78 research outputs found
Renal Sarcoidosis: a Rare Case
Sarcoidosis is a multisystemic granulomatous disease with rare renal involvement. We describe a case of a 45-year-old female patient admitted to the hospital with severe acute kidney injury and uveitis. After clinical investigation, sarcoidosis with renal, hepatic and ocular involvement was diagnosed. Renal biopsy revealed acute granulomatous interstitial nephritis and treatment with systemic corticosteroids was started with marked improvement in renal function.info:eu-repo/semantics/publishedVersio
Nitrite-free implications on consumer acceptance and the behavior of pathogens in cured pork loins
Research Areas Food Science & TechnologyCured pork loins are valued products due to their particular sensory characteristics. These products are usually prepared with nitrite to guarantee adequate color and pathogen control. The use of nitrite in meat products has been criticized due to its potential contribution to carcinogenic N-nitroso-compound formation. The present work aimed to evaluate the effect of eliminating nitrite from the manufacturing of cured loins made with wine- and water-based marinades on the color evaluation of consumers and on the behavior of Clostridium sporogenes, Listeria monocytogenes, and Salmonella. The use of nitrite in processing cured loins resulted in a color considered adequate by more than 50% of the consumers. When nitrite was not used, the color was described mainly as weak. The hedonic evaluation of cured loins did not reflect the color evaluation. The samples with a weak and an adequate color had similar hedonic evaluations. The present work did not allow us to infer the potential interest in injecting S. xylosus into meat to prepare cured loins. The use of nitrite did not affect the survival of Cl. sporogenes, L. monocytogenes, or Salmonella. The reduction in the aw was the primary determinant influencing pathogen survival. The production of nitrite-free cured loins seems possible once the control of pathogens can be achieved. However, the product will have a weaker color. Consumers appreciate sensory aspects other than color, which, combined with the positive impact of the “additive-free” claim, can support the possibility of producing cured loins without nitriteinfo:eu-repo/semantics/publishedVersio
Sensory changes and listeria monocytogenes behavior in sliced cured pork loins during extended storage
Cured pork loins are sausages with a production tradition in several regions worldwide. They are made from one of the noblest cuts of pork, and for this reason cured loins are one of the most expensive pork meat products. Establishing the correct shelf life allows products to be accepted by the consumer, and to avoid the costs associated with shorter shelf lives. The aim of this study is: (1) to establish proper shelf life by evaluating the willingness of participants to consume and the sensory modifications that occur during prolonged storage via Check All That Apply (CATA) questions; and (2) to study the behavior of Listeria monocytogenes through a microbial challenge test. Sliced cured pork loins can be stored at 6 ± 1 °C for 105 days while maintaining a consumer acceptance of more than 75%. The freshness loss was associated mainly with a decrease in aromatic notes (particularly the smoke and cured aroma), and with the appearance of spoiled characteristics, specifically a sour/vinegar aroma and acidic taste that were detected by a reduced proportion of participants. The freshness evaluation was positively influenced by the typical characteristics of cured products, such as color and a garlic and wine aroma. Sour/vinegar aroma and acidic taste were the attributes most associated with higher freshness penalization. During the period of the test, Listeria monocytogenes inoculated onto the cured loin slices did not grow.FCT: GO77 PDR2020-1.0.1-FEADER-0313/ UIDB/CVT/00772/2020.info:eu-repo/semantics/publishedVersio
Effect of packaging technology on microbiological and sensory quality of a cooked blood sausage, Morcela de Arroz, from Monchique region of Portugal
Morcela de Arroz (MA), a popular Portuguese blood sausage, with high pH and water activity (a(w)), is traditionally commercialized without preservatives and unpacked. This study evaluated the best packaging solution to extend MA shelf life stored at 4 +/- 1 degrees C for 44 days: without packaging (WP), vacuum (VP) and modified atmosphere packaging (MAP) (80% CO2; 20% N-2). Mesophilic (MTVC), psychrotrophic (PTVC), lactic acid bacteria (LAB), pseudomonads, molds and yeasts, Enterobacteriaceae, Listeria monocytogenes, Salmonella spp., Bacillus cereus, Clostridium perfringens, sensory properties, pH, moisture and aw were studied. Moisture and a(w) decreased (p < 0.05) in WP. pH decreased in WP and MAP during storage. MTVC and PTVC counts increased to values around 7 log CFU/g at 44 days of storage. LAB and Enterobacteriaceae counts were higher (p < 0.05) in VP. Pseudomonads were inhibited (p < 0.05) by MAP after 8 days of storage. Sensory parameters were affected (p < 0.05) by packaging and storage time. Globally, MAP performed better. (C) 2014 Elsevier Ltd. All rights reserved
Constraints of HACCP Application on Edible Insect for Food and Feed
In a near future there is a need to guaranty food security for approximately more than one billion people worldwide. Beyond the population increase other factors contribute to food and feed insecurity such as climate changes, rising costs of animal protein and consumer demands for protein. Edible insects are pointed out as one alternative as they have always been a part of human diets. The concern to guaranty food security cannot be dissociated from food safety and under the Codex Alimentarius principles of food hygiene, insects would be comparable to other types of foods of animal origin. The processing and storage of insects and their products should follow the same health and sanitation regulations as for any other food or feed in order to ensure their microbiological and chemical safety. Allergies induced through insects’ ingestion should also be considered. This review aims to identify potential hazards related to edible insects’ production and transformation. Preventive measures to their control will be presented considering pre-requirements in their production and transformation. An HACCP plan will be described as a study case in insects’ transformation, being discussed all constraints regarding implementation
The risk of salt reduction in dry-cured sausage assessed by the influence on water activity and the survival of salmonella
Research Areas: Food Science & TechnologyWater activity (aw) is the main hurdle for microbial control in dry-cured sausages. The
aw can be influenced by drying or adding electrolytes or humectants. Dry-cured meat products are
partially dried, which, together with added salt, results in safe aw values. Currently, there is a trend
to reduce salt in meat products, which can compromise the preservation process. The present work
aims to evaluate the influences of added salt levels (1% or 3%) and the use or omission of phosphates
and wine on the aw of a dry-cured sausage, and to evaluate the possibility of estimating the aw
from the moisture loss and the behavior of Salmonella during dry-cured sausage (chouriço) processing.
