Detection and identification of Penicillium spp. in a frozen chicken nuggets production facility

Frozen chicken nuggets can be stored over a long period, during which time they may be exposed to temperature abuse conditions leading to spoilage by psychrophilic filamentous fungi. The purpose of this study was to investigate the main sources of chicken nugget spoilage. Mycological analyses were performed using raw materials and products from each stage of processing, as well as from the industry's indoor air environment. The species were identified through observation of macroscopic and microscopic characteristics of isolates. The powder coating of samples showed counts between 10¹ and 10⁴ CFU/g, predominantly of the species Penicillium polonicum, Aspergillus flavus, Aspergillus candidus, Aspergillus (Eurotium) amstelodami and Penicillium citrinum. During chicken nugget processing, a reduction in fungal counts to 10¹ CFU/g was observed, with P. polonicum as the most dominant species present. Penicillium glabrum was the only species isolated from the final product analyzed (10%). Additionally, it was also the predominant species in the factory's air environment. According to the results, two possible sources of contamination of frozen chicken nuggets were detected, one from the lack of quality of the powder coatings used and another from the lack of clean air from the factory environment between the stages of baking and packaging.