Some species of mould fungi can produce toxins, called mycotoxins. It is the creation of mycotoxins in food that represents a health risk and not the mould in itself.
Moulds are micro-organisms that belong to the fungus family. Some mould fungi that can grow on food are of benefit, in the production of blue cheese, Brie and Camembert for example. In other types of food production, such as other cheese types, cured meats, bread and liver pate, the growth of mould is undesirable.
Some types of mould can produce toxins that are known as mycotoxins. Some, such as aflatoxin, can be extremely toxic and lead to acute illness, while other mycotoxins can be carcinogenic or affect the immune system. Mould fungi reproduce by creating spores. The spores are in a form that ensures good distribution. They loosen easily from the mould fungus itself and can easily be transported around the production area, in the air or on persons or equipment.
HACCP and mould
The meat industry is required to devise HACCP plans for its production. When the Hygiene Package comes into force, this will apply to the entire food industry. HACCP is a systematic method for identifying control points and maintaining control over the process, so that the products that are produced are safe for the consumer to eat. With HACCP, any critical control points (CCPs) are identified, so that they can be followed up on.
The critical control points are far from enough to ensure food safety on their own. There are a number of basic conditions that must be in place before the actual work on the HACCP plan starts. A systematic review must be made of the basic conditions and any changes made where necessary. Such basic conditions include the company’s routines for cleaning, zoning, training of personnel, hygienic design of equipment, personal hygiene etc. Many of these routines are extremely important if the products are to be safe and control points to check on cleaning and air, for example, can be absolutely essential. HACCP relates directly to the different production stages and how they are controlled, so control points for the basic conditions do not become CCPs. CCPs are however applied to the process for avoiding the creation of mycotoxins in the product or for reducing mycotoxins to an acceptable level. Heat treatment to kill mould spores, the addition of preservatives or packing methods to prevent the growth of toxin-producing mould can all be CCPs.
Does mould represent a threat to the safety of my product?
Mould can often be looked upon as a quality problem and is overlooked in terms of HACCP work. It is not the growth of mould itself that represents a health risk, but any mycotoxins in the product that represent a risk for the consumer. Handling mould problems in the HACCP plan can be difficult. For pathogenic bacteria that create toxins such as Staphylococcus aureus, a great deal is known about when the bacteria grow and create toxins. When it comes to mould types in food and toxin production in products, knowledge is much more limited. This makes it difficult for companies to evaluate the health risk that may be involved with mould growth on the products. In order to make the necessary assessments, knowledge is needed about what kinds of mould are growing on the individual product, whether - or under what conditions - they create mycotoxins and whether these can contaminate the edible part of the product. This requires specific knowledge that the company does not have available; indeed in a number of cases this knowledge may not exist at all. In the project “mould and cured meats”, the mould fungi that represent a problem were identified and then investigated to find if they could produce mycotoxins. This is vital in order to be able to assess what health risks could be connected with mould growth on the products.
Sources of infection
Mould may come from many sources, but experience shows that there are some conditions one must pay special attention to. If you have products with a mould growth on the premises, there is a great risk of contaminating other products. Only some mould fungi will grow on any individual product. Many of the mould fungi from other sources (ventilation systems, walls, the general environment etc.) do not necessarily represent any danger for the products. On the other hand, products with mould represent a growth of those mould fungi that can grow on products in the company and might possibly produce mycotoxins. Visible moulds in damp parts of the premises or the ventilation system could also be easily spread to the products. To find out if these mould fungi can grow on the product, one must either run trials or identify the species and decide whether it could grow on the product and create mycotoxins using available literature.
Mould problems differ from bacteria problems in that mould fungi are introduced and spread in production premises in a different way than bacteria or yeast. Bacteria and yeast are primarily introduced via raw materials, persons or contaminated equipment. Mould fungi are usually spread in the air and as a result they are often a bigger problem to deal with. The ventilation system may be a place where the mould fungus can establish itself and reproduce, and the spores are then sent around the premises in the air from the system. Currents of air caused by opening doors or by people and equipment moving around can also contribute to the spread of mould.
What needs to be done about mould in order to achieve safe food production?
In the HACCP plan, knowledge is needed about which mould fungi are a problem and whether these fungi can produce mycotoxins. A risk analysis must therefore be made of the consequences of mould growth on the products. It is also important to focus on air quality and ventilation, to prevent the spread of fungal spores around the premises. Handling products that have been contaminated with mould fungi requires routines to avoid contaminating other products. Training employees so that everyone understands how mould is spread is a prerequisite for success. The process must be reviewed in order to identify any CCPs that reduce or eliminate mycotoxins in the products. In some processes, there are no CCPs. The safety of the products must then be assured by controlling the basic conditions.