1,136 research outputs found
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
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
Sequential injection titration of chloride in milk with potentiometric detection
In this work, a sequential injection system for the pseudo-titration of chloride in milk is described. Milk was directly aspirated
into the system and sandwiched between two silver nitrate plugs (titrant). The aspirated zones were then propelled to the detector
(Ag2S/Ag tubular electrode), where the depletion in the titrant silver concentration (due to the formation of a AgCl precipitate) was
monitored. The results obtained by the developed sequential injection titration method were not statistically different from those
provided by the potentiometric reference procedure with relative standard deviations better than 3.4%. The sampling rates achieved
were 17 samples per hour.info:eu-repo/semantics/acceptedVersio
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
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
Antagonistic activities of Kefirgel and Kefirgel products against Staphylococcus aureus isolated from diabetic ulcers
Diabetic foot ulcers are often complicated by infection and among pathogens the Gram-positive Staphylococcus aureus is the most common isolated. Also concomitantly, the high prevalence of methicillin-resistant S. aureus (MRSA) was significant impact on successful treatment of infected foot ulcers. In this context, the purpose of the present study was to evaluate the antibacterial properties of Kefigel®, a natural product composed by nettle (Urtica dioica L), lavender (Lavandula angustifolia Mill) and kefir grains, which have been reported as to having antibacterial activity against several diseases. Here, antibacterial effect of Kefigel® and its components were investigated against 20 S. aureus isolates (10 MSSA and 10 MRSA) collected from several diabetic foot ulcers. To assess antibacterial activity, the disk diffusion assay method, minimum inhibitory concentration (MIC), minimal bacterial activity and effects on specific growth rate, were applied. Results showed that by diffusion method, only etanolic extracts of nettle and lavender showed antibacterial activity and their effects were mainly bacteriostatic. Compared to the antibiotic gentamicin, the nettle and lavender extracts showed an efficacy between 50 and 100% relative to the antibiotic. Generally, the MRSA isolates sowed higher inhibition halos comparing MSSA isolates. In turns, Kefigel® (40mg.mL-1) affects the specific growth rate of S. aureus isolates, since after incubation for 9h almost MSSA isolates growth were inhibited. A bactericide effect was observed only against one isolates MRSA. These findings indicate a potential use of Kefigel® as a natural product having an effective effect against Staphylococus aureus. The topical use of this product for prevention of diabetic foot ulcers infections can be useful, however further investigation will be made, namely tests with high Kefigel® concentrations and synergetic effects with antibiotics
Antibacterial potential of Urtica dioica and Lavandula angustifolia extracts against methicillin resistant Staphylococcus aureus isolated from diabetic foot ulcers
Despite the antibacterial potential of plant extracts against several bacterial infections, until now, no major
studies have been published about the effect of lavender and nettle leaves against methicillin-sensitive and
methicillin-resistant strains of Staphylococcus aureus (MSSA and MRSA, respectively). Thus, the authors studied
their antibacterial potential against MSSA and MRSA from diabetic foot ulcers in order to find alternatives to the
systematic use of antibiotics. Phenolic acids, flavonoids, flavones and flavonols were extracted from lavender
and nettle leaves and characterized by HPLC-DAD/Vis. Disc diffusion assay and minimum inhibitory
concentration (MIC) were used to assess their antibacterial activity. A direct association between the high
content of hydroxycinnamic acids (chlorogenic acid, caffeic acid, rosmarinic acid) and flavonoids (quercetin)
and decreasing bacterial growth activity was noted. The fact that lavender and nettle are rich in hydroxycinnamic
acids and quercetin seems to explain the high antibacterial potential of these plant and the
differences between them.The authors acknowledge the financial support provided by the
FCT-Portuguese Foundation for Science and Technology (Carla Dias-
SFRH/BD/90120/2012 and Alfredo Aires-SFRH/BPD/65029/2009),
under the Project PEst-OE/AGR/UI4033/2014.info:eu-repo/semantics/publishedVersio
Evaluation of antibiotic susceptibility of Lactobacillus plantarum isolated from traditional Portuguese sausage products
Nowadays the use of fermentative microbiota in food products is researched in order to confer protection to the products and furnish health benefits to consumers The aim of this work was to evaluate antibiotics susceptibility of Lactobacillus plantarum isolated from fermented traditional meat products in order to select them to be used as starters or protective bacteria on fermented meat products. The susceptibility of different L. plantarum isolates (n=44) from fermented/dry/smoked meat products of three different Portuguese industries were tested by Agar disc diffusion method for Vancomycin, Quinupristin/Dalfopristin, Rifampicin, Penicillin G, Erythromycine, Tetracycline, Gentamicin, Lincomycin and Chloramphenicol. Most of the studied L plantarum isolates were susceptible for Tetracycline (75%) and Erythromycin (71%) and could be used safely as starter cultures. Those that presented resistance need to be genetically evaluated since the mechanism of resistance is probably related to mobile genetic elements carried by L plantarum
Contribuição para a caracterização nutricional de alguns produtos de salsicharia
8º Encontro de Química dos Alimentos. Congresso. Beja, Portugal 4 – 7 Março 2007O consumo de produtos de salsicharia é comum na dieta mediterrânica. No entanto, eles são tidos como alimentos de elevado valor calórico e o seu consumo tem sido associado a doenças do foro cardiovascular. A maioria dos produtos de salsicharia disponíveis no mercado, não apresenta informação nutricional, a qual seria um atributo a acrescentar na rotulagem, facilitando a escolha do consumidor, visto que nem todos apresentarão o mesmo aporte energético. Este trabalho surge como uma tentativa de caracterização nutricional de alguns produtos de salsicharia. Com esse objectivo, utilizaram-se resultados de análises físico-químicas realizadas a um total de 383 amostras (fiambre da perna, n=31; fiambre da pá, n=12; filete afiambrado, n=18; mortadela, n=18; paio York; n=18; painho, n=13; toucinho fumado, n=9; chouriço corrente, n=217; chourição, n=26; salpicão, n=7; linguiça, n=14). Estas análises, realizadas no âmbito do controlo de qualidade, foram efectuadas em produtos finais de salsicharia de diferentes indústrias, a serem colocados no mercado. O valor energético foi determinado, utilizando os coeficientes de conversão de Atwater, expressando-se os resultados em kcal e em kJ por 100 gramas da parte edível. Concluiu-se que estes produtos apresentam distintas características nutricionais; com base nos resultados obtidos, propõe-se, tentativamente, a classificação em três grupos: (1) Baixo valor calórico: ( 627 kJ/100g) que inclui produtos como o Fiambre da Perna, Fiambre da Pá e o Paio York; (2) Médio valor calórico: (entre 150 e 300 kcal/100g 627 e 1254 kJ/100g) para produtos como Paínho, Filete Afiambrado, Salpicão e Mortadela; (3) Alto valor calórico: (>300 kcal/100g 1254 kJ/100g) que caracteriza produtos como o Toucinho Fumado, Chourição, Linguiça e Chouriço Corrente
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
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