Dietary administration effects of fenugreek seeds on skin mucosal antioxidant and immunity status of gilthead seabream (Sparus aurata L.).

Improving fish defense through the preventive administration of immunostimulants has an important role in controlling the outbreak of the disease in aquaculture. As a continuity of our previous studies, this paper describes the effects of dietary fenugreek (Trigonella foenum graecum) seeds on the skin mucosal antioxidant status and immune response of gilthead seabream (Sparus aurata L.). Fish were fed with four experimental diets: one a basal diet (control) and three diets with powdered fenugreek seeds incorporated in the fish feed at 1%, 5%, and 10%. After eight weeks of feeding, free radicals scavenging and antioxidant assays were assessed in skin mucus by measuring the peroxidation of phospholipid liposomes, hydroxyl radical and hydrogen peroxide scavenging, measurement of total antioxidant activity and the determination of antioxidant activity in a linoleic acid system. The skin mucosal immune response was evaluated by measuring the IgM levels and some enzymatic activities (peroxidase, antiprotease, protease, esterase, and ceruloplasmin). Our results demonstrated that fenugreek inclusion improved the hydroxyl radical scavenging capacity and conferred very high antioxidant activity. Besides, only the highest supplementation level (10%) was able to augment the peroxidase and protease activities confronted by a general decrement in the antiprotease activity in the experimental fed groups with 1% and 10%. These results suggest that the dietary administration of fenugreek at the higher inclusion dose enhances the skin mucosal immunity response and the antioxidant status of gilthead seabream a species with one of the highest rates of production in marine aquaculture.

Effect of dietary supplementation of probiotics and palm fruits extracts on the antioxidant enzyme gene expression in the mucosae of gilthead seabream (Sparus aurata L.).

Antioxidant activity is particularly important, since oxidation is an unavoidable reaction in all living bodies. At present, natural antioxidants to be used on food as an alternative to synthetic ones are being sought. Gilthead seabream (Sparus aurata L.) specimens were fed for 4 weeks with diets enriched with bacterial probiotics (Shewanella putrefaciens Pdp11 and Bacillus sp), single or in combination with Tunisian dates palm fruit extracts. The expression of the main antioxidant enzyme genes (superoxide dismutase, catalase and glutathione reductase) in the mucosae (gut, skin and gill) was evaluated after 2 and 4 weeks. Previously, free radical scavenging and several antioxidant assays were developed to know the antioxidant properties present on the palm fruits extracts. The results demonstrated that experimental diets alter the expression of the studied antioxidant genes, primarily in the gill and skin. Furthermore, the tested probiotics and mainly, the aqueous date palm fruits extracts had significant antioxidant properties based on their protective effect against the levels of intracellular reactive oxygen species, especially when administering during 4 weeks. For this reason, probiotics and date palm fruit extracts may serve as good natural antioxidants and could potentially be considered as a functional food ingredient for fish in farms.

Optimización del método captación del radical 2, 2-difenil-1-picrilhidrazilo (DPPH) para evaluar actividad antioxidante en bebida de café / Optimization of the DPPH method to evaluate antioxidant activity of coffee brew

El café es una de las bebidas más consumidas en el mundo siendo apreciado por sus características organolépticas y más recientemente por su potencial efecto beneficioso en la salud humana. Se han descrito compuestos en el café que le confieren propiedades antioxidantes. La actividad antioxidante puede ser medida con diferentes test y el método de captura del radical DPPH es un método utilizado por numerosos autores que han ido realizando adaptaciones del mismo para evaluar diversos alimentos (frutas, zumos, café, verduras).El objetivo de este estudio es evaluar la capacidad antioxidante del café mediante una optimización del ensayo DPPH en condiciones normales de consumo, empleando tres tipos de cafetera (filtro, expreso e italiana), comparado con cafés de distintos orígenes (Colombia, Kenia y Etiopía) y café descafeinado. Los resultados de la optimización del ensayo muestran valores de absorbancias inferiores (0,709) cuando la muestra es sometida a la etapa de centrifugación (modificación de Delgado-Andrade, 2005) respecto a aquellas que son sometidas solo a agitación (1,609). Los datos de actividad antioxidante obtenidos muestran una elevada capacidad antioxidante con porcentajes de inhibición superior a 50 % destacando el café Colombia, Etiopía y Kenia elaborados con cafetera de filtro con valores de 70,56%, 73,52% y 73,65% respectivamente. En conclusión, según los resultados obtenidos, vemos la necesidad de adaptar los métodos establecidos de captura de radicales a las características del alimento o producto evaluado para asegurar al 100% la actividad antioxidante del alimento. La actividad antioxidante de la bebida de café no varía en función de la procedencia del café ni del contenido de cafeína que presenta. Por otro lado, en nuestro estudio, sólo observamos diferencias de actividad antioxidante del café referidas al tipo de cafetera, donde el café elaborado mediante la cafetera tipo expreso presenta menor actividad antioxidante (p<0,05) que los otros dos procedimientos. Sería por ello interesante recomendar el uso de cafeteras (filtro e italiana) para la obtención de café y conseguir un buen aporte de antioxidantes dietéticos (AU)

