Metal contaminants in Largemouth bass (Micropterus salmoides) collected in large dams from Tejo River basin and small irrigation dams

Largemouth bass (Micropterus salmoides) is a very important fresh water fish in the Portuguese regional cuisine mainly in the countryside (Central region and north Alentejo). Because there’s no aquaculture industry, all eaten largemouth bass in Portugal are collected in large dams (Basins of Tejo and Guadiana rivers) and small irrigation dams. For decades, the Tejo River received environmental pollutants from non-point and point sources that included intensive agriculture, industrial entities, municipalities and nuclear power plant. The aim of this work was to evaluate some metals (Cd, Cr, Cu, Fe, Hg, Mn, Pb, Zn) present on largemouth bass muscle tissue collected in the section of Tejo River that makes border between Portugal and Spain (TR) (N=9) and collected in three irrigation reservoirs (IR) located near Castelo Branco – Portugal (N=11). Individual were weighted and measured. Age was determined by examining fish scales, and sex determined by gonads observation. Samples for liver, dorsolateral muscle and tail muscle were collected from the right side of the fish. TR average weight 435.14g (±109.15), average length 278.33mm (±23.28), average K condition factor 1.98 (±0.09) and average age 3.11 years (±0,78) were similar (P>0.05) to IR average weight 410.84g (±137.71), average length 278.36mm (±31.13), average K condition factor 1.86 (±0.17) and average age 3.18 years (±0,60). Total mercury was determined in freeze-dried samples by atomic absorption spectrometry with thermal decomposition and gold amalgamation. For the other metal analysis, freeze-dried powders were mineralized with a mixture of HNO3 and H2O2, followed by ICP-OES quantification. Cd and Pb presented concentrations below LOQ (0.025 and 0.15mg.kg-1wet.weight, respectively) for all muscle samples. These values are below legal limits in EU (0.05 and 0.3mg.kg-1wet.weight, respectively). Average Hg levels are below legal limits (0.5mg.kg-1wet.weight) and muscle presented higher levels than liver. These contaminant levels indicate that are no contamination sources in the sampling sites. Cu, Cr, Fe, Mn and Zn are essential micronutrients. Their concentrations were not significantly different between dorsal and tail muscle and were higher in liver (P>0.05), with mean concentrations on muscle being, respectively: TR 0.16 (±0.07), <LOQ(0.03), 1.45 (±0.42), 0.04 (±0.04) and 3.76 (±0.39) mg.kg-1wet.weight; IR 0.16 (±0.02), <LOQ(0.03), 1.80 (±0.52), 0.05 (±0.05) and 4.17 (±0.56) mg.kg-1wet.weight. We concluded that metallic concentrations of largemouth bass muscle tissues were below the maximum permissible for a safety utilization of theses fishes in human nutrition

"Cachena" a bovine rustic Portuguese extensively reared autochthonous breed: meat texture analysis

‘Cachena’ is one of the world’s smallest bovine breeds. Extremely rustic and wild, they are extensively reared, and fed with natural pastures. Meat valorisation is essential to preserve this breed, with a limited livestock. ‘Cachena’’s meat is tender, juicy, low-fat, and highly appreciated due to the association of animal, terroir and producer, balanced by the ecosystem’s sustainability. The aim of this study was to increase the weight of Longissimus dorsi (LD) and Psoas major (PM) muscles, without depreciating their sensory quality. Two groups of 16 animals were slaughtered: (A) 9-17 months old animals with 140-225 kg slaughter live weight (SLW); (B) 17-20 months old animals with 260-335 kg SLW. LD and PM muscles’ fresh weight was recorded, and microbiological and physicochemical parameters (pH and aW) were evaluated two days, while instrumental texture (Texture Profile Analysis (TPA) and Warner-Bratzler shear force (WBSF)) and sensory analyses by a trained sensory panel were performed four days after slaughter. Microbiological analyses were conducted following international standards to ensure food safety. LD and PM weights significantly increased with the animals’ age (P<0.01, LD, and P<0.001, PM). pH values were similar for both groups and aW was significantly higher in group A (P<0.001). Listeria monocytogenes and Salmonella spp. were not detected in any of the analysed samples. All analysed meat samples were generally tender, with PM tender than LD. Group A meat was tender (P<0.001) and easier to chew (P<0.001), for both muscles. Nevertheless, WBSF was higher (P<0.001). Regarding sensory analysis, no significant differences were observed in hardness, elasticity, succulence, and global appreciation between the two groups for LD meat. Moreover, fibrousness values were higher in group A (P<0,01). The higher SLW, from older ‘Cachena’ animals, associated to larger meat cuts, does not decrease meat tenderness

