Antimicrobial susceptibility assessment of Campylobacter on outdoor iberian pig sows

Both Campylobacter and Salmonella are considered the most frequent bacterial causes of human enteritis in industrialized countries. The consumption of raw or undercooked poultry and pork contaminated meat products are the main sources of human infection. The prevalence of Campylobacter and Salmonella was determined in the present work for extensive production Iberian pig sows, Sus mediterraneus. Samples were collected at the maternity area of a creator from, water drinkers, feed and feed containers as well as from sows faecal matter. Of 42 samples, 31 and 23 carried Campylobacter spp. and Salmonella spp. respectively. Only Salmonella spp. was found in all 3 tested water and feed containers. Of the 58 isolated Campylobacter strains only one was identified, by multiplex-PCR, as Campylobacter jejuni, all other were C. coli. Antibiotic susceptibility was performed by disc diffusion method with Nalidixic acid, Ciprofloxacin, Erythromycin, Tetracycline, Chloramphenicol and Ampicilin. While 95% of the tested strains were susceptible to chloramphenicol, 66% and 53% were resistant to the tested fluoroquinolones, Ciprofloxacin and Nalidixic acid respectively. Erythromycin resistance was fairly low in comparison to previous publications with 14% of resistant strains. 38% were resistant to Tetracycline and 57% to Ampicilin. Seven of the 58 Campylobacter strains were entirely susceptible and none were resistant to all the antimicrobials tested. Multiple drug resistance was found in 88% of strains. Cross contamination may occur between sows inside maternity facilities and piglets may become infected in an early age by their mothers. New and better control measures are therefore necessary to minimize transmission between animals reducing the number of contaminated individuals and the potential transmission to human handlers and consumers

Impact of a 25% salt reduction on the microbial load, texture and sensory attributes of a traditional dry-cured sausage.

Catalão is a Portuguese dry-cured traditional sausage, highly appreciated for its distinctive sensory properties. The aim of this study was to evaluate the impact of a 25% salt reduction on Catalão manufactured with either purebred Alentejano (Al) or crossbred Iberian × Duroc (IDr) pork meat, on its physicochemical and microbiological stability, texture parameters, and sensory attributes. No significant effect of salt reduction or genotype was observed for pH, aW, and microbiological parameters. PUFA content was significantly higher for Al Catalão, particularly due to the content in linoleic and linolenic fatty acids. IDr 3% NaCl samples had the highest mean n6/n3 PUFA ratio, and the highest mean values for the atherogenicity and thrombogenicity indices, showing that both genotype and salt content influence these nutritional indices. Texture profile of Catalão was significantly influenced by salt content and genotype. Al samples were less adhesive, cohesive, and easier to chew. Low-salt Catalão was harder, more adhesive, and less cohesive, with lower resilience and higher chewiness values. Regarding sensory attributes, salt content influenced the product aroma, with reduced-salt sausages being evaluated as significantly less aromatic. Overall, a 25% salt reduction did not have a significant impact on the quality, stability, and sensory evaluation of Catalão

Effects of genotype, salt content and calibre on quality of traditional dry-fermented sausages

The increasing demand for traditional food products is concomitant with higher nutritional and health concerns. The effect of genotype, salt content and calibre on physicochemical, microbiological and texture parameters, along with sensory acceptability, was studied on low-salt Portuguese traditional dry-fermented sausages. A few significant differences were found in different microbial counts between pork genotypes' sausages. Lauric and stearic fatty acids showed significantly higher values for hybrid genotype products, while contents in gadoleic, heneicosanoic, linoleic and linolenic acids were higher in Alentejano pork sausages. Unexpectedly, there are no significant differences between genotypes for oleic acid, although lower contents were found in the Alentejano genotype.Texture Profile Analysis revealed significant differences in hardness, adhesiveness, resilience and chewiness between genotypes, with Alentejano pork sausages being softer and thus easier to chew. Salt reduction does not negatively affect the quality and acceptability of sausages. Furthermore, the use of hybrid genotype meat does not mischaracterise a product traditionally made exclusively of Alentejano pig meat

Shelf-life extension and quality improvement of a Portuguese traditional ready-to-eat meat product with vinegar

