59 research outputs found

    Effect of heat on loofah gourd seeds chemical composition and fatty acids of raw seeds

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    Dehulled loofah gourd seeds (DLGS), Luffah cylindrica was divided into three parts namely; raw (DLGSR), boiled for 5 min at 100 oC (DLGSB) and cooked for 30 min (DGLSC). Proximate composition, amino acids, amino acid scores and energy were determined in DLGSR, DLGSB and DLGSC and fatty acids constituents only in DLGSR on dry matter basis. Crude protein content of DLGSB and DLGSC were similar and significantly lower (p<0.05) than DLGSR while crude fibre, carbohydrate, ash, and the ether extract were not (p>0.05). Glutamic acid (Glu), aspartic acid (Asp), leucine (Leu), arginine (Arg), lysine (Lys), valine (Val) and phenylalanine (Phe) were concentrated in DLGSR in the order listed. Arg, Thr, Asp, Glu, Pro,Gly and Ala were significantly highest (p<0.05) in DLGSC while Lys, Asp and Ser were highest (p<0.05) in DLGSR and Gly and Tyr in DLGSB. The percent total non-essential amino acid (TNEAA) and the protein efficiency ratio (P-PER) were highest (p>0.05) in raw and boiled seeds respectively. The limiting amino acid in the samples was Met+Cyst. The fatty acid constituents were myristic, palmitic, palmitoleic, stearic, oleic, linoleic and arachidic acid. DLGSR contained 99.1% total fatty acids, 31.4% total saturated fatty acids, 67.7% total unsaturated fatty acids. Loofah gourd seed is a good potential vegetable protein source as food/feed.Keywords: Boiled, cooked, dehulled, proximate, energy

    Agents sans frontiers: cross-border aquatic weed biological control in the rivers of southern Mozambique

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    Biological control is an effective ways of controlling aquatic plants, especially in South Africa. Release of biological control agents has been limited to Mozambique, where water hyacinth (Eichhornia crassipes (Mart.) Solms-Laubach (Pontederiaceae)), water lettuce (Pistia stratiotes L. (Araceae)), red water ferns (Azolla spp. (Azollaceae)) and salvinia (Salvinia molesta DS Mitch. (Salviniaceae)) are significant weeds in the south of the country. In 2009, we assessed the status of these weeds in seven rivers across southern Mozambique and recorded whether any biocontrol agents were present. The weevils Neochetina eichhorniae Warner (Coleoptera: Curculionidae) and N. bruchi Hustache (Coleoptera: Curculionidae) were on water hyacinth, along with the pathogen Acremonium zonatum (Sawada) W. Gams (Hypocreales) and the mite Orthogalumna terebrantis Wallwork (Acarina: Sarcoptiformes: Galumnidae). Pistia stratiotes supported small numbers of the weevil Neohydronomus affinis Hustache (Coleoptera: Curculionidae). The red water fern in the rivers was A. cristata Kaulfuss (Azollaceae) not the more widely recorded A. filiculoides Lam. (Azollaceae), and it supported small numbers of the weevil Stenopelmus rufinasus Gyllenhal (Coleoptera: Curculionidae). No agents were present on S. molesta. Most of these agents are likely to have dispersed from South Africa, and the rivers of southern Mozambique are likely to be benefitting from the transnational dispersal of these agents

    First discovery of Holocene cryptotephra in Amazonia

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    The use of volcanic ash layers for dating and correlation (tephrochronology) is widely applied in the study of past environmental changes. We describe the first cryptotephra (non-visible volcanic ash horizon) to be identified in the Amazon basin, which is tentatively attributed to a source in the Ecuadorian Eastern Cordillera (0–1°S, 78-79°W), some 500-600 km away from our field site in the Peruvian Amazon. Our discovery 1) indicates that the Amazon basin has been subject to volcanic ash fallout during the recent past; 2) highlights the opportunities for using cryptotephras to date palaeoenvironmental records in the Amazon basin and 3) indicates that cryptotephra layers are preserved in a dynamic Amazonian peatland, suggesting that similar layers are likely to be present in other peat sequences that are important for palaeoenvironmental reconstruction. The discovery of cryptotephra in an Amazonian peatland provides a baseline for further investigation of Amazonian tephrochronology and the potential impacts of volcanism on vegetation

    Politics of nanotechnologies in food and agriculture

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    The chapter discusses the reasons for the delay in the regulatory intervention concerning nanotechnologies used in the agriculture and food sectors. The main finding is that unregulated introduction of nanoinnovation into the food system is due to the current neoliberal food policy and to the power struggles that characterize the economic, social and political dynamics within the global supply chain. Therefore, it is necessary to put the ‘question concerning technology’ at the center of the regulatory debate in order to implement a regulatory system able to face nanorisks. Which means looking at the way in which technology controls power relationships within society. Attention should be shifted from efficiency to power issues, and new technologies should be assessed from a political rather than an economic or ethical perspective

    Tephrochronology

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    Tephrochronology is the use of primary, characterized tephras or cryptotephras as chronostratigraphic marker beds to connect and synchronize geological, paleoenvironmental, or archaeological sequences or events, or soils/paleosols, and, uniquely, to transfer relative or numerical ages or dates to them using stratigraphic and age information together with mineralogical and geochemical compositional data, especially from individual glass-shard analyses, obtained for the tephra/cryptotephra deposits. To function as an age-equivalent correlation and chronostratigraphic dating tool, tephrochronology may be undertaken in three steps: (i) mapping and describing tephras and determining their stratigraphic relationships, (ii) characterizing tephras or cryptotephras in the laboratory, and (iii) dating them using a wide range of geochronological methods. Tephrochronology is also an important tool in volcanology, informing studies on volcanic petrology, volcano eruption histories and hazards, and volcano-climate forcing. Although limitations and challenges remain, multidisciplinary applications of tephrochronology continue to grow markedly
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