Establishing tenderness threshold of beef using instrumental and consumer sensory evaluation

The consumers consider tenderness one of the most important qualitative characteristics of meat, so they are willing to pay a higher price for beef as long it is guaranteed tender. However, tenderness is also a highly variable property, depending on many intrinsic and extrinsic factors, such as animal breed, feed, and management, and on their interaction. Establishing a tenderness threshold could serve as a precise quality control system to guarantee tender meat ant to assure consumer acceptability. A threshold is defined as a point on the sensory stimulus scale at which a transition occurs in a series of sensations or judgements. The present study aims to establish a tenderness threshold for beef steaks using a consumer sensory test. About 250 consumers were asked to rate consumption frequency, mode of preparation, and their palatability of beef. Consumers were further asked to assess which tenderness category was most appropriate for each one of four beef samples of commercial origin, considering an affective acceptance test through a 5-category hedonic scale (Very Hard, Hard, Ideal Tenderness, Tender and Very Tender). The same beef samples were evaluated through Warner-Bratzler shear force (WBSF) and texture profile analysis (TPA) to define their instrumental tenderness. The results obtained allowed us to conclude that there is a correlation between the sensory and instrumental evaluation of beef tenderness. However, a correct definition of the threshold must always consider both instrumental evaluation methods, WBSF and TPA. A tender meat should have shear force values between 15 and 32N and a compression force between 11 and 20N, while a hard meat should have a shear force greater than 37N and a compression force greater than 30N. Both instrumental tests give different information: WBSF test evaluates the meat fibres perpendicularly, as do incisor teeth, while TPA mimics the chewing with molar teeth. It is not possible to discard one of the instrumental tests, if the aim is to correlate beef measured tenderness with its sensory evaluation

The added value of aged beef

Beef ageing does not refer to the age of the cattle, but to the amount of time that the meat has been stored and refrigerated after slaughter. Beef ageing is a common practice in the meat industry, because it improves the sensory quality of meat (increased juiciness and better aroma and flavour), and the texture is effectively improved through complex changes in muscle metabolism after slaughtering. Two types of beef ageing are considered: vacuum or wet ageing, and dry ageing. Vacuum ageing is a widely used practice in the beef industry in which meat is aged in a sealed barrier package under controlled low temperature to improve tenderness and extend the shelf-life. On the other hand, dry ageing, refers to ageing meat without packaging, and requires greater environmental control practices (strictly controlled conditions, including temperature, moisture, and air speed) to achieve a consistent product quality. For this reason, vacuum ageing is widely used in industry due to its high production yield and convenient storage and transport, whereas dry ageing is an expensive process due to high ageing shrinkage, trim loss, contamination risk, and requirement of ageing conditions and space. However, when consumers become familiar with this type of meat, they are willing to pay more for dry-aged products and may also prefer the dry-aged flavour. For the academic community it remains controversial whether the sensory quality of dry-aged beef is higher than that of wet-aged. Beef ageing is considered a premium product, with an added value, and its price is substantially higher than that of good quality fresh meat. For this reason, it is of extreme importance for meat producers, but also for consumers, that the method of obtaining ageing meat is well studied and defined to guarantee constant high quality and safety standards. The Food Technology group at the University of Évora has recently developed a study on the safety and quality of Cachena meat. In this autochthonous breed, beef ageing has been considered an opportunity to valorize some meat cuts, with lower tenderness, that are usually sold at lower prices than the so-called noble meat cuts

Bs∗BKB_s^* B K vertex from QCD sum rules

The form factors and the coupling constant of the $B_s^* B K$ vertex are calculated using the QCD sum rules method. Three point correlation functions are computed considering both $K$ and $B$ mesons off-shell and, after an extrapolation of the QCDSR results, we obtain the coupling constant of the vertex. We study the uncertainties in our result by calculating a third form factor obtained when the $B^*_s$ is the off-shell meson, considering other acceptable structures and computing the variations of the sum rules' parameters. The form factors obtained have different behaviors but their simultaneous extrapolations reach to the same value of the coupling constant $g_{B_s^* B K}=10.6 \pm 1.7$. We compare our result with other theoretical estimates.Comment: 11 pages, 11 figure

The Safe-Port project: an approach to port surveillance and protection

SAFE-PORT is a recently started project addressing the complex issue of determining the best configurations of resources for harbour and port surveillance and protection. More specifically, the main goal is to find, for any given scenario, an adequate set of configuration solutions — i.e., number and type of sensors and equipments, their locations and operating modes, the corresponding personnel and other support resources — that maximize protection over a specific area. The project includes research and development of sensors models, novel algorithms for optimization and decision support, and a computer-based decision support system (DSS) to assist decision makers in that task. It includes also the development of a simulation environment for modelling relevant aspects of the scenario (including sensors used for surveillance, platforms, threats and the environment), capable to incorporate data from field-trials, used to test and validate solutions proposed by the DSS. Test cases will consider the use of intelligent agents to model the behaviour of threats and of NATO forces in a realistic way, following experts’ definitions and parameters

The Chihuahua dog: A new animal model for neuronal ceroid lipofuscinosis CLN7 disease?

