Survival of Enterobacteriaceae during processing of Chorizo de cebolla, a Spanish fermented sausage

Chorizo de cebolla is a popular semi-dry fermented sausage from Galicia (NW of Spain). The survival of Enterobacteriaceae was investigated in three batches of C. de cebolla (one of them hand made and the other two manufactured industrially). The maximum count of Enterobacteriaceae was obtained in each lot after 2 days of the raw sausage mix being stuffed and from then on it started to decrease until it disappeared in the fourth week of ripening in one of the batches manufactured industrially and after 6 weeks in the other. In the artisanal sausages the counts practically decreased exponentially until the third week of ripening, increasing in the following week before again decreasing until the end of ripening, though they never disappeared. Escherichia coli, Serratia odorifera and Enterobacter intermedius were the only species isolated during the curing process of the hand made sausages, E. coli being the dominant species. In the industrial ones a higher number of species were isolated, with the predominance of E. coli and Hafnia alvei.