Product Analysis and Trade Issues

David Conoulty Commodity Inspection Services Australia

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

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

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

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

Proficiency Test on Feed Product

FACTORS INFLUENCING ANALYSIS OUTCOMES

A number of factors can impact on the accuracy of analysis results

A number of factors can influence outcomes:

• Product Variability• Changes in Product Characteristics• Sample Collection, Reduction and Preparation• Different Methods of Analysis

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

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

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

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

SAMPLING AND REDUCTIONThe importance of correct procedure

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.

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 trucksEach dot represents a sampling point for a two metre probe

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

Sample Reduction

• The use of a sample splitter or riffle divider will preserve integrity of the sample.

Riffle Divider

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.

TEST METHODS

Variances Resulting from Different Test Methods

• Methods commonly used for Protein Analysis are: • Kjeldahl• Dumas (or Combustion)• Near Infrared Spectroscopy (NIR)

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

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

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.

QUALITY CONTROL IN LABORATORIES

Achieving Valid Data

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

ANALYTICAL METHODSDevelopments

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.

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.

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)

Conclusion

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.

• 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.

Thanks

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