A mycotoxin produced by Penicillium urticae, Penicillium patulum, Penicillium expansum, 12 other species of Penicillium, Aspergillus, and Byssochlamys nivea. It is a wide-spectrum toxicant that is poisonous to mammals, plants, and many lower forms of life. Patulin is stable under conditions required for fruit juice production and preservation. In experimental animals, it has been shown to cause hemorrhages, formation of edema, and dilatation of the intestinal tract. In sub-chronic studies, hyperemia of the epithelium of the duodenum and kidney function impairment were observed as main effects. Factors involved in fungal growth and patulin production include moderate temperature, high moisture content, and a pH between 3 and 5. Occurrence of patulin is mainly reported in fruits, such as apples, peaches, pears, apricots, and cherries. Patulin is an indicator of poor manufacturing practice (use of moldy raw material) and can pose a serious threat to human and animal health.