Recently attention has turned to the ability of some fungi on food raw materials to produce mycotoxins, which can be toxic to humans if consumed in significant quantities. Harmonised European legislation is being introduced to limit the level of mycotoxins in foods.
There are two types of fungi/mould that can infect cereal crops, one is field fungi on the growing crops in the field, and the other is storage fungi.
Field fungi are easily avoided by the maltsters; they can be visually detected, which leads to an automatic rejection of the grain as not being suitable for malting. Fusarium moulds are common field fungi on growing cereal crops and do little damage to the plants themselves. However, under certain conditions they can also produce a range of toxins.
Storage fungi are less likely be present on grain at intake to maltings, unless the grain has been held for some period under poor stored conditions. Storage mould or fungi can develop if the grain is poorly stored above 14.5% moisture over an extended period of time, particularly if the grain temperature is high. Damp, badly aerated grain is a high-risk area for fungi growth, with the subsequent risk of toxin production. If storage moulds are present in grain at 17.0% moisture or above, then there is a risk that the combination of time, temperature and moisture could be sufficient for the mould to start producing toxins. A limit of 5 parts per billion in barley has been set by the EU legislators for the storage mould toxin, Ochratoxin A.
Storage fungi information
Ochratoxin A is the mycotoxin most likely to be produced by Aspergillus and Penicillium fungi on grain grown in Europe. This is less toxic than Aflatoxin, which may occur on maize, sorghum and other cereals in sub-tropical and tropical parts of the world.
The UK system of taking barley from the harvest field and drying it before storage has always been used to keep grain “sweet” and protect its germinative capacity. Long-term grain storage in the UK is usually at around 12% moisture content in the grain, as it has been proved by experts at CSL that in order to protect the germ in long term grain storage to 98% capacity and above the grain moisture should not exceed 13%. These two factors in UK malting operations also prevent the development of any mould, and hence any mycotoxin. The importance of avoiding long term storage of grain above 14.5% has only recently been signalled, but the MAGB has been testing UK barley for Ochratoxin A since 1994. As long ago as 1885 Mr H Stopes was urging UK maltsters only to buy barley with its own clean, identifiable odour, and to avoid all other smells on the grain. Excellent practical advice, long before the potential problem of mycotoxins was known!
UK tests results over the years have shown that Mr Stopes’ advice, and UK maltsters’ storage practices have ensured that grain free from mould infection has been used, and that there is no mycotoxin risk from using malt produced in the UK.
Field Fungi information
Although maltsters barley intake procedures should avoid the intake of grain infected with field fungi, the MAGB has tested for the toxins deoxynivalenol (DON), nivalenol (NIV) and zearaleone (ZEA) that can be produced by field fungi, to show maltsters diligence in this matter. The tests were done on malts to ensure that the finished product met the likely limits that the EU is considering introducing. Only very small traces of these compounds were detected, well below the EU proposed action levels, and substantially less than has been reported in the growing barley crop.
For more information on due diligence work on mycotoxins Click Here
There will be a continual increase in the knowledge of what makes food safe, and there will be an ever-greater emphasis placed on what makes certain foods more beneficial in the diet than was previously realised. The MAGB will continue its important task of helping UK maltsters show how diligent they are in meeting food safety requirements.
The AHDB Cereals & Oilseeds Food Safety and Due Diligence work, carried out by crop year, on Malting Barley and UK made Malt is an important part of the industries coverage of Food Safety and Due Diligence. The MAGB and AHDB Cereals & Oilseeds work closely together on issues that are of interest for Food Safety of UK Malt made from UK Malting Barley. For more information on AHDB Cereals & Oilseeds click on the logo below.