Food safety review of UK cereal grain for use in malting, milling and animal feed

Abstract

This project aimed to investigate the occurrence of key contaminants in UKgrown wheat, barley and oats in order to demonstrate safety for use for milling, malting and animal feed, and the extent of compliance with legal and guideline limits. Samples of each type of grain were collected from harvests 2005, 2006, 2007 and 2008, either immediately after harvest, or after a period of storage.

Relevant contaminants were identified by regular "horizon scanning" of official publications and the scientific and agricultural literature, together with a steering committee consisting of representatives of the relevant Trade Associations, the HGCA and scientists from the contract laboratories involved in the project. The contaminants selected were mycotoxins (aflatoxins, Fusarium toxins and ochratoxin A), pesticides, including some growth regulators and desiccants, and certain heavy metals.

Analytical results showed that the overwhelming majority of samples complied with legal and guideline limits. Levels of heavy metals and pesticides were in most cases well within legal limits, and did not vary substantially from season to season. Aflatoxins were absent from all samples tested.

The other storage mycotoxin investigated, ochratoxin A, although quite common in most sample types, was generally detected only at low concentrations and did not vary significantly from year to year, suggesting that mould growth and toxin synthesis was being adequately controlled, presumably as a result of good storage practice. Fusarium mycotoxins, which are produced during growth in the field, showed significant seasonal variations, overlying what appears to be an increasing trend over the years surveyed.

This observation is complicated by the fact that the earlier years of the project were dry while the later years were wet, so a definitive conclusion cannot be drawn. It is certain, however, that the prevalence of certain Fusarium toxins (particularly T-2 and HT-2 toxins), has increased in the UK.

The horizon scanning exercise identified polycyclic aromatic hydrocarbons and masked mycotoxins as emerging issues for cereals, and these are being investigated in other HGCA-funded projects (an extension project to RD-2004-3100 for PAHs and RD-2008-3572 "Food safety review of UK cereal grain for use in malting, milling and animal feed" for masked mycotoxins).