Advances in Food Mycology

18 Jens C. Frisvad et al.
4.5. Mycophenolic acid
Despite having a low acute toxicity, mycophenolic acid may be a
very important indirect mycotoxin as it highly immunosuppressive,
perhaps influencing the course of bacterial and fungal infections
(Bentley, 2000).
Major sources. Penicillium brevicompactum is a ubiquitous species
and may produce mycophenolic acid in foods, e.g. ginger (Overy and
Frisvad, 2005). Two other major species producing mycophenolic acid
are P. roqueforti and P. carneum. Another important producer is
Byssochlamys nivea (Puel et al., 2005). Mycophenolic acid has been
found to occur naturally in blue cheeses (Lafont et al., 1979).
Minor sources. The soil-borne species Penicillium fagi also produces
mycophenolic acid (Frisvad and Filtenborg, 1990, as P. raciborskii).
Septoria nodorum (Devys et al., 1980) is another source but is unimportant
as a food contaminant.
4.6. Ochratoxin A (see also Aspergillus)
Major sources. Penicillium verrucosum (Frisvad, 1985; Pitt, 1987) is
the major producer of ochratoxin A in cool climate stored cereals
(Lund and Frisvad, 2003).
Penicillium nordicum (Larsen et al., 2001) is the main OA producer
found in manufactured meat products such as salami and ham. Both
OA producing Penicillium species have been found on cheese also, but
have only been reported to be of high occurrence on Swiss hard
cheeses (as P. casei Staub, 1911). The ex type culture of P. casei is a
P. verrucosum (Larsen et al., 2001).
4.7. Patulin
Patulin is generally very toxic for both prokaryotes and eukaryotes,
but the toxicity for humans has not been conclusively demonstrated.
Several countries in Europe and the USA have now set limits on the
level of patulin in apple juice.
Major sources. Penicillium expansum is by far the most important
source of patulin. P. expansum is the major species causing spoilage of
apples and pears, and is the major source of patulin in apple juice and
other apple and pear products.
Byssochlamys nivea may be present in pasteurised fruit juices and
may produce patulin and mycophenolic acid (Puel et al., 2005).