Microbiological profile of Salpicão de Vinhais and Chouriça de Vinhais from raw materials to final products: Traditional dry sausages produced in the North of Portugal

Salpicão de Vinhais and Chouriça de Vinha North of Portugal. The microbiological profi is are t le during production of both produ processing units. Lactic acid bacteria were the smoking process and a consequent de This study demonstrated that when highl eliminated during processing (from seas highlight that to produce safe Salpicão an necessary to work under hygienic conditio Industrial relevance: Preservation of pork cts was followed in three small t prevalent microorganisms, with enhanced growth during of pH. inated raw ingredients are used, pathogens might not be ntil the end of smoking). Therefore, it is important to riça following traditional recipes and methodologies it is g raw materials of good microbiological quality. the form of semi-dry, fermented and smoked products ocess that is still practiced in many areas of the world. In nt impact on the local economy and food supply, but these in urban areas. In a more widespread distribution of such are not exposed to undue risks of food-borne infections or n of the microflora and microbiological safety during the cts in the North of Portugal, and during storage of the final Porkmeat conserved in the formof fermenteddry sausages is typical, and represents an important part of the traditional Portuguese diet. The production of these kinds of products has a significant impact on the economy of rural areas in the north of Portugal. Salpicão and Chouriça de Vinhais are dry-fermented sausages produced in Vinhais, a small region of Trás-os-Montes, where the natural conditions and specific climate allow a peculiar curing process and unique flavor. The essential ingredients of these products are raw pork meat from Bísaro, an autochthonous pig breed, salt, spices and regional wine. The process includes a first stage of seasoning for 48 h at 4 °C; stuffing of themixture innaturalpork casings, and afinal stage of curingby traditional smoking, at 20–30 °C for, approximately, 3 weeks for Chouriça and 4 weeks for Salpicão. In the production of Salpicão, only loin pork meat is used and stuffed into large intestine (cylindrical formed sausages, ca. 15–20 cm long), while in Chouriça, meat and pork fat are used, and stuffed into small intestine (horseshoe-shaped sausage, ca. 30–35 cm long). +351 22 50 903 51. Several authors have described the importance of the natural microflora during the fermentation process, namely lactic acid bacteria (LAB) and Micrococcaceae, responsible for inhibition of undesirable microbial growth (either by decreasing the pH or by production of anti-microbial compounds such as bacteriocins), and development of color and flavour (Bruna, Hierro, Ordóñez, & de la Hoz, 1999; Nout & Sarkar, 1999; Parente, Grieco, & Crudele, 2001; Ammor & Mayo, 2007; Benito, Martín, Pérez-Nevado, Ruiz-Moyano, & Córdoba, 2007; Martín, Colín, Aranda, Benito, & Córdoba, 2007). Together with the addition of salt and progressive decrease of water activity (aw), fermentation is the only guarantee of safety in these products that do not receive any antimicrobial heat treatment before consumption. Since these sausages aremainly produced by traditional customs at small processing units, conditions as time and temperature during the different processing stages are not controlled. Therefore, deviations may result in insufficient fermentation-drying processes, not assuring the absence of pathogens in the final products. The presence of foodborne pathogens in fermented sausages such as Listeria monocytogenes, Escherichia coli O157:H7, Salmonella spp., Clostridium botulinum, and Staphylococcus aureus, has been reported (Siriken, Pamuk, Özakin, Gedikoglu, & Eyigör, 2006; Ferreira et al., 2006; Ferreira, Barbosa, Silva, Felício, et al., 2007; Ferreira, Barbosa, Silva, Vendeiro, et al., 2007; Talon et al., 2007; Keskinen, Todd, & Ryser, 2008) and Moore (2004) reported various gastrointestinal disease outbreaks associated with the consumption of fermented meats. The present work aimed to investigate the evolution of natural microflora during maturation of Salpicão and Chouriça de Vinhais produced at three different traditional plants and assess microbiological safety from the raw ingredients until final product. Products from three traditional producers, located in the same area, were studied. In viewof the fact that these are small industrial units, only one batch of each product is manufactured at each time. Therefore, for each producer, samples of onebatch of Salpicão and one batch ofChouriça at different stages of production were collected: raw meat immediately after addition of spices and wine (T0); 48 h after seasoning at 4 °C (T1); after stuffing and before smoking (T2); in the middle period of smoking, corresponding to 11 and 15 days of smoking for Chouriça and Salpicão, respectively (T3); and final product (T4) (in a total of 22 days of smoking for Chouriça and 30 days for Salpicão). The processing stages and the Fig. 1. Processing stages of “Salpicã respective sampling are described in Fig.1. From each batch, two samples were analyzed. Samples were transported to the laboratory in portable, insulated cold-boxes and stored at 4 °C until they were analyzed. Twenty-five grams of each sample were added aseptically to 225 ml of sterile Buffered Peptone Water (Merck, Darmstadt, Germany), and homogenized in a stomacher (Interscience, Saint Nom la Bretèche, France) for 2 min. Appropriate decimal dilutions were prepared in Ringer's solution (LabM, Bury, UK) for microbial enumeration: Total viable counts on Plate Count Agar (PCA, LabM) incubated at 30 °C for 72 h, according to the Portuguese Standard NP 4405, lactic acid bacteria on de Man, Rogosa Sharpe Agar (MRS, LabM) and on M17 (Lab M) incubated at 30 °C for 72 h, according to the International Standard ISO 15214 (F); Enterococcaceae on Bile Esculin Azide Agar (BEA, Biokar Diagnostics, Beauvais, France), incubated at 30 °C for 72 h; Micrococcaceae on Mannitol Salt Agar (MSA, Biokar Diagnostics), incubated at 37 °C for 48 h; yeasts and moulds on RoseBengal Agar supplemented with 0.1 g L of chloramphenicol (RBCA, Oxoid, Hampshire, UK), incubated at 25 °C for 5 days, according to the Portuguese Standard NP 3277-1; Enterobacteriaceae on Violet Red Bile o” and “Chouriça” de Vinhais.