MYCOTOXINS, AN INTERNATIONAL OVERVIEW - APRIL 2003

[Guest guest]

MYCOTOXINS, AN INTERNATIONAL OVERVIEW - APRIL 2003

TED CLARK - Epol, a Division of Rainbow Farms (Pty) Ltd, P.O. BOX

101, PINEGOWRIE 2123

http://www.afma.co.za/AFMA_Template/jun03_4.htm

GENERAL BACKGROUND

Mycotoxins are toxic secondary metabolites of moulds. It has been

estimated that there are between 100 000 and 1 500 000 mould

species, producing anywhere between 200 000 and 3 000 000 unique

secondary metabolites. Based on an assumption that approximately 10%

of the secondary metabolites may be toxins there are potentially 20

000 to 300 000 unique mycotoxins (CAST, 2003). At present there are

approximately 70 000 recognised mould species and 500 known

mycotoxins (Marais, 2000). Clearly our current knowledge of

mycotoxins is just the tip of the iceberg.

MAJOR MOULDS AND MYCOTOXINS

The CAST report of 2003 (CAST, 2003) identifies the major mycotoxins

based on world-wide occurrence and cause of mycotoxicosis as:

Aflatoxins - produced by various Aspergillus moulds

Deoxynivalenol - DON, the most common trichothecene, produced by

Fusarium moulds

Ochratoxin A - produced by both Aspergillus and Penicillium

moulds

Fumonisins - produced by Fusarium moulds

Zearalenone - produced by Fusarium moulds

This view is confirmed by numerous papers presented at the World

Mycotoxin Forums of 2001 and 2003, held in the Netherlands. Based on

importance of the mycotoxins the moulds of major importance are

Fusarium, Aspergillus and Penicillium. The later two are

predominantly associated with storage whilst Fusarium is associated

with growing crops, often as a pathogen.

MYCOTOXIN OCCURRENCE

Moulds grow on crops before- and/or after harvest, with any

resultant mycotoxin contamination being additive (CAST, 2003).

Conditions favourable for mould growth vary greatly between- and

within species. The mycotoxins produced are relatively stable and

most not destroyed by processing (Marais, 2000). Complete

elimination mycotoxin contamination is currently not feasible.

Symposium

MYCOTOXIN WORKSHOP : 29 OCTOBER 2003

Loutjie Dunn* – Senwesko Feeds, PO Box 52, Viljoenskroon 9520

Mycotoxins have for a number of years been high on the priority list

of AFMA's Technical Committee. This well attended workshop on

Mycotoxins was the second organised by this committee and attendees

as well as invited speakers covered the entire chain of possible

role players. The papers were very well prepared and presented and

communicated lots of good and new information on the subject. The

Animal Feed Industry finds itself in the middle of this chain using

ingredients contaminated with mycotoxins to produce animal feed.

Taking into account the importance of mycotoxins locally and

internationally, the Animal Feed Industry is worried about the slow

progress made in the control of mycotoxin contamination in feed and

food.

1. What do we know about Mycotoxins?

There is a lot of good information available, but we have to say

that it is not nearly enough. The normal thing people do when they

know a lot, but not enough is to start assuming things. History

taught us NEVER to ASSUME, but a lot of the current " facts " is

nothing else than assumptions.

2. What must we do? (The next step)

The most important step is to get the entire chain involved in

addressing the problem. HACCP, GMP and GAP principles need to be

implemented and not talked about. It is the responsibility of the

entire chain to ensure that these principles are no window dressing

but effective measures that can reduce mycotoxin contamination.

What do we need?

3.1 Legislation (Regulations) with teeth is necessary. It must be

based on scientific information (facts) and NOT political emotions.

Most important it needs to be applied consistently.

3.2 Effective communication.

3.3 Funds (government and other) to enforce the legislation and for

all the other actions needed to address this issue which is of

national importance.

3.4 Specific research that will enable us to make better progress.

We do not need research that confirms the same old thing over and

over again. Researchers and research institutions seem to be

endangered species.

3.5 Every role player in the entire chain to act in a responsible

manner.

3.6 Quantify the financial losses due to mycotoxin contamination on

a national basis.

3.7 A national mycotoxin information system available to everybody

that needs to make informed decisions in order to reduce the

mycotoxin risk.

* Loutjie Dunn is the Vice –chairman of AFMA's Technical

Committee.