Impact of dietary Laminaria digitata with alginate lyase or carbohydrase mixture on nutrient digestibility and gut health of weaned piglets.

Laminaria digitata is a brown seaweed rich in prebiotic polysaccharides, mainly laminarin, but its alginate-rich cell wall could compromise nutrient access. Carbohydrase supplementation, such as individual alginate lyase and carbohydrases mixture (Rovabio® Excel AP), could enhance nutrient digestibility and prebiotic potential. This study aimed to evaluate the effect of these enzymes on nutrient digestibility and gut health of weaned piglets fed with 10% L. digitata. Diets did not affect growth performance (P > 0.05). The majority of the feed fractions had similar digestibility across all diets, but the supplementation of alginate lyase increased hemicellulose digestibility by 3.3% compared to the control group (P = 0.047). Additionally, we observed that algal zinc was more readily available compared to the control group, even without enzymatic supplementation (P < 0.001). However, the increased digestibility of some minerals, such as potassium, raises concerns about potential mineral imbalance. Seaweed groups had a higher abundance of beneficial bacteria in colon contents, such as Prevotella, Oscillospira and Catenisphaera. Furthermore, the addition of alginate lyase led to a lower pH in the colon (P < 0.001) and caecum (P < 0.001) of piglets, which is possibly a result of released fermentable laminarin, and is consistent with the higher proportion of butyric acid found in these intestinal compartments. L. digitata is a putative supplement to enhance piglet gut health due to its prebiotic polysaccharides. Alginate lyase supplementation further improves nutrient digestibility and prebiotic potential. These results suggest the potential use of L. digitata and these enzymatic supplements in commercial piglet-feeding practices.

Innovative processing strategies and technologies to obtain hydrocolloids from macroalgae for food applications.

The macroalgal hydrocolloid industry is a rapidly growing industry with an annual growth in the global production of 2-3 %. Hydrocolloids from macroalgae are mainly in the form of polysaccharides with other nutrients, such as vitamins, minerals, and proteins. Due to its potential industrial applications, macroalgae have been used as raw materials for hydrocolloids extraction. Compared to the conventional extraction methods, emerging innovative assisted extraction technologies (e.g., Ultrasound/Microwave assisted extraction) have been developed to maximise the extraction yields, efficiency and thereby, maintaining sustainability along the process. These novel techniques are considered as clean and green strategies, with a potential for a large-scale production; thus, avoiding or reducing the use of chemicals. However, more research is required to establish their mechanism of action in order to finally implement them at industrial level. This paper reviews the most relevant strategies and technologies involved in the production of hydrocolloids from macroalgae.

Reliability assessment and correlation analysis of 3 protocols to measure trunk muscle strength and endurance.

Different methods have been developed to quantify trunk muscle strength and endurance. However, some important protocol characteristics are still unclear, hindering the selection of the most suitable tests in each specific situation. The aim of this study was to examine the reliability and the relationship between 3 representative tests of the most common type of protocols used to assess trunk muscle strength and endurance. Twenty-seven healthy men performed each test twice spaced 1 month apart.Trunk strength and endurance were evaluated with an isokinetic dynamometer and 2 field tests including Biering-Sørensen test and Flexion-rotation trunk test. All tests showed a good relative consistency (intraclass correlation coefficient [ICC]> 0.75), except for the isokinetic endurance variables which had low-moderate reliability (0.37 < ICC > 0.65). Absolute reliability seemed slightly better in the isokinetic protocol than in the field tests, which showed about 12% of test-retest score increase. No significant correlations were found between test scores. After a familiarisation period for the field tests, the 3 protocols can be used to obtain reliable measures of trunk muscle strength and endurance. Based on the correlation analysis, these measures are not related, which highlights the importance of selecting the most suitable trunk test for each situation.

Polysaccharides from macroalgae: Recent advances, innovative technologies and challenges in extraction and purification.