Cabec a de xara is a traditional ready-to-eat meat product (RTEMP) from the Portuguese region of Alentejo. It is a moulded galantine made of low value pork pieces. The aim of this work was to test the addition of vinegar in reducing the spoilage microbiota, as well as controlling Listeria monocytogenes, in order to increase the shelf-life of cabec a de xara. Physicochemical (fatty acids and biogenic amines profiles), microbiological (mesophiles, psychrotrophic bacteria, enterobacteria, yeasts and L. monocytogenes) and sensory analyses were performed throughout the storage period. RTEMP vinegar samples always showed lower microbiological counts than control samples. Moreover, RTEMP vinegar samples showed significantly lower contents in vasoactive amines throughout the storage period, which might be explained by their significantly lower enterobacteria counts. Concerning sensory analysis, RTEMP vinegar samples generally scored higher in overall appreciation. Our results showed that shelf-life of cabec a de xara may be extended from 1 to 3 months

The calibre effect on two traditional dry fermented sausages from Alentejo, Portugal, made from the same dough

Traditional food products are an important part of European gastronomy and it has been long empirically known that traditional fermented foods are vital to a good digestive health. However, and also due to health concerns, an extensive evaluation of food quality and safety parameters is crucial. Two low-salt dry-fermented sausages were manufactured from the same dough with two different casing calibres (small-“Catalão”/large-“Salchichão”) using two pig genotypes (Alentejano/Iberian x Duroc) and two NaCl concentrations (3%/5%). Three independent batches with replicates were prepared. The effects of calibre, genotype and salt concentration on the microbiological, physicochemical and textural parameters, as well as on sensory acceptability were considered. Analyses of variance were performed considering calibre, genotype and salt concentration. Regarding food safety of these traditional products, no Salmonella spp., Campylobacter spp. and Listeria monocytogenes, nor Enterobacteriaceae or in particular E. coli, were detected in the analysed products. Different numbers of lactic acid bacteria (LAB), enterococci and Micrococaceae were observed between the two calibres (p<0.05). Significantly different pH values were observed between genotypes and calibre (p<0.05). On the other hand, aw values differ significantly with salt (p<0.05). The Texture Profile Analysis (TPA) revealed significant differences between the two calibres regarding hardness, cohesiveness, resilience, gumminess and chewiness (p<0.05). Concerning the sensorial analysis, the calibre effect was sensed in the attributes succulence and tenderness (p<0.05). Salt differences were noted by panellists, but have minor impact on other studied parameters. Overall, the calibre effect was the most distinctive one, followed by the effect of genotype. Acknowledgements This work was supported by national funds through project PRODER 13.021 (QREN/PRODER/Medida 4.1), Fundação para a Ciência e a Tecnologia (FCT) under the Strategic Project PEst-OE/AGR/UI0115/2014 and co-funded by FEDER Funds through the COMPETE Programme. The authors thank PALADARES ALENTEJANOS Lda., A. Oliveira, G. Pias and R. Bicho for their collaboration

A dynamic programming heuristic for vehicle routing with time-dependent travel times and required breaks.

For the intensively studied vehicle routing problem (VRP), two real-life restrictions have received only minor attention in the VRP-literature: traffic congestion and driving hours regulations. Traffic congestion causes late arrivals at customers and long travel times resulting in large transport costs. To account for traffic congestion, time-dependent travel times should be considered when constructing vehicle routes. Next, driving hours regulations, which restrict the available driving and working times for truck drivers, must be respected. Since violations are severely fined, also driving hours regulations should be considered when constructing vehicle routes, even more in combination with congestion problems. The objective of this paper is to develop a solution method for the VRP with time windows (VRPTW), time-dependent travel times, and driving hours regulations. The major difficulty of this VRPTW extension is to optimize each vehicle’s departure times to minimize the duty time of each driver. Having compact duty times leads to cost savings. However, obtaining compact duty times is much harder when time-dependent travel times and driving hours regulations are considered. We propose a restricted dynamic programming (DP) heuristic for constructing the vehicle routes, and an efficient heuristic for optimizing the vehicle’s departure times for each (partial) vehicle route, such that the complete solution algorithm runs in polynomial time. Computational experiments demonstrate the trade-off between travel distance minimization and duty time minimization, and illustrate the cost savings of extending the depot opening hours such that traveling before the morning peak and after the evening peak becomes possible

Dry‐Cured Meat Products According to the Smoking Regime: Process Optimization to Control Polycyclic Aromatic Hydrocarbons

