Transcript
  • Validation of Loss on Drying Methods in Pet Foods

    Dr. Jane M. Caldwell 2018 AAFCO Annual Meeting

    Fort Lauderdale, FL July 31, 2018

  • Pet Food Categories

    • Dry pet food (15%) • Wet pet food (>30%) • Freeze-dried pet treats (

  • MoistureinDryPetFoodDeterminedbyTitration(KarlFischer)andLoss-on-Drying(LOD)OvenMethods(Study1)

    MethodNumber OfficialName Temp(⁰C) Time(hr) Equipment/Procedure N MeanMoisture

    (%)

    RelativeRecovery

    (%)

    AOAC930.15 LODforFeeds 135 2 ConvectionOven 33 8.03a* 112

    AOAC935.29/945.15 LODinMalt 104 3 ConvectionOven 33 7.73a 108

    AOAC950.46 LODinMeat 125 4 ConvectionOven 24 7.63a 106

    AOAC2001.12(I) MoistureinFeed,Grain&Forage(MEOH/Formamide)

    50 n/a Titration(KarlFischer) 24 7.18ab 100

    ASTMD6869-03 MoistureinPlastics 130 var Titration(KarlFischer) 24 7.06ab 98

    AOAC2001.12(II) MoistureinFeed,Grain&Forage(boilingMEOH)

    66 n/a Titration(KarlFischer) 8 6.80ab 95

    AOAC969.35/925.45A LODinSugars(Mod.) 70 4 VacuumOven 33 6.25b 87

    *Levelsnotconnectedbythesameletteraresignificantlydifferent(p>0.05)

  • MoistureinDryPetFoodDeterminedByTitration(KarlFischer)andLoss-on-DryingOven(LOD)OvenMethods(Study2)

    Moisture(%)

    Sample AOAC2001.12(I) ASTMD6869-03 AOAC950.45B(b) AOAC945.15 AOAC969.35N=3 KarlFischer(Feed) KarlFischer(Plastic) Convection(125⁰C,4h) Convection(105⁰C,3h) Vacuum(70⁰C,4h)

    1 6.57a 6.79a 6.46a 7.03 5.55

    2 6.97a 7.31a 7.14a 7.60 5.79

    3 7.50a 7.93 7.69a 8.41 7.18a

    4 7.63a 8.19a 7.70a 8.99 7.67a

    5 6.17a 5.78 6.07a 6.23a 4.49

    6 6.03a 5.31 5.70 6.03a 3.79

    7 7.80 6.86 7.53 7.46 5.80

    8 7.20a 6.31 7.30a 7.06a 5.50

    9 4.66a 3.93 4.28a 4.09 2.58

    10 9.47a 9.16a 10.00 9.97 8.45

    11 7.20a 6.73a 7.16a 7.07a 5.6112 7.33a 7.23 7.34a 7.48a 6.19

    aMeanswithinarowwiththesameletterarenotstatisticallydifferent(p>0.05)fromKarlFischerAOAC2001.12(I)mean.

  • Observations for LODs in Dry Pet Food

    •  KF (AOAC 2001.12) is LOD validation standard

    •  Convection •  135⁰C too hot (118%) •  125⁰C okay •  104⁰C okay

    •  Vacuum: too low at 4 h

  • MoistureinDryPetFood(Grain-free)DeterminedbyTitration(KarlFischer)andLoss-on-Drying(LOD)OvenMethods*

    Method Lab Temp(⁰C) Time(hr) Equipment/Procedure MeanMoisture

    (%)

    RelativeRecovery

    (%)

    AOAC930.15 X 135 2 ConvectionOven 8.72a** 110

    AOAC930.15/925.10 Y 133 2 ConvectionOven 8.42ab 106

    AOAC930.15 Z 135 2 ConvectionOven 8.18ab 103

    AOAC991.02 Y n/a n/a Titration/Methanolextraction(KarlFischer)

    7.93bc 100

    AOCSCa2e-84 X n/a n/a Titration(KarlFischer) 7.79bcd 98

    AOAC935.29 X 104 3 ConvectionOven 7.78bcd 98

    NFTA2.2.2.5 Z 105 3 ConvectionOven 7.76c 98

    AOAC934.06/925.45 Y 70 Overnight VacuumOven 7.48cd 94

    ASTMD6869-03 Z 130 n/a Titration(KarlFischer) 7.24de 91

    AOAC925.09 X 100 5 VacuumOven 6.75ef 85

    AOAC969.35 Z 70 4 VacuumOven 6.24f 79

    *TotalN=34;LabX&Yhad2N/method;LabZhad5N/method

    **Levelsnotconnectedbythesameletteraresignificantlydifferent(p>0.05)

  • MoistureinDryPetFood(HighProtein/Meat)DeterminedbyTitration(KarlFischer)andLoss-on-Drying(LOD)OvenMethods*

