David Conoulty of Commodity Inspection Services outlines the various factors involved with testing for the quality of agricultural commodities during the shipping process. The presentation covers the analysis process, the reliability of results, analytical methods and the improved equipment used to perform quality laboratory analysis.

1. Product Analysis and Trade Issues
David Conoulty
Commodity Inspection Services Australia

2. Introduction
• Analysis determines quality at time
of shipment
• Many factors can affect reliability of
results
• Differences between loading and
discharge analysis
• Precision and accuracy important
• Benefits from improved technology

3. Shipment Analysis
• Shipment testing determines the quality of goods at time of loading
• Done in accordance with a set of agreed parameters
• Certificate of Quality or Analysis issued

4. Other Roles of Analysis
• Pre shipment testing addresses quality issues prior
to loading
• Testing for conformity with government regulations
• Discharge Analysis
• Damage Assessment
• Quality Disputes

5. Differences in Shipped vs Arrival Analysis
- Laboratory Proficiency
• Quality disputes can arise from load port and discharge port differences
• Large differences may require explanation
• A UK Food Proficiency Assessment Scheme (FAPAS) study 1990-1996, found
that for Pig Feed Proximate analysis only 76% of laboratories had
satisfactory results.
• The percentage improved when laboratories participated
in regular proficiency testing programmes

6. Proficiency Test on Feed Product

7. FACTORS INFLUENCING ANALYSIS
OUTCOMES
A number of factors can impact on the accuracy of analysis results

8. A number of factors can
influence outcomes:
• Product Variability
• Changes in Product Characteristics
• Sample Collection, Reduction and Preparation
• Different Methods of Analysis

9. Product Variability
PROTEIN % MOISTURE % FAT % ASH %
MBM 55 55% Min. 4% Min. 10% Max. 15% Max. 30% Max.
MBM 50/38 50% Min. 4% Min. 10% Max. 15% Max. 38% Max.
MBM 50/36 50% Min. 4% Min. 10% Max. 15% Max. 36% Max.
MBM 50/32 50% Min. 4% Min. 10% Max. 15% Max. 32% Max.
MBM 50/28 50% Min. 4% Min. 10% Max. 15% Max. 28% Max.
MBM 48 48% Min. 4% Min. 10% Max. 15% Max. 37% Max.
MBM 45 45% Min. 4% Min. 10% Max. 15% Max. 38% Max.
GTA Standards 2012/2013 list seven quality specifications for Australian Meat and Bone Meal

10. Changes In Product
Characteristics
• Tallow is susceptible to
chemical and physical
change.
• Excess moisture and
heat can result in
hydrolysis and
increased FFA
Hydrolysis of Fats and Oils

11. Changes in Product
Characteristics
• Oxidation occurs in
presence of
heat, fines, metal
ions, oxygen and
light, causing
rancidity, colour and
bleaching problems.
• Careful heating and
handling required
Oxidation of Fats and Oils

12. Changes in Product
Characteristics
• The Effect of Moisture
on FFA
• Higher the moisture
the more rapid the
increase in FFA
• The rate of increase
reduces at lower
moisture levels.
FFA of Tallow before and after Storage for
6 Weeks at 49 Deg.C

13. SAMPLING AND REDUCTION
The importance of correct procedure

14. The Importance of Sample Collection
• Sampling is vital to the accuracy and reproducibility of test results.
• Inappropriate sampling will introduce error and affect analysis results.
• Rendered products are not homogeneous.
• Separation can take place in handling.
• Sampling procedures should reflect this.

15. The Importance of Sample
Collection
• Bulk meal is best sampled from
a moving stream.
• Sampling is often done in static
situations which are more
prone to error.
• Some parts have little or no
chance of being collected.
• Following recognised
procedures gives validity.
• Procedures are published by
ISO, FOSFA, GAFTA, Codex and
others.
Sampling dry bulk material in trucks
Each dot represents a sampling point for a two metre probe

16. Sample Reduction
• Sampling usually results in
more primary sample than is
needed for analysis.
• Reduction in size is required for
handling purposes.
• This should be done using
appropriate equipment.
Quartering Device

17. Sample Reduction
• The use of a sample splitter or riffle
divider will preserve integrity of the
sample.
Riffle Divider

18. Sample Preparation
• A study by Hildebrand and Koehn concluded that sampling, sub-sampling
and preparation, were jointly responsible for over 60%
of the total error in analysis.
• Preparation usually involves milling, drying or extraction.
• Sound laboratory procedures must be followed.
• Poor technique can adversely affect the integrity of meal samples.

