Purpose: The objective of this study was to evaluate the effects of frying and baking of frozen chicken nuggets on Penicillia.
Methods: P. commune (NGT 16/12), P. polonicum (NGT NGT 23/12 and 33/12), P. glabrum (NGT NGT 29/12 and 35/12 ), P. solitum (NGT 30/12) and P. crustosum (NGT 51/12) previously isolated from spoiled frozen chicken nuggets were used in this study. Conidia solutions of each species were prepared after growth in appropriate conditions and washing and centrifugation procedures. Then, the ability of conidia from these fungi to survive to thermal shock (80°C/30 min) in phosphate buffer (PB) at pH 7.2 in thermal death tubes (TDTs) was assessed. After, each fungus was inoculated separately in frozen chicken nuggets and further submitted to: frying, baking and the combined treatment (frying and baking). The number of decimal reductions caused by these treatments was determined.
Results: None of the strains was able to survive to heat shock in heat resistant, and all of them were inactivated with heat shock in PB. On the other hand, the conidia of P. commune, P. polonicum NGT 23/12, P. solitum and P. crustosum inoculated chicken nuggets and subjected to heat treatments were able to survive to the combined treatment. The number of decimal reductions in Penicilia counts varied from 1.8 to 5.2 log CFU/g.
Significance: The results found highlight the need for the use of raw materials of high mycological quality, because Penicilia may be able to survive heat treatment employed during nugget processing and further spoil the frozen chicken nuggets during shelf life.