    Method Lab Temp(⁰C) Time(hr) Equipment/Procedure MeanMoisture

    (%)

    RelativeRecovery

    (%)

    AOAC930.15 Z 135 2 ConvectionOven 6.10a** 111

    AOAC930.15 X 135 2 ConvectionOven 5.98ab 109

    AOAC930.15/925.10 Y 133 2 ConvectionOven 5.82abc 106

    NFTA2.2.2.5 Z 105 3 ConvectionOven 5.74bc 105

    ASTMD6869-03 Z 130 n/a Titration(KarlFischer) 5.52cd 101

    AOAC991.02 Y n/a n/a Titration(KarlFischer) 5.48cd 100

    AOCSCa2e-84 X n/a n/a Titration(KarlFischer) 5.44cd 99

    AOAC935.29 X 104 3 ConvectionOven 5.17de 94

    AOAC934.06/925.45 Y 70 Overnight VacuumOven 4.98ef 91

    AOAC925.09 X 100 5 VacuumOven 4.70fg 86

    AOAC969.35 Z 70 4 VacuumOven 4.40g 80

    *TotalN=34;LabX&Yhad2N/method;LabZhad5N/method

    **Levelsnotconnectedbythesameletteraresignificantlydifferent(p>0.05)

  • MoistureinDryPetFood(Potato)DeterminedbyTitration(KarlFischer)andLoss-on-Drying(LOD)OvenMethods*

    Method Lab Temp(⁰C) Time(hr) Equipment/Procedure MeanMoisture

    (%)

    RelativeRecovery

    (%)

    AOAC930.15 Z 135 2 ConvectionOven 9.21a** 126

    AOAC930.15 X 135 2 ConvectionOven 9.12ab 125

    AOAC930.15/925.10 Y 133 2 ConvectionOven 8.90ab 122

    NFTA2.2.2.5 Z 105 3 ConvectionOven 8.52bc 116

    AOAC935.29 X 104 3 ConvectionOven 7.96cd 109

    ASTMD6869-03 Z 130 n/a Titration(KarlFischer) 7.63d 104

    AOAC934.06/925.45 Y 70 Overnight VacuumOven 7.56d 103

    AOAC991.02 Y n/a n/a Titration(KarlFischer) 7.32de 100

    AOCSCa2e-84 X n/a n/a Titration(KarlFischer) 7.24de 99

    AOAC925.09 X 100 5 VacuumOven 6.60ef 90

    AOAC969.35 Z 70 4 VacuumOven 6.44f 88

    *TotalN=34;LabX&Yhad2N/method;LabZhad5N/method

    **Levelsnotconnectedbythesameletteraresignificantlydifferent(p>0.05)

  • MoistureinDryPetFood(Economy)DeterminedbyTitration(KarlFischer)andLoss-on-Drying(LOD)OvenMethods*

    Method Lab Temp(⁰C) Time(hr) Equipment/Procedure MeanMoisture

    (%)

    RelativeRecovery

    (%)

    AOAC930.15 Z 135 2 ConvectionOven 8.45a** 109

    AOAC930.15 X 135 2 ConvectionOven 8.20abc 106

    NFTA2.2.2.5 Z 105 3 ConvectionOven 8.08ac 105

    AOAC930.15/925.10 Y 133 2 ConvectionOven 7.76abcd 101

    AOAC991.02 Y n/a n/a Titration(KarlFischer) 7.72abcd 100

    ASTMD6869-03 Z 130 n/a Titration(KarlFischer) 7.50bd 97

    AOCSCa2e-84 X n/a n/a Titration(KarlFischer) 7.37bcd 95

    AOAC935.29 X 104 3 ConvectionOven 7.28de 94

    AOAC934.06/925.45 Y 70 Overnight VacuumOven 6.99def 91

    AOAC969.35 Z 70 4 VacuumOven 6.51f 84

    AOAC925.09 X 100 5 VacuumOven 6.45ef 84

    *TotalN=34;LabX&Yrunduplicatereps/method;LabZranquintuplicatereps/method

    **Levelsnotconnectedbythesameletteraresignificantlydifferent(p>0.05)

  • Observations for LODs in Dry Pet Food; part 2

    Did NOT use KF standard for animal feed (1-15%) It depends…LAB and INGREDIENT variation

