110 research outputs found

    Male movement patterns and bioacoustic activity of the Western Cuban Grassfrog, Eleutherodactylus varleyi (Anura: Eleutherodactylidae)

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    In this study, we examined movement patterns, vocal activity, and variation in advertisement calls at individual and populational levels in a population of Western Cuban Grassfrogs (Eleutherodactylus varleyi) at the National Botanical  Garden of Cuba in July and September in 2007. Males appear to be very sedentary with peaks of movement early in the night and just before dawn that could be related with the search of calling sites and diurnal retreats, respectively. We detected eight patterns of frequency modulation of advertisement calls for note 1 and six for note 2. Patterns II and VI were the most frequent for note 1 and note 2, respectively. Note duration was the only acoustic parameter that was significantly variable among individuals for note 1, whereas the maximum frequency and rise time were signifi- cantly variable within individuals for note 2, suggesting that the latter is more reliable for distinguishing individual calls

    Pine Bark and Green Tea Concentrated Extracts: Antioxidant Activity and Comprehensive Characterization of Bioactive Compounds by HPLC–ESI-QTOF-MS

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    The consumption of polyphenols has frequently been associated with low incidence of degenerative diseases. Most of these natural antioxidants come from fruits, vegetables, spices, grains and herbs. For this reason, there has been increasing interest in identifying plant extract compounds. Polymeric tannins and monomeric flavonoids, such as catechin and epicatechin, in pine bark and green tea extracts could be responsible for the higher antioxidant activities of these extracts. The aim of the present study was to characterize the phenolic compounds in pine bark and green tea concentrated extracts using high-performance liquid chromatography coupled to electrospray ionization mass spectrometry (HPLC–ESI-QTOF-MS). A total of 37 and 35 compounds from pine bark and green tea extracts, respectively, were identified as belonging to various structural classes, mainly flavan-3-ol and its derivatives (including procyanidins). The antioxidant capacity of both extracts was evaluated by three complementary antioxidant activity methods: Trolox equivalent antioxidant capacity (TEAC), ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC). Higher antioxidant activity values by each method were obtained. In addition, total polyphenol and flavan-3-ol contents, which were determined by Folin–Ciocalteu and vanillin assays, respectively, exhibited higher amounts of gallic acid and (+)-catechin equivalents.This work was supported by the project AGL2011-29857-C03-02 and AP2010-1551 (Spanish Ministry of Science and Innovation), as well as P09-CTS-4564, P10-FQM-6563 and P11-CTS-7625 (Andalusian Regional Government Council of Innovation and Science). The authors are also grateful to Instituto de Salud Carlos III for the Sara Borrell Grant (CD12/00672

    Extraction and Analysis of Phenolic Compounds in Rice: A Review

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    Rice represents the main source of calorie intake in many world countries and about 60% of the world population include rice in their staple diet. Whole grain rice, also called brown rice, represent the unpolished version of the more common white rice including bran, germ, and endosperm. Many health-promoting properties have been associated to the consumption of whole grain rice and, for this reason, great attention has been paid by the scientific community towards the identification and the quantification of bioactive compounds in this food item. In this contribution, the last five years progresses in the quali-quantitative determination of phenolic compounds in rice have been highlighted. Special attention has been devoted to the most recent strategies for the extraction of the target compounds from rice along with the analytical approaches adopted for the separation, identification and quantification of phenolic acids, flavonoids, anthocyanins, and proanthocyanidins. More specifically, the main features of the “traditional” extraction methods (i.e., maceration, ultrasound-assisted extraction) have been described, as well as the more innovative protocols involving advanced extraction techniques, such as MAE (microwave-assisted extraction). The predominant role of HPLC in the definition of the phenolic profile has been examined also presenting the most recent results obtained by using mass spectrometry-based detection systems. In addition, the most common procedures aimed to the quantification of the total amount of the cited classes of phenolic compounds have been described together with the spectrophotometric protocols aimed to the evaluation of the antioxidant properties of rice phenolic extracts (i.e., FRAP, DPPH, ABTS and ORAC)

