FOOD SAFETY SUMMIT AFRICA CONFERENCE & EXPO

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Emery Singleton
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1 FOOD SAFETY SUMMIT AFRICA CONFERENCE & EXPO STATHMORE UNIVERSITY KENYA 28-29, MAY /20

2 AFLATOXIN RISK MANAGEMENT Key Lessons from Corn Wet Milling Experience in Kenya BY THOMAS O. OCHIENG 2/20

Career Passport: 14 Yrs 2001-2005: QC Chemist ACFC, Muhoroni, KE 2005-2012: QA Manager Eldoret

3 Career Passport: 14 Yrs : QC Chemist ACFC, Muhoroni, KE : QA Manager Eldoret Plant, KE : Corporate QA Manager Mumias, KE 2015-to-Date: Site Quality Manager Nairobi, EA 3/20

4 1.0. ABSTRACT Aflatoxin Naturally occurring mycotoxin Produced by two types of mold: Aspergillus flavus and Aspergillus parasiticus. Aspergillus flavus is common and widespread in nature Most often found when certain grains are grown under stressful conditions such as drought. The mold occurs in soil, decaying vegetation, hay, and grains undergoing microbiological deterioration and 4/20

5 Abstract Cont d. Invades all types of organic substrates whenever and wherever the conditions are favorable for its growth. Favorable conditions include high moisture content high temperature. At least 13 different types of aflatoxin are produced in nature Aflatoxin B1 is considered as the most toxic. While the presence of Aspergillus flavus does not always indicate harmful levels of aflatoxin, it does mean that the potential for aflatoxin production is present. 5/20

6 Abstract cont d. From risk management standpoint, containment at the Farm Level is key Aflatoxin once present in the Grains, no process step exists that can eliminate the same or reduce the levels to acceptable, safe levels (10 ppb; B1, 5 ppb, Max) Regulatory Specs in Kenya is 10 ppb for Dry Shelled Maize and resultant milling products Use of Aflatoxin binding agents not permitted in Kenya 6/20

7 Abstract cont d. Screening step equally important QUALITATIVE (at farm/trade level for grains) Confirmatory test QUANTITATIVE (at factory level prior receipt for processing) Quantitative method is material sensitive Use of right method/kit key to assuring safety of the consumer Knowing the product to be tested key in method/kit selection 7/20

8 2.0 CONTAINMENT STRATEGY FUNDAMENTALS Corn Structure compositional matrix Aflatoxin of significance B1, B2, G1, G2 Specifications target consumer specific Regulatory standards applicable Post Harvest Handling/Cultural Practices at Source Choice of method of analysis/test Kit Between laboratory tolerances 8/20

9 3.0 EXPERIENCE QC Tests Analyzed for Aflatoxin 386,400 MT/4.3Mi 90kg Bags of Dry Shelled Maize 259,000 MT of Starch (67%) 70,000 MT of Gluten Feed (18%) 15,000 MT of Gluten Meal (4%) 27,048 MT of Corn Germ (7%) Aflatoxin when present in Corn got entrained in the Coproducts (29%) Nil entrainment in Starch matrix (67%) Milling process (separation) the determinant 9/20

10 Corn Structure Soft large granules Hard small granules 10/20

11 Corn Composition (%db) Key to containment strategy are 1)Corn Compositional matrix Starch = 70-74% (Endorsperm Matrix) Protein = 7-13% (Bran) Oil = 5 % (Germ) Fibre = 8% 2) Milling process employed (DRY or WET?) 3) Target Consumer (FOOD or FEED?) 4) Mold growth localized at the outer aleurone layer, Germ and Bran (feed components) 11/20

12 Lesson 1: Corn Matrix/Entrainment Stream Starch matrix (67%) of Corn was the U/F Feed matrix (29%) of Corn was the O/F Aflatoxin present in corn separated as O/F 100% Aflatoxin present in corn entrained in 29% of the matrix Levels of Aflatoxin present in Corn increased 3X in Co-products (Feed, Germ, Meal) Correlation Table in 2011 developed to guide receipts of Corn A Key Organizational Learning 12/20