    •  Grain-Free •  135⁰C might work (103-110%) •  104⁰C good (98%) •  Vacuum OVERNIGHT (94%)

    •  High Protein •  KFs all close (99-101%) •  104⁰C good (94 & 105%) •  DID NOT RUN 125⁰C

  • Observations for LODs in Dry Pet Food; part 2

    It depends… •  Potato

    •  135⁰ too hot (122-126%) •  104⁰C hot (109-116%) •  Vacuum ON (103%)

    •  Economy •  133⁰C great (101%) •  DID NOT RUN 125⁰C •  104 & 105⁰C okay (94 & 105%)

    Validate with AOAC 2001.12

  • MoistureinSemi-MoistPetTreatsDeterminedbyTitration(KarlFischer)andLoss-on-Drying(LOD)OvenMethods

    MethodNumber OfficialName Temp(⁰C)

    Time(hr)

    Equipment/Procedure N MeanMoisture

    (%)

    RelativeRecovery

    (%)

    AOAC930.15 LODforFeeds 135 2 ConvectionOven 34 24.61a* 120

    AOAC935.29 LODinMalt 104 3 ConvectionOven 34 24.08a 118

    ASTMD6869-03 MoistureinPlastics 130 var Titration(KarlFischer) 34 21.12b 103

    AOAC969.35/925.45A LODinSugars 70 4 VacuumOven 34 20.75b 102

    AOAC991.02 MoistureinSemi-MoistPetTreats

    n/a n/a MethanolExtractionTitration(KarlFischer)

    25 20.43b 100

    *Levelsnotconnectedbythesameletteraresignificantlydifferent(p>0.05)

    Glycerinandotherhumectantsintreats.

    AOAC991.02titratesformoistureinsoft-moistandsemi-moistpetfoodscontaining20-30moistureandothervolatilematerials.

    Goldstandardforthismatrix.

    Samplesrangefrom17to26%moisture.

  • Observations for LODs in Semi-Moist Pet Treats

    • LOD in Sugars (102%): How sweet it is! • Vacuum oven • 70⁰C • 4 hours

  • MoistureinWetPetFoodDeterminedbyTitration(KarlFischer)andLoss-on-Drying(LOD)OvenMethods

    MethodNumber OfficialName Temp(⁰C) Time(hr) Equipment/Procedure N MeanMoisture

    (%)

    RelativeRecovery

    (%)

    NFTA2.2.1.1/2.1.4 LODforForages,Silage,WetFeeds(Two-stepmethod)

    55(105)

    ON(3)

    ConvectionOvens 20 76.64a 100

    AOAC991.02 MoistureinSemi-MoistPetTreats(Two-stepmethod)

    55(n/a) ON(n/a) ConvectionOvenMethanolExtractionTitration(KarlFischer)

    20 76.54a 100

    AOAC935.29 LODinMalt 104 3 ConvectionOven 20 75.39a 98

    AOAC950.46B(b) LODinMeat 125 4 ConvectionOven 20 75.37a 98

    AOAC930.15 LODforFeeds 135 2 ConvectionOven 20 75.35a 98

    AOAC991.02 MoistureinSemi-MoistPetTreats n/a n/a MethanolExtractionTitration(KarlFischer)

    20 71.76b 94

    *Levelsnotconnectedbythesameletteraresignificantlydifferent(p>0.05)

    AOAC991.02titratesformoistureinsoft-moistandsemi-moistpetfoodscontaining20-30moistureandothervolatilematerials.

  • Observations for LODs in Wet Pet Food

    •  Two-step methods for KF and LOD •  104, 125 & 135⁰C also 98% •  KF for semi-moist low (94%) •  More data needed.

