Evaluation of different methods to prevent Penicillium nordicum growth on and ochratoxin A production in country-style sausages

Penicillium nordicum is the main ochratoxin A (OTA)-producing fungal species isolated from artisanal sausages of different areas of Italy and other European countries. P. nordicum grows on and produces OTA in the sausage casing, thereby posing a health risk to Italian consumers, who commonly eat both the meat and casing of artisanal sausages. Different methods have been proposed to eliminate OTA and P. nordicum on the casings, including brushing, brushing and washing, the use of fungal starter cultures (Penicillium nalgiovense) and gaseous ozone. The aim of this study was to compare these methods with regard to eliminating the risk of OTA contamination in sausages. Three concentrations of gaseous ozone were assessed, i.e. 0.5, 1.0 and 1.5 mg/l. Only 1.5 mg/l prevented P. nordicum growth and production of OTA in sausages without influencing the physicochemical parameters and the sensory characteristic of the products. Application of this gaseous ozone concentration was then compared to the other methods, i.e. brushing, brushing and washing, a one-step starter culture of P. nalgiovense (inoculation after casing) and a two-step starter culture (inoculation after both casing and drying). The results obtained showed that only the use of gaseous ozone and a two-step starter culture of P. nalgiovense achieved complete inhibition of P. nordicum growth and OTA production. However, sensory analysis of the treated sausages showed that the use of starter cultures was the best method.