Coffee is one of the most consumed beverages in the world, being appreciated for its organoleptic characteristics and more recently for its potential beneficial effects on human health. Coffee is also known to be a rich source of compounds with potent antioxidant activity. The antioxidant activity can be measured with different test and method of capture radical DPPH, is a method used by many authors that have been carried out to assess adaptation in various foods (fruits, juices, coffee, vegetables).This study aim to evaluate the antioxidant capacity, by the DPPH assay, of coffee brew prepared in three commonly used ways (filter, espresso, italian) from different countries of origin (Colombia, Kenya and Ethiopia) and decaffeinated coffee. The optimization results of the test show lower values of absorbance (0.709) when the sample is subjected to centrifugation step (modification to Delgado-Andrade, 2005) with respect to only those that are subjected to agitation (1.609). The antioxidant activity data obtained show a high antioxidant capacity with inhibition percentages above 50%, with the coffee Colombia, Ethiopia and Kenya coffee filter made with values 70.56%, 73.52% and 73.65% respectively. In conclusion, according to the results, we see the need to adapt the methods set out radical capture the characteristics of the food or product evaluated to ensure 100% food antioxidant activity. The antioxidant activity of coffee drinking from different origins is similar and does not vary depending on the presence or absence of caffeine. Moreover, we observed only differences antioxidant activity relating to the type procedure, where coffee type "espresso" has less antioxidant activity (p<0.05) than the other two procedures. It would be interesting therefore recommend the use of the procedures (filter and Italian) for the obtaining of coffee and get a good intake of dietary antioxidants (AU)

Antioxidant activity of minimally processed (in modified atmospheres), dehydrated and ready-to-eat vegetables.

The antioxidant activity of vegetables subjected to minimal processing (in MAP, and intended for cooking or for use in salads), dehydrated condiments and ready-to-eat vegetables such as soups and purees, was assessed by reference to their ability to scavenge lipoperoxyl and hydroxyl radicals and Trolox-equivalent antioxidant capacity. In the case, the MAP vegetables the measurements were repeated during eight days of storage in a domestic refrigerator and after cooking (boiling, microwaving, pressure cooking, griddling, frying and baking). MAP vegetables had a good or very good antioxidant capacity, and showed no significant loss of antioxidant activity or scavenging capacity compared with fresh vegetables. The cooking treatments that keep the antioxidant activity of MAP vegetables are microwaving, sautéing and baking. The most aggressive method of cooking were steaming, boiling and frying. The dehydrated condiments (tablets) showed higher antioxidant activity than the ready-to-eat soup. The enrichment of stews and casseroles, with dehydrated vegetable tablets, and the consumption of soup or vegetable purees represent an increased antioxidant intake in our diet. Also "ready-to-eat" vegetable soups show antioxidant activity after they have been submitted to heat treatment to increase their shelf-life. They can be recommended as alternatives in our non-stop "life style".

Influence of cooking methods on antioxidant activity of vegetables.

The influence of home cooking methods (boiling, microwaving, pressure-cooking, griddling, frying, and baking) on the antioxidant activity of vegetables has been evaluated in 20 vegetables, using different antioxidant activity assays (lipoperoxyl and hydroxyl radicals scavenging and TEAC). Artichoke was the only vegetable that kept its very high scavenging-lipoperoxyl radical capacity in all the cooking methods. The highest losses of LOO. scavenging capacity were observed in cauliflower after boiling and microwaving, pea after boiling, and zucchini after boiling and frying. Beetroot, green bean, and garlic kept their antioxidant activity after most cooking treatments. Swiss chard and pepper lost OH. scavenging capacity in all the processes. Celery increased its antioxidant capacity in all the cooking methods, except boiling when it lost 14%. Analysis of the ABTS radical scavenging capacity of the different vegetables showed that the highest losses occurred in garlic with all the methods, except microwaving. Among the vegetables that increased their TEAC values were green bean, celery, and carrot after all cooking methods (except green bean after boiling). These 3 types of vegetables showed a low ABTS radical scavenging capacity. According to the method of analysis chosen, griddling, microwave cooking, and baking alternately produce the lowest losses, while pressure-cooking and boiling lead to the greatest losses; frying occupies an intermediate position. In short, water is not the cook's best friend when it comes to preparing vegetables.

