Crude Fat Methods in Corn Derived DDGS

Transcription

1 Crude Fat Methods in Corn Derived DDGS AAFCO Meeting, August

2 Agenda DDG Market DDG Working Group Method Data Conclusions Source presentation EDR: 1-F-MK-PRE Source modification date: 02/11/2011 2

3 AFIA Definition 3

4 Typical Specifications Corn DDGs Minimum Crude Protein...27% Wheat DDGs Minimum Crude Protein...34% Minimum Crude Fat...8% Minimum Crude Fat...4% Maximum Crude Fiber...15% Maximum Crude Fiber...8.5% Common Commercial Requirement = 35% Profat No Commercial Requirements for Analytical Methods 4

5 DTIWG AFIA DDGS Analytical Methods Sub-Working Group (Operating under the AFIA DDGS Technical Issues Working Group) Members: Shon Van Hulzen Dr. Lance Forster Charlie Staff Dr. Thomas Robb Dr. Phil Smith Thomas Sliffe Trace Yates Mark Host Lars Reimann Broin Management ADM Distillers Grain Technology Council Abengoa Bioenergy Tyson Foods, Inc. Perten Instruments Tyson Foods FOSS North America Eurofins Scientific 5

6 SDSU Study - Interlab Mean Comparisons 6

7 Intralaboratory Precision 7

8 Interlaboratory Precision 8

9 DITWG conclusion Crude Fat AFIA Working Group - Crude Fat The three non-hydrolysis fat methods (AOAC , AOAC , and AOAC ) were determined to be statistically equivalent methods for the analysis of DDGS, however, in the interlaboratory portion of the study, AOAC , Oil in Cereal Adjuncts (Petroleum Ether), had a significantly lower coefficient of variation than the other non- hydrolysis methods and has thereby proven to be a more robust method in the analytical community, and is therefore chosen as the recommended test method for the analysis of fat in DDGS 9

10 Methods currently used in the commercial trade AOAC Pet Ether Soxhlet Extraction Weigh 5-10 grams sample as-is Soxhlet Extract 6 hours Pet Ether Evaporate collected solvent and weigh extracted oil Total processing time 8 9 hours 10

11 Methods currently used in the commercial trade AOAC Ethyl Ether Soxhlet Extraction Weigh 2 gram test portion Wash with 5 x 20 ml portions DI water Dry C for 3 hours Soxhlet Extract 4-16 hours Ethyl Ether Evaporate collected solvent and weigh extracted oil 11

12 Methods currently used in the commercial trade AOAC Hexane- Randall/SoxTec Submersion Extraction Weigh 1-5 grams sample into tared extraction thimble Dry 102C for minimum 30minutes Immerse into solvent and boil min 20 minutes Raise and extract thimbles for 40 minutes Evaporate Solvent and weigh extracted oil by difference 12

13 AAFCO Interlab Results 2009 AAFCO Sample DDG Corn Distillers Grain Avg Range of Dups Inter-lab Precision on both ethyl ether methods significantly higher than Intra-lab precision Ethyl ether extraction results remain higher in general but Soxtec / EE is much higher Avg Range of Dups Method Ref AAFCO Method # Labs Pass 1 Mean Pass 1 Stdev # Labs Pass 2 Mean Pass 2 Stdev Fat, Ethyl Ether, Direct Fat, Ethyl Ether Indirect Fat, Pet ether Fat, Soxtec, Ethyl ether Fat, Soxtec, Pet Ether Fat, NIR Fat, Hexane Fat, Soxtec, Hexane Fat, Ankom Fat, Misc Method

14 Single Lab Comparison Ethyl Ether vs Pet ether 2015 Cal ID AOAC Ethyl Ether Extraction (%) AOAC Pet Ether Extraction (%) Difference % Relative Diff % 0713B % 0713B % 0713B % 0713B % 0713B % 0713B % 0713B % 0713B % 0609B % 0609B % 14

15 Single Lab Precision AOAC Long Term Analyte: CAL SOP: Fat M-4.1 QC Sample ID: DDG-7.2 QC Sample descdried Distillers Grain Expected value: 6.57 % Running stats: (used only for statistics & bias) Average: 6.60 StDev: Stdev: StDev: StDev: StDev: StDev: StDev: 6.29 # Data points 190 % RSD: 1.59% Reporting units: % NOPA stats (used for determining in/out of spec) Avg StDev: Stdev: StDev: StDev: StDev: StDev: StDev: 6.26 Avg Bias

16 Single Lab Precision Short Term AOAC Variance of Pairs over range of DDG Fat values Rep1 Rep2 Avg Std %RSD Average RSD % % % % 1.09% 16

17 Intra-lab comparison with other Fat Methods Sample ID Pet Ether Ethyl Ether AH -EE by AH- GC B B B B

18 Fat in Crude extracts So far inconsistent data 18

19 Observations on AOAC / Ethyl ether is much more volatile, and tap water cooling of condensers must be degrees C. In summer, requires chiller unit in some parts of the USA AOAC requires 2-day completion as written Higher bias appears to be generally higher than original SDSU study comparing Ethyl ether vs. Pet ether methods Intra-lab Precision appears to be improved over original SDSU study comparing Ethyl ether vs. Pet ether methods A proficiency study or ring trial is needed to produce updated Inter-lab data for these current methods 19

20 AOCS DDGS Proficiency series Dear LPP Participant, AOCS is excited to introduce a proficiency testing series for Distillers Dried Grains with Solubles (DDGS) from corn meal. The first year includes 6 samples (2 in September; 2 in December; 2 in March). The analytes of interest are: moisture, crude protein, crude fat, crude fiber, and ash (optional). Results are requested in duplicate for method validation purposes. Laboratories are encouraged to use the listed methods (see below) though alternate methods are acceptable provided a method reference is remitted. Methods Moisture: NFTA (105 C / 3 hr) Protein: AOAC (Combustion) and AOAC (Kjeldahl, Cu Catalyst) Crude Fat: AOAC , AOAC , and AOAC Crude Fiber: AOAC and AOCS Ba 6a-05 Enrollment will open August 1, 2015, with a deadline of August 20, Sign up today! 20

21 AOCS DDGS PT Series Benefits of a trade based Proficiency Series 1) Comparison between labs on recent methods 2) Restudy Precision in commercially practicing labs 3) Provide a vehicle for improved lab harmonization 21

22 Thank you!! 25 Years of Laboratory Excellence Title: Back-up / Appendix Document name: Company Presentation_Food_Feed_additional slides.ppt EDR: 1-F-MK-PRE Document owner: Florian Heupel Last modified on: 02/11/