13 Lesson 2: Corn Supplies Source Determined Q Trans Nzoia, North Rift, Trans Mara (80%); Uganda (15%); Ukraine (5%) Traders (85%); Contracted Farmers (15%) Local maize --- Good Aflatoxin quality (0 ppb) Maize from Uganda --- Varied Aflatoxin quality (>20 ppb) Post harvest handling/cultural practices the difference Blends rampant in supplies from traders varied quality AFLATEST Screening made final acceptance criteria per delivery in 2011 (3 ppb). 13/20

14 Lesson 3: Aflatoxin B1- Critical Indicator Aflatoxin in maize & maize products: B1, B2, G1, G2 Specification is Max 10 ppb (B1, 5 Max) KS EAS 2:2005 (Dry Shelled Maize Standard) Coproducts Gluten Feed, Gluten Meal tolerance limits the same as for Maize In the US specification varied as per the target consumer ppb! Corn is a Staple Food in Kenya hence the conservative spec of 10 ppb. 14/20

15 Lesson 4: Cultural Practices/P-Harvest Handling In Kenya, Aflatoxin levels in Corn generally low (0-3ppb) Uganda crop showed high OOS Aflatoxin levels ( ppb) Difference in Aflatoxin quality dependent on post harvest handling Maize is staple food in Kenya hygienic handling In Uganda, handling the main contributor to Aflatoxin prevalence P-HARVEST HANDLING KEY TO MITIGATE AFALTOXIN RISK IN CORN SUPPLIES. 15/20

16 Lesson 5: Aflatoxin Screening RAPID BGYF test box deployed Used in North America with good measure of success for corn receipts False Positives/False Negatives was the main challenge on Local Corn Bias for Yellow Dent Corn not confirmed In Kenya, White Corn predominant SEE ATTACHED FOR BGYF METHOD 16/20

17 Lesson 6: Quantitative Method Selection Accurate quantification of Aflatoxin levels critical to assure safety of the consumer Accuracy dependent on the choice of test method Test method dependent on the test material and expected Aflatoxin Levels Qualitative replacing Quantitative test methods common practice in Kenya Major reason for between Labs variances. SEE ATTACHED RECOMMENDED TEST METHODS/KITS 17/20

Lesson 7: Bentonite Clay: Aflatoxin Binder In the period 2011, stocks of Gluten Feed & Meal produced with OOS Aflatoxin levels Ran trials using Bentonite Clay as an Aflatoxin Binder in

18 Lesson 7: Bentonite Clay: Aflatoxin Binder In the period 2011, stocks of Gluten Feed & Meal produced with OOS Aflatoxin levels Ran trials using Bentonite Clay as an Aflatoxin Binder in CG Meal - 50 MT ( ppm) Dry mixing in rotary drum (mortar) mixer Dosing rate was 2% (20kg in 1 MT Product) Achieved reduction rate of 70-92% in Gluten Meal (5000 MT CGM reworked) 18/20

19 CONCLUSION Post harvest handling of Corn at Farm Level (GAP) key in containing risk of Aflatoxin contamination across the food chain GOOD QUALITY CORN WITH LOW LEVELS OF AFLATOXIN ASSURED SAFE PRODUCTS FROM WET MILLING PROCESS Use of Aflatoxin Binder e.g. Bentonite Clay in feed formulation OPPORTUNITY or RISK? 19/20

20 Thank You! 20/20

mycotoxin-contaminated contaminated food or feed

mycotoxin-contaminated contaminated food or feed Poisons in our Food By Melvin Newman, Ph.D. Professor Entomology and Plant Pathology Foods that may contain toxins Introduction Fungi: produce an array of chemical products called secondary metabolites.