19. TEST METHODS

20. Variances Resulting from Different Test
Methods
• Methods commonly used for Protein Analysis are:
• Kjeldahl
• Dumas (or Combustion)
• Near Infrared Spectroscopy (NIR)

21. Kjeldahl Method
• Digest in hot sulphuric acid.
• Convert ammonium ions to ammonia
gas, distil off and collect.
• Titrate to determine Nitrogen content.
• Can take up to 2 hours.
• Labour and reagent intensive .
• Numerous potential sources of error.
Sketch of Traditional Kjeldahl Method

22. Dumas Method
• Sample is combusted at 900 Deg.C in presence of
pure oxygen.
• Nitrogen is isolated and measured by Thermal
Conductivity Detector.
Potential sources of error:
• Requires use of ultra pure Oxygen and Helium gases.
• EDTA calibration standard must be pure and dry.
• Strict daily start-up and standardisation routine is
necessary.
• Regular equipment maintenance is mandatory.
Combustion Instrument for Nitrogen
Determination

23. Near Infrared Spectroscopy (NIR) An NIR Whole Grain Analyser
• Samples are irradiated with light from Near Infrared
spectral range.
• Calibration Models need to be constructed.
• Calibrations based on results from an appropriate
reference method.
• Very fast. Results in a few seconds.
• Minimal sample preparation.
• Quality of results depends on the accuracy of reference
values.
• Separate calibration model required for each sample
type.
• Good operator training important.

24. QUALITY CONTROL IN
LABORATORIES
Achieving Valid Data

25. Quality Control in Laboratories
• Principal 1 – Use of properly validated methods
• Principal 2 – Certified reference materials (CRM’s) should be used
• Principal 3 – Participate in Proficiency Testing Schemes
• Principal 4 – Accreditation with recognised standards such as
ISO/IEC 17025

26. ANALYTICAL METHODS
Developments

27. Developments in Analytical Methods
• Many traditional methods done by wet chemistry
• Innovations made in equipment to either semi or fully automate some
procedures, eg., Soxhlett Fat Extraction and Crude Fibre.
• Improved speed, safety and efficiency have resulted.
• Many rapid moisture instruments.
• Spectrophotometer based Colorimeters remove much of the subjectivity
from colour tests.

28. Developments in Analytical Methods
• Kjeldahl systems have been significantly automated, improving safety and
enhancing control over system variables.
• The precision and efficiency of Combustion instruments continues to
improve.
• With NIR, protein, moisture, fat, ash and fibre can be determined
simultaneously on meals.
• New applications for NIR include real time quality monitoring in process
situations.

29. Developments in Analytical Methods
• The Role of Mass Spectrometry in Analysis of Trace Contaminants
– Increasing requirement for Food and Agricultural Products to meet
Maximum Residue Limits for Contaminants.
– Recent cases of Melamine adulteration.
– Environmentally persistent contaminants such as Heavy
Metals, PCB’s, Dioxins, and Chlorinated Pesticides.
– Mass Spectrometry is used to analyse these and many more
compounds.
– Used in conjunction with Gas Chromatography (GC-MS), Liquid
Chromatography (LC-MS) and Inductively Coupled Plasma
(ICP-MS)

30. Conclusion

31. Conclusion
• The role of analysis in trade is to provide an accurate representation of
quality at the time of shipment and discharge
• Factors such as product variability and chemical change can affect quality
• Sampling is a critical component of shipment analysis
• There are steps which laboratories can take to achieve a high level of
proficiency.

32. • Developments in analytical methods have seen improvements in a
number of procedures.
• There is widespread use of fast alternative techniques such as Dumas
and NIR.
• Mass Spectrometry has revolutionised the detection of trace
contaminants in the area of food safety in internationally traded
commodities.

33. Thanks
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