The manufacturing of dry‐cured meat products usually includes a smoking step. Polycyclic aromatic hydrocarbons (PAHs) are potentially carcinogenic chemical compounds that may result from smoking. The aim of the present study was to optimize the smoking regime of traditional dry‐cured meat products in order to minimize the presence of PAHs. Dry‐cured sausages were submitted to different smoking regimes: (A) no smoking; (B) 20 h effective smoking; (C) 60 h effective smoking; (D) effective smoking until reaching 38%–40% weight losses. Three independent batches were produced per smoking regime, and three samples per batch were analyzed. Microbiological, physicochemical, and sensory analyses were performed. The total PAHs content was generally low and did not differ significantly in meat products submitted to the four different smoking regimes. The PAH4 and benzo(α)pyrene levels were below the established legal limits in all analyzed dry‐cured sausages. Nevertheless, non‐smoked sausages always showed lower PAHs values for all PAHs groups

Characterisation of "Catalão" and "Salsichão" Portuguese traditional sausages with salt reduction

The present study evaluated the effect of salt reduction on traditional dry-cured sausages' safety, quality and product acceptance, comprising physicochemical and microbiological parameters, biogenic amines, fatty acids, texture profile and sensory analysis. According to our results, salt content had a major effect on microbiological counts, although not compromising the products' safety. Marked differences were identified regarding biogenic amines, in particular for histamine, tyramine and cadaverine, which were detected in larger amounts in products with 3%. Moreover, significant differences in the fatty acids profile have also been found, but only in less abundant components such as linoleic, lauric and heneicosanoic acids. Texture profile analysis of low-salt products, revealed a decrease in hardness and chewiness, along with an increase in adhesiveness values. Sensory evaluations revealed that despite the less intense aroma, products with 3% salt, had a more balanced salt perception. Our results suggest that salt content may be reduced to 50% in dry-cured products, with the obvious health-related advantages

Addition of vinegar to extend the shelf-life of "Cabeça de Xara"

Cabeça de xara es un producto de carne listos para comer, cuya producción es muy característica en el Alentejo, una región de Portugal. Es una galantina que generalmente se moldea en forma de paralelepípedo. Se elabora con varias carnes obtenidas de la raza porcina Alentejana y criada en la misma región, cabezas de cerdo deshuesadas, lengua y tejido conectivo, a la que se le añade una serie de condimentos como sal, perejil, vino y pimienta. Este trabajo se pretende poner a prueba la viabilidad de añadir vinagre con el fin de aumentar la vida útil de la cabeça de xara, mediante la reducción de la microbiota contaminante responsables del deterioro, así como el control del patógeno Listeria monocytogenes. Tres lotes independientes fueron producidos y con composición proximal parecida, se evaluó pH, aw, parámetros microbiológicos y contenido de aminas biogénicas. El análisis sensorial se realizó también durante todo el período de almacenamiento. No se encontraron diferencias significativas entre las muestras control y vinagre en cuanto a la composición proximal de cabeça de xara. Como era de esperar, el pH fue menor en las muestras con vinagre, sin embargo se observaron diferencias en aw entre los dos tratamientos. L. monocytogenes estuvo presente desde el primer mes sólo en un lote, en el tratamiento control. Sin embargo, es inhibida por la adición de vinagre de vino hasta el tercer mes de almacenamiento, donde L. monocytogenes está presente pero por debajo del límite establecido en el Reglamento 2073/2005. La presencia de vinagre redujo significativamente el contenido de aminas biógenicas, en particular cadaverina, putrescina y tiramina, durante todo el período de almacenamiento. En cuanto a la evaluación sensorial, el sabor a vinagre fue evaluado por los panelistas de manera negativa

Impact of salt reduction on biogenic amines, fatty acids, microbiota, texture and sensory profile in traditional blood dry-cured sausages

Meat industry needs to reduce salt in their products due to health issues. The present study evaluated the effect of salt reduction from 6% to 3% in two Portuguese traditional blood dry-cured sausages. Physicochemical and microbiological parameters, biogenic amines, fatty acids and texture profiles and sensory panel evaluations were considered. Differences due to salt reduction were perceptible in a faint decline of water activity, which slightly favoured microbial growth. Total biogenic amines content ranged from 88.86 to 796.68 mg kg 1 fresh matter, with higher amounts, particularly of cadaverine, histamine and tyramine, in low-salt products. Still, histamine and other vasoactive amines remained at low levels, thus not affecting consumers’ health. Regarding fatty acids, no significant differences were observed due to salt. However, texture profile analysis revealed lower resilience and cohesiveness in low-salt products, although no textural changes were observed by the sensory panel. Nevertheless, low-salt sausages were clearly preferred by panellists