Application of a multivariate concentric method system for the location of Listeria monocytogenes in a poultry slaughterhouse M.L. Escudero-Gilete a , M.L. Gonza ´lez-Miret a , R. Moreno Temprano b , F.J. Heredia a, * a A ´ rea de Nutricio ´ n y Bromatologı ´a, Universidad de Sevilla, Facultad de Farmacia, 41012 Sevilla, Spain b Nutreco Poultry & Rabbit Research Center (NUTRECO), Ctra. CM-4004, Km 10,500, 45950 Casarrubios del Monte, Toledo, Spain Received 20 October 2004; received in revised form 28 April 2005; accepted 30 April 2005 Abstract A methodology for food quality control, consisting of several consecutive concentric stages, is shown. It deals with a systematic and concentric study method, based on statistical results. The aim of this technique is to find the source of dissemination of a defined risk along the operations of a food process. It has been applied to the location of the presence of Listeria monocytogenes (Lm) within the different stages in a poultry slaughterhouse. By means of application of statistical techniques like chi-square test, the classifying stage, where the carcasses are greatly handled, has been identified as the main source of the Lm in the studied poultry slaughterhouse. Besides, by means of the application of logistic regression the Lm psychrotropic behavior has been confirmed. Ó 2005 Elsevier Ltd. All rights reserved. Keywords: Poultry meat; Quality control systems; Statistics; Listeria monocytogenes 1. Introduction Nowadays, food industries apply an important part of their resources to ensure the quality of their manufactured products, mainly with regard to the hygienic-sanitary qual- ity, due to the great economical losses produced as a con- sequence of the microbiological alteration, both in the foods and the consumers. Poultry meat is one of the main food that commonly is involved in food infections because of the presence of pathogens (Forsythe & Hayes, 2002), where Listeria monocytogenes (Lm) highlights in impor- tance. This is a psychrotropic bacterium that grows well under refrigeration temperature (Farber & Peterkin, 1991; Walker, Archer, & Banks, 1990), although it shows a slow growth at 4–5 °C. Besides, this bacterium is extraordinarily ubiquitous, since it can grow in soil, water, fodder, straw, feed stuffs or faeces. Because of that, the global control of Lm involves particular difficulties. In food industry, Lm is able to colonize contact surfaces, creating biofilms that are quite difficult to be removed (Blackman & Frank, 1996; Helke & Wong, 1994; Maurice, 1994; Ronner & Wong, 1993; Spurlock & Zottola, 1991), and promote a potential contamination source for food products (Cox et al., 1989; Sammarco, Ripabelli, Ruberto, Iannitto, & Grasso, 1997). The contamination of the prod- uct in cutting and chilling areas is mainly due to cross con- tamination. This hypothesis is supported by the psychrotropic characteristic of this microorganism and by its capability to fix and grow on the surfaces (Ferna ´ndez & Blanco, 1992; Mafu, Roy, Goulet, & Magny, 1990). Therefore, it is necessary not only to prevent but to know the prevalence of Lm in the different points of the food pro- duction chain, from the raw material to consumption (Vi- tas, Aguado, & Garcia-Jalon, 2004), and the decisions should be taken based on accurate researches. In that sense, is fundamental the application of statistical techniques. 0956-7135/$ - see front matter Ó 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.foodcont.2005.04.020 * Corresponding author. Tel.: +34 954556761; fax: +34 954557017. E-mail address: heredia@us.es (F.J. Heredia). www.elsevier.com/locate/foodcont Food Control 18 (2007) 69–75