abstract
This study aimed at determining whether Penicillium spp. strains could survive through the heat
treatment applied during the processing of frozen chicken nuggets. Firstly, it was found that the conidia
of Penicillium were not able to survive the heat shock in phosphate buffer at pH 7.2 in thermal death
tubes (TDT) at 80 C/30 min. Subsequently, each Penicillium strain was inoculated in frozen chicken
nuggets, which were subjected to the following treatments: i) only deep frying (frying oil at 195e200 C),
ii) only baking (120e130 C until the internal temperature reached 70 C) and iii) deep frying followed by
baking (frying oil temperature of 195e200 C and baking temperature of 120e130 C, until the internal
temperature reached 70 C). The results indicated that Penicillium polonicum NGT 23/12, Penicillium
commune NGT 16/12, Penicillium solitum NGT 30/12 and Penicillium crustosum NGT 51/12 were able to
survive after the combined treatment (deep frying followed by baking) when inoculated in chicken
nuggets. P. polonicum NGT 23/12 was the most resistant strain to the combined treatment (deep frying
and baking), as its population was reduced by 3 log cycles CFU/g, when the internal temperature reached
78 C after 10 min and 30 s of baking. The present data show that if Penicillium spp. is present in high
numbers in raw materials, such as breading flours, it will survive the thermal processing applied during
chicken nuggets production.