Over the last few years a considerable spread of ethnic foods was observed in Italy. Among them is the Döner kebab. During 2014-2015, in order to evaluate the effectiveness of traditional cooking process, raw product (defrosted), sliced cooked por- tions cut through electric knife and assem- bled sandwich were officially sampled in kebab houses and in a local industrial kebab producer in Reggio Emilia (a province in Italy). Microbiological researches for safety and hygienic microbiological indicators were carried out (research of Salmonella, Listeria monocytogenes, Campylobacter and Shiga toxin-producing Escherichia coli; enumeration mesophilic aerobic bacte- ria, lactic acid bacteria, sulfite-reducing bacteria growing under anaerobic condi- tions, yeasts and molds). Between the raw and the cooked product an average of 3 log reduction in mesophilic aerobic bacteria counts was observed. In two out of three kebab houses sampled, which were supplied by the same local industrial producer, the presence of L. monocytogenes was detected. During the official inspection carried out at the production plant a contamination of L. monocytogenes was assessed in both ambi- ent and instruments. Furthermore, 3 lots of products were analyzed and all were found to be contaminated by L. monocytogenes (always above 100 CFU/g). In order to ver- ify the capability of the traditional cooking process to reduce the risk of contamination at an acceptable level, a batch of naturally contaminated kebab (4.5 log CFU/g) was cooked and sliced simulating a day work activity in a kebab shop. The product was then sampled during preparation and enu- meration of L. monocytogenes was obtained. After an hour of cooking, the residual contamination was 1.8 log CFU/g, after two hours and a half L. monocytogenes was no longer detectable in the product, but half an hour later it was again detectable in 25g. At the end of the experiment, the con- tamination grown up to the same level enu- merated after an hour of cooking (1.8 log CFU/g). Considering the microbiological results, traditional cooking obtained a rate of -2.40 log CFU/gh-1, a D=26 min that cor- responds to a temperature of maximum 60°C (z=6). In conclusion, our experiment demonstrates the traditional kebab cooking process could not always guarantee a com- plete product decontamination.

Kebab: can the traditional cooking process sanitized a natural contamination by Listeria monocytogenes? / Bonilauri, Paolo; Leonelli, Roberto; Ferrarini, Gabriele; Carobbi, Diego; Ossiprandi, Maria Cristina; Dottori, Michele; Cuccurese, Antonio. - In: ITALIAN JOURNAL OF FOOD SAFETY. - ISSN 2239-7132. - 7:7167(2018), pp. 121-125. [10.4081/ijfs.2018.7167]

Kebab: can the traditional cooking process sanitized a natural contamination by Listeria monocytogenes?

Maria Cristina Ossiprandi
;
2018

Abstract

Over the last few years a considerable spread of ethnic foods was observed in Italy. Among them is the Döner kebab. During 2014-2015, in order to evaluate the effectiveness of traditional cooking process, raw product (defrosted), sliced cooked por- tions cut through electric knife and assem- bled sandwich were officially sampled in kebab houses and in a local industrial kebab producer in Reggio Emilia (a province in Italy). Microbiological researches for safety and hygienic microbiological indicators were carried out (research of Salmonella, Listeria monocytogenes, Campylobacter and Shiga toxin-producing Escherichia coli; enumeration mesophilic aerobic bacte- ria, lactic acid bacteria, sulfite-reducing bacteria growing under anaerobic condi- tions, yeasts and molds). Between the raw and the cooked product an average of 3 log reduction in mesophilic aerobic bacteria counts was observed. In two out of three kebab houses sampled, which were supplied by the same local industrial producer, the presence of L. monocytogenes was detected. During the official inspection carried out at the production plant a contamination of L. monocytogenes was assessed in both ambi- ent and instruments. Furthermore, 3 lots of products were analyzed and all were found to be contaminated by L. monocytogenes (always above 100 CFU/g). In order to ver- ify the capability of the traditional cooking process to reduce the risk of contamination at an acceptable level, a batch of naturally contaminated kebab (4.5 log CFU/g) was cooked and sliced simulating a day work activity in a kebab shop. The product was then sampled during preparation and enu- meration of L. monocytogenes was obtained. After an hour of cooking, the residual contamination was 1.8 log CFU/g, after two hours and a half L. monocytogenes was no longer detectable in the product, but half an hour later it was again detectable in 25g. At the end of the experiment, the con- tamination grown up to the same level enu- merated after an hour of cooking (1.8 log CFU/g). Considering the microbiological results, traditional cooking obtained a rate of -2.40 log CFU/gh-1, a D=26 min that cor- responds to a temperature of maximum 60°C (z=6). In conclusion, our experiment demonstrates the traditional kebab cooking process could not always guarantee a com- plete product decontamination.
Kebab: can the traditional cooking process sanitized a natural contamination by Listeria monocytogenes? / Bonilauri, Paolo; Leonelli, Roberto; Ferrarini, Gabriele; Carobbi, Diego; Ossiprandi, Maria Cristina; Dottori, Michele; Cuccurese, Antonio. - In: ITALIAN JOURNAL OF FOOD SAFETY. - ISSN 2239-7132. - 7:7167(2018), pp. 121-125. [10.4081/ijfs.2018.7167]
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11381/2848444
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