Polysaccharides obtained from macroalgae have promising prospects and could contribute greatly to the future of a marine based bio-economy. Specifically, laminarin and fucoidan from brown macroalgae have a wide variety of potential industrial applications including functional foods and nutraceuticals, due to their broad range of biological activities. These beneficial biological activities are related to the chemical composition and structure of the macroalgal polysaccharides. The molecular weight, monosaccharide composition and sulphate content of these polysaccharides could be influenced by both macroalgal biology (i.e. variations in polysaccharide composition due to macroalgae species and their biological cycle) and different extraction/purification techniques employed to obtain polysaccharide enriched products (i.e. de-sulphation or fragmentation of sulphated polysaccharides). This review focuses on the extraction and purification methods for the macroalgal polysaccharides laminarin and fucoidan used in the recent literature. The application of innovative extraction technologies (such as ultrasound, microwave and enzyme-assisted extractions), as well as new purification techniques (i.e. membrane separation), are also discussed together with the challenges concerning molecule structure-function relationship and macroalgal variability.

Assessment of the functional properties of protein extracted from the brown seaweed Himanthalia elongata (Linnaeus) S. F. Gray.

A protein extract from the brown seaweed Himanthalia elongata (Linnaeus) S. F. Gray was prepared and its functional properties, colour and amino acid composition were assessed for its potential future use by the food industry. The total content of amino acids was determined as 54.02±0.46gaminoacids/kg dry weight, with high levels of the essential amino acids lysine and methionine. SDS-PAGE showed 5 protein bands with molecular weights of 71.6, 53.7, 43.3, 36.4 and 27.1kDa. The water holding capacity and oil holding capacity were determined as 10.27±0.09gH2O/g and 8.1±0.07goil/g respectively. Foaming activity and stability were higher at alkaline pH values. The emulsifying capacity and stability of the extract varied depending on the pH and oil used. These results demonstrate the potential use of Himanthalia elongata protein extract in the food industry.

Essential and toxic trace element concentrations in different commercial veal cuts in Spain.

The aim of this study was to evaluate essential and toxic element concentration of ten commercially available veal cuts, together with diaphragm, cardiac muscle and liver tissue from 10 animals of "Galician Supreme Veal". Essential trace elements (Co, Cr, Cu, Fe, Mn, Mo, Ni, Se and Zn) and toxic elements (As, Cd, Hg and Pb) were determined by ICP-MS. Essential trace element concentrations ranged from 0.002-55.64mg/kg between muscles. Toxic element concentrations were very low, and high numbers of samples showed unquantifiable residues of Cd and Pb. Veal cuts including muscles with a high proportion of oxidative slow-twitch fibers (diaphragm and cardiac muscle) showed significantly higher essential trace element concentrations, the lower concentrations being found in veal cuts including glycolytic fast-twitch fibers (eye round). Our results suggest that essential and toxic trace element concentration could be used as a new meat quality parameter, or to add further value to certain products (i.e. livestock reared on extensive systems with high physical activity).

Histochemistry evaluation of the oxidative stress and the antioxidant status in Cu-supplemented cattle.

The aim of this paper is to evaluate at a histopathological level the effect of the most commonly used copper (Cu) supplementation (15 mg/kg dry matter (DM)) in the liver of intensively reared beef cattle. This was done by a histochemistry evaluation of (i) the antioxidant capacity in the liver - by the determination of metallothioneins (MT) and superoxide dismutase (SOD) expression - as well as (ii) the possible induction of oxidative damage - by the determination of inducible nitric oxide synthase (iNOS), nitrotyrosine (NITT), malondialdehyde (MDA) and 8-oxoguanine (8-oxo) - that (iii) could increase apoptotic cell death - determined by cytochrome-c (cyto-c), caspase 1 (casp1) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL). Liver samples from Cu-supplemented (15 mg Cu sulphate/kg DM, n = 5) and non-supplemented calves (n = 5) that form part of other experiments to evaluate Cu status were collected at slaughter and processed for immunohistochemistry and TUNEL. MT expression was diffuse and SOD showed slight changes although without statistical significance. iNOS and NITT positive (+) cells significantly increased, mainly around the central veins in the animals from the Cu-supplemented group, whereas no differences were appreciated for the rest of the oxidative stress and apoptosis markers. Under the conditions of this study, which are the conditions of the cattle raised in intensive systems in NW Spain and also many European countries, routinely Cu supplementation increased the risk of the animals to undergo subclinical Cu toxicity, with no significant changes in the Cu storage capacity and the antioxidant defensive system evaluated by MT and SOD expression, but with a significant and important increase of oxidative damage measured by iNOS and NITT. The results of this study indicated that iNOS and NITT could be used as early markers of initial pathological changes in the liver caused by Cu supplementation in cattle, although more studies in cattle under different levels of Cu supplementation are needed.

