The dietary supplement industry has grown from $4 billion in 1994 to an estimated value of $35 billion in 2015 in the United States, and many “mushroom” containing dietary supplements are formulated with one to several fungal species. The world production of mushrooms for this industry has been estimated to be around $18 billion, and their trade has been compared to the value of coffee sales worldwide. In 2002, the global market value of mushrooms in dietary supplement was approximated to range from $5-6 billion.
However, the industry is facing the challenge of ensuring reliable species identifications for process material. A multitude of modifications along a multilevel supply chain makes it particilar difficult for samples containing fungal mycelia. Processes such as milling, drying, and extraction usually destroy important morphological characters and as a consequence species identification based on such methods is out of the question.
A group of US researchers has now successfully demonstrated the utility of the DNA barcode standard marker ITS to provide reliable species IDs for all sorts of fungi found in the food and dietary supplement products. Their results confirm - not unexpected - that barcoding works quite well and, if properly executed, could enrich the tool set available to regulators and researchers.
Barcoding methods highlighted here could ensure the industry of product reliability, thereby ensuring both consumer safety and product integrity. Even when morphology can be discerned, for example in culinary mushrooms, we have revealed that a sample labeled as B. edulis and sold in a U.S. grocery store was actually a new species that was recently reported from grocery stores in the UK. We have also demonstrated that some fungal containing products sold commercially as dietary supplement are not entirely accurate in terms of the scientific names that were displayed on the product label.