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!