Effect of moderate Cu supplementation on serum metabolites, enzymes and redox state in feedlot calves.

The aim of this investigation was to evaluate whether, in the nutritional management of commercial feedlots, copper (Cu) supplementation is justified to maintain the physiological requirements. This study compared beef calves fed concentrates with an average Cu basal content of 5 and 8 mg/kg in growing and finishing periods (10 animals) or supplemented with 15 mg/kg for each phase (20 animals) as regards production indices, metabolic parameters [glucose, nonesterified fatty acids (NEFA), cholesterol, serum urea nitrogen (SUN), creatinine, total serum protein (TSP), albumin, aspartate transaminase (AST) and γ-glutamyl transferase (GGT)] and markers of oxidative stress (reactive oxygen species (ROS) and serum antioxidant capacity (SAC)). Data were recorded at ages 12, 24 and 36 weeks. In general, Cu supplementation was neither detrimental nor beneficial for animal health and performance, and the levels of the measured metabolites and enzymes were within their normal ranges stated for feedlot with the same management during the whole study. However, in keeping with reported higher hepatic Cu levels at slaughter, animals on supplemented feed had higher GGT activities at the end of the finishing stage, although the difference was not statistically significant. On the other hand, lower SAC levels at the end of the growing period in the supplemented group suggest the possibility of a positive effect of Cu supplementation on redox state. Further research is necessary to clarify the potential role of Cu in limiting the ROS production associated with fattening diets, and to evaluate the hepatobiliary consequences of supplementation, including hepatic Cu accumulation.

Influence of Cu supplementation on toxic and essential trace element status in intensive reared beef cattle.

The aim of this study is to evaluate if dietary Cu supplementation that leads to a hepatic Cu accumulation over the normal range has an influence on trace element status that could contribute to the pathogenesis of other mineral related disorders. Samples (liver, kidney, spleen, diaphragm and brain) of beef calves receiving typical commercial diets Cu supplemented and non-supplemented were tested for differences in non-essential and essential trace elements determined by ICP-MS. As (kidney and diaphragm), Hg (liver and kidney), and Pb (liver, kidney and spleen) were significantly lower, while Cd residues (liver and kidney) were significantly higher in the Cu supplemented group. Mn and Ni significantly decreased and Mo increased in the brain, and Se (diaphragm) decreased in the Cu supplemented group. These interactions are unknown, and possibly with more than two metals involved as suggested in the case of the ratio Se:Cu in the animals of this study. The possible role of Cu supplementation on the status of certain metals associated to neurological diseases (Mn-Ni) in the brain deserves further investigation. Finally new research on Cu-Se supplementation is necessary to better understand the risk of the animals to suffer from Se deficiency.

Effect of type of muscle and Cu supplementation on trace element concentrations in cattle meat.

Considering that meat is an important source of metals exposure to humans it is important to explore trace element concentrations in different types of muscles. Because of the demonstrated effect of Cu-supplementation on mineral status, the influence of Cu-supplementation was also evaluated. Samples of four different muscles (diaphragm, cardiac, semitendinous and pectoral, n=120) from beef calves receiving typical commercial diets Cu-supplemented (15 mg Cu(2)SO(4)/kg DM) and non-supplemented were taken and acid digested. The levels of non-essential (As, Cd, Hg, Pb and Sn) and essential (Co, Cr, Fe, Mn, Mo, Ni, Se and Zn) elements were analyzed by ICP-MS. The statistical analyzes included two way Anova, post hoc DHS Tukey and Spearman correlations. The most active and less fat containing muscles showed in general the highest essential and the lowest non-essential trace element accumulation. As and Hg muscular residues are indicative of animal exposure, however, in situations of an adequate mineral status, essential trace element concentrations in muscle are irrespective of the mineral status of the animal and could be possibly related to their own particular muscular metabolism. Cu-supplementation significantly reduced As but caused a significant decrease of Se, which could have significance for the animal's health.

