silicone bakeware

Nelson Barber et al



18

pp 43ndash51

47


Results of testing









Sensory testing


=

500

t

=

533

P

=

lt


=

500

t








48






n = 57Bakeware










Bluesilicone

Temperature reading

Watertemperature


Watertemperature




49




Discussion









50







Acknowledgement


References





51










Silicone bakeware

Nelson Barber et al



18

pp 43ndash51

45


Sensory testing



et al



et al



et al



et al









deg


deg


Silicone bakeware

Nelson Barber et al



18

pp 43ndash51

46


deg


deg




L


+minus

a


+minus

b


a

w





1 Moistness


2 Crust color


3 Adhesiveness


4 Firmness


5 Mouthfeel


et al


Coding example




Silicone bakeware

Nelson Barber et al



18

pp 43ndash51

47


Results of testing









Sensory testing


=

500

t

=

533

P

=

lt


=

500

t








48






n = 57Bakeware










Bluesilicone

Temperature reading

Watertemperature


Watertemperature




49




Discussion









50







Acknowledgement


References





51










Silicone bakeware

Nelson Barber et al



18

pp 43ndash51

46


deg


deg




L


+minus

a


+minus

b


a

w





1 Moistness


2 Crust color


3 Adhesiveness


4 Firmness


5 Mouthfeel


et al


Coding example




Silicone bakeware

Nelson Barber et al



18

pp 43ndash51

47


Results of testing









Sensory testing


=

500

t

=

533

P

=

lt


=

500

t








48






n = 57Bakeware










Bluesilicone

Temperature reading

Watertemperature


Watertemperature




49




Discussion









50







Acknowledgement


References





51










Silicone bakeware

Nelson Barber et al



18

pp 43ndash51

47


Results of testing









Sensory testing


=

500

t

=

533

P

=

lt


=

500

t








48






n = 57Bakeware










Bluesilicone

Temperature reading

Watertemperature


Watertemperature




49




Discussion









50







Acknowledgement


References





51












48






n = 57Bakeware










Bluesilicone

Temperature reading

Watertemperature


Watertemperature




49




Discussion









50







Acknowledgement


References





51












49




Discussion









50







Acknowledgement


References





51












50







Acknowledgement


References





51












51










silicone bakeware: does it deliver a better product?

Documents