Transcript Assuring Quality Control - Food Fortification Initiative
Section 5
Quality Control / Assurance
including
Government ’ s Role In Monitoring
Quality Control / Assurance
Ramadan Deliu, Head of Laboratory at M & Sillosi Milling Company, prepares flour for an iron spot test.
Photo by Kate Wheeler.
An effective quality assurance and quality control program throughout a country’s flour fortification program: • Ensures adequate levels of vitamins and minerals to improve nutrition among the population • Prevents the cost of over-using premix • Gains customer satisfaction • Adheres to government regulations
Quality Control / Assurance
Internal External Five parts of the program
Flour millers conduct process control and quality checks Food control authorities inspect flour mills and analyze flour samples Inspectors check fortified products at retail stores
Commercial Intake
Household surveys confirm consumption
Impact
Biological impact is verified
Source: Chapter eight of the Guidelines on Food Fortification with Micronutrients published by the World Health Organization and the Food and Agricultural Organization of the United Nations
Quality Control / Assurance
Internal External Five parts of the program
Flour millers conduct process control and quality checks Food control authorities inspect flour mills and analyze flour samples
This tool kit focuses on the internal quality control with the assumption that the millers purchased high-quality wheat to meet the customers
’
expectations.
The tool kit also highlights the quality assurance process at external laboratories.
Internal Quality: Overview
Use these five quality control methods in every mill: 1. Monitor the fortification system regularly 2. Conduct qualitative testing regularly 3. Monitor premix feed rate and flour flow rate 4. Keep records of premix usage and fortified flour production 5. Submit samples for quantitative testing
Qualitative Flour Testing
Used to: • Determine if flour sample has been fortified • Provide visual estimate of fortification level A common qualitative test is the iron spot test. If iron is detected by this method, it is assumed that other nutrients in the premix are present.
The iron spot test is formally Method 40-40.01: Iron Qualitative Method as approved by the American Association of Cereal Chemists ( AACC )
.
Photo by Kate Wheeler.
Iron Spot Test Procedures
These procedures are for ferrous sulfate, ferrous fumarate and electrolytic iron. See following slides for modified version when using sodium iron EDTA.
1. Take a sample of fortified flour. Make an impression in the sample. 2. Add the reagents with a plastic, disposable dropper. 3. Wait for red spots to appear to indicate presence of iron.
Iron Spot Test Procedure
4. Compare test with prepared samples or images such as these to estimate premix addition level 22 ppm ½ treatment 44 ppm Target Treatment 88 ppm Double Treatment (ppm = parts per million) 5. Discard sample
Spot Test for Sodium Iron EDTA
When sodium iron EDTA is used, make two changes to the iron spot test procedures: 1. In step one, use a larger sample testing surface to make it easier to observe the smaller quantities of sodium iron EDTA indicated by red spots 2. In step two, omit hydrogen peroxide as a reagent. Hydrogen peroxide is used to change other compounds from ferric to ferrous, but this is not necessary with sodium iron EDTA. Instead, with sodium iron EDTA, hydrogen peroxide prevents the color change
Test Responses
• Variability is expected (quantitative test show below)
Feeder Test Results- May 31, 2012 Running Average (N=3) 26,0 25,5 Upper Control Limit 25,0 Target 24,5 24,0 23,5 1 3 5 7 9 11 13 Hour of Day 15 17 19 21 23 Lower Control Limit
Iron Spot Test Response
• Make adjustments based on systematic trends over time established by multiple observations.
• Adjusting a premix addition system based on one or two spot test results could widen the system variability and complicate future measurements.
• If 2 out of 5 consecutive samples do not meet expectations, increase the sampling frequency as outlined on the next page.
Iron Spot Test Sample Frequency
• If 2 of 5 consecutive samples do not meet the requirements, increase sampling frequency. • If the next 2 of 5 samples fail to meet requirements, implement corrective actions. Verify that the feeder is operating properly then consider adjusting the: premix feeder control flour transport scales mixing machinery • If the next 2 out of 5 consecutive sample fail to meet requirements, stop production until the error is found and corrected.
• Once production restarts, continue frequent sampling.
• Return to normal sampling schedule after 3 consecutive samples are correct.
Iron Spot Test
Advantages
• Simple, fast, inexpensive • Requires no sample pre-treatment.
• Requires two or three reagents: – potassium thiocyanate (KSCN) or sodium thiocyanate (NaSCN) – hydrochloric acid (HCI) – Hydrogen perixode (H 2 0 2 ), which is not used with sodium iron EDTA • Food grade NaSCN is available if desired • Easy: personnel with minimum training can perform this
Limitation
• Not quantitative: does not determine amount of iron in sample.
Qualitative Alternatives to Iron Spot Test, if Desired
• Ask premix provider for alternatives • If the premix has riboflavin, use a black light test – Riboflavin (vitamin B2) will fluoresce under ultraviolet light. Perform this test in a dark room or box using a wet Pekar slick to compare fortified with unfortified flour. • If the premix has vitamin A, use a color test – Must be done in a laboratory to compare the intensity of color when vitamin A mixes with copper sulfate.