Toxic and essential metals in liver, kidney and muscle of pigs at slaughter in Galicia, north-west Spain.

The aims of the study were to evaluate toxic and essential metal concentrations in meat and offal from pigs in north-west Spain to compare these with reported metal concentrations in pigs in other countries and in cattle in this region, and to relate the observed concentrations to maximum acceptable concentrations. Samples from 63 pigs aged 6 months were randomly collected at slaughter. After acid digestion, levels of metals were determined by ICP-OES and ICP-MS. As regards the toxic metals, mean concentrations in liver, kidney and muscle were 0.073, 0.308 and 0.009 mg kg(-1) fresh weight for cadmium, 0.004, 0.008 and 0.003 mg kg(-1) for lead, 0.013, 0.011 and 0.003 mg kg(-1) for arsenic, and 0.001, 0.002 and 0.001 mg kg(-1) for mercury. These concentrations can be considered low, and in general similar to those reported in similar studies in recent years. In addition, maximum admissible concentrations established by the European Union were not exceeded in any sample. As regards the essential metals, concentrations in liver, kidney and muscle were 14.9, 5.63 and 6.85 mg kg(-1) for copper, 81.3, 28.9 and 42.5 mg kg(-1) for zinc, 195, 51.6 and 26.5 mg kg(-1) for iron; 1.17, 2.51 and 0.656 mg kg(-1) for selenium, 3.32, 1.56 and 1.01 mg kg(-1) for manganese, 0.023, 0.027 and 0.003 mg kg(-1) for cobalt, 0.120, 0.077 and 0.131 mg kg(-1) for chromium, 0.009, 0.027 and 0.026 mg kg(-1) for nickel, and 1.62, 0.683 and 0.140 mg kg(-1) for molybdenum. These concentrations are all within the accepted adequate-safe ranges for this animal species, and in general are in line with those previously reported in the literature.

Análisis de anfetamina en orina por medio de microextracción en fase sólida / Analysis of amphetamine in urine by headspace solid phase microextraction

En este trabajo se presenta un método automatizado de extracción y análisis por GC (gas chromatography)-MS (mass spectrometry) para la detección de anfetamina en muestras de orina. El sistema esta constituido por un muestreador automatico, un cromatografo de gases y un espectrometro de masas de trampa de iones. El muestrador esta equipado con una aguja en cuyo interior hay una pequeña fibra retráctil de polidimetil siloxano, que puesta en contacto con la muestra, líquido o gas, absorbe selectivamente los analitos. La técnica es conocida como microextracción en fase sólida, SPME (Solid Phase MicroExtraction). En el estudio se hace un análisis detallado de todos los parámetros que afectan al rendimiento de las fibras, esto es; volumen de muestra, tipo de fibra, temperatura de absorción, tiempo de absorción, pH y fuerza ionica del medio. En la preparación de la muestra, tras ajustar manualmente el pH (pH 12) e incrementar la fuerza ionica de la muestra, 200 ml de orina son dispensados en un vial encapsulado de 2 ml. Tras solocar el vial en el carrusel termostatizado, Tª absorción 60°C, la fibra es introducida en el vial. Pasados 10 minutos de absorción, la fibra se retrae en la aguja y se inserta en el portal de inyección del cromatografo de gases, donde debido a alta temperatura, Ta desorbción 200°C, el analito desorbe de modo inmediato. El límite de detección es de 0.25 mg/l, el coeficiente de correlación lineal es de 0.9916 y la desviación estándar relativa menor del 5 por ciento. La concentración mínima de anfetamina que en la muestra pudo ser confirmada mediante un espectro de masas con índice de correlación mayor del 90 por ciento con su correspondiente espectro de librería, fue de 0.5 mg/l(AU)