    Shadowing and blocking effect optimization for a variable geometry heliostat field

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    Optimization software is currently a key tool when designing heliostat fields. Shadowing, blocking, atmospheric attenuation, spillage and cosine effect losses can be hugely minimized with proper use of this tool, so they are widely used in this field of work. However, variable geometry is a ground breaking concept that is only recently been researched, and existing optimization software for conventional heliostat fields perform poorly when applied to this new concept, due to the fact that they do not use the advantages that it provides. The code here presented explores this idea to fully exploit the capabilities of variable geometry heliostat fields

    Optimizing vacuum drying process of polyphenols, flavanols and DPPH radical scavenging assay in pod husk and bean shell cocoa

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    The objective of this study was to optimize different vacuum drying conditions for cocoa pod husk and cocoa bean shell in order to enhance these by-products for commercial applications. To carry out the optimization, the response surface methodology was applied using a Box–Behnken experimental design with 15 experiments for which different conditions of temperature (X1), drying time (X2) and vacuum pressure (X3) were established. The response variables were the content of total polyphenols, the content of flavanols and the radical scavenging activity evaluated in the extracts of the different experiments. Temperature (50–70 °C), drying time (3–12 h) and vacuum pressure (50–150 mbar) were considered as independent variables. The main factors affecting the response variables were temperature, followed by vacuum pressure. For the content of polyphenols, the optimal response values predicted for the cocoa pod husk was 11.17 mg GAE/g with a confidence limit (95%) of 9.05 to 13.28 mg GAE/g (optimal conditions: 65 °C, 8 h and 75 mbar), while for the cocoa bean shell cocoa was 29.61 mg GAE/g with a confidence limit (95%) of 26.95 to 32.26 mg GAE/g (optimal conditions: 50 °C, 5 h and 100 mbar). Therefore, results of this study suggest a high content of phenolic compounds obtained from these by-products that show relevance as functional ingredients for application in the food, nutraceutical, and cosmeceutical industriesFondo Nacional de Desarrollo Científico, Tecnológico y de Innovación Tecnológica of Perú, project number 184-2020-FONDECY

    Diet Supplementation with Polyphenol-Rich Salicornia ramosissima Extracts Protects against Tissue Damage in Experimental Models of Cerebral Ischemia

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    Strokes are the secondmost common cause of death worldwide and a leading cause of disability. Regular consumption of polyphenols has been shown to reduce the risk of suffering a cardiovascular event. For this reason, we have investigated the protective effect of Salicornia ramosissima, a seasonal halophyte that synthetizes high amounts of bioactive compounds, including polyphenols, in response to environmental stress. Aqueous, hydroalcoholic, and ethanolic extracts were prepared to investigate if dietary supplementation prior to ischemic challenge can prevent subsequent damage using two animal models. First, we screened the protective effect against hypoxia–reoxygenation in Drosophila melanogaster and observed that both ethanolic and hydroalcoholic extracts protected flies from the deleterious effects of hypoxia. Second, we confirmed the protective effect of S. ramosissima ethanolic extract against brain ischemia using the transient middle cerebral artery occlusion mice model. Four weeks of oral supplementation with the ethanolic extract before artery occlusion reduced infarct volume and lowered the plasma levels of the DNA peroxidant product 8-hydroxydeoxyguanosine. Phytochemical profiling of S. ramosissima ethanolic extract revealed 50 compounds. Thus, it represents a valuable source of bioactive compounds that show promising disease-modifying activities and could be further developed as an effective food supplement for the prevention or treatment of neurovascular disorders.PE-0527-2019 Programa Operativo FEDERConsejería de Transformación Económica, Industria, Conocimiento y Universidades[PY20_01351]ISCIII, grant number [CD21/00148
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