Record Keeping
Maintaining accurate records is an essential part of internal monitoring. Develop a system to track:
Flour Ingredient Usage Report First Shift Date: Mill:
• Premix delivery and usage
Beginning Lot # Flour Production
Time Grade
7:00 8:00 9:00 10:00 11:00 12:00 13:00 14:00 Shift Total
MT Flour 0.00
701 CCN Enrichment
% KG 0.00
052 AGU
%
Malt
KG
700 CCN
%
Bleach
KG • • Flour production 0 0 Comparison of premix usage with target needs based on flour production
Shift Total
MT Flour 0 KG 0.00
KG KG 0 0 • Results of check weighing tests
Begin Inventory Transfer to Mill Floor Total to account for Closing Inventory Disappearance
0 0 0 0 0 0 0 • Internal and external quality control testing results.
INGREDIENT Enrichment Malt Bleach NEW LOT # START TIME STOP TIME
SUPERVISOR (name): OPERATOR (name):
These records help the mill assure quality and may be required during an external inspection.
Internal Quality Control Schedule
1. Check premix feeder hourly. Make sure the speed detector shows that it is running. Fill hopper if it is low.
2. Run feeder check weights at least every 8 hour shift. 3. Run iron spot tests at least every 8 hour shift. 4. Conduct inventory control of premix usage and fortified flour production at least quarterly.
Detail the quality control responsibility, frequency, protocol, and reporting activities in the mill’s quality assurance manual. Instruct all mill personnel in the procedures. Assign reporting to someone with authority to act on the information.
Internal and External Testing
Types of laboratories testing fortified flour
Quantitative tests of all added nutrients - Checks results and procedures of other labs
Reference Laboratory
-Certificate of analysis on premix
Premix Suppliers
- Quantitative tests of all added nutrients Quantitative tests.
- Runs or manages biological testing.
- Audits mills.
Government Laboratory Central Milling Laboratory
-Runs quantitative tests on indicator nutrient and other tests -Audits mills within the company
Mills
Laboratory/Production Activities - Fortificant inventory control - Feeder checks - Iron spot tests (if applicable) - Flour sampling
Quantitative Testing
• Send samples to laboratory using internationally recognized methods (AACC or ICC and AOAC) • Requires sophisticated equipment and careful adherence to protocols due to the small concentration of vitamins and minerals in a flour mixture.
• If results are suspect, the sample can be submitted to a certified, reference laboratory for further analysis.
Laboratories running quantitative tests should: • Make a sample of standardized flour fortified with a certified level of nutrients as a reference • Routinely conduct a blind analysis of the reference sample to verify laboratory procedures
Indicator Nutrient Testing
• One premix ingredient (usually iron) is typically tested as “indicator” of others. This is valid for premix that has been properly designed, manufactured and mixed.
• Because the ratio is constant, measuring one nutrients can verify the delivery of the others.
• Assumes no destruction or separation of the indicator nutrient after the premix was added.
Spectrophotometric test for iron
Creating Composite Samples
A composite sample may be used to estimate the weighted average nutrient value in a production run. For a composite sample: • Take 5 to 10 spot samples representative of a production lot, such as an 8-hour run • Collect the same sample size • Distribute sample collection evenly over the production time period
Capability Study Guideline
Quantitative testing determines a mill’s ability to produce a uniformly fortified flour, meeting specifications.
• Collect individual, not composite, flour samples • Take 7 or more samples over an 8-hour run • Calculate the coefficient of variation (CV). The CV is the standard deviation divided by the mean, expressed as a percent • Identify the analytical error for that lab assay
Assay
Iron Folic Thiamine – B1 Riboflavin – B2 Niacin – B3
Example values
(developed from FFI references)
Assay CV % Flour Mill Production CV
13.5
10.3
11.3
11.7
15.2
14.0
14.1
10.7
11.0
6.2
26,0
Control Chart
Feeder Test Results- May 31, 2012 Running Average (N=3) 25,5 25,0 24,5 Upper Control Limit Target 24,0 23,5 1 3 5 7 9 11 13 Hour of Day 15 17 19 21 23 Lower Control Limit
Government’s Role in Mill Monitoring
Government authorities conduct various roles in flour fortification monitoring, often including: • Confirming that technical specifications, process control and quality procedures and performance records are maintained at the mill, packaging sites, and points of entry into the country • Inspecting and verifying legal compliance with the country standard, based on a quantitative assay – Samples should contain the fortificant, and at least 80% of samples should present the legal minimum.
– Less then 20% of the samples should have a nutrient content above the maximum level, if one has been established.
Plant Audits
• Off-site audit with government official reviewing information supplied by mills • On-site audit with government official visiting the mill to determine if the mill is properly fortifying flour and to validate data supplied in off-site audits
More Information on Quality Control / Assurance
Chapter eight of the Guidelines on Food Fortification with Micronutrients published by the World Health Organization and the Food and Agricultural Organization of the United Nations The Flour Fortification Initiative at [email protected]