Post Harvest Management Technologies for Reducing Aflatoxin Contamination in Maize Grain and Exposure to Humans in Zimbabwe
Cultivate Africa’s Future
University of Zimbabwe
Dr. Loveness K. NyangaSenior Lecturer and Researcher, University of Zimbabwe
PhD, Wageningen University, The NetherlandsMSC and BSc, University of Zimbabwe
Funded under Cultivate Africa’s Future
By
Organisations Involved in the research
• Main Players– University of Zimbabwe, Institute of Food, Nutrition and
Family Sciences (UZ, IFNFS)– Action Contre la Faim (ACF)
• Third Party– International Rescue Committee (IRC)
• Government stakeholders– Ministry of Health and Childcare– Ministry of Agriculture, Mechanisation and Irrigation
Development
Why are we doing the research?
Food Security – quantity and quality When all people at all times have access to
sufficient, SAFE, nutritious food to maintain a healthy and active life (World Food Summit, 1996)
Concerned about people’s health Mycotoxins a risk to human health
Poor storage practices – Better storage facilities
University of Zimbabwe
Broad Objective
• To investigate the efficacy of hermetic storage technology in the reduction of aflatoxin contamination in maize grain and hence reduction in exposure to humans to these toxin, in Makoni and Shamva districts
Specific objectives
To assess knowledge, attitudes and practices with regard to good pre- and post- harvest management practices that minimizes mycotoxin contamination in maize;
To assess the reduction of aflatoxin B1 and
fumonisin B1 in stored grain from use of different postharvest storage practices
To assess the reduction of aflatoxin exposure to humans including infants in households using different storage methods
To determine levels of aflatoxins in legumes (groundnuts, bambaranuts, beans, and cowpeas) produced by the communities in Shamva and Makoni districts
To identify and assess different models for delivery of post harvest management technologies to smallholder grain producers; and
Specific objectives continued
Ethical Approval Study was approved by the Medical research
Council of Zimbabwe (MRCZ)
University of Zimbabwe
Study Design Randomized Control Trial – 480 Households (Shamva and
Makoni Districts)
Households with pregnant women and children under five (0 – 24 months)
Assigned to treatment grps
Intervention grp – metal silos and hermetic grain bags (Hermetic technology)
Control grp will continue following the conventional storage practices
Study parametersMain study parameters Aflatoxin B1 and Fumonisin B1 in the grains Aflatoxin M1 in breast milk and urine samples Aflatoxin B-albumin adduct in blood samples
Secondary study parameters Anthropometric variables (weight and height,
MUAC) Knowledge, attitudes and practices with regard to
pre and post harvest management Impact of Hermetic technology on gender
Sampling Plan Quarterly sampling for 2 years, of the
following: Grain – maize and legumes Biological samples – urine and breastmilk Anthropometric measurements IDDS for women and children
KAP Survey and Gender FGDs Baseline Midpoint Endpoint
University of Zimbabwe
Training and awareness campaigns on mycotoxin management and health risks
Training Agricultural extension officers Health workers Households
Awareness campaigns Communities national
University of Zimbabwe
Expected research outputs
Efficacy of hermetic technologies to reduce aflatoxin levels in stored grain
Aflatoxin levels in legumes
Infants exposure to aflatoxin M1 from breast milk from mothers
Association between anthropometric data and levels of aflatoxins in children under five
Knowledge, attitudes and perceptions of farmers in managing aflatoxin risks in maize
Household behaviours and perceptions in handling risks of aflatoxin contamination
Two masters graduates in Food Science and Technology
One masters graduate in Nutrition
Expected Developmental outcomes Increased adoption of innovative postharvest
technology by farmer communities (women and men) in Zimbabwe
Reduction in exposure of infants, women of
child bearing age and all grain consumers to harmful mycotoxins
Improved capacity of local artisans and agro-dealers to supply metal silos and super bags to farmers, respectively
Increased capacity building - Masters students and Communities