  • MoistureinFreeze-DriedPetFoodTreatsDeterminedbyTitration(KarlFischer)andLoss-on-Drying(LOD)OvenMethods

    MethodNumber OfficialName Temp(⁰C) Time(hr) Equipment/Procedure N MeanMoisture

    (%)

    RelativeRecovery

    (%)

    AOAC2001.12(I) MoistureinFeed,Grain&Forage(MEOH/Formamide)

    50 n/a Titration(KarlFischer) 7 3.31a* 100

    ASTMD6869-03 MoistureinPlastics 130 var Titration(KarlFischer) 7 2.86a 86

    AOAC935.29 LODinMalt 104 3 ConvectionOven 7 2.55a 77

    AOAC969.35/925.45A

    LODinSugars 70 4 VacuumOven 7 0.77b 23

    AOAC969.35/925.45D**

    LODinSugars 60 18 VacuumOven 7 0.77b 23

    *Levelsnotconnectedbythesameletteraresignificantlydifferent(p>0.05)

    **NodigestquartzsandusedinDmethod.

  • MoistureinFreeze-DriedPetFoodTreatsDeterminedbyTitration(KarlFischer)andLoss-on-Drying(LOD)OvenMethods–Study2

    MethodNumber OfficialName Temp(⁰C) Time(hr) Equipment/Procedure N MeanMoisture

    (%)

    RelativeRecovery

    (%)

    AOAC930.15 LODforFeeds 135 2 ConvectionOven 7 5.95a* 138

    AOAC950.46B(b) LODinMeat 125 4 ConvectionOven 7 5.17a 120

    AOAC2001.12(I) MoistureinFeed,Grain&Forage(MEOH/Formamide)

    50 n/a Titration(KarlFischer) 7 4.30a 100

    *Levelsnotconnectedbythesameletteraresignificantlydifferent(p>0.05)

  • Observations for LODs in Freeze-Dried Pet Food Treats

    •  Chewy.com • 

  • MoistureinDriedBeefSticksDeterminedbyTitration(KarlFischer)andLoss-on-Drying(LOD)OvenMethods

    MethodNumber OfficialName Temp(⁰C)

    Time(hr) Equipment/Procedure N MeanMoisture

    (%)

    RelativeRecovery

    (%)

    AOAC2001.12(I) MoistureinFeed,Grain&Forage(MEOH/Formamide)

    50 n/a Titration(KarlFischer) 7 13.66a* 100

    AOAC930.15 LODforFeeds 135 2 ConvectionOven 7 13.37a 98

    AOAC950.46B(b) LODinMeat 125 4 ConvectionOven 7 11.54a 84

    *Levelsnotconnectedbythesameletteraresignificantlydifferent(p>0.05)

  • Discussion of Pet Food LOD Results

    • Review data • Commentary period for labs/stakeholders • Suggestions for further studies • Can we make some conclusions/give guidance?

  • Dr. Jane Caldwell402-829-9858

    [email protected]

    Dr. Jane M. Caldwell402-979-1411

    [email protected]

  • Karl Fischer (Moisture by Titration)

    GOLD STANDARD: Reaction of iodine with water. Used for TRUE MOISTURE & NIR calibration

    Not free of procedural issues……..

    •  AOAC 2001.12 (I & II) (2005) – Moisture in Animal Feed, Grain and Forage (1-15%) •  AOAC 991.02 (1995) – Moisture in Soft-Moist & Semi-Moist Pet Treats (20-30%) •  ASTM D6869-03 (2011) - Moisture in Plastics (0.005-100%) •  AOCS Ca 2e-84 (1997) Moisture in Fats & Oils

  • AOAC 2001.12 (I) Moisture in Animal Feed, Grain and Forage (1-15%)

    •  High-speed homogenization in vessel? •  Pre-homogenization outside vessel

    •  MEOH/Formamide extraction (50⁰C)

    •  Time in titration vessel not a factor

    •  Run in triplicate •  Comparable to ASTM D6869-03

  • AOAC 2001.12 (II) Moisture in Animal Feed, Grain and Forage (1-15%)

    •  Boiling MEOH (66⁰C) •  No obvious advantages over (I).

    •  Small volume of water easy to release? •  Vapor pressure issues •  Never used

  • AOAC 991.02 – Moisture in Soft-Moist & Semi-Moist Pet Treats (20-30%)

    •  MEOH extraction with titration

    •  Shake 15 min @ room temperature

    •  10 g

    •  Results always low

    •  Limited by time

  • ASTM D6869-03 - Moisture in Plastics (0.005-100%)

    •  Used by global pet food giants

    •  0.10 to 1.0 g (

  • AOCS Ca 2e-84 (1997) Moisture in Fats & Oils

    •  5-25 g sample of fat or oil

    •  Chloroform/methanol extraction

    •  Electrometric end point

    •  No time restrictions


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