SA Grain June 2017

Junie 2017

ON FARM LEVEL

Integrated pest control

Aflatoxin remains the most widely legislated mycotoxin. At least

99 countries have regulatory limits for AFB

or the sum of AFB

AFB

, AFG

and AFG

in food and/or feed. Levels for DON, fumonisin

and fumonisin B

are regulated in South Africa since 2016.

Mycotoxin research requires a multi-faceted approach, involving the

following expertise: Epidemiology, human and veterinary toxicol-

ogy, human and animal nutrition, fungal taxonomy and biology, bio-

chemistry, molecular biology, genetics, structural organic chemistry,

synthetic organic chemistry, physical chemistry, analytical chemis-

try, food analysis, plant breeding, modelling expertise, risk assess-

ment, management of mycotoxin-producing fungi, and regulatory

expertise.

In 2009, on the invitation of the Maize Forum and the Maize Trust

management, I approached a number of leading mycotoxin re-

searchers from CSIR Biosciences, PROMEC Unit of the MRC, ARC-

Grain Crops and universities to develop a strategy, namely vision,

mission and objectives for mycotoxin research.

The mycotoxin research is currently co-ordinated by the Mycotoxin

Research Review Panel (MRRP), comprising senior scientists from

the ARC-Grain Crops, SA Grain Laboratory (SAGL), SANSOR, Stel-

lenbosch University (SU), Cape Peninsula University of Technology

(CPUT) and Mr Leon du Plessis (Maize Trust,

ex officio

Vision for mycotoxin research at the

Maize Forum/Maize Trust

To enable leading mycotoxin research for the maize industry in

South Africa.

Mission for mycotoxin research at the

Maize Forum/Maize Trust

It is the mission of the Maize Forum and the Maize Trust to have

world-class mycotoxin research undertaken at South African univer-

sities and research institutions in order to ensure that safe maize

is supplied to the food and animal feed industries, consumers and

export markets.

Main objectives for mycotoxin research at

the Maize Forum/Maize Trust

To support the establishment of the magnitude of mycotoxin

contamination of maize during the stages of its production, stor-

age, and processing in South Africa.

To support the regular monitoring of the occurrence of the

fumonisins, aflatoxins, zearalenone, and trichothecenes

(deoxynivalenol, DON, and nivalenol) in locally produced and

imported maize.

To support the determination of the factors which contribute to

mycotoxin contamination during the production (pre-harvest),

storage (post-harvest) and processing of maize.

To support the development of practical, affordable and envi-

ronmentally sound methods to manage toxigenic fungi in maize,

with particular emphasis on the introduction of resistance in

local maize cultivars.

To support the development of sound mycotoxin risk manage-

ment practices in the maize supply chain to ensure the delivery

of safe products to the consumer.

The Maize Trust mycotoxin research benefits from the rapid

multi-mycotoxin analytical technology available at the SAGL, Preto-

ria and at the Central Analytical Facilities of SU, both equipped with

UPLC’s connected to Quattro mass spectroscopy systems.

The characterisation and quantitation of the mycotoxins involved

in diplodiosis, however, still remain a challenge. In this regard, re-

searchers at the University of Pretoria are equipped with hyphenated

HPLC – Solid Phase Extraction – 500 MHz Bruker Nuclear Magnetic

resonance cryoprobe, which allows differentiation between known

and unknown compounds as well as establishing full constitutions

directly from the crude extract with a minimum amount of material.

The Maize Trust strongly advocates interinstitutional and interdisci-

plinary research, as a prerequisite for excellent mycotoxin research.

A management system for annually selecting and evaluating a num-

ber of research projects, based on peer review, has been established.

Early in the year, the management of the Maize Trust invites South

African researchers to submit concept research proposals aligned

to the main objectives listed above. These research proposals are

assessed by the mycotoxin research co-ordinator and sent for peer

review to South African and international peers (scientists from the

USA, Canada, UK, Europe, Africa, Russia, China and Japan).

The members of the MRRP examine the reviewers’ reports and se-

lect a number of the project proposals to be enhanced and submitted

to the Maize Trust as comprehensive research proposals (CRPs). The

successful authors of the CRPs are invited to present their proposals

at a meeting of the MRRP held in August.

2a - 2c: An example of

Stenocarpella maydis

(Diplodia).

Photos: Dr Belinda J van Rensburg, ARC-Grain Crops

Research strategy aims to eliminate myc toxi s