There was a strong relationship between moisture and aw, regardless of the salt level and the presence
of phosphates or wine. Predicting aw from moisture loss is possible using the Boltzmann sigmoid
function. The salt level strongly influences Salmonella behavior, mainly through aw reduction. An
increase in aw by 0.01 units reduced the odds of achieving a 5-log reduction in Salmonella counts to
half. Increasing added salt from 1% to 3% increased the odds of achieving a 5-log Salmonella reduction
7.5-fold. The current trend to reduce salt in foods must be carefully approached if applied to cured
meat products, as it has substantial consequences on aw evolution and Salmonella survivalinfo:eu-repo/semantics/publishedVersio
Impact of nitrite on the microbiological quality of a Portuguese SalpicĂŁo
info:eu-repo/semantics/publishedVersio
Modelling the kinetics of Listeria monocytogenes in refrigerated fresh beef under different packaging atmospheres
The objective of this study was to model the fate of Listeria monocytogenes inoculated in beef at two concentrations (2.5 and 4.0 log CFU/g), packaged under air, vacuum and three modified atmospheres MAP: 70%O 2 /20%CO 2 /10%N 2 , 50%O 2 /40%CO 2 /10%N 2 and 30%O 2 /60%CO 2 /10%N 2 , and refrigerated at a normal temperature (4 °C) and at a mild abusive temperature (9 °C). The experimental design produced a total of 20 environmental conditions. An omnibus model based on the Weibull equation proved statistically that L. monocytogenes survives better in vacuum (VP) than in aerobic conditions, although without significant difference in its ability to survive in the temperature range between 4 °C and 9 °C. Furthermore, regardless of the refrigeration temperature, the presence of CO 2 in the package atmosphere exerted a bactericidal effect on L. monocytogenes cells, being approximately 1.5 log of reduction when storage time reached 10 days. Since the pathogen can survive in VP/MAP beef, there is a need of maintaining its numbers below 100 CFU/g before packaging by placing efforts on the implementation of control measures during processing.The authors would like to thank CECAV-UTAD and the research is supported by national funds by FCT- Portuguese Foundation for Science and Technology, under the PEst-OE/AGR/UI0772/2014. Dr. Gonzales–Barron wishes to acknowledge the financial support provided by the Portuguese Foundation for Science and Technology (FCT) through the award of a five-year Investigator Fellowship (IF) in the mode of Development Grants (IF/00570).info:eu-repo/semantics/publishedVersio
Resonant Tunnelling Optoelectronic Circuits
Nowadays, most communication networks such as local area networks (LANs), metropolitan area networks (MANs), and wide area networks (WANs) have replaced or are about to replace coaxial cable or twisted copper wire with fiber optical cables. Light-wave communication systems comprise a transmitter based on a visible or near-infrared light source, whose carrier is modulated by the information signal to be transmitted, a transmission media such as an optical fiber, eventually utilizing in-line optical amplification, and a receiver based on a photo-detector that recovers the information signal (Liu, 1996)(Einarsson, 1996). The transmitter consists of a driver circuit along a semiconductor laser or a light emitting diode (LED). The receiver is a signal processing circuit coupled to a photo-detector such as a photodiode, an avalanche photodiode (APD), a phototransistor or a high speed photoconductor that processes the photo-detected signal and recovers the primitive information signa
Influence of salt level, starter culture, fermentable carbohydrates, and temperature on the behaviour of L. monocytogenes in sliced chouriço during storage
Sliced ready-to-eat traditional meat products presented in individual packaging with more convenience to the consumer is the way that food industry tries to adapt to the new consumer tendencies.
The current work assessed the survival of Listeria monocytogenes in a contaminated sliced vacuum packed chouriço with different sugar concentrations, two salt levels, and presence/absence of Lactobacillus sakei as starter culture along the storage period at two temperatures (8 °C and 22 °C). Neither the inoculation with L. sakei, nor the addition of carbohydrates influenced the survival of the pathogen. Higher amount of salt resulted in a significant reduction of L. monocytogenes, and storage at the higher temperature displayed a safer product. After 7 days, L. monocytogenes was not detected in any samples. The study of the association of the factors contributing for L. monocytogenes survival by logistic regression showed that increasing the level of salt addition from 1.5% to 3% reduces the odds of survival of L. monocytogenes to about one fifth (0.174). Worthy of attention is the significant reduction in the odds (OR=0.028) of finding viable L. monocytogenes when the samples are stored at room temperature (22 °C), when compared to low temperature (8 °C).
The general and indiscriminate use of refrigeration for meat products might increase the risk of presence of L. monocytogenes. The competitive advantage that L. monocytogenes has at low temperatures, as the potential inhibition of LAB activity, is probably the reason of the observed behaviour. The amount of salt was an important hurdle to control L. monocytogenes growth, so, manufacturing meat products with lower salt contents to meet the demands of healthy products might represent a risk for safety, since high levels of salt together with low aw are the keys for their conservation
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