Influence of the physical state of the membrane on the enzymatic activity and energy of activation of protein kinase C alpha.

The activation of protein kinase C alpha was studied by using a lipid system consisting of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC)/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoserine (POPS) (molar ratio 4:1) and different proportions of 1-palmitoyl-2-oleoyl-sn-glycerol (POG). The phase behavior of the lipidic system was characterized by using differential scanning calorimetry and 31P NMR, and a phase diagram was elaborated. The results suggested the formation of two diacylglycerol/phospholipid complexes, one at 15 mol % of POG and the second at 30 mol % of POG. These two complexes would define the three regions of the phase diagram: in the first region (concentrations of POG lower than 15 mol %) there is gel-gel immiscibility at temperatures below that of the phase transition between C1 and pure phospholipid, and a fluid lamellar phase above of the phase transition. In the second region (between 15 and 30 mol % of POG), gel-gel immiscibility between C1 and C2 with fluid-fluid immiscibility was observed, while inverted hexagonal HII and isotropic phases were detected by 31P NMR. In the third region (concentrations of POG higher than 30 mol %), gel-gel immiscibility seemed to occur between C2 and pure POG along with fluid-fluid immiscibility, while an isotropic phase was detected by 31P NMR. When PKC alpha activity was measured, as a function of POG concentration, maximum activity was found at POG concentrations as low as 5-10 mol %; the activity slightly decreased as POG concentration was increased to 45 mol % at 32 degrees C (above Tc) whereas activity did not change with increasing concentrations of POG at 5 degrees C (below Tc). When the activity was studied as a function of temperature, at different POG concentrations, and depicted as Arrhenius plots, it was found that the activity increased with increasing temperatures, showing a discontinuity at a temperature very close to the phase transition of the system and a lower activation energy at the upper slope of the graph, indicating that the physical state of the membrane affected the interaction of PKC alpha with the membrane.

The phase behavior of aqueous dispersions of unsaturated mixtures of diacylglycerols and phospholipids.

The phase behavior of mixtures of 1-palmitoyl-2-oleoyl-sn-glycerol (1,2-POG) with 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoserine (POPS) was studied by using DSC, small-angle X-ray diffraction and 31P-NMR. The results have been used to construct phase diagrams for both type of mixtures, in the 0-45 degreesC range. It is concluded that 1, 2-POG form complexes in the gel phases with both POPC and POPS. In the case of POPC, two complexes are postulated, the first one at a 1, 2-POG/POPC molar ratio of 40:60, and the second one at 70:30, defining three different regions in the phase diagram. Two eutectic points are proposed to occur: one at a very low 1,2-POG concentration and the other at a 1,2-POG concentration slightly lower than 70%. In the case of the 1,2-POG/POPS mixtures, the pattern was similar, but the first complex was seen to happen at a higher concentration, about 50 mol% of 1,2-POG, whereas the second was found at 80 mol% of 1,2-POG. This indicated a bigger presence of 1,2-POG in the complexes with POPS than with POPC. In the first region of the phase diagram, i.e. at concentrations of 1,2-POG lower than that required for the formation of the first complex, and at temperatures above the phase transition, lamellar phases were seen in all the cases. In region 2 of the phase diagram, i.e. at concentrations where the first and the second complexes coexist, a mixture of lamellar and non-lamellar phases was observed. Finally, at high concentrations of 1,2-POG, non-lamellar phases were detected as predominant, these phases being of an isotropic nature, according to 31P-NMR. An important conclusion of this study is that, using unsaturated lipids, similar to those found in biological membranes, it has been shown that diacylglycerols are found separated in domains, and that this process starts at very low concentrations of diacylglycerols. The formation of separated domains enriched in diacylglycerol is biologically relevant as it will allow them to have important effects on the membrane structure besides the fact that their concentration in the biomembrane is relatively low.