Survival of Salmonella in spaghetti alla carbonara

Spaghetti alla carbonara is a traditional Italian dish, which the sauce made of raw egg yolks is heated using only the heat of cooked pasta. Concerns about the safety of this preparation have been raised due the possibility of egg yolks be contaminated by Salmonella and the heat treatment may not be sufficient for total Salmonella inactivation. This study was undertaken to analyze the survival of Salmonella in spaghetti alla carbonara in which the only thermal processing of egg yolks was the heat transfer from the pasta. A pool of Salmonella was inoculated in egg yolks reaching 8.8 log(10) CFU/g. Contaminated egg yolks were added to the cooked spaghetti, away from the heat source. Results indicated that immediately after cooking and draining, the pasta reached 86.0 degrees C. After 4.5 min of contact with the egg yolks, the mean temperature of spaghetti alla carbonara decreased to lower than 60 degrees C. The preparation method was able to inactivate approximately 4.7 log(10) CFU/g of Salmonella and the spaghetti alla carbonara processed by this method had a creamy and silky sauce formed by yolks. Based on the results, it should be advisable the use of thermo-processed eggs to ensure the safety of this preparation.