Toxicity and Sorbate Sensitivity of Molds Isolated from Surplus Commodity Cheeses .

A total of 263 mold isolates were obtained from moldy surplus cheese released from government storage for distribution in the surplus commodity food distribution program in 1984. All of the molds belonged to the genus Penicillium , and consisted of four species, P. roqueforti (176), P. cyclopium (46), P. viridicatum (32) and P. crustosum (9). About 10% of the isolates were capable of producing known mycotoxins on laboratory media. The mycotoxins detected were patulin, penicillic acid and ochratoxin. Patulin was detected most often followed by penicillic acid and ochratoxin. When tested in chicken embryos, 10.1% of the isolates were toxic (causing 50% mortality or more) when grown on cheese, and 29.7% of the isolates were toxic when grown on rice. There was no correlation between having the ability to produce known mycotoxins and toxicity to chicken embryos. None of the isolates when grown on cheese contained any mutagenic activity in the Salmonella mutagenesis (Ames) test. The percentage of isolates showing a high or medium degree of resistance to sorbate were 77, 45, 3.6 and 0 at sorbate concentrations of 0.30, 0.45, 0.60 and 0.90%, respectively. There was no apparent relationship between sorbate resistance and toxigenic properties of the molds.