Page 62 - FoodFocusThailand No.180 March 2021

STRONG QC & QAQA
STRONG QC &

that can affect the accuracy of analytical testing. - Reports with clear details around the
An inappropriate allergen technique can produce method and the reporting units provided in the
a false negative result (the allergen is present, results

but the test is not capable of detecting the Method Requirements Whether using
allergen) or a false positive result (the allergen an external laboratory or performing in house
is not present, but the test incorrectly identifies analysis it is important to choose:
it as being present). An incorrect choice of - Methods or kits from a company with an
analysis test may result in an incorrect result. established history and record of performance.
Each technique is different and may not
- Methods where the performance has
necessarily produce comparable results. When been peer reviewed, published or approved by
choosing a test method, ensure that the an international body (eg. AOAC, AFNOR) or
limitations of the test and the required outcome has external validation data to support
for the test are considered. performance.
Choosing a Method Consider that the - Methods which perform well in proficiency
technique must be: programs
- Appropriately sensitive - Methods which are appropriately sensitive,
- Qualitative or quantitative specific and robust and able to detect the target
- Specific for the target substance allergen
- Able to detect the target substance in the - Methods which are designed to detect the
specific matrix (some matrices, like chocolate and meat, do not readily correct form of the allergen (eg. casein or whey or both dependent on
liberate proteins and produce false negatives) which milk component has been used by the facility).
- Able to be performed in an appropriate time frame (minutes to days) Analysis and VITAL The preferred method to identify and quantify
- Able to be performed by the person doing the test (simple to requiring
an experienced laboratory-based analysis) cross contact allergens in a VITAL risk assessment is to sum the cross
contact which is identified by the supplier in each raw material with
- Economical ($ to $$$) cross contact allergens identified during a physical audit of the production
- Validated (independently for its intended use) environment. However, there is a significant role for allergen analysis
• Identify Required Outcome: An understanding of the required
outcome will help to choose the correct method of analysis. Some methods in: - Validation of the VITAL risk assessment
provide quick results and may be useful for production scenarios such as - Verifying ingredient allergen statements and potential raw material
to check if a production line has been sufficiently cleaned. However, often cross contact
tests which can be performed rapidly do not provide quantitative results. - Targeted analysis of problem pieces of processing equipment
Scenarios where quantitative results may be required, such as finished - Confirming assumptions made during the implementation of VITAL
product testing to verify a VITAL risk assessment, may be required to be (such as validation of cleaning)
performed under laboratory conditions and be more time-consuming. - Testing allergen status of the final product to compare with
• Specificity of Test: Care should be taken to choose a test kit which
is looking for the correct target. Allergen testing may be highly specific for calculated results from VITAL assessment (this may be especially
relevant to high risk environments)
a particular target and it is important to establish which marker the test is - Monitoring the effect of critical changes.
looking for and whether it will be in the product being tested. For example,
kits which detect Beta Lactoglobulin are specific to the beta lactoglobulin Validation of VITAL Risk Assessment The concentration
fraction of milk. If the cross-contact allergen comes from the casein fraction of cross contact allergens in a final product may be validated using
of milk (which does not contain beta lactoglobulin) then a Beta Lactoglobulin analytical testing. It should be noted that this is not a mandatory part
kit would provide a false negative result for milk. of this procedure, but that it may be useful in some circumstances.
• Affect of Matrices: Different matrices will affect the validity of allergen Consult a skilled analyst to ensure that the correct methodologies
testing. Some matrices inconsistently and reluctantly liberate target are used and to ensure that the units of measure are appropriate to use
proteins for identification by test kits. Also, some matrices, such as cleaning with the VITAL Action Levels Grid.
or flush solutions, may destroy target proteins and give a negative result Where the concentration of allergens identified by analytical testing
which does not accurately reflect the allergen status of the product or is greater than found during the VITAL risk assessment, consider
flush. Extreme pH levels, high levels of sugars and salts and polyphenol reviewing the risk assessment for other factors. Consideration should
rich foods (e.g. blueberries, blackberries, vegetables including onion, be given to the type of analysis, nature and form of the allergen. It is
cabbage, and legumes) may all present challenges for analysis and require important to consider the nature of food processing as some processes
specialised extraction protocols to provide correct results. may reduce the amount of detectable allergen. Further to this, where
• Affect of Processing: The target protein can be adversely affected quantitative measure is done by both analytical and physical measures,
by processing, with high temperatures and/or hydrolysis possibly altering in order to consider the situation of greater risk, the greater of the two
the structure of the proteins and making it more difficult to detect. Whilst should be taken. Where analytical results are significantly higher than
these changes generally reduce the detectability of the allergen, they may would be expected based on calculation, consideration should be given
in fact enhance allergenicity. to other possible contributing factors.
- For example, soy trypsin inhibitor is a target used by some soy Finished product testing may be used to verify results from cross
allergen test kits. If the product that you are testing contains hydrolysed contact allergens identified in a VITAL risk assessment. When comparing
soy, or has been exposed to hydrolysis, then the presence of soy will not analytical test results with concentrations calculated from the VITAL
be detected in this kit and could produce a false negative result. risk assessment, it is important to ensure that the units of measure are
- Cleaning products may hydrolyse allergenic proteins so it is comparable. The VITAL Action Levels Grid uses concentration (parts
particularly important that this is considered when testing after a clean. per million [ppm]) of total protein. Analytical results use a range of units
of measure. Check with the analyst as some kits provide conversion
Laboratory Requirements When choosing an external contract factors to assist in standardising units of measure.
laboratory chose one with:
- Expertise in the field of allergen analysis
- NATA or equivalent accreditation for the performance of allergen เอกสารอ้างอิง/References
analysis http://allergenbureau.net/food-allergens/food-allergen-analysis/National Association
- Validated methods of Testing Authorities (NATA)
- A verification program for kit performance in the sample type AOAC INTERNATIONAL
submitted or has evidence that the sample is suitable for analysis Allergen Testing - Special Interest Group (AT-SIG)
- Participation in appropriate proficiency programs AT-SIG Briefing Note - Undeclared peanuts in pesto – analytical testing considerations
- Robust quality control processes (7 Feb 2020)

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