Untitled

Funder

Organizational Unit

Publications

Contaminación por Staphylococcus aureus en el procesamiento de un embutido fermentado português [linguiça]

Publication . Cadavez, Vasco; Pereira, Ana Paula; Gomes, Aline; Lopes-da-Silva, M.F.; Estevinho, Leticia M.; Gonzales-Barron, Ursula; Dias, Teresa

Linguiça is a Portuguese dry-fermented sausage, which has been found to harbour food-borne pathogens in the past. Hence, the objective of this study was to investigate the levels of total viable counts (TVC), Enterobacteriaceae, and S. aureus at the key production stages of linguiça by depicting their changes using principal component analysis. Unlike Enterobacteriaceae counts, which decreased from raw meat to final product, S. aureus increased significantly in the meats throughout processing. While Enterobacteriaceae was very sensitive to the decrease in water activity, S. aureus remained viable and developed during fermentation. The presence of S. aureus at all stages should prompt industries to reinforce good hygiene practices in the processing of linguiça.

2015Conference paper

Open access

Evaluación de la higiene e inocuidad de un embutido fermentado Portugués (linguiça) a lo largo de su procesamiento

Publication . Gonzales-Barron, Ursula; Pereira, Ana Paula; Aline, Gomes; Lopes-da-Silva, M.F.; Rodrigues, Paula; Fernandes, Conceição; Estevinho, Leticia M.; Cadavez, Vasco; Dias, Teresa

Linguiça is a Portuguese dry-fermented sausage, which has been found to harbour food-borne pathogens in the past. Hence, the objective of this study was to investigate the changes in the levels of total viable counts (TVC), Enterobacteriaceae, L. monocytogenes and S. aureus at the key production stages of linguiça. Overall, TVC counts did not change considerably from raw meat to stuffing (5.5 􀂱 5.9 log CFU/g), yet it increased significantly up to the end of drying (7.83 log CFU/g). Unlike the Enterobacteriaceae counts, which decreased (p<0.01) from batter before maceration (3.23 log CFU/g) to the end of drying (1.56 log CFU), S. aureus increased significantly between these two processing stages (2.58 log CFU/g in the finished product). L. monocytogenes was detected in the products of one of the factories although their counts decreased after batter maceration. The presence of these two pathogens should also prompt industries to reinforce good hygiene practices in the processing of traditional sausages.

2015Conference paper

Open access

Influence of starter culture and ripening temperature on survival of L. monocytognes in traditional Portuguese dry-feremnted sausage

Publication . Cadavez, Vasco; Pereira, Ana Paula; Gonzales-Barron, Ursula; Dias, Teresa

Linguiça is a Portuguese traditional dry-fermented sausage whose microbiological quality and safety have been reported to be highly variable. The present study evaluated the influence of the addition of a commercial starter culture and ripening temperature (10° C and 18°C) on the survival of L monocytogenes in linguiça

2016Conference paper

Open access

Estudio de meta-análisis del efecto de estimulación eléctrica en la fuerza de corte de la carne de vacuno

Publication . Xavier, Cristina; Gonzales-Barron, Ursula; Muller, Alexandra; Cadavez, Vasco

The objective of this work was to use meta-analysis to estimate the effect size of the electrical stimulation on beef tenderness through the study of the measurements of shear force. Eight independent studies were used based on comparison of shear force measurements on the Longissimus dorsi and Longissimus lumborum in cattle carcasses subject to electrical stimulation and unstimulated carcasses. For each study, the mean effect size and standard error was calculated in order to apply a random-effects meta-analysis model. The meta-analysis demonstrated that the electrical stimulation on beef carcasses decreases the values of shear-force of meat by an average of 1.34 kgf. Thus, this study confirmed the positive effect of the electrical stimulation on the beef meat tenderness. However, the effect size displayed high variation among studies which can be attributed to differences in their experimental conditions.

2015Conference paper

Open access

Relating microbiological and physicochemical patterns of a traditional Portuguese fermented sausage along processing

Publication . Pereira, Ana Paula; Gomes, Aline; Cadavez, Vasco; Fernandes, Conceição; Rodrigues, Paula; Estevinho, Leticia M.; Gonzales-Barron, Ursula; Dias, Teresa

Linguiça is a Portuguese popular ready-to-eat dry fermented sausage. Despite the high diversity of sausages produced in Portugal, all of them are made from cut pork meat macerated with water, wine, salt, garlic, pepper, and undergoes processes of maturation, smoking and drying. During the fermentation and drying of sausages, L. monocytogenes tends to decrease considerably. However, despite the various hurdles in the dry sausage manufacturing process, this foodborne pathogen is able to survive and is detected in the final product. Factors that may affect the growth or survival of foodborne pathogens in sausage products such as linguiça include water activity (aw), pH, temperature, use of starter cultures and use of ingredients with antimicrobial activity (e.g., garlic, smoke). The present study has evaluated the influence of the addition of a commercial starter culture and ripening temperature (10º C and 18ºC) on growth and survival of L. monocytogenes strains, isolated from sausage, in experimentally inoculated linguiça. Sliced raw meat was mixed with salt (20g/kg), dry garlic (4,5g/kg), sweet paper (12,5g/kg), laurel (0,5g/kg), dextrose (10g/kg), a mix of red/white wine (410ml/kg) and water (410ml/kg) and inoculated with L. monocytogenes (5 log10/g). Additionally Commercial starter culture (5 log10/g) was added to one batch. The batter was macerated for 3 days at 4ºC. After stuffing into natural pork casings, sausages were hung vertically in a climate controlled chamber, for ripening at 10℃ or 18ºC with 83% relative humidity (RH) during ten days. During maceration step was observed no changes in growth rate of LAB and L. monocytogenes. However during ripening step was verified an increase of the count of LAB and a concomitantly decrease of L. monocytogenes. In the batches not inoculated with a commercial starter culture was observed a decrease of L. monocytogenes of 1 log10/g at 10ºC and 1,57log10/g at 18ºC of ripening temperature. The addition of a commercial starter culture increased the reduction of pathogen at both temperatures (1,57log10/g at 10ºC and 2,24log10/g at 18ºC). This study points out the fact that the decrease of L. monocytogenes contamination rate during the manufacturing process of sausages is due to the drying and ripening step than to the maceration itself and is due mainly to the effect of starter culture and ripening temperature.

2015Conference object

Open access