Better awareness of government stakeholders, NGOs and donors in Zimbabwe on the importance of effective management of aflatoxin contamination on achieving food security, health and nutrition outcomes
Strengthened link between research and policy -project outcomes can feed into policy recommendations for aflatoxin management
Value added contribution of the research
Food and Nutrition Security Policy of Zimbabwe to promote food and nutrition security
Partnership for Aflatoxin Control in Africa (PACA) provide evidence of intervention impacts on
aflatoxin control Zimbabwe’s Agenda for Sustainable Socio-
Economic Transformation (Zim ASSET) Food and Nutrition Security Cluster
Improved proper storage of harvested crops Improved availability of quality food
Mechanisation cluster Promotion of metals silos
Research Results to date
University of Zimbabwe
Trainings done AGRITEX extension officers –cascaded the
information to participating farming households
Topics covered: Mycotoxins - Risks, Exposure, Health Impacts Pre and Postharvest Practices and Technology
Options Use and Handling of Hermetic Storage
Technologies Policy in Zimbabwe regarding mycotoxins
Trainings done Village Health workers – cascaded the
information to participating farming households Topics covered:
Maternal Nutrition (Pregnant and Breastfeeding) Early Initiation of Breastfeeding Exclusive Breastfeeding Dietary Diversity and Complementary Feeding Nutrition in the Lifecycle Steps of Behaviour Change Aflatoxin: Exposure, dietary sources, management
and prevention
Trainings done Fabrication of metal silos by local artisans
from Shamva and Makoni districts 6 artisans per district, who worked together (with technical
support from DAM) to fabricate: 150 x one-tonne capacity metal silos for the
research participants 12 x 20kg capacity dummy metal silos for training
demonstrations by AGRITEX 1 x 50kg metal silo for the university laboratory
Trainings done Agro dealers
Proper use and handling of hermetic bags
KAP survey Baseline A total of 492 research participants were interviewed (92.7%
sample size) from both districts. KAP results show that fungal/ mould attack was more
pronounced in the field (40.8%) and during storage (44%). This was attributed to poor crop management practices in the field and poor grain management during storage.
In terms of gender, both male and female members of the households have collaborative partnerships when carrying out pre and post-harvest tasks at household level.
73% of households do not further dry their maize after shelling and 98.7% apply insecticide to grain as pre-storage treatment.
35.9% of the respondents were knowledgeable about aflatoxins that affect maize and legumes.
In terms of attitude, farmers do not see any harm in consuming aflatoxin contaminated grain.
Laboratory results - baseline samples
Assessment of fumonisin B1(FB1) levels in stored maize samples using ELISA kits A total of 406 samples were analysed FB1 levels ranged from 13 – 606 µg/kg and these levels are
below the acceptable international regulatory limits of 2000 µg/kg for FB1+FB2
However, on calculating the average probable daily intakes (APDI) of fumonisin B1 for the farmers in both districts, the APDIs were all above the provisional maximum tolerable daily intake of 2 µg/kg/per body/day (WHO, 2002)
The calculated APDIs ranged from 3.08 – 5.68 µg/kg Most rural people consume maize sadza more than once a day Therefore, the farmers are exposed to FB1which is a health
hazard
Assessment of Aflatoxin B1 in stored maize samples
Assessment of aflatoxins in groundnuts – field samples
District Aflatoxins - µg/kg
AFB1 AFB2 AFG1 AFG2Shamva
No. of PositiveN = 105
14 14 8 6
Minimum 3.11 1.32 24.10 29.17Maximum 175.91 181.31 271.61 143.03
Makoni No. of PositiveN=103
12 8 10 4
Minimum 0.73 - 20.85 42.52Maximum 108.36 320.00 168.48 377.79
Conclusions and Recommendations
In both districts people have limited knowledge of mycotoxins and associated health risks
Poor pre and post harvest practices In both districts people are exposed to both
fumonisins and aflatoxins Need to mitigate mycotoxin contamination
of food to reduce exposure to humans at national level
Educate people on occurrence of mycotoxins and the associated health risks at national level
Thank you!
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