Neuronal ceroid lipofuscinoses (NCLs) are a group of incurable lysosomal storage disorders characterized by neurodegeneration and accumulation of lipopigments mainly within the neurons. We studied two littermate Chihuahua dogs presenting with progressive signs of blindness, ataxia, pacing, and cognitive impairment from 1 year of age. Because of worsening of clinical signs, both dogs were euthanized at about 2 years of age. Postmortem examination revealed marked accumulation of autofluorescent intracellular inclusions within the brain, characteristic of NCL. Whole-genome sequencing was performed on one of the affected dogs. After sequence alignment and variant calling against the canine reference genome, variants were identified in the coding region or splicing regions of four previously known NCL genes (CLN6, ARSG, CLN2 [=TPP1], and CLN7 [=MFSD8]). Subsequent segregation analysis within the family (two affected dogs, both parents, and three relatives) identified MFSD8:p.Phe282Leufs13*, which had previously been identified in one Chinese crested dog with no available ancestries, as the causal mutation. Because of the similarities of the clinical signs and histopathological changes with the human form of the disease, we propose that the Chihuahua dog could be a good animal model of CLN7 disease

Fresh Bovine Meat: Sensory and instrumental evaluation of tenderness.

The objective of the present work was to define the ideal tenderness of bovine meat and establish an index for the differentiation between hard and tender beef of commercial origin. Different beef cuts (“Chã de Fora”, “Rabadilha”, “Vazia” and “Lombo”) of different tenderness were considered for this study and were evaluated simultaneously by consumers using a hedonic scale and by instrumental methods. With these results, it was possible to compare the tenderness evaluation of commercial meat with Cachena meat

Staphylococcus spp. and Lactobacillus sakei Starters with High Level of Inoculation and an Extended Fermentation Step Improve Safety of Fermented Sausages

Paio do Alentejo (PA) is one of the most popular dry-fermented sausages in Portugal. The aim of the present work was to evaluate the effect of a high concentration of starter cultures with an extended fermentation step on the safety and quality of PA. Physicochemical parameters, microbiological parameters, biogenic amines, colour, texture profile, and sensory attributes were assessed. Five starters were selected based on our previous works. Staphylococcus equorum S2M7, Staphylococcus xylosus CECT7057, Lactobacillus sakei CV3C2, Lactobacillus sakei CECT7056, and a yeast strain (2RB4) were co-inoculated in meat batters at a concentration of 108 cfu/g for bacteria and 106 cfu/g for yeast strain, and 0.25% dextrose was added. Inoculated starters significantly reduced pH, Listeria monocytogenes counts, and total content in biogenic amines. The studied starter cultures did not compromise the sensory characteristics of PA, and thus, their use can be considered to protect these sausages and contribute to their safet

The Effect of a Mycotoxin Deactivation Product on Growth of Juvenile Rainbow Trout Fed Distillers Dried Grains

Distillers dried grains (DDG) with solubles (DDGS) is a product that has shown potential as a protein source for some fish species, but high inclusion rates of DDGS have not always been successfully achieved for Rainbow Trout Oncorhynchus mykiss. Our objective was to determine whether inclusion of a mycotoxin deactivation product (Biofix Plus) could improve the ability of high-protein DDG (HPDDG) to replace a portion of the fish meal in diets for Rainbow Trout. The 2 × 2 factorial feeding trial examined protein source (menhaden fish meal [MFM] or HPDDG) with or without Biofix Plus. A control diet (42% digestible protein, 20% crude lipid, 25% MFM) was compared to a test diet in which HPDDG replaced 12% of the total MFM on a digestible-protein basis (24% HPDDG inclusion). Diets were fed to juvenile Rainbow Trout (initial weight: mean ± SE = 30.5 ± 1.6 g) in four replicate tanks per treatment for 9 weeks in a 15°C recirculating system. At the conclusion of the feeding trial, we observed no negative effects of fish meal replacement on growth or feed conversion ratio; no benefit of Biofix Plus supplementation was observed. These data indicate that when Rainbow Trout diets containing a high-quality DDGS product are balanced for digestible protein, lysine, methionine, and threonine, dietary fish meal levels can be successfully reduced to 13% without compromising growth and without the need for mycotoxin deactivator inclusion