It was not until 1959 that an outbreak of poisoning of cattle, being fed
on an emergency ration of germinated barley malt sprouts, alerted the
veterinary profession to patulin as a mycotoxin. In this instance the
producing organism wasAspergillus clavatusbut the same toxin has been
implicated in several outbreaks of poisoning from such diverse materials
as apples infected withP. expansumto badly stored silage infected with a
species of Byssochlamys. As far as humans are concerned, it is the
common association ofP. expansumwith apples, and the increasing
consumption of fresh apple juice as a beverage, which has caused some
concern.
Patulin is not a particularly stable metabolite. It is stable at the
relatively low pH of apple juices, although it is destroyed during the
fermentation of apple juice to cider. Even if there was no concern over
the toxicity of patulin, the demonstration of its presence in a fruit juice is
a useful indicator that very poor quality fruit has been used in its
manufacture. However, at least 33 countries have now set limits on
patulin in fruit and fruit juices, the most common being 50 ppb.
The nephrotoxic metabolite citrinin, produced byP. citrinum, was also
first discovered as a potentially useful antibiotic but again rejected
because of its toxicity. It is probably not as important as ochratoxin,
produced byP. verrucosumas well asAspergillus ochraceus, although it
may be implicated in the complex epidemiology of ‘yellow rice disease’.
8.4.3.1 Yellow Rice Disease. A complex of disorders recognized in
Japan a number of times since the end of the last century has been
associated with the presence of several species of penicillia and their toxic
metabolites on rice. This moulded rice is usually discoloured yellow and
several of the toxic metabolites implicated are themselves yellow pig-
ments. There was an early awareness that moulds may be responsible for
cardiac beriberi and in 1938 it was demonstrated thatPenicillium citreo-
viride(P. toxicarium) and its metabolite citreoviridin were responsible.
The most toxic of the species of penicillia associated with yellow rice
disease isP. islandicumwhich produces two groups of toxins, hepato-
toxic chlorinated cyclopeptides such as islanditoxin, as well as the much
Figure 8.14 Patulin
Chapter 8 291