The traditional recommendation that shells should only be consumed in months with the letter "R" has traditional backgrounds. In our latitudes mussels have season from September to April and are offered mainly from German and Dutch harvest. Mussel poisoning occurs only in hot months (without the letter "R"), because in these months algae bloom and form toxins during flowering.
Toxins in algae
By filtration, clams pick up the algae toxins with the water. The toxins can thus accumulate in dangerous concentrations in the mussels. This process is called "shellfish poisoning" and is reflected in popular wisdom. In addition, earlier poorer storage and transport conditions prevailed, leading rather to spoilage. So it was only logical to forego mussels in the hot months.
Today, comprehensive EU legislation ensures that both coastal algal and bacterial rearing areas and all coastal areas relevant to the harvesting of shellfish are controlled through an algae toxin early warning system throughout the year.
In the cleaning and packaging centers, the mussels are released for consumption only after being checked for safety. Thus, a health impairment of consumers by Algentoxine and by harmful bacteria is largely excluded.
Earlier, the "R" rule made sense, as the toxins of algal blooms, which often cause mussel poisoning, were a major problem. This natural phenomenon occurs only in summer months, as it does not come in the winter to the algal bloom and associated toxin formation.
By their filtering action - a mussel filters up to 2 liters of water per hour - mussels absorb the highly toxic algae toxins of armored scabby algae with the water. This can result in dangerous concentrations of toxins in the shell, so that it is no longer suitable for consumption.
Today, the risk of shellfish poisoning by algae toxins or bacterial spoilage in the warm season is very low. Harvested shells are stored in special seawater sections on the coast, known as wet warehouses, until they are transported. Here a natural cleaning takes place, as the shells remove sand and other impurities. In addition, modern distribution processes enable a closed cold chain. However, mussels are a perishable food and consumers should pay a lot of attention when buying and preparing their home.
Tips for consumers
- If necessary, avoid eating in summer (June, July, August) as the mussels spawn during this time and their taste may be impaired.
- Store freshly bought mussels refrigerated and consume no later than the next day.
- For the preparation use only closed mussels and after cooking only eat the opened mussels.